# The Reference 6J5 Thread (L63, 6C5, 12J5, 6P5, etc.)



## chrisdrop (Nov 1, 2020)

*[Thanks to @tintinsnowydog **here is a consolidated list** of tubes in this family]*

Inspired by The Reference 6SN7 Thread, I thought I'd start one for the 6J5 "family of tubes".

Several people that I know have taken to using these as their drivers often, across a few different amps. The Glenn thread has been using them quite heavily ((2x) anywhere 6SN7 were formerly used). They have become my main input valve and I have a small collection of them now. As a quick reminder/summary, each 6J5 is 1/2 an 6SN7 (triode vs dual-triode). "Same as one triode unit of 6SN7GT"

What do I mean by the 6J5 "family of tubes"? I think all of these should be "in play" for the thread as they are equivalent or thereabouts the same: 6J5, 6C5, 6P5, L63, VT94, CV1932, (12J5 - 12v heater if your amp can support). There are many metal, glass tubular, shoulder-types and even metal-glass tube types out there. That means you will find 6J5 (metal), 6J5G, (shoulder-types), 6J5GT (glass-tubular), and 6J5MT (metal-tubular). The same mostly for 6C5. I haven't seen any metal 6P5s, L63s. Here is a 6J5 "tube of the month" post from 2013 that has some info.

What amps are these currently being used in (around here, that I am aware of)? Glenn OTLs (mostly via 6SN7 adapter), there is at least one Glenn OTL that was modified to have 2x 6J5 sockets.@Zachik's new Glenn (GEL3N?) amp has sockets for these. Some amps that @A2029 has built (and is building) have sockets for these. For example @leftside's amp (Thunder?) has sockets for these. I believe @L0rdGwyn has made at least one amp with these sockets. I am quite certain there are more. Of course other amps that use 6SN7 tubes will likely have users that have tried the 2x6J5 adapter route.

Many amps have 6SN7 sockets. 6SN7 tubes have become over-bid. I'd love for that *not* to happen to the 6J5 family. I also think it is also worth sharing impressions with this forum. If you have a single 6SN7 socket, you can call @Deyan and get a very nice 2x 6J5 > 6SN7 adapter (or search on eBay). If you have 6J5 sockets in your amp, well done! _Disclaimer: your amp, your tubes, your responsibility. Make sure this will work in your amp before taking my suggestion. _

Some users here on head-fi have very nice collections of these tubes. I look forwards to seeing them. I'll make a few posts with pics/ comments on some.

** Of exceptionally minor note (but amusement to me), I was going to call this "The Reference ^(6|12){1}(J|C|P){1}5(G|GT|MG){0,1}$ Thread", but I thought the tube matching regular expression was a bit too arcane except a small group of people!


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## chrisdrop

And now, a first post. *Mullard 6J5G*

I heard from another head-fier that these "brown base" Mullards are an uncommon variety. I did a bit of googling and it seems the same is true of other Mullard tubes too, brown base seems rarer. That is, a happy accident for me, not any of my tube-smarts. These came via Billington here in the UK. I highly recommend them. Always top quality and excellent service. 

I have used this pair for around 50h so far. They have taken some time to burn in and have changing characteristics. The sounded pretty "taught" in the beginning. They have slowly relaxed linearly from 10h to now - opening up. I have sometimes had a long burn in on other tubes (I think a pair of GEC tubes took ~80h to change, maybe even more). These are very solid and enjoyable tubes. They are pretty neutral in their representation, not bassy/trebly, etc. I have other tubes that I'd say are more coloured (posts on them eventually). 

At the 50h mark, they still sound a touch congested in the mids to me. They have very good tight representation of the whole spectrum. I like their clarity. They don't have the biggest headstage IMO, but they are presented very nicely nonetheless. 

Of note, I can't find a date code on these things. The only markings I can find are these "5"s on the bottom of each tube, visible in the picture below. 

They are pretty tubes. 

* 








*


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## chrisdrop

*"New logo" RCA CV1932 *

Radio Museum seems to denote CV1932 as = 6J5*G* but clearly this one is not a shoulder-type glass tube.

I didn't particularly fancy this pair. IMO it is hard to 6J5s wrong, especially the "ugly duckling" metal can ones, which are usually good sounding. Now, in all fairness - they are almost free, at ~$5 each, but still - usually the metal 6J5s are pretty good. 

RCA changed their logo in what looks like 1968 according to this link. That makes these newer build tubes than the older "beach ball logo" versions.


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## CAJames (Jun 12, 2020)

I'm in for any thread with a tube matching regex. Also I'm always looking for 6SN7 alternatives. So far I've been using 7N7s, but just recently started thinking about the 6J5 family. Guess I need to order some adapters....


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## chrisdrop

*GEC 6J5G Grey Glass*

These are my favourite drivers. I like others, but I always love coming back to these. 

These are pre-1945 tubes according to the knowledgable folks over on the Glenn thread. They were expensive-ish but most excellent. 

These too a loooong time to get to peak performance. I wasn't even sure I liked them until > 50h perhaps, then they kept getting better and better. 

In short, they have all of the right characteristics; clarity, excellent representation across the frequency spectrum, thump, speed, and so on. 

I'd love to get more of the M-OV family of tubes from this era, but I believe they will be similar. 

_These pictures were shared in Nov on the Glenn thread, but it is worth posting them again here:_


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## chrisdrop

*Fivre 6J5GT*

These are interesting tubes. They have some of the "air", pleasant mid and treble representation, and a feeling of "delicate sounds". They are quite spacious sounding. They lack a bit in the heft and lower end, but it is compensated nicely by the rest. They do sort of remind me of C3G tubes, which are very clear and can sometimes (to me) become fatiguing. 

I can't tell when exactly they are from. The date on them is a tax date from the ministry of finance (in 1959), not a manufacture date. Also the "MM" faintly visible on them denotes that they are military tubes (I think like JAN in the US). 

These tubes make me want to hear more Fivre tubes...


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## CAJames (Jun 13, 2020)

I decided to  start at the bottom and ordered a pair of 6J5 -> 6SN7 adapters and some (cheap, metal) KenRad 6J5s. I'm also interested in 6P5s because I'm looking for a way to turn down the gain a little on my amp. The tubes you're posting are beautiful, but seem like they cost as much or more than a lot of 6SN7s, esp. if you need 4 of them like me.


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## chrisdrop (Jun 13, 2020)

CAJames said:


> I decided to  start at the bottom and ordered a pair of 6J5 -> 6SN7 adapters and some (cheap, metal) KenRad 6J5s. I'm also interested in 6P5s because I'm looking for a way to turn down the gain a little on my amp. The tubes you're posting are beautiful, but seem like they cost as much or more than a lot of 6SN7s, esp. if you need 4 of them like me.


You are right. So far, I have posted 2 more expensive pairs. The GECs are expensive (170 GBP for the pair if I recall correctly). The Fivres I got for ~40 EUR, which is very good.

I also want to get some 6P5 tubes (successor of the 76 tube, which I also plan on getting - with yet-another-adapter!).

Several users on the Glenn thread prefer the metal tubes. I love my 5$ GE 6C5 tubes. They are great. I really like the metal KenRads, which are inexpensive and have great thump. I will post more inexpensive ones too.

There are some overpriced 6SN7 tubes that are good; (not so expensive) KenRad VT231, Tung Sol Black Glass Round Plates, Sylvania Bad Boys, (expensive) ECC32, ECC33 etc - all are expensive relatively IMO. While I like those tubes, I still think the 6J5s have been generally cheaper and better.


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## leftside

As nice as the coke bottle glass GEC tubes are, I find the best bang for the buck 6J5 are the early metal base tubes from KenRad, Sylvania, TungSol, etc with foil getters.


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## Bonddam

I was told to go with a 6j5 socket over 6sn7 for the type of music I listen to. I planning to get a glenn amp made. Is this the way to go?


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## chrisdrop

Bonddam said:


> I was told to go with a 6j5 socket over 6sn7 for the type of music I listen to. I planning to get a glenn amp made. Is this the way to go?


I would do that.
In my Glenn amp I usually use 6J5 and related tubes in the 6sn7 slot.


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## Bonddam

chrisdrop said:


> I would do that.
> In my Glenn amp I usually use 6J5 and related tubes in the 6sn7 slot.


Ok
Stupid question 
Is there particular tubes that are best with electronic music? There’s so many to get I’d like simplicity and get the best right away. I figure bass fast detailed great highs.
This amp will be for listening to my Verite open.


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## CAJames

Bonddam said:


> I was told to go with a 6j5 socket over 6sn7 for the type of music I listen to. I planning to get a glenn amp made. Is this the way to go?



JMO but if you get a 6SN7 socket that gives you a lot more options. Fairly straightforward to go from 6SN7 -> 6J5 and also gives you the option of using e.g. 7N7 or 6CG7s with adapaters. Seems like if you get a 6J5 socket you are committed to the single triodes, unless you want to buy dual triodes and only use half of them.


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## leftside

You can always get an amp with both 6J5 and 6SN7 sockets...
https://www.head-fi.org/threads/1101-audio-custom-crafted-headphone-amps.919425/


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## CAJames

leftside said:


> You can always get an amp with both 6J5 and 6SN7 sockets...
> https://www.head-fi.org/threads/1101-audio-custom-crafted-headphone-amps.919425/



Holy $%&%*!!! That isn't an amp, that's a lifestyle choice. Well done.


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## chrisdrop

CAJames said:


> JMO but if you get a 6SN7 socket that gives you a lot more options. Fairly straightforward to go from 6SN7 -> 6J5 and also gives you the option of using e.g. 7N7 or 6CG7s with adapaters. Seems like if you get a 6J5 socket you are committed to the single triodes, unless you want to buy dual triodes and only use half of them.


That is a fair comment. 

Isn't @leftside's amp a beauty (and a beast) ?!

In my Glenn amp, I 90+% use the 6SN7 socket via an adapter for 6J5-like tubes. Another possibility in a Glenn OTL amp is to replace the C3G slots with 2x 6J5 sockets , keeping the 6SN7 socket. I am not sure which was suggested to you @Bonddam. I like the C3G sockets and have a number of adapters for those sockets. 



leftside said:


> As nice as the coke bottle glass GEC tubes are, I find the best bang for the buck 6J5 are the early metal base tubes from KenRad, Sylvania, TungSol, etc with foil getters.


Perhaps today, I'll pop in some metal base Sylvania 6J5GTs. I only have full the metal KenRads, and no TunSols in this family... More toobz!


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## chrisdrop

*Sylvania 6J5GT/VT-94D (metal base)*

As per @leftside's comment, I rolled in some Sylvania 6J5GTs today. 

These tubes were, for some period of time (probably during Christmas this past year) my most reliable, oft returned to inputs. It is nice to have them back for listening today. Rolling from the Fivres pictured above, a few things are noticeable. By contrast, the Sylvanias are a bit warmer and fuller in the lower end. They have solid representation across the spectrum. They don't sparkle quite like the Fivres, but that is _their_ key trait. I could happily live with these for some time. I consider them neutral to slightly warm with a good sized stage. 

These are not expensive tubes FYI. I think they can be had for $10-$20 each NOS. 

I don't know the date of these things. I don't have good notes on Sylvania date codes.


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## CAJames (Jun 14, 2020)

My adapters are a couple weeks away and I've started shopping for 6[J|C|P]5GTs. Seems the Ps are the most expensive, and apparently no metal can version. Curious if you've had any (good) experience with the Russian versions?


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## chrisdrop

CAJames said:


> My adapters are a couple weeks away and I've started shopping for 6[J|C|P]5GTs. Seems the Ps are the most expensive, and apparently no metal can version. Curious if you've had any (good) experience with the Russian versions?


Sadly, I have not. I have not tried however. Nor Chinese. For other tube types, I have tried Russian tubes and never had much luck. 

FYI: Billington has US made NOS 6P5G and 6P5GT at 15GBP/ each.


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## CAJames

Thank you for the link. I know Billington but I struggle with them. I'd love to order a bunch of Mullard/GEC/Brimar but my Scottish heritage simultaneously insists on ordering at least 250GBP to get the wholesale discount and refuses to spend 250GBP on tubes.


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## leftside

CAJames said:


> Thank you for the link. I know Billington but I struggle with them. I'd love to order a bunch of Mullard/GEC/Brimar but my Scottish heritage simultaneously insists on ordering at least 250GBP to get the wholesale discount and refuses to spend 250GBP on tubes.


Doesn't take too many Mullard/GEC/Brimar to reach 250GBP... and you'll be saving money in the long run.


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## chrisdrop

CAJames said:


> Thank you for the link. I know Billington but I struggle with them. I'd love to order a bunch of Mullard/GEC/Brimar but my Scottish heritage simultaneously insists on ordering at least 250GBP to get the wholesale discount and refuses to spend 250GBP on tubes.


Martin at Billington is also very reasonable, so I am sure you could find a way. Also, on inexpensive tubes, any lack of discount is not that material  Regardless, understood.


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## leftside

I make no guarantees about these tubes, and I don't know the seller, but this is a good price:
https://www.ebay.co.uk/itm/MARCONI-L63-6J5G-VALVES-TESTED-PAIR-TUBES/324199272487


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## CAJames (Jun 16, 2020)

chrisdrop said:


> Martin at Billington is also very reasonable, so I am sure you could find a way. Also, on inexpensive tubes, any lack of discount is not that material  Regardless, understood.



Yeah, it didn't take long for me to send them a shopping list. 6P5s, GEC L63s (GT not the older coke bottle) and pair of 6F8Gs to get the discount. Since I need 4 plus a spare the GECs are pretty much the top of my price range. I'm finding some 6C5s and 6P5s over here too. Scottish heritage will just have to deal with it.


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## leftside

CAJames said:


> Yeah, it didn't take long for me to send them a shopping list. 6P5s, GEC L63s (GT not the older coke bottle) and pair of 6F8Gs to get the discount. Since I need 4 plus a spare the GECs are pretty much the top of my price range. I'm finding some 6C5s and 6P5s over here too. Scottish heritage will just have to deal with it.


Martin knows me very well


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## leftside

Here's some BLACK METAL 6C5 for @Monsterzero. The Mazda even have the word "METAL" on the tube.


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## CAJames

leftside said:


> Martin knows me very well



That looks so cool! I never get tired of the pictures you post.


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## leftside

CAJames said:


> That looks so cool! I never get tired of the pictures you post.


Thanks. I have boxes of 6J5/6C5/6C5V/6P5/L63 tubes... These tube sockets in an amp are also very versatile. With adapters you can also use EL3, 5693, 76, EL11 and a bunch of others. I can also use 6N7 in the 6J5 sockets in my amp.


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## Monsterzero

Bonddam said:


> Ok
> Stupid question
> Is there particular tubes that are best with electronic music? There’s so many to get I’d like simplicity and get the best right away. I figure bass fast detailed great highs.
> This amp will be for listening to my Verite open.



Its hard to go wrong with Ken Rad VT94s and either a six pack of 6BX7s or a pair of Bendix 6080s for a fast hard hitting roll.



leftside said:


> Here's some BLACK METAL 6C5 for @Monsterzero. The Mazda even have the word "METAL" on the tube.



\m/ Horns up!

That amp is stunning! Im afraid to ask,and if youre not comfortable saying it publicly I understand,but what did that beast set you back?

Oh...I think all Glenn owners should know about this thread. @zach915m @Hansotek 

Great thread idea @chrisdrop


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## Hansotek

Drooling all over myself. Love that design @leftside


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## leftside

Hansotek said:


> Drooling all over myself. Love that design @leftside


Thanks. I will take credit for the design (you can see the history of the build over on the 1101 thread), and yes I "borrowed" features/ideas from Glenn's amps, but the actual build was performed by the highly skilled @A2029


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## Hansotek

leftside said:


> Thanks. I will take credit for the design (you can see the history of the build over on the 1101 thread), and yes I "borrowed" features/ideas from Glenn's amps, but the actual build was performed by the highly skilled @A2029



Oh don't worry, I took the liberty of cyberstalking your amp already.


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## chrisdrop (Jun 19, 2020)

*GEC L63/ CV1067 Straight Tubes*

These are going to be next to go in.

I believe the codes on them are:

*Ut* for the date code. That makes this tube 1963, but still not clear on the lowercase t... 
*Z* for the Plant = MO Valve Co. Hammersmith
I got a good deal on these so I grabbed them. I will update the post when I get > 50h or so on them to talk sound...

*EDIT #1*: Interesting that these tubes sound pretty good right away. One hour in the amp and they already sound nice. I'm surprised also because my coke-bottle GEC 6J5Gs took FOREVER to change/calm. Will these change or stay?


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## leftside

chrisdrop said:


> *GEC L63/ CV1067 Straight Tubes*
> 
> These are going to be next to go in.
> 
> ...


A = 1945 for the year. Good luck figuring out the date codes before 1945...

Those GEC L63 come in two slight variations - the rarer earlier 'D' getter and the latter 'O' getter. I can't tell if there's any difference in sound though. The versions before these had black base and either cup getter (first version) or 'D' getter:
https://www.ebay.co.uk/itm/2-x-L63-MARCONI-6J5G-MWT-BRAND-TUBE-NOS-NIB-RCB383/133404627942


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## chrisdrop

leftside said:


> A = 1945 for the year. Good luck figuring out the date codes before 1945...
> Those GEC L63 come in two slight variations - the rarer earlier 'D' getter and the latter 'O' getter. I can't tell if there's any difference in sound though. The versions before these had black base and either cup getter (first version) or 'D' getter:
> https://www.ebay.co.uk/itm/2-x-L63-MARCONI-6J5G-MWT-BRAND-TUBE-NOS-NIB-RCB383/133404627942


Hey there. How sure are you w/ the A=1945 vs A=1939?
Googling gave A=1939 and they switch date code styles in 1969. 

@leftside - now for dumb question-time. When you say getter type, are you referring to the inner getter structure shape or the silvery flashing shape?


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## leftside (Jun 19, 2020)

chrisdrop said:


> Hey there. How sure are you w/ the A=1945 vs A=1939?
> Googling gave A=1939 and they switch date code styles in 1969.
> 
> @leftside - now for dumb question-time. When you say getter type, are you referring to the inner getter structure shape or the silvery flashing shape?


Google again  Also do the math of 'A' starting from 1945 to 1969 (with a couple of letters/years missed out)
https://www.diyaudio.com/forums/tubes-valves/16854-gec-date-codes.html

The getter is the piece of wire that looks like a 'D', 'O' (or halo) and earlier getters look like a piece of foil/spade, inverted tray, inverted cup, flat saucer, etc. For a surprising change, most tube manufacturers seemed to use the different getters around the same time, so it's relatively easy to spot an earlier tube. Of course companies like GEC would occasionally use spare parts lying around - so you might see one of the earlier getters in one of the latter tubes!

A lot of the 6J5 tubes I've seen have the earlier foil/spade getters - especially the ones with the metal base. If you're wondering why a particular tube goes for more than a very similar looking tube - it's often because the more expensive tube has one of the earlier getters and black plates. Not always the case... but more often than not. Edit: the 6J5 metal base seem to be an exception to the norm - grab them while you can


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## mordy

chrisdrop said:


> *Sylvania 6J5GT/VT-94D (metal base)*
> 
> As per @leftside's comment, I rolled in some Sylvania 6J5GTs today.
> 
> ...


Hi Chrisdrop,
Enjoyed reading through your posts!
Re dating the Sylvania: The VT designation is a US military designation and very hard to decipher lol - it means Vacuum Tube. Usually VT means from around WW2.
The SC 966 A probably is a quality inspection stamp (like the Russian OTK stamp) and possibly means Signal Corps Inspector 966A.
What about the date code? Well, you already have the calculator with you - your fingers! One tube has silk screened on the glass K 4 and the other G 4. The letters denote the month. Counting the alphabet  on my fingers G is the 7th letter = July; K is a little more difficult (lol); let's see - 11th letter = November (Did I get it right?)
The 4 should be 1944.
JAN is military: Joint Army and Navy. It also means that the tube has to meet some more exacting military tolerances.
CHS is the military designation for Sylvania.


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## L0rdGwyn (Jun 19, 2020)

I have been meaning to contribute something to this thread, thought I'd post some pictures of my Fivre 6C5G collection.

Here are the earliest model, black base, mesh shields, wire spacers.  The bottle of these tubes is a bit taller and skinnier than the later models, have some interesting decals as well.  All of these tubes are early makes with foil getters, the getters are suspended from the internal shields, which are grounded through pin 1.



Next are the somewhat more common type, brown bases, shorter bottle, mesh shields, wires are replaced by mica.  It is a common misconception that the earlier makes of European tubes (Mullard, GEC, Fivre, etc.) have brown bases, but it is actually the black bases that came first.



Last type is somewhat unique, at least I have only ever seen one pair, with brown bases and solid shields.



Here are some of the earliest type in my amplifier.  Very nice smooth Fivre midrange, slightly warm, very nice tubes.


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## leftside

L0rdGwyn said:


> I have been meaning to contribute something to this thread, thought I'd post some pictures of my Fivre 6C5G collection.
> 
> Here are the earliest model, black base, mesh shields, wire spacers.  The bottle of these tubes is a bit taller and skinnier than the later models, have some interesting decals as well.  All of these tubes are early makes with foil getters, the getters are suspended from the internal shields, which are grounded through pin 1.
> 
> ...


Very nice! I find the 6C5 to be very similar to the 76 in my amp. Lighter/airy/spacious sound. Great to have in your arsenal of tubes.


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## chrisdrop

L0rdGwyn said:


> I have been meaning to contribute something to this thread, thought I'd post some pictures of my Fivre 6C5G collection.
> 
> Here are the earliest model, black base, mesh shields, wire spacers.  The bottle of these tubes is a bit taller and skinnier than the later models, have some interesting decals as well.  All of these tubes are early makes with foil getters, the getters are suspended from the internal shields, which are grounded through pin 1.
> 
> ...


All of those are beautiful. I think Fivres in general are physically lovely. The labels make them look ... Italian I guess - LOL. I am sad I will not be heading over to Italy for a normal summer break I must admit, so perhaps I'll have to import some more Italian tube-charm.

Posts like yours make me want to collect these little beauties even more. I had been on a multi-month metal casing tube listening. Posts like this make me want aesthetically beautiful tubes that sound great and look great too.



> Here are the earliest model, black base, mesh shields, wire spacers.


Regarding the dating/age; are they labelled/dated, or do you know the history of construction? It reminds me of @leftside's comments above on getters; you can infer the age/era based on the getter style. The base style, getter style, etc all give you info on the age. Fascinating.


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## L0rdGwyn

leftside said:


> Very nice! I find the 6C5 to be very similar to the 76 in my amp. Lighter/airy/spacious sound. Great to have in your arsenal of tubes.


Nice looking tubes and still widely available  I'll put them on the short list to try out some day.



chrisdrop said:


> Regarding the dating/age; are they labelled/dated, or do you know the history of construction? It reminds me of @leftside's comments above on getters; you can infer the age/era based on the getter style. The base style, getter style, etc all give you info on the age. Fascinating.



Hey Chris - they have codes, but no explicit dates, I can't make sense of them and have never found a resource on Fivre.  For instance, one says 7/F, another 1/B, but then another says 3/6 (I think? hard to make out the second character).  Perhaps the first is the year the second the month, 7/F could be June of 1947, for example, and 1/B February 1951.

This is a nice summary of the Italian tube manufacturers from Radiomuseum: https://www.radiomuseum.org/forum/a...largest all,by distinctive violet-glass bulbs.

Specific information on Fivre is somewhat sparse it seems.


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## mordy

L0rdGwyn said:


> I have been meaning to contribute something to this thread, thought I'd post some pictures of my Fivre 6C5G collection.
> 
> Here are the earliest model, black base, mesh shields, wire spacers.  The bottle of these tubes is a bit taller and skinnier than the later models, have some interesting decals as well.  All of these tubes are early makes with foil getters, the getters are suspended from the internal shields, which are grounded through pin 1.
> 
> ...


Hi LG,
Are there any differences in the sound between the different Fivre variations of the 6C5G?
Re the brown and black bases, I read somewhere that the brown bases was a development with better characteristics but I think that this only refers to US made (Tung Sol (?) tubes - found this quote:
*According to the TungSol manual, the difference is the brown micanol base,  which minimized leakage and gas currents* 
Cannot verify if there is any substance to this claim.


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## L0rdGwyn

mordy said:


> Hi LG,
> Are there any differences in the sound between the different Fivre variations of the 6C5G?
> Re the brown and black bases, I read somewhere that the brown bases was a development with better characteristics but I think that this only refers to US made (Tung Sol (?) tubes - found this quote:
> *According to the TungSol manual, the difference is the brown micanol base,  which minimized leakage and gas currents*
> Cannot verify if there is any substance to this claim.



Did a little A-Bing on the different Fivre 6C5G builds, I had not compared them critically before.  There are easily discernible differences, the early black base are more airy and detailed than the brown, smoother, the brown base are a little more "up front and personal" in the midrange, the black base seem more even across the frequency spectrum, handle greater complexity of music with more ease, larger soundstage, more diffuse whereas the brown base staging is more round with more clearly defined boundaries.

Been doing a lot of tube comparisons today, it has been a while since I have.  I acquired about half this collection of Fivre 6C5G while working on other things and never got around to doing any critical listening with the black bases.  Since I already had them in and I was so impressed, I kept going and compared them to the gray glass GEC L63, can't believe it, maybe tastes are changing, but I prefer the black base Fivre...so they stay.  Guess I have a new daily driver, maybe it is tube synergy or just my mood, I am seeking a sort of "easy on the ears" sound lately, which isn't to say the L63 aren't, but the Fivre are very chill and smooth.  I'll double back in a few days to be sure.


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## CAJames

Black gold:






Adapters in Never-Never-Land so I can't tell you how they sound, but the tubes are starting to arrive. Tung-Sol 6C5s across the top and a smorgasbord of 6J5s on the bottom. I'm surprised how small the tubes are, they are adorable!


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## mordy

Great condition und rost-frei! I have all of these, and you will be very pleased with them!


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## leftside

L0rdGwyn said:


> Did a little A-Bing on the different Fivre 6C5G builds, I had not compared them critically before.  There are easily discernible differences, the early black base are more airy and detailed than the brown, smoother, the brown base are a little more "up front and personal" in the midrange, the black base seem more even across the frequency spectrum, handle greater complexity of music with more ease, larger soundstage, more diffuse whereas the brown base staging is more round with more clearly defined boundaries.
> 
> Been doing a lot of tube comparisons today, it has been a while since I have.  I acquired about half this collection of Fivre 6C5G while working on other things and never got around to doing any critical listening with the black bases.  Since I already had them in and I was so impressed, I kept going and compared them to the gray glass GEC L63, can't believe it, maybe tastes are changing, but I prefer the black base Fivre...so they stay.  Guess I have a new daily driver, maybe it is tube synergy or just my mood, I am seeking a sort of "easy on the ears" sound lately, which isn't to say the L63 aren't, but the Fivre are very chill and smooth.  I'll double back in a few days to be sure.


I'll have to dig out the brown base and do a comparison. You'll definitely like the 76 as well. Mood has a huge impact on the type of music I listen to and the tubes I select. At one end of the spectrum is the 6C5, then the 6J5 somewhere in the middle and then the 6N7G. Obviously this is somewhat an over-generalization, and different makes and years of tubes have further subtle differences.

You'll swap out the 6C5 in a few days for the L63 and probably prefer the L63...


----------



## chrisdrop

leftside said:


> I'll have to dig out the brown base and do a comparison. You'll definitely like the 76 as well. Mood has a huge impact on the type of music I listen to and the tubes I select. At one end of the spectrum is the 6C5, then the 6J5 somewhere in the middle and then the 6N7G. Obviously this is somewhat an over-generalization, and different makes and years of tubes have further subtle differences.
> 
> You'll swap out the 6C5 in a few days for the L63 and probably prefer the L63...


So 76s just a different base of the same lineage 76>6P5>6C5,6J5. Going back farther to 56 or even (ala @gibosi) 27s needs external heating. Do you just run them in the 6J5 slots w/ adapters in your 1101 Mischa amp? 

More tubes to put on the watch-list. eBay has these pretty ones at the moment.


----------



## leftside (Jun 21, 2020)

chrisdrop said:


> So 76s just a different base of the same lineage 76>6P5>6C5,6J5. Going back farther to 56 or even (ala @gibosi) 27s needs external heating. Do you just run them in the 6J5 slots w/ adapters in your 1101 Mischa amp?
> 
> More tubes to put on the watch-list. eBay has these pretty ones at the moment.


Yes. 76 to 6J5 adapters.My Fivre 76 didn't come with original boxes like those, but they were only 15 euros each.


----------



## CAJames

chrisdrop said:


> ....More tubes to put on the watch-list. eBay has these pretty ones at the moment.



Very pretty indeed. Sadly I need a quad, and a winning lottery ticket.


----------



## chrisdrop (Jun 25, 2020)

*Hytron 6C5GT*

Here is some general info on Hytron. According to this post (tx @rosgr63, you can see an old Bendix of yours in the background) the boxes appear to be older (pre CBS). It looks like CBS purchase was mid-50s, so these seem to be earlier than that. The date should be bounded between ~1941-1951. Not sure how to date them otherwise. There are 2 sets of characters: "2A5" and "M R".

EDIT: according to this the CBS merger was 1951


Anyone know how to date Hytron tubes? My 15 mins of google were not up to the challenge..


----------



## mordy

Nice find! 
M R dates these tubes to 1942-1945. Vacuum tubes were rationed because of the war effort, but some were set aside for civilian use: M R means Manufacturers Replacement.
2 A 5? As you stated, very hard to find information on this small high quality Massachusetts manufacturer. My guess is February (2) 1945 (5). Or January (A)1945.  
Rationing went into effect in May 1942 so it does not seem likely that the tube is from 1942.
Hytron was founded in 1921 and was bought by CBS in 1951 - production ceased in 1961.


----------



## chrisdrop

mordy said:


> Nice find!
> M R dates these tubes to 1942-1945. Vacuum tubes were rationed because of the war effort, but some were set aside for civilian use: M R means Manufacturers Replacement.
> 2 A 5? As you stated, very hard to find information on this small high quality Massachusetts manufacturer. My guess is February (2) 1945 (5). Or January (A)1945.
> Rationing went into effect in May 1942 so it does not seem likely that the tube is from 1942.
> Hytron was founded in 1921 and was bought by CBS in 1951 - production ceased in 1961.


Thanks @mordy. I got these in December last year, and haven't really put them in. They were inexpensive additions to a batch at that time. Going through my box, I though - hey, time to try! I suspect I have to put some hours on them as they are probably at 5h max at this point.


----------



## mordy

They are supposed to be good sounding tubes in general - I think Phantaminum liked the treble in a Hytron 6SN7.


----------



## CAJames (Jun 25, 2020)

My adapters seem to be enjoying an extended layover in Arizona, sometimes that last hop is the hardest I suppose. So instead of listening impressions I can only offer a selection of tube porn c/o the latest USPS delivery:





Nation Union 6C5s in the top middle flanked by Raytheon and Sylvania 6C5GTs. On the bottom Sylvania JAN 6P5GTs and a "Wizard" 6P5G. All used, but in nice shape, none over 10 dollars. Can't wait to actually hear them.


----------



## chrisdrop

CAJames said:


> My adapters seem to be enjoying an extended layover in Arizona, sometimes that last hop is the hardest I suppose. So instead of listening impressions I can only offer a selection of tube porn c/o the latest USPS delivery:
> 
> 
> 
> Nation Union 6C5s in the top middle flanked by Raytheon and Sylvania 6C5GTs. On the bottom Sylvania JAN 6P5GTs and a "Wizard" 6P5G. All used, but in nice shape, none over 10 dollars. Can't wait to actually hear them.


I don't know the Wizard brand. Cool


----------



## mordy

Wizard is not a brand - it is a re-brander; a company that buys tubes from  different sources and puts their name on it.
By looking at pictures of name brand tubes (eBay as an example) it is often possible to identify the manufacturer.
In the UK famous rebranders were Pinnacle and Haltron. Sometimes you can pick up great bargains under these names such as GEC tubes; at other times it is an inexpensive Russian made tube. 
Because of lax laws such Russian made tubes could have Made in England printed on them.
The copyright laws in Germany were stricter but manufacturers found a way to get around it. Manufacturers such as Siemens would put their name on say a Japanese made tube and write “Foreign” on it without specifying the origin country.
Then you have situations where a name brand like Tung Sol needed to fulfill a government contract and didn’t have enough capacity to do it. No problem, just buy the same tube from GE and put the Tung Sol name on it! Problem is that those little sandblasted dots on the GE tube don’t come off so the tube has both the Tung Sol name and the GE dots.
In the late 50s and 60s cross branding was very common among US manufacturers.


----------



## CAJames

chrisdrop said:


> I don't know the Wizard brand. Cool



Exactly what @mordy said: I bought 4 6P5Gs branded Wizard, Zenith, Philco and Wards Super Airline. The dark side of the rebranders is that they would sometimes (often?) buy the primary manufacturers seconds, so while you can identify a name brand tube that has been rebranded it is hard to know if you are really getting name brand quality.


----------



## chrisdrop

CAJames said:


> Exactly what @mordy said: I bought 4 6P5Gs branded Wizard, Zenith, Philco and Wards Super Airline. The dark side of the rebranders is that they would sometimes (often?) buy the primary manufacturers seconds, so while you can identify a name brand tube that has been rebranded it is hard to know if you are really getting name brand quality.


Instead of 6P5s I am going to be inspired by @leftside and get some 76s. Of course, more adapters!


----------



## CAJames

chrisdrop said:


> Instead of 6P5s I am going to be inspired by @leftside and get some 76s. Of course, more adapters!



I saw that, and look forward to your experience. I've got plenty of octal tubes to keep busy....for now. Unless I can find a deal on 76 tubes of course .


----------



## mordy

I am not convinced that rebranders as a rule sold seconds. There may have been shady ones, but as a rule my impression is that most of them sold legitimate merchandise.
Jobbers may have bought overruns or surplus stocks, and individual department stores and manufacturers put their names on tubes, but it would not be in their best interest to sell seconds.


----------



## CAJames

mordy said:


> I am not convinced that rebranders as a rule sold seconds. There may have been shady ones, but as a rule my impression is that most of them sold legitimate merchandise.
> Jobbers may have bought overruns or surplus stocks, and individual department stores and manufacturers put their names on tubes, but it would not be in their best interest to sell seconds.



Certainly the rebrander I know best, Realistic, was infamous for doing exactly that. But I have no idea what companies like Wizard or Wards Super Airline were up to. That said, I wouldn't necessarily call it "shady" or "illegitimate" to sell seconds. You pays your money and you takes your chances, right?


----------



## mordy

When you speak of Realistic (Radio Shack), are you speaking of electronics in general or tubes in particular?
A number of their tubes were made in Japan and all their tubes had a lifetime warranty.
Here is an interesting blog about Realistic tubes:
https://antiqueradios.com/forums/vi...sid=455d02936f1c615d4d5deebc78c25404&start=20
It seems that they honored the lifetime warranty and the tubes they sold came from name brand US and foreign manufacturers.


----------



## CAJames (Jun 26, 2020)

Realistic tubes in particular. Life time warranty or not a lot of the tubes they sold were indeed made in Japan. They were seconds from the   Matshushita/Mullard plant. Doesn't mean they were bad necessarily, but there was a reason they typically cost a lot less then the name brand. Craftsman tools from Sears had a lifetime warranty too, doesn't mean they were great tools.


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## mordy

I hear you....


----------



## mordy

CAJames said:


> Certainly the rebrander I know best, Realistic, was infamous for doing exactly that. But I have no idea what companies like Wizard or Wards Super Airline were up to. That said, I wouldn't necessarily call it "shady" or "illegitimate" to sell seconds. You pays your money and you takes your chances, right?


Hi CD,
Wards Super Airline or Wards Airline were a line of radios sold by the department store chain Montgomery *Ward*. If you ordered 500 or more tubes you could get your own name on it.
Many times department store chains or radio manufacturers made deals with specific manufacturers. An example is Sears that often used Sylvania tubes.


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## mordy

More information: Wizard was one of the brand names used by Western Auto that was a chain store that sold auto parts and many other items. At it's height they had over 2000 stores but the chain is long gone.
They produced beautiful radios under the Truetone brand- here is a 1935 radio:


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## mordy

Just to give the amp designers out there some art-deco inspiration; here is another Truetone radio that has a very striking design:



For sale now: https://www.ebay.com/itm/VINTAGE-TR...540367?hash=item1f11bc510f:g:zKIAAOSwNX1e8ymB


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## CAJames

Thanks for the info, and those gorgeous radios! I wondered if Wards Super Airline was connected with Montgomery Wards, I was pretty sure it wasn't an actual airline.

In other news my adapters have finally left Arizona and arrived in California so (hopefully) in a couple of days I'll be posting about how these tubes sound.


----------



## mordy

Feel like splurging on some excellent sounding tubes? Don't.
You can get great sounding tubes for a song. Here is a date matched pair of 1942 GE 6C5 tubes with authentic rust spots (they don't affect the performance of the tubes):



These tubes sound great and you can get them for a few dollars each, especially if you buy them in small lots.
GE started with the infamous sandblasted dots date codes in 1952; try as I might, it is very difficult to find information on GE date codes from the 30's and 40's. The date code on this pair is 43-C2. My guess is second week of March 1943 but this is only a guess.
I have another GE 6C5 that says C
                                                      3
                                                      R
The printed logo is similar but not the same as the above tubes. It cannot be 1933 since this tube came out in 1935; and not 1953 since it would have the dots then. This leaves us with 1943 but then it doesn't match the date code on the pair above. Who knows? Maybe 3rd week of May 1943? Or perhaps March 1943 *R*eplacement (M-R = Manufacturers Replacement - see below).
Well, maybe I solved the mystery of the different design of the date codes and the slight difference in the print! 
Just looked through the offerings on eBay and found a tube that looks similar. No date, but this one comes with a box that has the stamp M-R. This dates the tube to 1942-45. Possibly military and civilian date codes differed - that could be an explanation.
One more comment: Some people claim that GE tubes in general aren't good sounding tubes. Maybe so, but these (and some others) are the exceptions.
Have fun!


----------



## chrisdrop

mordy said:


> Feel like splurging on some excellent sounding tubes? Don't.
> You can get great sounding tubes for a song. Here is a date matched pair of 1942 GE 6C5 tubes with authentic rust spots (they don't affect the performance of the tubes):
> 
> These tubes sound great and you can get them for a few dollars each, especially if you buy them in small lots.
> ...


I have a pair of GE 6C5s that I think are also really good sounding tubes, and were so cheap it is amazing. Recommended! Pictured (somewhat poorly) here:





FWIW - even without all the extra tubes, just the 6C5s and trusty 2x Bendix 6080WBs, all is lovely.


----------



## CAJames (Jul 1, 2020)

The adapters finally arrived, and all I can say is they are worth the wait. First up are the Tung-Sol 6C5s. They don't show up great on the black amp, but hey, you don' buy them for their looks, right?





I've been listening to them for about an hour and they are fantastic! Probably the my best sounding drivers, beating out the Sylvania "bad boy" tall bottle 7N7s. Liquid (but not lush) and detailed for days. Only downside is I have a bit of a hum problem, hopefully because the tubes are new and not because of the adapters or new geometry, which is a little cramped. I could happily listen to them forever, but where's the fun in that? So I've got the 6P5GT Sylvania JANs cooking as I write this. More to follow.


----------



## CAJames

6P5GTs might look a little better, but don't sound a good as the 6C5s. It is hard to beat Tung-Sol.





They still sound good, but a little edgier and with more bass. Zeppelin rocks, but the classical music I listen to most suffers in comparison to the Tung-Sols. They are used so probably aren't going to improve much with use. Also the hum persists, which offends my sensibility more than it actually bothers my listening. The tubes themselves are interesting, labeled JAN and with the USN anchor. They have clear tops, bottom getters, 2 hole "bad boy" plates, and no date code that I can see. I'd guess probably 40's or very early 50's.

Tomorrow I'm gong to try the 6P5Gs (Wizard, Ward Airline etc.) and some National Union 6C5s for whom I have high hopes.


----------



## chrisdrop

CAJames said:


> 6P5GTs might look a little better, but don't sound a good as the 6C5s. It is hard to beat Tung-Sol.
> 
> 
> 
> ...





CAJames said:


> The adapters finally arrived, and all I can say is they are worth the wait. First up are the Tung-Sol 6C5s. They don't show up great on the black amp, but hey, you don' buy them for their looks, right?
> 
> 
> 
> I've been listening to them for about an hour and they are fantastic! Probably the my best sounding drivers, beating out the Sylvania "bad boy" tall bottle 7N7s. Liquid (but not lush) and detailed for days. Only downside is I have a bit of a hum problem, hopefully because the tubes are new and not because of the adapters or new geometry, which is a little cramped. I could happily listen to them forever, but where's the fun in that? So I've got the 6P5GT Sylvania JANs cooking as I write this. More to follow.


Let the good times roll. 

Is your hum happening across both tube sets? Is it left/right/both? Try to bisect and isolate the issue; switch left/right, move tubes between sides to see if it is 1 tube. It could also be an adapter. Sometimes I will grab a random object (like a book) and touch the top of the tube (gently) to see if it changes/stops the noise. 

I think the experience of replacing the dual triodes with pairs these single triodes is pretty consistently "better". Glad you are experiencing the fun.


----------



## leftside

CAJames said:


> 6P5GTs might look a little better, but don't sound a good as the 6C5s. It is hard to beat Tung-Sol.
> 
> 
> 
> ...


With the WA22 you might want to try the 2 * 6BL7 to 6AS7G adapters.


----------



## mordy

CAJames said:


> 6P5GTs might look a little better, but don't sound a good as the 6C5s. It is hard to beat Tung-Sol.
> 
> 
> 
> ...


Hi CAJ,
I think I remember somebody trying the 6P5GT and mentioning the edgy quality.
Re the hum with 6C5 tubes, Glenn advised that it may be helped by connecting pins 1&8 in the adapter. These are the pins on each side of the center notch in the adapter - I also think that the Chinese adapters have the pins designated by number.
It is easily done by taking a little piece of very thin wire and and stripping off the insulation at each end long enough to go inside the pin socket. Leave the insulation on in the middle and make a little U and stick it in.


----------



## chrisdrop

mordy said:


> Hi CAJ,
> I think I remember somebody trying the 6P5GT and mentioning the edgy quality.
> Re the hum with 6C5 tubes, Glenn advised that it may be helped by connecting pins 1&8 in the adapter. These are the pins on each side of the center notch in the adapter - I also think that the Chinese adapters have the pins designated by number.
> It is easily done by taking a little piece of very thin wire and and stripping off the insulation at each end long enough to go inside the pin socket. Leave the insulation on in the middle and make a little U and stick it in.


Even better, @Deyan can make you 2x adapters


----------



## CAJames (Jul 2, 2020)

Thanks for the suggestions. The hum is (at least mostly) from the 6BX7 power tubes I've been using instead of 6080s. It has always been there, but the adapters have made it noticeably worse, but still listenable. Today I went back to the 6BL7s that have been dead quiet in the past with the National Union 6C5s. There is a tiny bit of hum, compared to dead quite with any dual triodes, but the 6C5s are new and I'm letting them cook a little before any serious listening. The picture doesn't look much different from the Tung-Sols, except you can see some of the labels.






I guess if I had to pick my favorite brand, or Team Tube, (sorry Chris, Side Valve sounds like plumbing to an American ear) it would NU. My phono stage uses a 12SN7, and you can get the 12V versions of many of the "famous" 6SN7s for literally pennies on the dollar if you shop around. And, long story short, I've tried a lot of 12SN7s and my favorite is a NU gray glass. My rectifier is also a NU VT-145 JAN 5Z3 which itself if the 4 pin version of a 5U4. It got mine for $10, I would imagine a similar 5U4 would go for 10x that at least.

How about we get jerseys made with our favorite tube company logos? And under served market for sure, but perhaps deservedly so.


----------



## leftside

CAJames said:


> Thanks for the suggestions. The hum is (at least mostly) from the 6BX7 power tubes I've been using instead of 6080s. It has always been there, but the adapters have made it noticeably worse, but still listenable. Today I went back to the 6BL7s that have been dead quiet in the past with the National Union 6C5s. There is a tiny bit of hum, compared to dead quite with any dual triodes, but the 6C5s are new and I'm letting them cook a little before any serious listening. The picture doesn't look much different from the Tung-Sols, except you can see some of the labels.
> 
> 
> 
> ...


Yep - a lot of those 12V tubes are great. I especially like the TS BGRP 12SN7. Sounds just like the expensive 6SN7.

They already exist 
https://www.aliexpress.com/item/32903907465.html


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## mordy

https://www.redbubble.com/shop/mullard+t-shirts


----------



## Monsterzero

CAJames said:


> Thanks for the suggestions. The hum is (at least mostly) from the 6BX7 power tubes I've been using instead of 6080s. It has always been there, but the adapters have made it noticeably worse, but still listenable. Today I went back to the 6BL7s that have been dead quiet in the past with the National Union 6C5s. There is a tiny bit of hum, compared to dead quite with any dual triodes, but the 6C5s are new and I'm letting them cook a little before any serious listening. The picture doesn't look much different from the Tung-Sols, except you can see some of the labels.
> 
> 
> 
> ...


Its been my experience that if you have noisy 6BX7s(or any other tube) that a good sandpaper cleaning will fix the issue. If that doesnt work simply try re-seating the tubes.
This has worked 100% of the time for me,though im sure there are some tubes that are beyond help.


----------



## bcowen (Jul 2, 2020)

Monsterzero said:


> Its been my experience that if you have noisy 6BX7s(or any other tube) that a good sandpaper cleaning will fix the issue. If that doesnt work simply try re-seating the tubes.
> This has worked 100% of the time for me,though im sure there are some tubes that are beyond help.



Could be as well that the solder has separated inside one or more of the pins. This is a known issue with '50's Russian 6N8S's (Fotons especially and some Melz). I've had a couple Tung Sols though with the same issue.  Best way is to suck out the old solder and replace it entirely, but almost as good is just reheating the pins until the solder melts and adding a little fresh solder.  Most times this problem manifests itself as a rustling, static-ey, or even squealing sound, but I've had a couple that had one triode testing totally dead -- until I resoldered the pins at which point it jumped up to NOS GM levels.

Edit:  a good cleaning of the pins as you suggest should always be the first course of action. Easy to do and can solve a lot of problems. And don't forget the sockets too -- not with sandpaper, but a pipe cleaner dipped in isopropyl alcohol works quite well.  If you've swapped a bunch of tubes in and out, it's surprising the amount of black gunk that ends up on the end of that pipe cleaner. Just _*please*_ (for the uninitiated) be sure the unit is turned off (and preferably unplugged from the wall socket) before sticking wet things in tube sockets.


----------



## CAJames (Jul 2, 2020)

mordy said:


> https://www.redbubble.com/shop/mullard+t-shirts



Those are awesome! However, I'm going to hold off on the National Union jersey for a while. Turns out at least one of the tubes was bad. Tried them with the known quite power tubes and they were still noisy, and then one of them went all mircophonic and the noise got much worse. Went back to the Tung-Sols with some old reliable 6080s and they were dead quite, and sounded really good. Not as good as with the 6BX7s modulo the noise, but as good or better then I ever remember the system sounding with the 6080s. This has been kinda exhausting, so now that it is sounding good again I'm just gong to listen for a little while. Plenty of time for more tube rolling later.

I appreciate everyone's suggestions for what to do with the noisy tubes, but I'm pretty sure the problem is a more fundamental than "noisy tubes." I've tried 3 different pairs from two different manufactures and all them have the same hum. The 6BX7 is very different from the 6080/6AS7 that my amp is supposed to use, and there is really no reason to think it should work even as well as it does.


----------



## leftside

CAJames said:


> Those are awesome! However, I'm going to hold off on the National Union jersey for a while. Turns out at least one of the tubes was bad. Tried them with the known quite power tubes and they were still noisy, and then one of them went all mircophonic and the noise got much worse. Went back to the Tung-Sols with some old reliable 6080s and they were dead quite, and sounded really good. Not as good as with the 6BX7s modulo the noise, but as good or better then I ever remember the system sounding with the 6080s. This has been kinda exhausting, so now that it is sounding good again I'm just gong to listen for a little while. Plenty of time for more tube rolling later.
> 
> I appreciate everyone's suggestions for what to do with the noisy tubes, but I'm pretty sure the problem is a more fundamental than "noisy tubes." I've tried 3 different pairs from two different manufactures and all them have the same hum. The 6BX7 is very different from the 6080/6AS7 that my amp is supposed to use, and there is really no reason to think it should work even as well as it does.


I had no hum with 6BL7 or 6BX7 when I had the WA22. Used those tubes all the time.


----------



## CAJames

Yes, and others too. But I have the "new improved" WA22, so who knows if that is really an apples to apples comparison. I don't have any hum with the 6BL7s.


----------



## mordy

CAJames said:


> Yes, and others too. But I have the "new improved" WA22, so who knows if that is really an apples to apples comparison. I don't have any hum with the 6BL7s.


I found it very tricky to get a quiet set of 6BX7 tubes. By listening to only one channel at a time I could determine which three tubes to check (instead of six) and by way of elimination identify the culprit.
Sometimes it even helped to switch the positions of the tubes.


----------



## mordy

bcowen said:


> Could be as well that the solder has separated inside one or more of the pins. This is a known issue with '50's Russian 6N8S's (Fotons especially and some Melz). I've had a couple Tung Sols though with the same issue.  Best way is to suck out the old solder and replace it entirely, but almost as good is just reheating the pins until the solder melts and adding a little fresh solder.  Most times this problem manifests itself as a rustling, static-ey, or even squealing sound, but I've had a couple that had one triode testing totally dead -- until I resoldered the pins at which point it jumped up to NOS GM levels.
> 
> Edit:  a good cleaning of the pins as you suggest should always be the first course of action. Easy to do and can solve a lot of problems. And don't forget the sockets too -- not with sandpaper, but a pipe cleaner dipped in isopropyl alcohol works quite well.  If you've swapped a bunch of tubes in and out, it's surprising the amount of black gunk that ends up on the end of that pipe cleaner. Just _*please*_ (for the uninitiated) be sure the unit is turned off (and preferably unplugged from the wall socket) before sticking wet things in tube sockets.


Could you describe how you add a little solder? I am always afraid that by heating up the solder it will flow inside the tube and create problems.


----------



## bcowen

mordy said:


> Could you describe how you add a little solder? I am always afraid that by heating up the solder it will flow inside the tube and create problems.



Sure, just position the tube horizontally before you start heating the pin.. Capillary action will help draw the new solder inside the pin. Don't need to add a lot...just a little.  Sometimes just reheating (re-melting) the old solder will do the trick too. When the tube was manufactured, the wire in each pin stuck out from the end of the pin and the excess wire was snipped off after soldering. So the wire itself should be right at the end tip of the pin -- just need to make sure the very tip has a good solder connection.  @Paladin79 has provided some very nice instructions in another thread and gave me a lot of great advice, just can't remember which thread that's in right now.  probably the Lyr 3 tube rollers thread or the main Lyr 3 thread...I'll see if I can find it tomorrow.


----------



## CAJames

mordy said:


> I found it very tricky to get a quiet set of 6BX7 tubes. By listening to only one channel at a time I could determine which three tubes to check (instead of six) and by way of elimination identify the culprit.
> Sometimes it even helped to switch the positions of the tubes.



So when you had noisy 6BX7s what was the noise like? I've been listening to tubes for a long time and I'm pretty sure I know the difference between "hiss" and constant 60 cycle hum that is equal in both channels. I've dealt with the former with all the techniques already mentioned (I'm a fanatic about DeoxIT) and including tube dampers which no one has mentioned (yet). But the noise I hear with 3 different pairs of 6BX7s (2 GE, one Sylvania), all with shiny new pins, is constant 60 cycle hum that is equal in both channels. Swapping left to right doesn't change it. It is certainly possible I've got 3 pairs of similarly bad tubes, and I've got one or two more pairs I can try, but this really seems like the tube is operating under conditions it doesn't like. The base of the tube also gets really hot, although the amp itself stays very cool.


----------



## Paladin79 (Jul 3, 2020)

bcowen said:


> Sure, just position the tube horizontally before you start heating the pin.. Capillary action will help draw the new solder inside the pin. Don't need to add a lot...just a little.  Sometimes just reheating (re-melting) the old solder will do the trick too. When the tube was manufactured, the wire in each pin stuck out from the end of the pin and the excess wire was snipped off after soldering. So the wire itself should be right at the end tip of the pin -- just need to make sure the very tip has a good solder connection.  @Paladin79 has provided some very nice instructions in another thread and gave me a lot of great advice, just can't remember which thread that's in right now.  probably the Lyr 3 tube rollers thread or the main Lyr 3 thread...I'll see if I can find it tomorrow.



You can always PM me and I will share photos. Personally I prefer to remove all the old solder, add liquid flux inside the pins and then re-solder using 3% silver solder. Here I am adding liquid rosin flux to the inside of each pin using a straight pick, I also use very tiny diameter solder, I want to say it is .021 but I will have to check that out later. You will see the wire @bcowen  mentioned on the inside of many pins. Flux cleans the metal you are about to solder, I use rosin core solder but when dealing with tubes that can be 60 years old or more, I prefer a more thorough cleaning since you cannot see how well the wire and inside of the pin are being cleaned.



Here are a couple ST Sylvania 6j5's in a headphone amp I designed, I also use quite a few 7A4"s which is the Loctal version of the 6j5.


----------



## bcowen

Paladin79 said:


> You can always PM me and I will share photos. Personally I prefer to remove all the old solder, add liquid flux inside the pins and then re-solder using 3% silver solder. Here I am adding liquid rosin flux to the inside of each pin using a straight pick, I also use very tiny diameter solder, I want to say it is .021 but I will have to check that out later. You will see the wire @bcowen  mentioned on the inside of many pins. Flux cleans the metal you are about to solder, I use rosin core solder but when dealing with tubes that can be 60 years old or more, I prefer a more thorough cleaning since you cannot see how well the wire and inside of the pin are being cleaned.



Thanks for responding!  

I will note that even after resoldering umpteen bazillion pins on my tubes, @Paladin79 's still look better.  I'm pretty sure the doctor had to cut a soldering iron cord rather than an umbilical cord when he was born.  

It's no issue to get a good solder connection that is electrically sound. It's keeping the solder off the outside of the pin that proves challenging for me.  Then you have to file it down to get it smooth again.  Not a big issue either, just kind of a PITA.  I've found that wiping any excess flux off the _outside_ of the pin before hitting it with the soldering iron helps a lot, as does using a very thin gauge solder as Paladin already mentioned. Mine look better and better as I get more experience, but I'd highly recommend practicing on a useless or worn out tube first before globbing up a prized treasure if this is your first attempt.  

Some of us have plenty to practice on.


----------



## CAJames

Paladin79 said:


> ... I also use quite a few 7A4"s which is the Loctal version of the 6j5.



Ah, the 7A4. I'm a big fan of the 7N7 (loctal version of the 6SN7) but that may be an adapter too far for me. Probably not a cliff I even want to look over.


----------



## Paladin79

bcowen said:


> Thanks for responding!
> 
> I will note that even after resoldering umpteen bazillion pins on my tubes, @Paladin79 's still look better.  I'm pretty sure the doctor had to cut a soldering iron cord rather than an umbilical cord when he was born.
> 
> ...


I just keep the solder inside the pin or on the outside edge of the pin where it can be easily removed. I just came across a large stash of Fotons I did not know I owned, 52,53, and 54.


----------



## Paladin79 (Jul 3, 2020)

CAJames said:


> Ah, the 7A4. I'm a big fan of the 7N7 (loctal version of the 6SN7) but that may be an adapter too far for me. Probably not a cliff I even want to look over.




These were NOS Sylvania VT 192’s. I say were because I listen to them on occasion.Military version of 7A4's.


----------



## CAJames

Listening to the Tung-Sols for the morning recharged the batteries so (instead of leaving well enough alone) I swapped in the P5Gs. And these might be the best yet. None of the hardness of the P5GTs, and more liquid than the Tung-Sols, albeit with a slight loss of transparency. Also dialed down the gain with the 6BL7 power tubes as I hoped, these are going to stay in the WA22 for a while. And handsome to boot.





Someone was selling like 3 dozen of these on ebay for US$ 99 and I seriously considered buying them but passed. I guess I blew it.


----------



## Paladin79 (Jul 3, 2020)

CAJames said:


> Listening to the Tung-Sols for the morning recharged the batteries so (instead of leaving well enough alone) I swapped in the P5Gs. And these might be the best yet. None of the hardness of the P5GTs, and more liquid than the Tung-Sols, albeit with a slight loss of transparency. Also dialed down the gain with the 6BL7 power tubes as I hoped, these are going to stay in the WA22 for a while. And handsome to boot.
> 
> 
> 
> Someone was selling like 3 dozen of these on ebay for US$ 99 and I seriously considered buying them but passed. I guess I blew it.


Nice, did you happen to make the table or shelf? I generally build audio racks out of woods other than maple just to annoy @bcowen


----------



## CAJames

Paladin79 said:


> Nice, did you happen to make the table or shelf? I generally build audio racks out of woods other than maple just to annoy @bcowen



No. I said in another thread that around the office I call myself a "software guy" and really admire those of you who are handy with a soldering iron or power tools. But one of my friends is an excellent woodworker and built my rack. Cherry frame with maple and walnut stripes on the shelves. It is very beautiful, I'll post a picture of the whole thing later.


----------



## Paladin79

CAJames said:


> No. I said in another thread that around the office I call myself a "software guy" and really admire those of you who are handy with a soldering iron or power tools. But one of my friends is an excellent woodworker and built my rack. Cherry frame with maple and walnut stripes on the shelves. It is very beautiful, I'll post a picture of the whole thing later.


I used solid cherry and copper on my racks but I may go with something more colorful.

This is my work with walnut and maple, and brushed copper.

One of the amps I designed, I gifted one to @bcowen but I kept his pretty simple.I donated four identical amps that will be doing a blind tube challenge using 6sn7 equivalents, including 6j5's, we have it down to 52 of the best tubes we can find. Such tests will have to wait for Covid 19 to let up, there will be a group of 50 listeners.


----------



## CAJames

Spectacular! The shelves on my rack are MDF, the hardwood is 1/8" IIRC.


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## Paladin79 (Jul 3, 2020)

CAJames said:


> Spectacular! The shelves on my rack are MDF, the hardwood is 1/8" IIRC.


Very nice, I generally go with solid wood myself. I own a lot of equipment and trade it out fairly often so I made this rack adjustable. The patinated copper pipe can be replaced  to change height on any given shelf. I know Jason at Schiit audio so I use some of his tube equipment on occasion and a DAC here and there.



I am also doing a steampunk amp so it should go along with the rack somewhat.
This is just a rough layout and I know I want to use exposed ladder pots, and I may do a copper Farday cage around the power transformer. I may would have to mount 6j5's longways but it is early still.


----------



## CAJames

I love the copper pipe supports! Can I assume you do that yourself too?

Since I wanted long shelves the MDF seemed to make sense. Also more economical, my Scottish heritage points out.


----------



## Paladin79

CAJames said:


> I love the copper pipe supports! Can I assume you do that yourself too?
> 
> Since I wanted long shelves the MDF seemed to make sense. Also more economical, my Scottish heritage points out.


Yes and I have done brushed copper supports as well. The electronics is easy for me so I challenge myself to learn cabinetry and metal work. MDF is wonderful for some applications and it stays very stable. 

Mr.Cowen wanted his amp to sit on a shelf like this, he “borrowed” my design to build his own shelf so I made him an amp to fit on said shelf.


----------



## bcowen (Jul 3, 2020)

CAJames said:


> Ah, the 7A4. I'm a big fan of the 7N7 (loctal version of the 6SN7) but that may be an adapter too far for me. Probably not a cliff I even want to look over.



But then you'll be missing out!  I need to get @Deyan to make me a _good_ adapter though. These elderly Hytrons sound quite nice. I've dubbed them the Frankentubelets (you know, kind of like pig / piglet......oh nevermind).


----------



## Paladin79

bcowen said:


> But then you'll be missing out!  I need to get @Deyan to make me a _good_ adapter though. These Hytrons sound quite nice.  I've dubbed them the Frankentubelets. (you know, kind of like pig / piglet......oh nevermind).


I am curious when it was you learned about 7A4's?  I can recall finding them in a tube manual and buying them and an adapter quite some time ago.


----------



## bcowen (Jul 3, 2020)

Paladin79 said:


> I am curious when it was you learned about 7A4's?  I can recall finding them in a tube manual and buying them and an adapter quite some time ago.



IIRC, it was right after I started playing with 7N7's....and you just had to be different.  

But since this is a 6J5 thread, I won't get started an 7AF7's.


----------



## bcowen

Paladin79 said:


> One of the amps I designed, I gifted one to @bcowen but I kept his pretty simple.



What?!?  Mine is *simple*?  I demand a refund.


----------



## Paladin79

bcowen said:


> IIRC, it was right after I started playing with 7N7's....and you just had to be different.


Well yeah, right after Ripper told me about 7N7’s lol. Anyway I admit you mentioned the military version, VT-192 so you were sorta helpful, sorta.


----------



## Paladin79

bcowen said:


> What?!?  Mine is *simple*?  I demand a refund.


Ok I will send you zero dollars to your PayPal account, just as soon as the virus vanishes magically. So expect it any day.


----------



## bcowen

Paladin79 said:


> Well yeah, right after Ripper told me about 7N7’s lol. Anyway I admit you mentioned the military version, VT-192 so you were sorta helpful, sorta.



 

I'm always kinda glad to share tube splendor, sometimes-ish.


----------



## bcowen

Paladin79 said:


> Well yeah, right after Ripper told me about 7N7’s lol. Anyway I admit you mentioned the military version, VT-192 so you were sorta helpful, sorta.



On a serious note, I have a couple pairs of '40's Sylvania VT-192's, but I like these Hytrons better. More whomp in the bass and more harmonic info in the mids. A bit smaller soundstage, but the other qualities overshadow that...at least for my preferences.


----------



## CAJames (Jul 4, 2020)

bcowen said:


> But then you'll be missing out!  I need to get @Deyan to make me a _good_ adapter though. These elderly Hytrons sound quite nice. I've dubbed them the Frankentubelets (you know, kind of like pig / piglet......oh nevermind).




Sure, in a perfect world I'd be scouring the globe for 7A4s. But, for me the attraction of the 7N7 (and 7AF7, although I've yet to hear a really good one of those) is that it *is *a 6SN7 but because everyone is afraid of loctal they haven't gone extinct like NOS 6SN7s. 6J5s don't have that problem so the attraction of a 7A4 is limited. Or to put it differently I've got to draw the line somewhere, and I draw it at the 7A4. But I hope we can still be friends  .


----------



## bcowen

CAJames said:


> Sure, in a perfect world I'd be scouring the globe for 7A4s. But, for me the attraction of the 7N7 (and 7AF7, although I've yet to hear a really good one of those) is that it *is *a 6SN7 but because everyone is afraid of loctal they haven't gone extinct like NOS 6SN7s. 6J5s don't have that problem so the attraction of a 7A4 is limited. Or to put it differently I've got to draw the line somewhere, and I draw it at the 7A4. But I hope we can still be friends  .



LOL!  I've always had a problem drawing lines, so you've one-upped me there for sure.


----------



## Paladin79

CAJames said:


> Sure, in a perfect world I'd be scouring the globe for 7A4s. But, for me the attraction of the 7N7 (and 7AF7, although I've yet to hear a really good one of those) is that it *is *a 6SN7 but because everyone is afraid of loctal they haven't gone extinct like NOS 6SN7s. 6J5s don't have that problem so the attraction of a 7A4 is limited. Or to put it differently I've got to draw the line somewhere, and I draw it at the 7A4. But I hope we can still be friends  .


The only thing I will say about loctals is that good loctal sockets are not that easy to find. I have built my own adapters so they can be used in place of 6j5's and I had to make several purchases before I found sockets I liked.


----------



## bcowen

Paladin79 said:


> The only thing I will say about loctals is that good loctal sockets are not that easy to find. I have built my own adapters so they can be used in place of 6j5's and I had to make several purchases before I found sockets I liked.



Totally agree -- *GOOD* loctal sockets are becoming as hard to find as good loctal tubes. I like the NOS Cinch sockets best followed closely by the Amphenols.  The Cinch's are better for tube rolling as they provide very good contacts but don't put an ultimate death grip on the tube the way the Amphenols do. Not cheap for just a socket either way though.


----------



## chrisdrop

bcowen said:


> Totally agree -- *GOOD* loctal sockets are becoming as hard to find as good loctal tubes. I like the NOS Cinch sockets best followed closely by the Amphenols.  The Cinch's are better for tube rolling as they provide very good contacts but don't put an ultimate death grip on the tube the way the Amphenols do. Not cheap for just a socket either way though.


Not cheap https://www.jacmusic.com/sockets/Socket-Yamamoto.htm


----------



## Paladin79 (Jul 4, 2020)

chrisdrop said:


> Not cheap https://www.jacmusic.com/sockets/Socket-Yamamoto.htm



It was nice of them to include tube pinouts, 7n7 and 6sn7 tubes are not pin 1 to pin 1, pin 2 to pin 2 in case you decide to build your own one day. I have built several and did some research before I started.

As far as my personal listening, if I really want to examine a tube or set of tubes I only use separate pots for each channel. It is nice to have perfectly balanced tubes but it does not always happen. If specific frequencies are more predominant on one channel over the other, I can key in on them a bit more if I can lower the opposite channel a bit. It also helps when trying to detect cross talk in dual triode tubes, single triode tubes are not subjected to this issue.


----------



## bcowen

chrisdrop said:


> Not cheap https://www.jacmusic.com/sockets/Socket-Yamamoto.htm



Those are most impressive.  Not cheap to be sure, but obviously not cheaply made either.


----------



## CAJames (Jul 4, 2020)

chrisdrop said:


> Not cheap https://www.jacmusic.com/sockets/Socket-Yamamoto.htm



I got my 7N7 - 6SN7 adapters from Jacmusic, along with some 7N7s. They have were my "daily driver" when I started this journey and still my baseline. The adapters use the CINCH socket and are very nice.


----------



## CAJames

Paladin79 said:


> ...As far as my personal listening, if I really want to examine a tube or set of tubes I only use separate pots for each channel. It is nice to have perfectly balanced tubes but it does not always happen. If specific frequencies are more predominant on one channel over the other, I can key in on them a bit more if I can lower the opposite channel a bit. It also helps when trying to detect cross talk in dual triode tubes, single triode tubes are not subjected to this issue.



So you do the balancing by ear and e.g. by matching plate dissipation?


----------



## Paladin79

CAJames said:


> I got my 7N7 - 6SN7 adapters from Jacmusic, along with some 7N7s. They have were my "daily driver" when I started this journey and still my baseline. The adapters use the CINCH socket and are very nice.


Unfortunately the 7n7's do not sound very good in my Incubus amps, @bcowen will attest to this, they sound much better in other amps. I designed my amps to have very little in the signal paths that might color or inhibit the sound of the tubes. That is my opinion of the outcome as well as 100 or so people who have heard the amp. 

Bill kept wondering why I was not impressed, and why we did not include the 7n7 in with the 52 included in our blind listening, then he knew why after I gave him an amp. I suppose some manufacturers are trying to emulate solid state, I have a few amps where you cannot detect much difference. They have an accuracy but lack the warmth and depth of a great tube amp.


----------



## Paladin79 (Jul 4, 2020)

CAJames said:


> So you do the balancing by ear and e.g. by matching plate dissipation?


If just listening in general, I adjust for where I believe the music levels should be, I also have VU meter stages I built and incorporated into my gear. I also have a fairly complete electronics shop with various scopes, signal generators etc. I also work closely with an engineering lab and several of those guys are in my audiophile group. If I do not own it, I can borrow it. On occasion I bring a few pieces in to do comparisons. I have checked emission, plate current, etc. but I only do that for specific purposes. Like when I worked to convince @bcowen that Foton tubes should not have to cook for 100 hours. I replaced solder in all pins then cooked one for 100 hours, it read a bit lower but only because of the hours I put on it lol. In fairness, Bill did convince me that a cable cooker had some benefits, I try to stick with science but I keep an open mind. My amps open up even more as the wire gets more playing time, and I use some serious wire inside the amps.



I should also mention much of the music we use for comparing tubes, or amps, or DACS for blind listening has 25 sonic spectrums we compare, each is scored on a four point scale so 100 is perfection. Much of this music was recorded for our exact purposes by an award winning audio engineer. The testing can be a bit grueling but it is not a bunch of guys sitting around drinking beer saying, oh that sounds good lol. One young woman in the testing can pick out wire types consistently, try that sometime, or high end output caps. I believe in the accuracy of masses so we take the average of fifty listeners. The young lady I mentioned has been spot on with what the group decided on DACS and she was not far off on power amps and some of the headphone amps we compared.


----------



## CAJames (Jul 4, 2020)

Paladin79 said:


> Unfortunately the 7n7's do not sound very good in my Incubus amps, @bcowen will attest to this, they sound much better in other amps. I designed my amps to have very little in the signal paths that might color or inhibit the sound of the tubes. That is my opinion of the outcome as well as 100 or so people who have heard the amp.
> 
> Bill kept wondering why I was not impressed, and why we did not include the 7n7 in with the 52 included in our blind listening, then he knew why after I gave him an amp. I suppose some manufacturers are trying to emulate solid state, I have a few amps where you cannot detect much difference. They have an accuracy but lack the warmth and depth of a great tube amp.



Interesting. Do 7N7s sound different than the same version of 6SN7, e.g. octal and loctal versions of the Sylvania XXX-GTA?If anything the math suggests loctal should sound better, everything else being equal. Which it never is.


----------



## Paladin79 (Jul 4, 2020)

CAJames said:


> Interesting. Do 7N7s sound different than the same version of 6SN7, e.g. octal and loctal versions of the Sylvania XXX-GTA?If anything the math suggests loctal should sound better, everything else being equal. Which it never is.


I will have locate the octal version and give them a listen. I should not say they sound bad, just not as exceptional as other tubes IMHO. I believe Bill put it, my amp makes tubes sound 100 compared to 50 compared to 60 compared to 50 in other amps. I hope that makes sense and I beg Bill’s pardon if I misquoted him. I know we have a Bad Boy and maybe a VT-231 represented but I have never considered loktal equivalents.

It is also best to mention a group of five is doing the tube selection for the blind listening so it is their decision which tubes to include. In the test group are GEC, Marconi, some well regarded Tung Sol, Mullard, Brimar, RCA, Hytron etc. You can place a price on those tubes but there is at least one, maybe two that are unique prototypes, never put up for sale. This is why blind listening is done, I received one of those tubes in a Pelican case and knew what it was and its history. It is not always easy to be objective unless you go by sound alone.


----------



## attmci

The "best" tube for your amp will depend on your chain of equipments (DAC, Headphones,plus more) and how your ears judge the tube's ability to reproduce music.


----------



## Paladin79 (Jul 5, 2020)

attmci said:


> The "best" tube for your amp will depend on your chain of equipments (DAC, Headphones,plus more) and how your ears judge the tube's ability to reproduce music.


That is part of it, but then I build amps.😉

I own at least five DAC's, 7 or 8 headphones and while I have modified some amps to fit friends needs certainly some tubes sound better than others. My testing with some local friends will mean fifty people will use the same Sennheiser headphones, 4 pairs, HD 800. Several DAC's were tried but the group favorite of twenty we tried is the Aqua La Voce S3. Those DAC's went through the same test cycle that we are using for tubes. 

As far as home use, sure if you own say a Lyr 3 and the new Bifrost your results would be different. (I have those devices and I am hard pressed to tell a difference in some tubes using the same music my group uses.)

If you pay $250 for a tube, then try it in your home amp there can be some expectation bias. Or maybe all your friends say a particular tube is the best they have ever heard, how does one stay impartial?

In my group test, we are careful to keep all things as close to the same as possible and we only switch between four tubes at any one time.With the scoring system and blind listening, and a large enough group it is not just one person's opinion. Price does not matter, or brand name or any one person's preferences.

Having done this with equipment before, it is kind of fun to see a $500 DAC rate higher than some going for several thousand dollars. If we find a tube that goes for $20 to be in the top five, and ranks ahead of many going for $250 -$2000 that would certainly be interesting.

I designed my amp to be as tube revealing as I could get it, and so far out of 100 listeners, one person did not hear a great deal of difference between tubes and he was pretty new to headphones, tubes, and headphone amps. This sounds a bit clinical I bet but my friends seem to love the musicality of the amp and I was a little shocked by that but yet, most of us do like tubes over transistors for a reason.


----------



## RoyGB (Jul 5, 2020)

Hi yall,
I'm coming over from the Project Ember Tube Rolling thread. Ember is a 48V plate starved tube hybrid so it is a bit of a different beast in terms of how it is dealing with its tubes.

I have been rolling a lot of 6J5 and 76 series tubes recently and have been enjoying some of them a lot.

I definitely feel like the 76 tubes should be thrown into the lot with the 6J5 series considering they were the predecessor tubes of the 6P5 and 6C5.

These are my current favorite tubes. Tung Sol 76's Lot's of tube character, warm, lush, with good dynamics.






I was also a really big fan of Hytron 6C5's. But my pair has a pretty bad gain imbalance so I really don't use them. I've been searching for another pair for a while now but I have had no luck finding any. I don't think a properly matched pair for sale exists on the internet at this moment in time. The closest I can find is an ebay listing with two different construction tubes.





I have a bunch more pairs that I can write impressions on in the upcoming days. Sometimes these writeups take some time.


----------



## leftside

RoyGB said:


> Hi yall,
> I'm coming over from the Project Ember Tube Rolling thread. Ember is a 48V plate starved tube hybrid so it is a bit of a different beast in terms of how it is dealing with its tubes.
> 
> I have been rolling a lot of 6J5 and 76 series tubes recently and have been enjoying some of them a lot.
> ...


I'll post up some pics and thoughts of the 76 tubes that I have over the next few days. I've acquired quite a few Fivre 76 recently. I find the 76 tube to be very similar to the 6C5. Airy and refined.


----------



## L0rdGwyn (Jul 6, 2020)

Something I find interesting is the evolution of these tubes.

The 76 being the precursor to the 6P5, it is then cited as the progenitor to subsequent tubes like the 6C5 and 6J5, but I'm not so sure.

The L63 has its own parent, the Marconi-Osram MHL4, which is actually much more similar in terms of specification to the 6J5 / L63 and existed before the 76 (the MHL4 was first in production in 1930, whereas the 76 was first made in 1933).  I wonder if there was a parallel evolution, or perhaps just a similar need for tubes of this spec at the time.

Here are the specs of the respective tubes from their sheets, in chronological order of first production from what I have been able to find.

MHL4 (1930): μ 20; ra 8000; gm 2500 μmhos
76 (1933): μ 13.8; ra 9500; gm 1450 μmhos
6C5G (1936): μ 20; ra 10000; gm 2000 μmhos
6J5G (1936): μ 20; ra 7700; gm 2600 μmhos
6P5G (1938): μ 13.8; ra 9500; gm 1450  μmhos

An aside, the earliest date I have found for the 6P5G is 1938.  Since it is equivalent to the 76 albeit with an octal base, I assume the 76 was used in its place until then, so it isn't necessarily a precursor to the 6C5 / 6J5, more like a replacement for the 76.

Looking at the specs, you can see the MHL4 is nearly an exact 6J5 equivalent, however with 4V 1A heaters and a lower grid voltage required.  Its electrical characteristics are much more similar to the 6J5 than the 76, so who is the real parent?  Most likely getting to the same result via different paths, just some food for thought


----------



## RoyGB

L0rdGwyn said:


> Something I find interesting is the evolution of these tubes.
> 
> The 76 being the precursor to the 6P5, it is then cited as the progenitor to subsequent tubes like the 6C5 and 6J5, but I'm not so sure.
> 
> ...



I think the biggest hurdle in including them is going to be the electrical requirements to run them. Considering this is somewhat of a tube rolling thread, it is going to be hard getting any representation for them because you cant just adapt into a 6SN7 socket. Likewise, I wouldn't lot in 56 tubes with 76 tubes even though 56 tubes were the precursor, due to their own wonky electrical requirements (2.5V 1A).


----------



## Paladin79

RoyGB said:


> I think the biggest hurdle in including them is going to be the electrical requirements to run them. Considering this is somewhat of a tube rolling thread, it is going to be hard getting any representation for them because you cant just adapt into a 6SN7 socket. Likewise, I wouldn't lot in 56 tubes with 76 tubes even though 56 tubes were the precursor, due to their own wonky electrical requirements (2.5V 1A).


Luckily on some amps like the Vali 2, the designer is there to ask. It will handle the filament current requirements of a 6sn7, even though it was made for a 6922.


----------



## L0rdGwyn

RoyGB said:


> I think the biggest hurdle in including them is going to be the electrical requirements to run them. Considering this is somewhat of a tube rolling thread, it is going to be hard getting any representation for them because you cant just adapt into a 6SN7 socket. Likewise, I wouldn't lot in 56 tubes with 76 tubes even though 56 tubes were the precursor, due to their own wonky electrical requirements (2.5V 1A).



Oh I'm sorry, I wasn't suggesting they be included, although I could be their representative, just sharing some information on the origin of the 6J5 I thought others might find interesting, my mistake.


----------



## chrisdrop

L0rdGwyn said:


> Oh I'm sorry, I wasn't suggesting they be included, although I could be their representative, just sharing some information on the origin of the 6J5 I thought others might find interesting, my mistake.


Certainly interesting.
Tx for sharing.


----------



## RoyGB

Paladin79 said:


> Luckily on some amps like the Vali 2, the designer is there to ask. It will handle the filament current requirements of a 6sn7, even though it was made for a 6922.


Vali likely wont be able to do any tube other than a 6V, and most amps using tubes like these are using them as preamp tubes and don't have nearly enough current to drive two 1A+ tubes. Most people running anything like the aforementioned usually require external power supplies to handle all the power requirements of the tube.


----------



## whirlwind

L0rdGwyn said:


> Something I find interesting is the evolution of these tubes.
> 
> The 76 being the precursor to the 6P5, it is then cited as the progenitor to subsequent tubes like the 6C5 and 6J5, but I'm not so sure.
> 
> ...




Interesting, great find!


----------



## Paladin79 (Jul 6, 2020)

RoyGB said:


> Vali likely wont be able to do any tube other than a 6V, and most amps using tubes like these are using them as preamp tubes and don't have nearly enough current to drive two 1A+ tubes. Most people running anything like the aforementioned usually require external power supplies to handle all the power requirements of the tube.


I only said it could do a 6sn7, and I double checked it with Jason at Schiit before doing that. I studied tube theory in college so I might know a little about them. I was also the first person to get a Coaster amp working, mini Vali, outside of Schiit. I caught a mistake in the schematic and BOM. 

I even made one into a snow globe, a flying saucer, and mounted one in an 8 ball. I never could get the glass cutting down well enough to mount one in a scotch bottle, but I tried.


----------



## RoyGB

Alright, I figure I might be the one to introduce these tubes to this thread as well as share some words of advice before you all go out and snatch up every last one of these.

These are know as 'Magic Eye' tubes. And some of them share the same electrical characteristics (or close enough) as the 6J5 tubes and the same pin base.

*PLEASE DON'T BUY THESE TUBES*

I know, I know. They are really cool and I am sure you all want a pair. So a couple reasons why I don't suggest you go out and buy them.

It is uncertain whether or not these would actually work as a preamp tube or allow audio to even get through them. When I first stumbled upon these tubes I wanted to buy a pair because they were the coolest tubes I had seen. The moving bands can be used as a level or VU meter for audio. After much digging to see if they would actually work as audio tubes results were inconclusive. It is a solid maybe. Maybe someone else has some info on these but a maybe was as far as I was able to get. Quite frankly I don't want to know as I detail below why.
These tubes are not for us. One of the main purposes of magic eye tubes is to be used to tune radios. Their main purpose was to tune radios. The antique radio repair community relies on these tubes as tuning indicators for their radios, and supply is only ever going down. Nobody makes these anymore. 
The lifespan on these tubes is in the mid to low hundreds of hours (300-500). This goes hand in hand with my prior point. A lot of people end up building in separate switches to turn these tubes off as soon as possible after their radios are tuned to save life on these tubes.
We enjoy our vintage audio tubes. Let the radio guys keep their radio tubes.
Who knows how much longer relics like this may be able to be used and enjoyed by their respective community.


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## Paladin79 (Jul 6, 2020)

RoyGB said:


> Alright, I figure I might be the one to introduce these tubes to this thread as well as share some words of advice before you all go out and snatch up every last one of these.
> 
> These are know as 'Magic Eye' tubes. And some of them share the same electrical characteristics (or close enough) as the 6J5 tubes and the same pin base.
> 
> ...



I have worked with those and even have a Chinese amp that uses the bar type, but they are meant for display, not for passing audio. Some of the ones I have used require 200 to 250 volts. They can be used as VU meters but you best know what you are doing if you try to incorporate them. Most in radios were used to show signal gain. I incorporated two in an amp I designed just to win a bet, I had to use the tubes and parts handed to me.

The Chinese still make the bar type but not the magic eye as far as I know.

https://www.ebay.com/itm/Douk-Audio...372442?hash=item3fb76de5da:g:lQMAAOSw0sVe4cx1



Here are some on a non working  amp I bought for $10, I rebuilt the thing three times and it is still a pretty crappy amp but it does have a light display and a built in DAC.


----------



## RoyGB

Paladin79 said:


> I have worked with those and even have a Chinese amp that uses the bar type, but they are meant for display, not for passing audio. Some of the ones I have used require 200 to 250 volts. They can be used as VU meters but you best know what you are doing if you try to incorporate them. Most in radios were used to show signal gain. I incorporated two in an amp I designed just to win a bet, I had to use the tubes and parts handed to me.
> 
> The Chinese still make the bar type but not the magic eye as far as I know.
> 
> https://www.ebay.com/itm/Douk-Audio...372442?hash=item3fb76de5da:g:lQMAAOSw0sVe4cx1



I was mainly referring to the ones that could be thrown into a 6J5 system. With a plate triode and all the bits that you would see in an audio tube. I could assume just by looking at many of the noval ones and even the 6SN7 style ones that they had no amplification ability like an audio tube but the ones like I showed in that picture look to have all the parts of a normal tube 6J5 so I thought maybe these could actually at least pass an audio signal through them. I wasn't sure if the amplification was only for the cathode ray on the top or if it had another purpose. At least that was my original thinking when I was first going after a pair.

Considering that a good amount of magic eyes follow the 6_5 designation, I thought that I would throw out some info on them.


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## Paladin79

RoyGB said:


> I was mainly referring to the ones that could be thrown into a 6J5 system. With a plate triode and all the bits that you would see in an audio tube. I could assume just by looking at many of the noval ones and even the 6SN7 style ones that they had no amplification ability like an audio tube but the ones like I showed in that picture look to have all the parts of a normal tube 6J5 so I thought maybe these could actually at least pass an audio signal through them. I wasn't sure if the amplification was only for the cathode ray on the top or if it had another purpose. At least that was my original thinking when I was first going after a pair.
> 
> Considering that a good amount of magic eyes follow the 6_5 designation, I thought that I would throw out some info on them.


I understand and I may grab a couple just to check them out, I do not recall that much about them, only a bit of theory.


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## L0rdGwyn (Jul 6, 2020)

Back to 6J5 tubes, here is another unusual one.  I've shared it on the 2359glenn thread, but an eBay seller just listed a pair for an absolutely absurd price, which reminded me to get them out of storage.

These are the East German RFT / OSW 6J5.  Back when I collected 6SN7 tubes, one of my favorites was the RFT 68HC with welded plates and ceramic spacers, beautiful tubes with a great tone.  I got to searching for a pair of the equivalent 6J5, and by luck one of my tube sellers discovered they had a triplet, I bought them eagerly.

These have a metallized coating grounded to pin 1, similar to the American-made metallized 6J5.



Came with the original boxes as well, but barely holding together.



And some reading material, in German of course.  This is a guarantee certificate, 6 months from the date of sale.  I guess I am outside the window if I have a failure, oh well.



Hmm these tubes match the color of my amp, this is the first time I've used them in it.  Not quite as spacious as the MOV L63 or Fivre 6C5G, but very nice tonally, not overally warm or bright, a neutralish tube to my ears, maybe a little rolled off up top, very easy to listen to.


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## bcowen

RoyGB said:


> Alright, I figure I might be the one to introduce these tubes to this thread as well as share some words of advice before you all go out and snatch up every last one of these.
> 
> These are know as 'Magic Eye' tubes. And some of them share the same electrical characteristics (or close enough) as the 6J5 tubes and the same pin base.
> 
> ...



The original Cary 805 amps used these as a sort of semi-VU meter. When the two halves lit and met, that was supposedly full power output.  They were entertaining to watch, but of little practical value as an actual VU meter. I think they were intended to be more bling/retro than functional (for VU purposes) anyway.


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## bcowen

RoyGB said:


> Hi yall,
> I'm coming over from the Project Ember Tube Rolling thread. Ember is a 48V plate starved tube hybrid so it is a bit of a different beast in terms of how it is dealing with its tubes.
> 
> I have been rolling a lot of 6J5 and 76 series tubes recently and have been enjoying some of them a lot.
> ...



I've never played with 76 tubes.  Looks like they have about about 60% of the gain of a 6J5 or 6C5. Obviously amp dependent, but does the lower gain result in any higher background noise level?


----------



## bcowen

L0rdGwyn said:


> Back to 6J5 tubes, here is another unusual one.  I've shared it on the 2359glenn thread, but an eBay seller just listed a pair for an absolutely absurd price, which reminded me to get them out of storage.
> 
> These are the East German RFT / OSW 6J5.  Back when I collected 6SN7 tubes, one of my favorites was the RFT 68HC with welded plates and ceramic spacers, beautiful tubes with a great tone.  I got to searching for a pair of the equivalent 6J5, and by luck one of my tube sellers discovered they had a triplet, I bought them eagerly.
> 
> ...



Interesting!  I have a bunch of RFT 12AU7's that are at best nothing special, so I've never looked closely at other RFT-made types.


----------



## L0rdGwyn

bcowen said:


> Interesting!  I have a bunch of RFT 12AU7's that are at best nothing special, so I've never looked closely at other RFT-made types.



They made some great tubes!  The RFT 6H8C / 6SN7 are quite rare and highly sought after (i.e. expensive), RFT EL34 are considered some of the best NOS EL34 available behind the Philips / Mullard makes, and much cheaper.  They manufactured very nice audio output pentodes like the EL11 and EL12, in addition to several rectifiers with the German 7-pin Y8A base, like the AZ12.  Yet another tube they made that I am particularly interested in using is the EC360, very appealing for use in an OTL design.

Anyway, I digress, RFT tubes are very nice but I have never used their miniatures so maybe they don't perform as well.


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## RoyGB (Jul 6, 2020)

bcowen said:


> I've never played with 76 tubes.  Looks like they have about about 60% of the gain of a 6J5 or 6C5. Obviously amp dependent, but does the lower gain result in any higher background noise level?


I have a few pairs of 76 tubes like my Arcturus (National Union) 76 tubes that have close to solid state levels of noisefloor. And the trend is that they are on average the quietest type of tube that I have. And I have like 4-6 pairs. This is before I further ground things out and sheild the tubes. This was at max volpot, high gain, with 24 ohm Denon D9200's. Not all but some. For instance, my Tung Sols have below average noisefloor but have a noisefloor. Not sure how much of that is my plate starved Ember and how much is the tubes. But to actually hear the noisfloor on some of my quiet tubes I need things to be very quiet in my place and I really need to go searching for it with no music playing.


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## chrisdrop

L0rdGwyn said:


> Back to 6J5 tubes, here is another unusual one.  I've shared it on the 2359glenn thread, but an eBay seller just listed a pair for an absolutely absurd price, which reminded me to get them out of storage.
> 
> These are the East German RFT / OSW 6J5.  Back when I collected 6SN7 tubes, one of my favorites was the RFT 68HC with welded plates and ceramic spacers, beautiful tubes with a great tone.  I got to searching for a pair of the equivalent 6J5, and by luck one of my tube sellers discovered they had a triplet, I bought them eagerly.
> 
> ...


I love the look of those metallized 6J5s + the beautiful globes. Amp is lookin' lovely. 

It seems like the "metallized" approach was older and stopped at some point? Any idea how it was done? Sometimes those tubes look a bit like they have "spray on metal" on the outside. Or are they just rugged looking metal cases?


----------



## L0rdGwyn (Jul 7, 2020)

chrisdrop said:


> I love the look of those metallized 6J5s + the beautiful globes. Amp is lookin' lovely.
> 
> It seems like the "metallized" approach was older and stopped at some point? Any idea how it was done? Sometimes those tubes look a bit like they have "spray on metal" on the outside. Or are they just rugged looking metal cases?



Hey Chris - I think you are right, for the tubes that have at thin coat over glass, it looks as though the coating is sprayed on as opposed to cast, like the American-made metal tubes.  I have not been able to find any information on the manufacturing process, however my best guess is the tube envelopes were spun and sprayed.  This type of metallization seems to be a strictly European, the coating is attached to a ground wire that wraps around the base of the tube, then exits down below to be grounded (pin 1 in the case of the 6J5 / 6C5, via the cathode in B5 base tubes in my collection).

Here close up you can see the ground wire on the base of the RFT 6J5.



In another example, a Marconi MH4, the ground wire is attached to the coating via a pad at the side of the envelope.



The exception to the sprayed-on coating of the metallized European tubes is what was used on the tube above.  This metallized coating, which I have seen on these Marconi MH4 and some Telefunken / Klangfilm REN904, is very thick and is much more prone to oxidation and flaking than the thin sprayed-on type.  I wonder if perhaps some other type of deposition process was used in this case, but again, no information that I have been able to find.

Now the American-made metallized tubes actually have their origins in the UK from the great innovators at Marconi-Osram Valve, once again  in the early 1930s, MOV developed the "catkin" type receiving tubes, vacuum tubes that had a true metal envelop as opposed to glass.  They didn't quite catch on, so were only made for a few years.  I have seen a pair or two for sale, MH4 that could be used in my other amplifier, but never went for it, they aren't exactly pretty HA!  But I do wonder how they sound.  This pair sold a few months ago, I resisted the urge to bid on them.



Here is a 1933 article discussing MOV catkin tubes:  https://www.rfcafe.com/references/radio-craft/new-english-all-metal-tube-radio-craft-august-1933.htm#:~:text=In brief, the Catkin tube,triodes, tetrodes, and pentodes.

Here is a diagram from the article.  One very interesting aspect of these tubes: the plate acts as the envelope to the tube and is air-cooled.  What you see on the outside is a shield with holes for ventilation.  Go poking around inside those holes and you might get a nasty shock  the next photo shows the tube plate exposed without the ventilated shield.

 

So how does it relate to the American metal tubes?  Their design was based on the catkin types, and the cast metal tubes were manufactured first in 1935.  Like the catkins, the tubes have a true metal envelope with a glass base, as opposed to coated glass.

There is a great article here discussing their design including a dissection of a metal RCA 6J5: http://www.r-type.org/articles/art-018.htm

So that's what I know about metallized tubes.  Some don't like the aesthetic, but I think they can look quite nice, even the American cast metal tubes.  This is my prettiest metallized tube.



As far as when it was stopped, I cannot say, but the tubes do tend to be of an older vintage.  My understanding is the metallized American tubes were expensive to manufacture, which led them being phased out.  I have seen metallized European tubes into the 1950s, beyond that I believe the practice was stopped as well, but I cannot say when exactly.


----------



## chrisdrop

L0rdGwyn said:


> Hey Chris - I think you are right, for the tubes that have at thin coat over glass, it looks as though the coating is sprayed on as opposed to cast, like the American-made metal tubes.  I have not been able to find any information on the manufacturing process, however my best guess is the tube envelopes were spun and sprayed.  This type of metallization seems to be a strictly European, the coating is attached to a ground wire that wraps around the base of the tube, then exits down below to be grounded (pin 1 in the case of the 6J5 / 6C5, via the cathode in B5 base tubes in my collection).
> 
> Here close up you can see the ground wire on the base of the RFT 6J5.
> 
> ...


THAT is a great post.


----------



## CAJames

chrisdrop said:


> THAT is a great post.



Indeed. This is a great thread, I've learned a bunch and found some really great sounding tubes. Thanks to everyone who has contributed. 

For me I just received a package that had been hung up in customs for weeks that contained some very nice Ken-Rad JAN VT-65s as well as some dual triodes that will remain nameless. Report to follow.


----------



## L0rdGwyn

@chrisdrop @CAJames thank you!  I am not really a tube historian, not like Ken on the 2359glenn thread, but I do like to know the timeline of the technology.  Like Glenn I do tend to think there is a positive correlation between tube age and sound quality.


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## RoyGB (Jul 8, 2020)

Alright here we go. I am about to use my words to describe sounds. Strap yourselves in folks this is a longer one. We are covering 11 pairs of tubes here in hopefully as much detail as any of you could ever want.

*Testing:* PC-> USB -> Monolith THX 788 DAC+AMP (Dual AKM 4493) -> RCA Preout -> Garage 1217 Project Ember 2.1

*Sources:* Denon D9200 (24 ohm, TOTL flagship, bright, slightly u shaped character), HD 650 (you know what these are), Preout to Denon PMA 800NE (Warm tilted speaker amp) > SVS Ultra Bookshelf (Bright leaning, very detailed, SVS flagship bookshelf) + SVS SB 12NSD (subwoofer. wubwub)
I did 90% of my listening on my D9200’s and most of the impression are taken with these headphones.

All noisefloor impressions were done with my 24 ohm Denons.

The playlist that I was using is predominantly this although I did use other music. It should be noted that I was searching out certain points in most of these songs or utilizing them for certain frequency ranges or instruments.
I let each tube warm up for about 3-5 minutes. Not ideal, but then again, most tubes normalize after like 60 seconds and I am trying to retain some memory of what things sound like. Because I cannot do direct tube comparisons, I used my Solid state as an intermediate step. Jumping back and forth between tube and solid state to compare the relative differences. I do have a good ear for tubes though and can pick out their relative characteristics fairly well at this point in my tube rolling journey.

Some disclaimers:

I am in the tube game for tubes to do something to my music and to have tube qualities. I don't like incredibly clean or solidstate-like tubes. That is my bias.
My amp is a 48V plate starved tube hybrid. It is not a cheap Chinese plate starved amp but still is plate starved. It is fairly tube revealing from my experineces but this is the only tube amp I have ever used. It may very well be that tubes in my amp sound different than tubes in a transformer'ed amp pushing 300+ volts. If anyone want's to send something with a transformer my way. I would gladly test all the tubes again.
Average noisefloor is relative to all the tubes I have ever tried on my Ember. It is extremely crude and by no means scientific or precise methodology. I'm just using my ears and memory. The Ember is capable of running pretty much any 6v or 12v tube under 1A of heater current. So it encompasses a wide range of tubes. Below average is low noise, above average is high noise.
"Tubey" refers to stereotypical tube characteristics like treble presentation, reduced harshness, softness, and warmth. Does not have to tick all the boxes, but does have to leave an impression of "tube" sound. Distinguishable from solid state refers to how similar to solid state clean, neutral, and dynamic they are. There is overlap between the two terms. Tube treble refers to a tubes tendency to reduce the FR, dynamics, and/or harshness of treble.
Remember we are still dealing with audio here. I may make statements that make it sound like that a tube is completely changing a song. I want to address this upfront. Audio is weird. Psychoacoustics are weirder. Words are hard. Relativity and perspective are harder. If you have more than 1 pair of headphones you know what this is like. They can sound completely different, yet you are still dealing with the same source audio, and as different as it sounds, it sounds completely the same. Is that difference between your two headphones a 1% difference a 10% difference or a 40% difference? Realistically all 3 could be argued effectively. There is no objective way to categorize that when dealing with subjective listening. There is no relative frame of reference that is the same for everyone. I have no idea how to put that level of relativity and objectiveness into descriptions. I try, but just keep this all in-mind with the statements I am making. Driam all you want, but tubes are not going to turn your BL03 into an Orpheus.
Lets get started.

*Zenith 6J5:*
_Technical Achievement Award_






I can see why people like these tubes. They have great bass dynamics and overall retain much of the microdetail that is lost on other tubes. They are a very good technical performer, that being said, they were not ‘tubey’ more so they were really good at reproducing audio. Elevated bass slam and elevated vocal midrange this is done without necessarily sounding warm. Very neutral. Less than average tube treble. Very close to the detail and cleanliness of solidstate. It appears that these are made by Sylvania, they look nearly identical to my Sylvania 6J5 tubes, but they do not sound the same as my Sylvania 6J5's.



Zenith is in the rear Sylvania in the front. Very close to identical construction.

Not easily distinguishable from SS
Not Tubey
Average Noisefloor

*United Electronic (Tung Sol?) 6L5:*
_Theremin Award_





I am unsure who manufactures this tube. My best guess is Tung Sol. These are VERY similar to my Tung Sol 76 tubes. Same micas, same mica fins, same getters, and the rest of the construction is extremely similar.













From a bit of reading this seems like United Electronic is a tube rebranding brand.



Wonder who they are trying to emulate here...

The biggest standout thing about this tube is its noisefloor. This tube has a very noticeable 60Hz hum and it only gets worse the closer you are to it. Likewise if I ground myself on my Ember by touching the top of the caps, the screws, or the metal base the noise immediately goes away and it almost sounds like you become an electrical shield if you hold your hands over the tubes. A couple of tubes have this theremin effect but it is BAD on these tubes.

The best way I can think to mitigate this would be a faraday cage. Or possibly grounding the ember.

This may be in part due to how exposed the grid and cathode are as the plate only covers about 70% of the triode. [SPECULATION, no scientific backing to my statement]

So on to the actual audio characteristics. Wider than SS. Kills some of the upper mids and that presents a soundstage-like sound. Typical tube treble. Going back over to soildstate those two areas are immediately noticeable as the presentation seems to close in and clear up. Bass seems slightly elevated on the tubes as well. This may just be from that 60Hz hum though. Which does largely go away once you get music playing. It is still there if you go searching but I can largely ignore it.

The thing is these tubes don’t sound articulate or enjoyable. They are a bit sloppy and I want to say all over the place. It might just be my headphones and my gear, but I do not think these tubes sound all that great. Articulation and instrument separation are nowhere near what it is on other tubes. I am sacrificing quite a bit for tube sound, which I don’t think I need to do, other tubes have better characteristic tube sound while also sounding better at the same time.

Another interesting note is that the Tung Sol 6L5 that I received as detailed in the National Union 6L5 post looks completely different than both the United Electronic 6L5 and the Tung Sol 76. It looks closer to a RCA tube with a similar top mica design. The gentleman that I purchased these tubes from mentoined they were made by RCA but the reasoning that he gave was lackluster at best.








Last of the 3 images is the Tung Sol 6L5 compared to an RCA 76. Note the top mica similarities. I don't know of another brand to do top micas like this.

Moderately Tubey
Distinguishable from SS
Noisefloor is dependent on proximity to yourself and other electronics. At its quietest, noisefloor was below average. At its loudest, far above average.


*Ken Rad 6C5G:*
_Fuzzy Wuzzy Award_





The key thing that stands out to me with this tube is how ‘soft’ it sounds. It retains a good amount of detail but is lacking microdetail of solidstate.

It can almost be psychoacoustically confused with soundstage because it does make music sound ‘further away’ in the sense that microdeail is equally gone from all ranges creating a soundstage-like sound. Contrast with many tubes where it seems like a certain range has certain characteristics like loss of microdetail.

That being said on my 9200’s I don’t inherently perceive this as a bump in soundstage as I did the Marconi’s.

The best way I would describe these tubes is soft. Granted, once again to what degree is the hard part to describe. Enough to matter, not enough to overwhelm. Whatever that means. It feels like it retains a very good amount of solid state detail, but with smoother edges, music seems to flow and slur a bit more, but still keeps good instrument separation. The smoothing seems to take place within the instruments themselves rather than across the spectrum of music. Once again this is with Denon D9200’s and SVS Ultras. Expensive gear that already has good separation and clarity.

Dynamics are also a bit behind solidstate but I don’t know how much of that is the softness making me perceive a loss of dynamics due to less slam and fast decay and how much of that is actually lowered dynamics. The answer probably lies somewhere in the middle.

As far as FR characteristics go. Treble seems just a touch splashy with hi hats, snare drums, and cymbals. This feels bothersome to me. But I feel that this is subjective to both the person and the gear. I am not getting as much as a ‘tube treble’ feel with this tube as I do others. I do not like this tube for drum heavy music where that splashiness just tends to get to me a bit too much. Granted it is very subtle, and I believe halfly due to the other characteristics of this tube changing other bits of the music my perception of drums relative to everything else. It does really well though with vocal and lounge tracks and music that does not have heavy emphasis on drums, or the treble instruments are mastered so their levels are neutered significantly so they are not prominent in the music.

Changing over to the 650’s the softness is still there. This makes the 650’s very soft and very mellow. Meanwhile, the splashiness is a non factor with these. In fact treble seems more articulate although still very 650.

There might be some part of the midrange or upper bass with a slight lowering. No idea though. Might just be the general softness changing characteristics enough.

Easily distinguishable from SS
Tubey
Average noisefloor.

*National Union 6L5G:*
_¯\_(ツ)_/¯  Award_





This is a bit of a weird review. The seller that I bought these from messed up my order and sent over one Nat union tube and one Tung Sol. They are very different construction and they are not audibly identical. They are close enough, and the gain match is good so I still feel like I can glean some impressions out of my one Nat Union. I will post a better impression at the end of the month when the actual pair comes in.

Very technically impressive. It sounds very solid state outside of a softer treble. I would categorize this as strong tube treble in the sense that treble is softer than most tubes I have heard. Detail and articulation are fantastic everywhere else. But I would not consider this tube ‘tubey’. It really does not add much in the way of character. I’m really not getting ‘warmth’ or ‘darkness’ or ‘soundstage’ out of this tube. All I am getting is a softer treble. Which is by no means a bad thing. That’s kinda one of the things tubes do is soften treble. Maybe the bass is slightly elevated, but that could just be an effect of the softened treble. The softness does extend into the midrange, but is still very articulate.

Compared to my left ear Tung Sol, this tube retains more detail and is more articulate with better instrument separation. This might just be a gain difference.
I also wouldn’t trust this review too much until my actual pair comes in.

*Hytron 6C5:*
_$1600 On Red Award_







Originally I had a date matched pair of 6C5's but the glue on one of the metal bases was failing so the metal base was falling off and there was a gain imbalance on the tubes as well. But I knew that there was something special here. So I took a gamble on a single and it matches well enough.

These tubes are like skydiving. Fun and unlike anything else. But you best hope that everything works.

Both my replacement and my falling apart Hytron have times when they just freak out. If this happens, they get crazy staticky and cause some really loud crackling and popping in your ear. Both not great for your hearing and your $1000+ audio gear.

I am not sure exactly what causes this. Or why it goes away.

Sometimes it happens when turning it on, sometimes it is a buildup over time. Sometimes it goes away when I ground the base to the Ember's metal chassis. Sometimes it doesn’t. Sometimes it goes away when I touch the glass on the tube. My best guess is charge buildup of some sorts but truthfully, I have no idea whatsoever.

When I first turn my amp on, I always check these tubes with a cheap pair of headphones first. After they are good, I am usually safe as I can hear the static noise buildup over time. It tends to creep up rather than just appear.

The predominant sound characteristic of these tubes is their dark sound signature, and how tubey they sound. They sound great. IDK exactly what it is about these tubes but they do some wonderful things to the sound.

Out of every tube I have tried so far these change the sound the most. Bass sounds different, vocalists sound different, these tubes give a completely new flavor to the music. Once again, sanity check. Completely different, but still very much the same.

There is definitely a dark shift to things but overall I have no idea how to describe these tubes due to just how much they change. I really don’t know how to put my finger on it. Detail is reduced but I don’t care with these tubes. It does not matter because they are doing something else really well.

Bass is elevated, and treble is reduced more than average.

I still want a strong matched pair that also have identical construction. As the two I now have are much better than what I had before but they are still not entirely perfect although close.

I am checking near daily for a strong matched pair with identical construction for sale. If anyone has a pair that they are willing to sell. PM me. I have a pair pending at the moment.

Tubiest tube I have heard.
Easily distinguishable from SS
Has some of the theremin effect. Noisefloor is about average.

*Sylvania 6J5:*
_Meets expectations award_







Classic Sylvania sound signature.
There is a definite increase in the energy in the treble. It does this without feeling harsh or ‘too much’ on my already bright D9200’s. I also don’t perceive it to suffer from a splashiness like the Ken Rad 6C5.

Midrange and bass just seem a touch lacking. IDK exactly what it is that feels lacking though. Possibly dynamics? Possibly detail? Probably both and something else. Music in these ranges just seems a bit thinner and lacking substance on these tubes. I liked these tubes a lot on my KPH30i’s. But I only really have these headphones for convenience, and I don’t typically turn on my tubes if I want to wear my KPH’s.

Likewise I think these do wonderful things to the veil on the 650’s. The reduction to the midbass paired with a bit of extra treble energy allows them to keep their characteristic FR while also helping combat the veil. It’s like going from artificial store bought thick viscous maple syrup to the authentic stuff which is a lot more liquid and flowing. Still that thick sweet HD650 syrup but a whole lot less syrupy. Also the noisefloor is inaudible on the 650’s.

Not really tubey per se(but characteristically different)
Distinguishable from SS
Below average noisefloor.

*Tung Sol 76:*
_Coffee Coffee__ Award_






These are tube tubes.
Lush, good bass dynamics, retains a good amount of detail while still providing a fair bit of tube character. More smooth than warm, but is on the warmer side of neutral. The defining characteristics are definitely the tube character that these provide. These tubes sounded wonderful on everything. These are my default tubes and have a near permanent home in my ember.

Below Average Noisefloor
Very Tubey
Easily distinguishable from SS

*Marconi 76:*
A_pologetically Good Award_





When I hit the play button on my music for the first time after slotting these in my Ember I immediately said aloud “whoa soundstage”.

I have yet to hear a tube do soundstage better than these tubes. They excel at soundstage.

This is mainly accomplished through a reduction in midrange dynamics, reduction in midrange FR, as well as a blanket reduction in microdetail. I have not heard the Sennheiser HD800 lineup, but from what most reviewers say, they don’t have the best midrange, but they do have incredible soundstaging. I think these tubes do a similar thing. That midrange reduction leads itself to a soundstage like experience. Then again, I could just be spewing nonsense and have no idea what I am talking about so that is your disclaimer.

They sound good. Worse articulation than SS, and feels a bit slow but overall, very pleasant with great presentation. This is another one of the instances where detail is gone but it really does not matter with these tubes because they do it so well. There are some tubes where that is almost a dealbreaking feature, but these do it to an extent that it works really well with the character of these tubes.

These tubes do have a bit of ‘tube character’ as well. They are more smooth than warm, but there is a twinge of warmth in their presentation. They have less tube treble than most tubes but do take a small amount of the edge and harshness out of the treble.

Midrange is not nonexistent. It is still there; it just sounds somewhat damped. Dynamics and extension are excellent. Overall wonderful tubes.

Exceptionally low noisefloor
Tubey
Distinguishable from SS

*RCA 76:*
_Wedding DJ Award_





My first impression was that this was another soundstagey tube. But wholly different than the Marconi.
But after more and more listening I began to realize what that presentation was. It was middle to upper midrange that was harsh and elevated.

So why did I think that this was a soundstagey tube?

Have you ever been to an outdoor event at like a park, house party, or wedding and they had a DJ or a band with music going? That is what these sound like. The bass is lackluster and dead because it does not have nearly the power or displacement needed to make impactful bass in an outdoor environment. Likewise, the treble is not the best because it’s a high frequency and it decays a bit to quickly and has no room reflections like you would get with speakers indoors. This just leaves you with a mid heavy presentation. That is the best analogy I could give into how these sounds and why it can be confused with soundstage. Because we have all heard what this sounds like before.

By no means should it be made out to be a bad thing. Depending on the rest of your gear I guarantee things will still sound good with these tubes. It is just an analogy to try to give an idea of how these sound. The effect is a lot less than in a scenario that I described above. Bass is still there in plenty. Along with treble. It is just an analogy.

These can very easily be interpreted as soundstagey, and anyone looking for soundstage in a headphone should give these a try.

So how is that midrange… elevated and slightly harsh. It is on the shouty side of things. This is not your HD650 warm vocal type of midrange. This is upper midrange. If you are sensitive to upper midrange frequencies, I think that these could be bothersome. They are a unique listen. My best guess is somewhere around 1k these start to get crazy and tails off in the lower treble. They are not bad tubes and have a character really unlike anything else I have heard.

On my KPH30i’s these provided a ‘fuller’ sound to the music. Which is to be expected. These are a fairly thin sounding headphone in the first place so they appreciated the extra midrange.

Not tubey
Distinguishable from SS
Below average noisefloor.

*Arcturus (National Union) 76:*
_Coolest Boxes Award_






See RCA 37 below for the audio characteristics. Dead quiet noisefloor. Probably the quietest tube that I have heard in terms of noisefloor. Blue lettering is also cool.

*RCA 37:*
_Æ S T H E T H I C C Award_






37’s are electrically similar (identical?) to 76’s and share the same current and voltage requirements. They are the only other pair of tubes in the 76 family that are direct drop in replacements without worrying about weird voltages and currents like the 56 tubes.

Sexiest tube. For some reason I really dig the look of these things. Photos don’t really do it justice. The bulb tube towers just have something about it that I adore looking at. Bulb tube towers >>>>>>> Coke bottle tube tower.

Soundwise they kill detail everywhere and do not have good dynamic range. An interesting listen if you really want to emulate a ‘old music experience’ for lack of better phrasing. Comparable to the Arcturus (National Union) 76 tubes audibly, but with a higher noisefloor.

Easily distinguishable from SS (but for all the wrong reasons).
Somewhat tubey. Maybe???
Average noisefloor. Theremin effect

*Conclusions: *

Favorites

Tung Sol 76 - warm, smooth, and tubey
Hytron 6C5 - Dark, colorful, and tubey
Marconi 76 - Soundstage and presentation
Sylvania 6J5 - Bright and pairs strongly with 650's
76's are on average the quietest tubes that I have heard. But the 6_5 series tends to be quieter than 6SN7 from my experiences with my amp. Tubes in these series are a tossup. some of the worst and best tubes I have heard are in these series'. The only other tubes that I would put up here with these tubes are an Amperex 6DJ8 and a Tung Sol opposed black T-plate top getter 6SN7 granted I have not tried every tube in existence.

Look forward to a review of a pair of Russian 6S5S/6C5 tubes as well as those National Unions closer to the end of the month when I get back from a work trip.

I am willing to trade or sell any of these tubes besides the Tung Sols, Hytrons, and RCA 37’s. The Sylvanias and Marconis I would like to keep but if you put up a good enough offer, I will consider it. I have measurements for all of them and most of these never see the light of day besides the few hours I put on them when I initially got them.

I also have 3 pairs of 56 tubes that I have no use for and will sell for a good price if anyone has an amp capable of running them.


----------



## Paladin79

Interesting, if ever you want to do some A/B testing I would help with the setup. I like to be able to go back and forth between tubes or tube sets so I can compare them directly and setting them up at the same volume level is pretty important as well especially for bass. A fine selection of tubes!


----------



## leftside

Paladin79 said:


> Interesting, if ever you want to do some A/B testing I would help with the setup. I like to be able to go back and forth between tubes or tube sets so I can compare them directly and setting them up at the same volume level is pretty important as well especially for bass. A fine selection of tubes!


I've sometimes thought about getting two of the same amps built so that I could more easily compare tubes. My preamp can drive multiple amps at the same time. I think only on here that would seem reasonable?  

I use this same preamp to compare the same recordings (playing at the same time) via my DAC and turntable. It makes for some very interesting comparisons.


----------



## Paladin79 (Jul 8, 2020)

leftside said:


> I've sometimes thought about getting two of the same amps built so that I could more easily compare tubes. My preamp can drive multiple amps at the same time. I think only on here that would seem reasonable?
> 
> I use this same preamp to compare the same recordings (playing at the same time) via my DAC and turntable. It makes for some very interesting comparisons.


My situation is not exactly the same as the casual listener and I often have two of the same headphone amps around of my own design. I also do not use hybrid amps, I want to hear tubes and only tubes. Sometimes within hybrid amps and pre-amps, a tube is added as a buffer, a way of imparting some tube sound but not enough of it to tell a lot of difference between tubes. I have used identical Bottlehead Cracks, as well as my amp, the Incubus Elegan that was designed for pure tube listening. I also built a box so that I can have RCA in and 1/4 inch female out so that when I hook to a switchbox I can use the same headphones, push one button and be listening to the same track on another amp, or three other amps, I generally do two or four myself.

It is not only here that hearing two amps seems reasonable, my audiophile group uses multiple amps and compares multiple DACS, and power amps all the time cause we want to get opinions from multiple people.  

That does not mean I do not do my own comparisons at home, there are single and double triode tubes I personally test all the time. I am always curious though how my thoughts stack up against a larger group that includes some highly qualified people. Because of some of my work I have tested most every type of wire made that could feasibly be used for headphone cables and interconnects. I have also modified my own speakers and headphones to get the sound I wanted.

It is easy enough to hear one tube or tubes, score a tube, hear another, then do the same. Personally I do better when I can do a direct comparison going back and forth between specific tracks to rate the tube on 25 specifics. Even the most subjective things can be made somewhat objective.

This is the setup I sent Schiit audio so they could use four pre-amps operating from one source. The signal is split four ways so it is identical going into each pre-amp, I built all cables and two of the three boxes. The final result could be one pair of headphones or one power amp and one pair of speakers. All tubes were concealed for a blind listening. Four tubes and a switchbox to hear all four.

.




I should mention that @bcowen was gracious enough to send me parts and assisted in building some extension sockets they used. Bill had heard some of the test tubes and his ability to spot differences is remarkable.


----------



## RoyGB

For me personally I have found that I don't need to AB tubes.

If I need to AB tubes to hear a difference between them, then they are likely similar enough where it really wouldn't matter too much because I either like its character or I dont. But most of the times tubes are chocolate and vanilla icecream both are great and picking between them is done on a whim of the moment. They do different things and impart a different character on the sound so ABing them really has no purpose IMO. Being able to put into words what a tube does and how exactly it differs from a different tube is useful for reviews, but outside of reviews my lizard brain just gravitates to what makes the air wiggle in my favorite way. 

I think when I was first getting into tubes the ability to AB them would have been nice, because my ears were not the best at discerning differences and I percieved many more tubes as sounding like  solidstate before I began to make sense of what tube sound was and how to listen to and appreciate it. I think it would have helped me understand tubes better at the time. But at this point my ears have kinda dialed into tubes where I can just appreciate tube sound and pick out a tubes character very quickly.

Now granted, rolling these tubes into a different amp, that has potential to add strawberry into the mix.


----------



## Paladin79 (Jul 8, 2020)

RoyGB said:


> For me personally I have found that I don't need to AB tubes.
> 
> If I need to AB tubes to hear a difference between them, then they are likely similar enough where it really wouldn't matter too much because I either like its character or I dont. But most of the times tubes are chocolate and vanilla icecream both are great and picking between them is done on a whim of the moment. They do different things and impart a different character on the sound so ABing them really has no purpose IMO. Being able to put into words what a tube does and how exactly it differs from a different tube is useful for reviews, but outside of reviews my lizard brain just gravitates to what makes the air wiggle in my favorite way.
> 
> ...


I use both methods but I am also a member of a scientific community so in order to offer something to that group, I need to think as they do. I personally do not own the $70,000 device that Schiit used to match signal levels, but my group does. There are a lot of things even a lay person can do at home to check that level for $20 or so. For a quick down and dirty test I use VU meters. I have been working with tubes since an early age and I do listen for the pure joy of listening but I also like to compare apples to apples and if the gain is off a bit between triodes, I like to adjust for that, as well as signal level if comparing between two tubes. As I said, my situation is different and many do not own identical amps so this is out of the question for them. I also mentioned I will just listen and develop a like for one tube over another. That is easy enough for anyone. My group will be dealing with 52 6sn7 equivalents and 50 listeners so this speeds up the process and I am afraid to say, makes it more accurate. We have done studies of people hearing a group of tubes then describing their favorites, try it a second and a third time blind, and they can rarely pick the same tubes again. Do that with identical signal and the criteria we use, and more often than not they will score the tubes the same way the second and third times. That is with A/B testing as well.


----------



## leftside

If you look closely at the date codes and the getters on these Osram 6J5 you can see roughly when they switched from inverted saucer getter to D getter. I also have the tall MWT black base version with inverted saucer getter and D getter with similar date codes. In my amp, I can't tell a sonic difference between these tubes, but they are some of my favourite.


----------



## leftside

Fivre 76


----------



## leftside




----------



## leftside

Fivre 6C5G


----------



## chrisdrop




----------



## leftside

chrisdrop said:


>


LOL <blush>. I think most people like to see pics of tubes? I know I do when other people post. When I first started purchasing tubes, it was nice to see the pictures, different types and learning how to identify various tubes and approx years of manufacturing just by looking at their construction, getter types, etc.


----------



## leftside

Those Fivre 76 tubes were a total mess when I purchased them. I should have posted before and after pics. The pins were covered in some sort of grey soot like they were kept with coal, the bases were filthy, tons of gunk inbetween the glass and the base, old test result stickers on the bases, dusty glass and whiteout/tippex markings also on the glass and bases. Took me over an hour to clean them up, but they came out ok. Shame those red labels aren't a little more complete. But, more importantly they are very quiet and sound great. And were cheap at 10 euros each.


----------



## chrisdrop

leftside said:


> 10 euros each.


Wow.


----------



## CAJames

chrisdrop said:


>



Those tubes are dead sexy.


----------



## RoyGB

Would love to get some audio impressions of those tubes.
I have not tried any European tubes in this family yet. Most of them are too expensive for me to justify, but I have always been curious on how they stack up to American tubes.


----------



## whirlwind

leftside said:


> If you look closely at the date codes and the getters on these Osram 6J5 you can see roughly when they switched from inverted saucer getter to D getter. I also have the tall MWT black base version with inverted saucer getter and D getter with similar date codes. In my amp, I can't tell a sonic difference between these tubes, but they are some of my favourite.




I bet these tubes sound killer...very nice


----------



## leftside

These have the earlier getter types, just a few months before they switched to the 'D' getter:
https://www.ebay.com/itm/2-x-L63-MARCONI-6J5G-MWT-BRAND-TUBE-NOS-NIB-RCB383/133460882520


----------



## chrisdrop

*KenRad 6J5*

These are pretty good/ thumpy tubes. They were cheap as chips. Date code C5, I think/ assume that is March 1945 (maybe 55?). 

Of all the metal 6J5 tubes I have, I think these are the "bassiest". They don't have the staging of the GECs, but IMO they are worth having if you are using brighter outputs.


----------



## bcowen

leftside said:


> LOL <blush>. I think most people like to see pics of tubes? I know I do when other people post. When I first started purchasing tubes, it was nice to see the pictures, different types and learning how to identify various tubes and approx years of manufacturing just by looking at their construction, getter types, etc.



I find tube porn more enjoyable these days than the other kind.  Maybe I'm just getting too old, or maybe my addiction is more serious than previously diagnosed.  

Keep the pics coming please.  Love 'em!!


----------



## CAJames (Jul 12, 2020)

I've been listening to my Ken-Rad JAN VT-65s (6C5) and even after 30 hours they sound like they aren't broken in. Or I need to try some different rectifiers and/or power tubes. Or maybe they just aren't that great, which would be disappointing even though they were also "cheap as chips."

Next up is my "Amp of Hope and Glory." GEC L63s (c/o Martin Billington), Brimar 5Z4 and, I wish I had some nice Mullard 6080s to complete the trifecta, but have to go with French tubes that I bought from a guy in the UK.





And these sound great right out of the box, and not with my favorite rectifier and power tubes. They have the detail of the Tung-Sol 6C5s and the liquidity of the 6P5Gs and the mind boggles at the possibility of them sounding better after some run in.


----------



## leftside

CAJames said:


> I've been listening to my Ken-Rad JAN VT-65s (6C5) and even after 30 hours they sound like they aren't broken in. Or I need to try some different rectifiers and/or power tubes. Or maybe they just aren't that great, which would be disappointing even though they were also "cheap as chips."
> 
> Next up is my "Amp of Hope and Glory." GEC L63s (c/o Martin Billington), Brimar 5Z4 and, I wish I had some nice Mullard 6080s to complete the trifecta, but have to go with French tubes that I bought from a guy in the UK.
> 
> ...


You might find the 6C5 to be a little "lightweight" in the WA22. I know I was always trying to extract the last drop of bass from it. 6J5's were good. ECC32 also good (but yes very expensive I know - especially a matching construction pair). Another good option is ECC31 or 6N7G (with adapter). The biggest problem with the 6J5 and related is you need 4 of them with the WA22, but you already have some of the best right there.

I bought a bunch of Mullard 6080 from Martin last year. He might still have some more. I absolutely love these power tubes in the "V6 Thunder", but didn't like them as much as the TS 5998 in the WA22.


----------



## CAJames (Jul 12, 2020)

leftside said:


> You might find the 6C5 to be a little "lightweight" in the WA22. I know I was always trying to extract the last drop of bass from it. 6J5's were good. ECC32 also good (but yes very expensive I know - especially a matching construction pair). Another good option is ECC31 or 6N7G (with adapter). The biggest problem with the 6J5 and related is you need 4 of them with the WA22, but you already have some of the best right there.
> 
> I bought a bunch of Mullard 6080 from Martin last year. He might still have some more. I absolutely love these power tubes in the "V6 Thunder", but didn't like them as much as the TS 5998 in the WA22.



You're right, the bass is a little thin but that isn't my issue with the Ken-Rads. They sounded "scratchy." A little bright, a little harsh and just not pleasant. But the Tung Sol 6C5 sound great, if lacking that last drop of bass. Of course that can often be adjusted with different power tubes and/or rectifiers. I'm thinking they might match well with RCA 6AS7s and a 5Y3.

I actually had Mullard 6080s in my initial order, but decided something had to give and it was them. But I could easily see getting some along with a few more L63s down the road. The L63s really sound fantastic.

As much as I'd love some T-S 5998s, I don't know if that will ever happen, unless some I find some at a garage sale or something. There aren't any bargains out there.


----------



## Monsterzero

I would try a different batch of Ken Rads. In my GOTL both the 6/12sn7s as well as the 6J5s and the VT equivalent have zero grain or harshness. What they do have is a mellow warm sound with thunderous,deep bass. Like ridiculous bass.


----------



## bcowen

CAJames said:


> You're right, the bass is a little thin but that isn't my issue with the Ken-Rads. They sounded "scratchy." A little bright, a little harsh and just not pleasant. But the Tung Sol 6C5 sound great, if lacking that last drop of bass. Of course that can often be adjusted with different power tubes and/or rectifiers. I'm thinking they might match well with RCA 6AS7s and a 5Y3.
> 
> I actually had Mullard 6080s in my initial order, but decided something had to give and it was them. But I could easily see getting some along with a few more L63s down the road. The L63s really sound fantastic.
> 
> As much as I'd love some T-S 5998s, I don't know if that will ever happen, unless some I find some at a garage sale or something. There aren't any bargains out there.



I haven't tried any Tung Sol 6C5's, but the round plate Tung Sol 6J5 is becoming one of my favorites...


----------



## CAJames

bcowen said:


> I haven't tried any Tung Sol 6C5's, but the round plate Tung Sol 6J5 is becoming one of my favorites...



I'm curious how you know what kind of plates are in a metal tube?


----------



## bcowen

CAJames said:


> I'm curious how you know what kind of plates are in a metal tube?



I'm clairvoyant.  

Seriously, the TS 6J5's I'm referring to are glass bottles. Perhaps I should clarify that properly with 6J5*GT*.  Apologies for the avoidable confusion.


----------



## L0rdGwyn

bcowen said:


> I'm clairvoyant.
> 
> Seriously, the TS 6J5's I'm referring to are glass bottles. Perhaps I should clarify that properly with 6J5*GT*.  Apologies for the avoidable confusion.



I believe what you have there are Tung-Sol branded Sylvania 6J5GT, the Tung-Sol 6J5 and 12J5 have ladder plates, like below.  Not that it matters much, good sound is good sound, just FYI


----------



## bcowen

L0rdGwyn said:


> I believe what you have there are Tung-Sol branded Sylvania 6J5GT, the Tung-Sol 6J5 and 12J5 have ladder plates, like below.  Not that it matters much, good sound is good sound, just FYI



Entirely possible.  I have a pair of Sylvania branded 6J5GT's (also with round plates) that don't sound near as good.  Could be a manufacturing_* year*_ thing though rather than a manufacturer thing.


----------



## CAJames

L0rdGwyn said:


> I believe what you have there are Tung-Sol branded Sylvania 6J5GT, the Tung-Sol 6J5 and 12J5 have ladder plates, like below.  Not that it matters much, good sound is good sound, just FYI



Yes. I was going to say the one on the right looks like Sylvania "Bad Boy" plates, but feel like I've already caused enough trouble.


----------



## GDuss

I like those ladder plate Tung Sol's so much I bought both 6 and 12V versions of them for the GOTL.  They're the tubes I put in if I really want 3D sound on a level where I'm looking around the room to see where sounds are coming from.  The 6V is metal base, but they sound almost identical.


----------



## GDuss

For anyone who can use the Tung Sol 12J5's, the seller I bought them from still has them (if you're interested of course, and if you are, they're reasonably priced):

https://www.ebay.com/itm/Tung-Sol-J...123600?hash=item51e5e1ae10:g:hfgAAOxyTyBSXaSh


----------



## Old Deaf Donkey

Anyone ever tried 6j5wgt Jan Philips Ecg?


----------



## chrisdrop

Old Deaf Donkey said:


> Anyone ever tried 6j5wgt Jan Philips Ecg?


The ones at Langrex seem to have very recent date codes (1980s). I would avoid such recent manufactured tubes in general. Perhaps that is an invalid bias, but the tubes I have from the 80s I don't love.


----------



## Old Deaf Donkey

chrisdrop said:


> The ones at Langrex seem to have very recent date codes (1980s). I would avoid such recent manufactured tubes in general. Perhaps that is an invalid bias, but the tubes I have from the 80s I don't love.


Thank you, same view here, these are advertised as 1985 at Langrex. I wondered if anyone heard them? Yet probably not worth bothering


----------



## GDuss

chrisdrop said:


> The ones at Langrex seem to have very recent date codes (1980s). I would avoid such recent manufactured tubes in general. Perhaps that is an invalid bias, but the tubes I have from the 80s I don't love.



The only JAN/Philips tubes I have ever used are 6080's, from the 80's.  I have a couple of them from when I bought the Woo WA3 (I think the amp came with them).  They're definitely not my favorite tubes, and may actually be my least favorite 6080's in my collection.  That said, I'd hate to characterize all 80's tubes as not worth bothering with, I'm sure there are some good ones out there.


----------



## CAJames (Jul 18, 2020)

Old Deaf Donkey said:


> Anyone ever tried 6j5wgt Jan Philips Ecg?



Philips ECG has a pretty bad reputation (for audio, I don't know about the actual military applications). Worst tubes I ever bought are JAN Philips ECG 6922s, and it isn't close. From the 80's, naturally.


----------



## Old Deaf Donkey

GDuss said:


> For anyone who can use the Tung Sol 12J5's, the seller I bought them from still has them (if you're interested of course, and if you are, they're reasonably priced):
> 
> https://www.ebay.com/itm/Tung-Sol-J...123600?hash=item51e5e1ae10:g:hfgAAOxyTyBSXaSh


I reckon I cannot use them through an adapter in Vali 2 as I use 6J5 and 7A4 tubes. Or can I? 12A*U tubes can be used in Vali 2 through an adapter...


----------



## bcowen

CAJames said:


> Philips ECG has a pretty bad reputation (for audio, I don't know about the actual military applications). Worst tubes I ever bought are JAN Philips ECG 6922s, and it isn't close. From the 80's, naturally.



Could not agree more.  Same with the Philips ECG 5814.  I have yet to hear any Philips ECG (blue or green print) that sounds much different than a cheap AM clock radio.  Shrill, screechy, fatiguing, harmonically bereft, and basically awful sounding tubes, not to exaggerate or anything.   Add ECG labeled 6SN7's and 12AU7's to the list.  I haven't tried them all obviously, but after 4 types that sound like *E*specially *C*rappy *G*arbage, I wouldn't touch another one even if it was free. In fact, I'd probably want to send an invoice for a free one if it added to my trash pickup cost for the month.


----------



## bcowen (Jul 18, 2020)

Old Deaf Donkey said:


> I reckon I cannot use them through an adapter in Vali 2 as I use 6J5 and 7A4 tubes. Or can I? 12A*U tubes can be used in Vali 2 through an adapter...



The Vali 2 has a 6.3 volt heater circuit. I'm not aware of an adapter that can increase that to 12.6 volts, although one may exist somewhere that I haven't seen. The 12A*7 group of tubes work fine in the Vali because they were designed to operate at either 6.3 or 12.6 volts, so the adapter simply wires them for 6.3v operation.


----------



## GDuss

bcowen said:


> The Vali 2 has a 6.3 volt heater circuit. I'm not aware of an adapter that can increase that to 12.6 volts, although one may exist somewhere that I haven't seen. The 12A*7 group of tubes work fine in the Vali because they were designed to operate at either 6.3 or 12.6 volts, so the adapter simply wires them for 6.3v operation.



Thanks for the input on the Vali 2.  I don't know the details of this amp.  The GOTL has a switch to change the SN7 driver slot from 6V to 12V (or even 25V if you want).  So you can easily use tubes of any of those voltages.  I haven't noticed much difference in the sound between a 6V and 12V version of the same tube type (assuming everything else is equivalent).  The 12V versions are just usually cheaper.


----------



## leftside

GDuss said:


> Thanks for the input on the Vali 2.  I don't know the details of this amp.  The GOTL has a switch to change the SN7 driver slot from 6V to 12V (or even 25V if you want).  So you can easily use tubes of any of those voltages.  I haven't noticed much difference in the sound between a 6V and 12V version of the same tube type (assuming everything else is equivalent).  The 12V versions are just usually cheaper.


The 12V option is a great option to have. For example the TS BGRP 12SN7 sounds exactly the  same as the TS BGRP 6SN7.

Custom amp builders can build whatever you want (within reason). I have a 6SN7/6SL7/6J5/C3g/12SN7/12SL7 selector switch. I can also run 6N7 in the 6J5 sockets. And then with adapters in the C3g, 6J5, 6SN7 sockets...


----------



## L0rdGwyn

You could technically build an adapter to run 12.6VDC on the heaters from a 6.3VAC supply using a voltage doubler (depending on what is going on inside the Vali 2 heater supply and its compatibility, I am not familiar with it), but that would be one heck of an adapter!  Better off just using the 6.3V versions methinks.


----------



## Old Deaf Donkey

bcowen said:


> The Vali 2 has a 6.3 volt heater circuit. I'm not aware of an adapter that can increase that to 12.6 volts, although one may exist somewhere that I haven't seen. The 12A*7 group of tubes work fine in the Vali because they were designed to operate at either 6.3 or 12.6 volts, so the adapter simply wires them for 6.3v operation.


Thank you, I see the light now


----------



## bcowen

GDuss said:


> Thanks for the input on the Vali 2.  I don't know the details of this amp.  The GOTL has a switch to change the SN7 driver slot from 6V to 12V (or even 25V if you want).  So you can easily use tubes of any of those voltages.  I haven't noticed much difference in the sound between a 6V and 12V version of the same tube type (assuming everything else is equivalent).  The 12V versions are just usually cheaper.



Adjustable filament voltage like that is WAY cool. I'm betting there's a bunch of awesome sounding 12v octals out there that are super cheap because most everyone is stomping all over the 6 volt-ers. 

I sure hope @Paladin79 is listening.    

I have a 1633 tube (a 25v 6SN7) I bought by mistake because I was too much of a dumba$$ to notice the 25v part.   Since your amp can be set to supply 25v to the heaters, PM me your shipping address (if you're comfortable doing that) and I'll be happy to gift it to you.  I can't use it, and no sense in letting it just sit here unloved. Already have too many love-less tubes.    Might be an awesome sounding tube in an amp that can run it.


----------



## GDuss

bcowen said:


> Adjustable filament voltage like that is WAY cool. I'm betting there's a bunch of awesome sounding 12v octals out there that are super cheap because most everyone is stomping all over the 6 volt-ers.
> 
> I sure hope @Paladin79 is listening.
> 
> I have a 1633 tube (a 25v 6SN7) I bought by mistake because I was too much of a dumba$$ to notice the 25v part.  Since your amp can be set to supply 25v to the heaters, PM me your shipping address (if you're comfortable doing that) and I'll be happy to gift it to you. I can't use it, and no sense in letting it just sit here unloved. Already have too many love-less tubes.   Might be an awesome sounding tube in an amp that can run it.



The voltage switch is a great feature as I'm sure other owners of the GOTL would agree with.  It's been helpful in cases where the 12V version of a tube was available but the 6V wasn't (e.g. in the case of the TS BGRP 12SN7 that @leftside mentioned above).

And you are way too kind to offer the 1633 tube.  Funny enough, I already have that exact tube, although I'm not sure of the year it was made.  It's a great sounding tube, and sounds similar to the smoked glass RCA 12V and 6V versions I have that I know are from the early to mid-40's.  

If you are willing to keep the offer open, maybe there is another GOTL (or similar amp) owner who hasn't tried that 25V tube.  Either way, thanks for the offer.  It's always great to meet generous fellow members of this forum.


----------



## Old Deaf Donkey

bcowen said:


> Adjustable filament voltage like that is WAY cool. I'm betting there's a bunch of awesome sounding 12v octals out there that are super cheap because most everyone is stomping all over the 6 volt-ers.
> 
> I sure hope @Paladin79 is listening.


So do I. But he has his own views on this, I am sure


----------



## CAJames

bcowen said:


> Adjustable filament voltage like that is WAY cool. I'm betting there's a bunch of awesome sounding 12v octals out there that are super cheap because most everyone is stomping all over the 6 volt-ers....



Indeed. My phono stage uses a 12SN7 and it has been a lot of fun to buy cheap 12V versions of the famous Tung-Sol, RCA, Sylvania, National Union etc. 6SN7s for which I would never pay market price. 12SX7 is also a great sub for 12SN7, FWIW.


----------



## bcowen

Old Deaf Donkey said:


> So do I. But he has his own views on this, I am sure



@Paladin79 having his own views?  Yeah, right.


----------



## bcowen

CAJames said:


> Indeed. My phono stage uses a 12SN7 and it has been a lot of fun to buy cheap 12V versions of the famous Tung-Sol, RCA, Sylvania, National Union etc. 6SN7s for which I would never pay market price. 12SX7 is also a great sub for 12SN7, FWIW.



The phono stage built into my Alana preamp uses a pair of 6922's.  My least favorite of all tube types (but that's just personal opinion).  The mid-70's Russian SWGP 6N23P's sound quite good in that spot and are quiet as church mice, and sound even better than some uber-priced Siemens CCA's and GEC's and such.  My favorites are '50's Telefunken 6DJ8's, but I only have one pair and the '50's manufacture have all but disappeared from the planet. Worse, getting a pair that's not noisy or microphonic is even harder.


----------



## CAJames

bcowen said:


> The phono stage built into my Alana preamp uses a pair of 6922's.  My least favorite of all tube types...



Well the 6DJ8 family is favorite tube type, but I hope we can still be friends   .

So apologies for going OT, and probably being pedantic. Since you like Telefunken have you tried Telsa (old Tesla, not new JJ/Tesla)? After rolling through some highly regarded 12AX7 types in my phono stage (they do the gain, the 12SN7 is just a buffer) I bit the bullet and got Telsa frame grid E83CCs, a copy of the (in)famous TFK ECC803s and it blew them all away. 

There is also the 7DJ8 aka PCC[88|188|189]  which usually replace 6DJ8s. You can get actual TFK at a decent price, and as a bonus be reasonably confident they are real, not fakes.


----------



## L0rdGwyn

Now is your chance, don't miss out, 50x Marconi-Osram L63, for 2,500 GBP.

https://www.ebay.com/itm/283952245163?ul_noapp=true

In terms of price per tube, it is actually below market value!


----------



## CAJames

L0rdGwyn said:


> Now is your chance, don't miss out, 50x Marconi-Osram L63, for 2,500 GBP.
> 
> https://www.ebay.com/itm/283952245163?ul_noapp=true
> 
> In terms of price per tube, it is actually below market value!



Anyone want to go halves?  

When this thread first started someone was selling a batch of 30+ (used) 6P5G/GTs for 99 US$ that I seriously considered buying and now regret.


----------



## bcowen

CAJames said:


> Well the 6DJ8 family is favorite tube type, but I hope we can still be friends   .
> 
> So apologies for going OT, and probably being pedantic. Since you like Telefunken have you tried Telsa (old Tesla, not new JJ/Tesla)? After rolling through some highly regarded 12AX7 types in my phono stage (they do the gain, the 12SN7 is just a buffer) I bit the bullet and got Telsa frame grid E83CCs, a copy of the (in)famous TFK ECC803s and it blew them all away.
> 
> There is also the 7DJ8 aka PCC[88|188|189]  which usually replace 6DJ8s. You can get actual TFK at a decent price, and as a bonus be reasonably confident they are real, not fakes.



I'm much more fond of 6DJ8's than 6922's.  Sounds stupid I guess, but 6DJ8's (in general) just have a more natural sound than 6922's.  Biggest issue is noise and microphonics with them though that seems to be much less prevalent and/or problematic with 6922's.  

I have some '60's Teslas that i haven't listened to in quite some time. Not my faves in the preamp I was using then, but all my components are different now so could be a different story altogether. Thanks for the reminder...I'll give them a listen.

I have some 60's Tungsram 6922's in my Cary DAC right now that I like quite a bit in that application. Strange, but they sound like dogvomit in the phono section of the Alana.  Synergy and all, I guess.  I have some Matsu and Tungsram 7DJ8's which both sound good, but not top 'o the heap for my preferences. I have not tried the Telefunken 7DJ8/PCC88 -- I'll seek some out.  Thanks!


----------



## GDuss

CAJames said:


> Anyone want to go halves?



After shipping, these are like $66 each.  You could crowdfund it.  If 25 people each buy a pair up front, then there you go  .


----------



## bcowen

CAJames said:


> Well the 6DJ8 family is favorite tube type, but I hope we can still be friends   .
> 
> So apologies for going OT, and probably being pedantic. Since you like Telefunken have you tried Telsa (old Tesla, not new JJ/Tesla)? After rolling through some highly regarded 12AX7 types in my phono stage (they do the gain, the 12SN7 is just a buffer) I bit the bullet and got Telsa frame grid E83CCs, a copy of the (in)famous TFK ECC803s and it blew them all away.
> 
> There is also the 7DJ8 aka PCC[88|188|189]  which usually replace 6DJ8s. You can get actual TFK at a decent price, and as a bonus be reasonably confident they are real, not fakes.



Apologies for continuing the off-topic, but there is usually some inherent value in consistency.  

Any idea who made these? I have some Zaerix labeled 12AU7's that are clearly East German RFT's (and rather meh), but I know Zaerix sourced from quite a few different manufacturers. I don't have any 6922's/6DJ8's/7DJ8's that match up to these from what I can make out in the pics, but I don't have any RFT's in that tube type to compare.


----------



## CAJames

Aren't those Sylvania Bad Boy plates?

But seriously, that seems like a pretty distinctive mica, but I don't recognize it.


----------



## GDuss

Got some 12J5's in yesterday.  I've been curious about these for a while, mostly to determine whether they are different than the RCA metal 6J5's from the same era.  I put them in the amp last night (both functional and quiet) and they have an extremely pleasing tonality.  I'm a big fan of the metal RCA J5/C5 tubes from the early to mid-40's and so far, with only 2-3 hours of listening, the 12J5's are very close to what I'm used to.  It will take more time and burn in to figure out whether they are different than their metal cousins, but first impressions are very good.  

I don't know what it is about these 40's RCA tubes that I like.  They don't have the best technicalities, but they are just so enjoyable to listen to.  There is something "real" sounding about them.  Plus they're inexpensive, these were $10 each and look like they have never been out of their original boxes.


----------



## L0rdGwyn

Nice pair of Sylvania VT-94D here if anyone is interested 

https://www.ebay.com/itm/1843608451...v=DefaultOrganic&brand=SYLVANIA&ul_noapp=true


----------



## chrisdrop (Jul 24, 2020)

Anyone want 2 of these at cost? I'll buy 'em and we can split 'em... 1951 Fivre 6C5Gs. Not cheap, but not crazy IMO. I'll also offer/haggle as he is accepting offers. Just PM me.


----------



## Velozity

chrisdrop said:


> Anyone want 2 of these at cost? I'll buy 'em and we can split 'em... 1951 Fivre 6C5Gs. Not cheap, but not crazy IMO. I'll also offer/haggle as he is accepting offers. Just PM me.




I was going to do the same as I only wanted two.  I contacted him and he's willing to sell a pair for GBP100.  I wasn't willing to do it and lost interest but maybe you can negotiate a better deal.


----------



## Velozity

L0rdGwyn said:


> Nice pair of Sylvania VT-94D here if anyone is interested
> 
> https://www.ebay.com/itm/184360845161?_trksid=p11021.c100851.m5053&_trkparms=aid=1110006&algo=HOMESPLICE.SIM&ao=1&asc=20170803121420&meid=e01de098655246bd822a3023106eb60b&pid=100851&rk=2&rkt=4&mehot=none&b=1&sd=114305451320&itm=184360845161&pmt=0&noa=1&pg=11021&algv=DefaultOrganic&brand=SYLVANIA&ul_noapp=true




Thanks for the tip Keenan.  Not bad for $42  I bought them to compare to my L63 / CV1067.


----------



## L0rdGwyn

Velozity said:


> Thanks for the tip Keenan.  Not bad for $42  I bought them to compare to my L63 / CV1067.



No problem, enjoy!


----------



## RoyGB

My 3 latest pairs and very likely the last tubes that I will be purchasing for a good while. Being away from my gear for so long has caused me to completely lose my internal refrence on tube sound vs solid state so I have no idea when I will actually get around to reviewing these. 

National Union 6L5




Brand New Hytron 6C5's (I am very happy I was able to find these they are some of my favorite tubes)



Russian 6S5S (6C5)


----------



## CAJames

I haven't posted in a while because the GEC L63s have the WA22 sounding better than ever. Both with headphones and as a preamp, and not just because I'm an unrepentant Anglophile who has always wanted GEC valves in my system. Also baseball season is starting and I needed to dust off my fantasy team.

But enough about that, I wouldn't be in this thread if I could leave well enough alone so today I decided to revist the 6P5GTs that I found an little edgy previously with some more forgiving power tubes. And I'll be darned if they don't sound really good as well. Not the vividness or the sparkle of the L63s, but plenty of detail, lots of bass and the hard edge is gone. Very enjoyable and I think I'll keep them in the system for a while.


----------



## chrisdrop

CAJames said:


> I haven't posted in a while because the GEC L63s have the WA22 sounding better than ever. Both with headphones and as a preamp, and not just because I'm an unrepentant Anglophile who has always wanted GEC valves in my system. Also baseball season is starting and I needed to dust off my fantasy team.
> 
> But enough about that, I wouldn't be in this thread if I could leave well enough alone so today I decided to revist the 6P5GTs that I found an little edgy previously with some more forgiving power tubes. And I'll be darned if they don't sound really good as well. Not the vividness or the sparkle of the L63s, but plenty of detail, lots of bass and the hard edge is gone. Very enjoyable and I think I'll keep them in the system for a while.


Glad you are loving the GECs. I have been largely stuck on those brown-base L63s for a few weeks. I have been rolling outputs with those fixed in the input sockets... I think you are using the same ones (pic'd below)?

_(However, I am cheating on the 6J5s this weekend, with some 6J7s. I'm sure something for this thread will roll in ASAP!)_


----------



## CAJames (Jul 26, 2020)

chrisdrop said:


> Glad you are loving the GECs. I have been largely stuck on those brown-base L63s for a few weeks. I have been rolling outputs with those fixed in the input sockets... I think you are using the same ones (pic'd below)?
> 
> _(However, I am cheating on the 6J5s this weekend, with some 6J7s. I'm sure something for this thread will roll in ASAP!)_



Yes, those look familiar. Got them from our buddy Martin. Of course I use four and that makes them (by far) the most expensive driver tubes I have. I sort of wonder what I could get if I spent that much on a pair of high dollar famous label 6SN7s, but that wouldn't be GEC so I'm not going to find out. Thanks for turning me on to them,   .


----------



## leftside

CAJames said:


> Yes, those look familiar. Got them from our buddy Martin. Of course I use four and that makes them (by far) the most expensive driver tubes I have. I sort of wonder what I could get if I spent that much on a pair of high dollar famous label 6SN7s, but that wouldn't be GEC so I'm not going to find out. Thanks for turning me on to them,   .


GEC B65 are equivalent to 6SN7, but very expensive, and I find the GEC L63 to have the same qualities anyway. I liked the B65 a lot, but didn't want to use it because it was so expensive - and that led me to the L63/6J5. There is also the 12v version - the GEC B36.


----------



## CAJames

leftside said:


> GEC B65 are equivalent to 6SN7, but very expensive, and I find the GEC L63 to have the same qualities anyway. I liked the B65 a lot, but didn't want to use it because it was so expensive - and that led me to the L63/6J5. There is also the 12v version - the GEC B36.



Thanks. I thought I would check out the B36 for my phono stage. It is very expensive, the B65 is freaking nutz. I’ll stick with the L63.


----------



## L0rdGwyn

Not sure if these have been posted already, but it is one of the better from this family I think, the STC / Brimar 6J5G.

 

They come in a few different plate and getter constructions with later models having black ribbed plates, gray ribbed plates, D getters.  These are an earlier construction, perhaps the oldest, smooth black plates and foil getters.  Right up there with the best of the 6J5G but can be a bit expensive, spacious, slightly warm perhaps, but very detailed.


----------



## GDuss

L0rdGwyn said:


> Not sure if these have been posted already, but it is one of the better from this family I think, the STC / Brimar 6J5G.
> 
> 
> 
> They come in a few different plate and getter constructions with later models having black ribbed plates, gray ribbed plates, D getters.  These are an earlier construction, perhaps the oldest, smooth black plates and foil getters.  Right up there with the best of the 6J5G but can be a bit expensive, spacious, slightly warm perhaps, but very detailed.



Thanks LG.  Any thoughts on these (somewhat related 6C5G)?  The plate structure is not visible due to the mesh and there are no markings on the base.

https://www.langrex.co.uk/products/6c5g-brimar-stc-nos-valve-tube/


----------



## L0rdGwyn

GDuss said:


> Thanks LG.  Any thoughts on these (somewhat related 6C5G)?  The plate structure is not visible due to the mesh and there are no markings on the base.
> 
> https://www.langrex.co.uk/products/6c5g-brimar-stc-nos-valve-tube/



Hey @GDuss - you are in luck, as I own both  I have way too many tubes...

Here is the STC / Brimar 6C5G.



Here is my best shot at the internal construction.  The plate sits just behind the internal shield.  Hard to make out in my photo, but this is really a converted 6J7G, there is a control grid and a screen grid internally with the screen connected to the plate.  Essentially this is a triode strapped 6J7G without a top cap and no suppressor grid.



Compare to the internal construction of a Brimar 6J7G.  You can see they are quite similar.



This is an easy way to diversify your product catalog 

In terms of sound, they are both very nice tubes, definitely worth trying, especially at that price.  I think I prefer the 6J5G, a little more spacious and airy than the 6C5G, but also 4-5x the price.


----------



## GDuss

L0rdGwyn said:


> Hey @GDuss - you are in luck, as I own both  I have way too many tubes...
> 
> Here is the STC / Brimar 6C5G.
> 
> ...



I was in luck!!!  Not only do you have them, you either already had photos or are quick on the draw with your camera  . I'm guessing the fact that they have 270 of those 6C5G's in stock keeps the price down. Sounds like these are worth checking out.


----------



## L0rdGwyn

GDuss said:


> I was in luck!!!  Not only do you have them, you either already had photos or are quick on the draw with your camera  . I'm guessing the fact that they have 270 of those 6C5G's in stock keeps the price down. Sounds like these are worth checking out.



Just quick on the draw  I have the day off, so I am home rolling some tubes and enjoying some music.  Just so happens the Valve Museum had the perfect photo of the Brimar 6J7G ready for me, it was meant to be.

NOS Brimar 6C5G do seem to be pretty widely available in the UK.  I purchased mine from Billington some time ago, in addition to some GEC branded Mullard 6C5G, I think I paid 15 GBP a tube!  Yes, please, Martin.


----------



## chrisdrop

L0rdGwyn said:


> Just quick on the draw  I have the day off, so I am home rolling some tubes and enjoying some music.  Just so happens the Valve Museum had the perfect photo of the Brimar 6J7G ready for me, it was meant to be.
> 
> NOS Brimar 6C5G do seem to be pretty widely available in the UK.  I purchased mine from Billington some time ago, in addition to some GEC branded Mullard 6C5G, I think I paid 15 GBP a tube!  Yes, please, Martin.


All beautiful tubes. 
Your STC/ Brimars have that "101" on them. Any idea that that is? Been trying to identify the "NAPL 101" on the AnM 6J7G tubes (posted on the Glenn thread).


----------



## L0rdGwyn

chrisdrop said:


> All beautiful tubes.
> Your STC/ Brimars have that "101" on them. Any idea that that is? Been trying to identify the "NAPL 101" on the AnM 6J7G tubes (posted on the Glenn thread).



Hi Chris - not sure why the STC tubes have the "101" label, I haven't been able to find any information on it, sorry!


----------



## GDuss

chrisdrop said:


> All beautiful tubes.
> Your STC/ Brimars have that "101" on them. Any idea that that is? Been trying to identify the "NAPL 101" on the AnM 6J7G tubes (posted on the Glenn thread).



The "101" mystery continues.  LG said he got his Brimar 6C5G's that have the 101 from Billington, so maybe Martin knows what the 101 means?


----------



## chrisdrop

GDuss said:


> The "101" mystery continues.  LG said he got his Brimar 6C5G's that have the 101 from Billington, so maybe Martin knows what the 101 means?


I'll ask him. What's the worst he can do? ... raise my tube prices !


----------



## CAJames (Jul 30, 2020)

Let me ask the collected wisdom of the thread this: is it possible used tubes need to break in again? I'm shocked at how good my (used) 6P5GT tubes are sounding after 5 or 6 hours listening. After the first hour they sounded like Phillips ECG, but now they sound like Telefunken. Super transparent and detailed in a way some people think is lean but I'd call neutral and kickin' bass.

Maybe the were actually close to new, or my hearing has rolled off another 6 dB in the last few weeks. But I've never encountered this with used tubes.


----------



## whirlwind

GDuss said:


> Thanks LG.  Any thoughts on these (somewhat related 6C5G)?  The plate structure is not visible due to the mesh and there are no markings on the base.
> 
> https://www.langrex.co.uk/products/6c5g-brimar-stc-nos-valve-tube/



I was just looking at these Brimar 6C5G from Langrex a couple of days ago....I did not pull the trigger yet.


----------



## GDuss

whirlwind said:


> I was just looking at these Brimar 6C5G from Langrex a couple of days ago....I did not pull the trigger yet.



I saw them a few days ago as a related item on eBay (from Langrex/yitry) when I was looking for something else.  I haven't pulled the trigger yet either, but need to figure out whether there is anything else I want to order from them at the same time.  Those GEC L63's are interesting as well based on the comments from others.


----------



## chrisdrop

chrisdrop said:


> I'll ask him. What's the worst he can do? ... raise my tube prices !


Here is what Martin (polite and helpful as ever) had to say:



> Whenever the military printed anything it was done in  code. So it's not always obvious  what they’re trying to say. ……………. for example they wrote kB/D instead of Mullard. They write CV4024 instead of ECC81.  Long ago I went to an MoD auction , some metal plates were labelled "plate, metal" .
> 
> AM. I am sure you're correct that this is air ministry. I think you are also correct to say ANM is air ministry. .
> 
> ...


----------



## GDuss

Thanks for asking him CD.  Not surprising that the military would be using confusing codes on purpose.  

I thought the same thing about North American in the NAPL, but who knows, maybe that is purposefully confusing as well.  If 101 is a UK Brimar factory then that doesn't make sense with North America i.e. NAPL 101 wouldn't fit.


----------



## chrisdrop

GDuss said:


> Thanks for asking him CD.  Not surprising that the military would be using confusing codes on purpose.
> 
> I thought the same thing about North American in the NAPL, but who knows, maybe that is purposefully confusing as well.  If 101 is a UK Brimar factory then that doesn't make sense with North America i.e. NAPL 101 wouldn't fit.


With the prior info, these quotes:

(for 6J7G) NOS, CV1935, mesh plate, KB/N (*made by STC Footscray Factory)(prior to August 1951*), same operation to WE 348A   
"The Foots Cray site was shared with Brimar, another STC company founded in 1933 to manufacture American pattern valves for the British market."
Leave me to believe these were made by STC, at the Foots Cray Factory, according to the "American pattern" for those valves. Not certain, but my best current guess.


----------



## whirlwind

GDuss said:


> I saw them a few days ago as a related item on eBay (from Langrex/yitry) when I was looking for something else.  I haven't pulled the trigger yet either, but need to figure out whether there is anything else I want to order from them at the same time.  Those GEC L63's are interesting as well based on the comments from others.



Langrex has many of both GEC L63 straight glass and the Brimar 6C5G tubes....so no rush
Both should be very nice tubes.


----------



## CAJames (Aug 1, 2020)

Just realized I had 6C5GTs that I hadn't tried yet. A bit of a ragtag bunch, 3 Sylvania (two tall and and one small) and 1 Raytheon. Interesting construction of the tall Sylvanias (left front, right back) with all the tube guts kind of enclosed in a cylinder, and no getter flashing. Looks sorta art deco. Sound is a lot like the metal 6C5s: detailed, a little cool and lacking that last drop of bass. Nice enough.


----------



## CAJames

Uh oh, what happened here:





Did the postperson just deliver some RCA 76 tubes? And did I order some UY5 sockets and Octal bases? 

Yes too all. Found some 76 tubes and I'm going to dust off the old soldering iron (actually my wife's soldering iron) and am going to attempt my own 76 -> 6J5 adapters. I can read a datasheet so I'm confident I know what to do in theory, but I'm not so clear about how to stick the socket to the base. I'm thinking cyanoacrylate, because that is the answer to (almost) everything, but if anyone has a better idea please share.


----------



## GDuss

CAJames said:


> Uh oh, what happened here:
> 
> 
> 
> ...



Funny how these deliveries happen sometimes, especially when you order from overseas and forget you did it.  "Who ordered these tubes, and how did they know I wanted them?"  Almost as bad as having so many tubes that when you try to order something, you check your inventory first to be sure, and then realize you already have what you are trying to order.  @JazzVinyl asked me recently whether I had any 7N7's, and I told him I couldn't remember.  When I checked, it turned out that not only did I have them, but I got them from him  .

So you are making 76 to 6J5 adapters, that will then plug into your 6J5 to SN7 adapters?


----------



## CAJames

GDuss said:


> ...So you are making 76 to 6J5 adapters, that will then plug into your 6J5 to SN7 adapters?



Yes, I blame @chrisdrop. He mentioned 76 tubes and "more adapters" early in the thread and I guess it stuck in my subconscious. Next thing I know I'm ordering 76 tubes (and of course an 83 rectifier to complete the ensemble) and asking @Deyan if he'll make me 76 -> 6J5 adapters in addition to  6J5 -> 6SN7 adapters. Since it looks like I'm going single triode all the way I need to do that part right. Anyway, he can't get UY5 sockets so I figure what the heck, I went to college, I can make them myself.

So yeah, 76 -> 6J5 adapters to plug into the 6J5 -> 6SN7 adapters. With a couple socket savers thrown in for good measure. It'll be great. 

Sort of serious note, I do have both a multi meter and a tube tester, and I'm not afraid to use them so I'm (fairly) confident I'm not going to plug anything into my amp that will damage it or me.


----------



## GDuss

CAJames said:


> Yes, I blame @chrisdrop. He mentioned 76 tubes and "more adapters" early in the thread and I guess it stuck in my subconscious. Next thing I know I'm ordering 76 tubes (and of course an 83 rectifier to complete the ensemble) and asking @Deyan if he'll make me 76 -> 6J5 adapters in addition to  6J5 -> 6SN7 adapters. Since it looks like I'm going single triode all the way I need to do that part right. Anyway, he can't get UY5 sockets so I figure what the heck, I went to college, I can make them myself.
> 
> So yeah, 76 -> 6J5 adapters to plug into the 6J5 -> 6SN7 adapters. With a couple socket savers thrown in for good measure. It'll be great.
> 
> Sort of serious note, I do have both a multi meter and a tube tester, and I'm not afraid to use them so I'm (fairly) confident I'm not going to plug anything into my amp that will damage it or me.



@chrisdrop is to blame for several of my recent tube purchases, like multiple pairs of 6J7's.  But it's ok, we'll get him back at some point.

Is there a rule somewhere about plugging adapters into adapters?  Like extension cords into extension cords?  In any case, stay safe.  The world is dangerous enough as it is.  Don't get injured by your tube amp.


----------



## chrisdrop (Aug 5, 2020)

CAJames said:


> Yes, I blame @chrisdrop. He mentioned 76 tubes and "more adapters" early in the thread and I guess it stuck in my subconscious. Next thing I know I'm ordering 76 tubes (and of course an 83 rectifier to complete the ensemble) and asking @Deyan if he'll make me 76 -> 6J5 adapters in addition to  6J5 -> 6SN7 adapters. Since it looks like I'm going single triode all the way I need to do that part right. Anyway, he can't get UY5 sockets so I figure what the heck, I went to college, I can make them myself.
> 
> So yeah, 76 -> 6J5 adapters to plug into the 6J5 -> 6SN7 adapters. With a couple socket savers thrown in for good measure. It'll be great.
> 
> Sort of serious note, I do have both a multi meter and a tube tester, and I'm not afraid to use them so I'm (fairly) confident I'm not going to plug anything into my amp that will damage it or me.


@CAJames & @GDuss  - you'll thank me later!


----------



## CAJames

I both thank and curse you, @chrisdrop. My music sounds better than ever but life was a lot simpler when I only needed to look for tall bottle 7N7s. Of course life used to be simpler in a lot of ways, so I guess that makes you a bit of a metaphor. Cheers!


----------



## bcowen

GDuss said:


> Is there a rule somewhere about plugging adapters into adapters?



It's illegal in NC, but not sure about other states.


----------



## GDuss

bcowen said:


> It's illegal in NC, but not sure about other states.




I think the only thing that really matters in Texas is whether the adapter is shaped like the state.  And if it is, you can charge 3X as much for it.


----------



## CAJames (Aug 5, 2020)

GDuss said:


> I think the only thing that really matters in Texas is whether the adapter is shaped like the state.  And if it is, you can charge 3X as much for it.



So, I guess in California it is OK as long as you have avocado with your adapters...dude.


----------



## wenbinbin2010

I've joined the weird-looking adapter camp...I wish someone had told me about these adapters before I started out with a bunch of 12**7, 6922, and 5670 adapters! I guess I got those because I had some good NOS variants from past amps, but I just rolled these RCA 12J5GTs and I'm blown away. $20 total for the pair, and already better than any other tube variant I've rolled. I also picked up the Sylvania 12J5GTs that were linked earlier in the thread, as well as a pair of Tung-Sol 12J5GTs. The RCA pair beats both hands down. There's a new unexplainable sense of realism with these RCAs that the other tubes don't give me. It's not just clarity, but really does more natural, realistic, life-like, etc. I also have a pair of GEC L63s that I'm saving to roll, but I might stock up on more of these RCA 12J5s...


----------



## bcowen

wenbinbin2010 said:


> I've joined the weird-looking adapter camp...I wish someone had told me about these adapters before I started out with a bunch of 12**7, 6922, and 5670 adapters! I guess I got those because I had some good NOS variants from past amps, but I just rolled these RCA 12J5GTs and I'm blown away. $20 total for the pair, and already better than any other tube variant I've rolled. I also picked up the Sylvania 12J5GTs that were linked earlier in the thread, as well as a pair of Tung-Sol 12J5GTs. The RCA pair beats both hands down. There's a new unexplainable sense of realism with these RCAs that the other tubes don't give me. It's not just clarity, but really does more natural, realistic, life-like, etc. I also have a pair of GEC L63s that I'm saving to roll, but I might stock up on more of these RCA 12J5s...



Oh for an amp with switchable heater voltage.  But I'll keep that to myself so that @Paladin79 doesn't hear it.


----------



## CAJames

Agree, 12 volt tubes seem like the final frontier for NOS. Well, I guess there are also the 25V tubes....


----------



## Paladin79 (Aug 7, 2020)

bcowen said:


> Oh for an amp with switchable heater voltage.  But I'll keep that to myself so that @Paladin79 doesn't hear it.


There are easy ways to do that but I am not interested. Things that are well made to suit one purpose interest me. Why not buy a receiver instead of separate components made to do their job in a superlative fashion.
 Or a zoom lens for a camera when fixed lenses are much better. I believe in building an amp to get the most out of that circuitry designed around one tube, not a whole lot of different tubes that may not be well supported. Heater voltage is just one aspect, as is heater current, or plate voltage.

Many things CAN be done but it can take away from the purity of something very well designed.


----------



## CAJames

Paladin79 said:


> ... I believe in building an amp to get the most out of that circuitry designed around one tube, not a whole lot of different tubes that may not be well supported. Heater voltage is just one aspect, as is heater current, or plate voltage.
> 
> Many things CAN be done but it can take away from the purity of something very well designed.



Sure, but with the 6/12 volt octal tubes that we're talking about isn't heater voltage the only thing that is different? I haven't read _all_ the datasheets, but many of them are literally the same for both tubes, just noting the different heater voltage.


----------



## Paladin79

CAJames said:


> Sure, but with the 6/12 volt octal tubes that we're talking about isn't heater voltage the only thing that is different? I haven't read _all_ the datasheets, but many of them are literally the same for both tubes, just noting the different heater voltage.


Some can be but look up plate voltages sometime. Some can use a max of 250 volts, others 450 and I can change my own amp into 12 volts but output current can be cut in half depending on how it’s done. Voltage is only part of it, you can design an amp to do very well with specific tubes or you can try for one size fits all and not do justice to any one type of tube. I do not do that, nor would I.


----------



## Paladin79

Now as far as Nos tubes and their price and availability, there are plenty of NOS 6C8-G's out there for very little money and with proper adapter they run fine in 6sn7 amps IMHO. I do not like to change an amp from within to accommodate other types of tubes but each to their own. I run loctals with adapters, 6J5's, 7A4's and the like.


----------



## chrisdrop

Paladin79 said:


> Now as far as Nos tubes and their price and availability, there are plenty of NOS 6C8-G's out there for very little money and with proper adapter they run fine in 6sn7 amps IMHO. I do not like to change an amp from within to accommodate other types of tubes but each to their own. I run loctals with adapters, 6J5's, 7A4's and the like.


One of the great benefits of Glenn's amps is that you can roll tubes galore. However, I can never tell if I am liking a tube because the amp is well suited to it (it is close to design spec), or because it is distorted in a pleasing way (to my ears). I'm not really sure how I could assess such a thing. Is it possible to do so by looking at tube data sheets, if so, what info about the amp is needed?


----------



## Paladin79

chrisdrop said:


> One of the great benefits of Glenn's amps is that you can roll tubes galore. However, I can never tell if I am liking a tube because the amp is well suited to it (it is close to design spec), or because it is distorted in a pleasing way (to my ears). I'm not really sure how I could assess such a thing. Is it possible to do so by looking at tube data sheets, if so, what info about the amp is needed?


I located the files where my audiophile group did a blind listening and compared it with other tube amps. Unfortunately I missed that session so I have not heard one, I only saw test results from the blind listening. If you like it that is all that matters.

 I might carry a Swiss Army knife for convenience but it is a bit unfair to compare that to well made items serving only one purpose.🙂 Then again a Randall knife does not have scissors, bottle opener, or tweezers etc. so things can be looked at from different angles.

I got many a Schiit device loaded with extra add ons like a multibit dac card or phono input but I hesitate to compare them to the Gungnir or Cary phono preamp. YMMV. I designed an amp to show differences in specific 6SN7 equivalent tubes, it was not made because certain tubes might be less pricey or easily obtainable, that is a different set of goals.😉


----------



## GDuss

The acquisitions and purchases of gear in this hobby never ends.  We are always chasing something different.  Whether that something is better or not might be debatable, but it's different.  I greatly appreciate the ability of an amp that allows me to try all the tubes in the title of this thread (some inexpensive, some not), and evaluate their differences, by only needing adapters in some cases.  If that keeps me from needing a new amp on a regular basis, I'm all for it.  If at the same time it does in my opinion spectacular job with the tubes it can run, even better.  I won't claim to have heard every OTL amp available, but of the ones I have heard, I don't think I am missing much (if anything) with the GOTL.

This is obviously just my opinion, but I will also say I don't like swiss army knives, or multitools etc.  I'd rather use actual screwdrivers than the ones on those tools.  I'd rather open a bottle of wine with a wine opener (a waiter's corkscrew by the way, not those rabbit things) than with the opener on a multitool.  I actually think that opening a bottle of wine is part of the experience, and I enjoy the manual process, but that's another discussion for another thread.  

Again, just my opinion, but there is a major difference between opening a wine bottle with a specifically designed corkscrew for the job and opening a bottle with a swiss army knife.  I suppose I would need to hear how different an amp specifically designed to run 6J5's sounds from the way they sound in the GOTL (when adapted to the 6SN7 slot), but I can't imagine the gap is anywhere near as wide.  I'm happy to run that experiment and be proven wrong though, I just need a 6J5 amp, preferably on loan  .


----------



## Paladin79 (Aug 8, 2020)

GDuss said:


> The acquisitions and purchases of gear in this hobby never ends.  We are always chasing something different.  Whether that something is better or not might be debatable, but it's different.  I greatly appreciate the ability of an amp that allows me to try all the tubes in the title of this thread (some inexpensive, some not), and evaluate their differences, by only needing adapters in some cases.  If that keeps me from needing a new amp on a regular basis, I'm all for it.  If at the same time it does in my opinion spectacular job with the tubes it can run, even better.  I won't claim to have heard every OTL amp available, but of the ones I have heard, I don't think I am missing much (if anything) with the GOTL.
> 
> This is obviously just my opinion, but I will also say I don't like swiss army knives, or multitools etc.  I'd rather use actual screwdrivers than the ones on those tools.  I'd rather open a bottle of wine with a wine opener (a waiter's corkscrew by the way, not those rabbit things) than with the opener on a multitool.  I actually think that opening a bottle of wine is part of the experience, and I enjoy the manual process, but that's another discussion for another thread.
> 
> Again, just my opinion, but there is a major difference between opening a wine bottle with a specifically designed corkscrew for the job and opening a bottle with a swiss army knife.  I suppose I would need to hear how different an amp specifically designed to run 6J5's sounds from the way they sound in the GOTL (when adapted to the 6SN7 slot), but I can't imagine the gap is anywhere near as wide.  I'm happy to run that experiment and be proven wrong though, I just need a 6J5 amp, preferably on loan  .


Very well said!  I have had a couple Glenn owners ask if my amp does 6 and 12 volt tubes, as if it were supposed to lol. Also I should point out I only designed an amp for a single purpose and donated seven of them. I am not trying to appeal to the masses and I do own seven or eight tube amps at this time so I tend to run tubes in amps designed for them. Friends did like my amp so I helped them out on occasion but I would like to wrap up my amp building pretty soon and I have had offers for my design so I may go that route, provided they do not try to turn it into a swiss army knife lol. And I know this sounds silly but I like an amp that looks good as well as sounding good. I did just add some improvements to the top end so a couple buddies may find it more appealing than before or they may send me death threats. One never knows.


Unless you go back in time I doubt if you will find many amps designed around the 6j5 and then they might not be two channel amps. I could design an amp around 6J5's pretty easily but it would be a one off, I doubt there would be many takers and the adapters to 6sn7 work very well.


----------



## chrisdrop

GDuss said:


> I just need a 6J5 amp, preferably on loan  .


Close, but not sure about the "on loan", you'll have to buzz @magicman2020 when his arrives soon to ask how he is enjoying it. While this one will do 6J7 & 6SN7 (or 12v), it will also do one or the other of course. There are no output tubes int he design. SO - there you have it - an amp running on just (6,12)J5s. 

Which brings me to a photo op. These were a lucky eBay buy; Marconi Osram 6J5Gs. I am not sure how to date them (posted on another thread to enquire). They were used but perfectly silent and in great condition (notwithstanding faded text on the outside of the tubes).


----------



## GDuss

Paladin79 said:


> Very well said!  I have had a couple Glenn owners ask if my amp does 6 and 12 volt tubes, as if it were supposed to lol. Also I should point out I only designed an amp for a single purpose and donated seven of them. I am not trying to appeal to the masses and I do own seven or eight tube amps at this time so I tend to run tubes in amps designed for them. Friends did like my amp so I helped them out on occasion but I would like to wrap up my amp building pretty soon and I have had offers for my design so I may go that route, provided they do not try to turn it into a swiss army knife lol. And I know this sounds silly but I like an amp that looks good as well as sounding good. I did just add some improvements to the top end so a couple buddies may find it more appealing than before or they may send me death threats. One never knows.
> 
> 
> Unless you go back in time I doubt if you will find many amps designed around the 6j5 and then they might not be two channel amps. I could design an amp around 6J5's pretty easily but it would be a one off, I doubt there would be many takers and the adapters to 6sn7 work very well.



Donating amps is the ultimate contribution to this madness hobby. Certainly well beyond anything I have contributed. It's also great to have amp builders in these discussions to hear thoughts on how a given design may or may not be optimized for any of the tubes we talk about.

I can also appreciate wanting equipment to look good as well as sound good.  There is nothing silly about that.  I also own a ZMF headphone.  You should check out what goes on in those threads where people are drooling over different wood grains.

I don't know about anyone else, but I don't consider much of anything I say on this forum to be rational.  When it comes to head-fi, my sanity went out the window a long time ago


----------



## bcowen

GDuss said:


> I don't know about anyone else, but I don't consider much of anything I say on this forum to be rational.  When it comes to head-fi, my sanity went out the window a long time ago



LOL!  

I'm with you (and @Paladin79 ) on the appearance.  I'm not one of those that really appreciates a 1" thick faceplate milled from solid unobtanium that adds_ substantially _to the price of whatever it's mounted on while doing nothing to enhance the sound quality, but I *do* want my equipment to look nice. Although beauty is always in the eye of the beholder, I like the look of Schiit gear -- minimalist but attractive and appropriate at the price points. @Paladin79 's work is altogether different (obviously), but I love the looks of it. It's an eye catcher with outstanding craftsmanship, even when it's gifted.  

As far as logic or rationale when it comes to this hobby, I'm pretty sure that's an oil / water type relationship.   I have enough tubes to last probably 10 human lifetimes, but for some reason I continue to buy more. Obviously no logic to be found there...


----------



## GDuss

bcowen said:


> I have enough tubes to last probably 10 human lifetimes, but for some reason I continue to buy more. Obviously no logic to be found there...



True statement.

I decided a week ago or so to do a tube inventory and make a document so I know what is here (partially so I don't buy the same tubes again).  It's not done yet, but what it's told me so far is that I have enough tubes for a similar number of human lifetimes.  Also that I have a list of tubes I haven't even tried yet.

The really crazy part is that some of my favorite tubes are some of the least expensive.  Yet I still have those GEC L63's in my cart at Langrex (ok not the most expensive tubes), just waiting to convince myself that I really need them (and by need, of course I mean want).  All it will take is another impression from someone on how they sound and they will be on their way here (with those Brimar 6C5G's that are also in the cart).  And we all know those won't be the last.

In the meantime, I'm still really enjoying the RCA 12J5GT's from 1942.  Sounds like @wenbinbin2010 is also on board with them.


----------



## CAJames

Yes to all the above. But let's be honest and admit that part of the fun is simply learning about and acquiring interesting tubes. The thrill of the chase if you will. For example I just rolled in a quad of Zenith brand 6J5Gs, I believe they are Sylvania round plates. They sound great, and I feel good about getting them for 15 USD each.


----------



## CAJames (Aug 8, 2020)

chrisdrop said:


> ... However, I can never tell if I am liking a tube because the amp is well suited to it (it is close to design spec), or because it is distorted in a pleasing way (to my ears). I'm not really sure how I could assess such a thing. Is it possible to do so by looking at tube data sheets, if so, what info about the amp is needed?



I think the "right way" to tell would be with an oscilloscope. If you knew the operating point of the amp you might be able to tell something from the current/voltage curves in the datasheet, but I'm not sure what exactly that would be. But of course, as others have said, this seems like mostly an academic exercise. What matters is how it sounds to you.


----------



## Paladin79

CAJames said:


> I think the "right way" to tell would be with an oscilloscope. If you knew the operating point of the amp you might be able to tell something from the current/voltage curves in the datasheet, but I'm not sure what exactly that would be. But of course, as others have said, this seems like mostly an academic exercise. What matters is how it sounds to you.


I use both listening (often a group of 50 when it is safe) and test equipment. I believe in the accuracy of large groups with their test results averaged. You can look at a square wave as it enters and leaves an amp and vary that over the audible range as a fairly quick way to compare tubes in an amp. I am also fortunate to have access to an engineering dept. which sets up blind tests for various gear. After age 50 your high frequency range starts going down hill so I like to use young listeners in the groups as well as musicians and audio engineers.


----------



## CAJames (Aug 8, 2020)

If the question is "does the amp distorting the input signal?"  a square wave (or even a sine wave) is pretty much unambiguous. If the question is "does this amp sound good?" then a square wave is much more biguous.


----------



## wenbinbin2010 (Aug 8, 2020)

GDuss said:


> True statement.
> 
> I decided a week ago or so to do a tube inventory and make a document so I know what is here (partially so I don't buy the same tubes again).  It's not done yet, but what it's told me so far is that I have enough tubes for a similar number of human lifetimes.  Also that I have a list of tubes I haven't even tried yet.
> 
> ...



I was going to hold off a few days before listening to my GEC L63s until I got used to these RCA 12J5GTs, but ended up putting them in today just to make sure there weren't any technical issues (or let's be honest, we're all terrible at delayed gratification). And.....they are the real deal. I will still have to make more comparisons with the other 12J5/6J5 tubes I have, but they are certainly very pleasing to listen to. Early impression, but they sound just as "natural" as the RCAs with a slight increase in detail and forwardness. EDIT: Maybe even a little too bass-heavy. Are they worth 5x more than the RCAs? Definitely diminishing returns, but it's nice to have a premium tube option as a comparison for all the cheaper ones.

All that being said, I just ordered another of the 1940s RCA 12J5GTs, along with some metal RCA 6J5/6C5s for comparison. I think I'll be set for now in exploring these types of tubes. Even though I said earlier that these 6J5/12J5 tubes seem to be the best, I know for certain some of my other tube types are still pretty good, with different qualities. I can see myself still rotating between tubes like my Amperex 7308s, WE396As, and 12**7 variants.


----------



## GDuss

wenbinbin2010 said:


> I was going to hold off a few days before listening to my GEC L63s until I got used to these RCA 12J5GTs, but ended up putting them in today just to make sure there weren't any technical issues (or let's be honest, we're all terrible at delayed gratification). And.....they are the real deal. I will still have to make more comparisons with the other 12J5/6J5 tubes I have, but they are certainly very pleasing to listen to. Early impression, but they sound just as "natural" as the RCAs with a slight increase in detail and forwardness. Are they worth 5x more than the RCAs? Definitely diminishing returns, but it's nice to have a premium tube option as a comparison for all the cheaper ones.
> 
> All that being said, I just ordered another of the 1940s RCA 12J5GTs, along with some metal RCA 6J5/6C5s for comparison. I think I'll be set for now in exploring these types of tubes. Even though I said earlier that these 6J5/12J5 tubes seem to be the best, I know for certain some of my other tube types are still pretty good, with different qualities. I can see myself still rotating between tubes like my Amperex 7308s, WE396As, and 12**7 variants.



Well I guess I'm on the hook now to buy those GEC's  .   I don't have a choice at this point, has to be done.  I'm glad to hear more opinions that rank them highly, especially compared to the RCA's that I am so fond of.

What metal RCA's did you buy?  Which logo style are they?  I think the meatball logo will be most similar to the glass 12J5GT's you have, although I'm not sure that's what you want.

I like the Sylvania 6J5/12J5 tubes I have, as well as the Tung Sol's.  I haven't had much luck with Ken Rad's of this type for some reason.  They're ok, but not among my top 5.  I have some National Union 12J5GT's from the early 50's that are also good.

On the way are some Visseaux 6J7MG and AnM (GEC) 6J7G's that @chrisdrop has talked about.  Maybe the other non-RCA J5 tubes will work better with them but RCA has been what I use most so far for 6J5/12J5 tubes.


----------



## Paladin79

CAJames said:


> If the question is "does the amp distorting the input signal?"  a square wave (or even a sine wave) is pretty much unambiguous. If the question is "does this amp sound good?" then a square wave is much more biguous.


It is always a combination of testing and listening but because I like something does not mean others will. @bcowen was one of the first I allowed to have a serious listen along with local friends. One local  girl can hear differences in three foot pieces of wire so she was a must. I was kind of worried my friends would just humor me, till they all wanted an amp.


----------



## Paladin79

chrisdrop said:


> One of the great benefits of Glenn's amps is that you can roll tubes galore. However, I can never tell if I am liking a tube because the amp is well suited to it (it is close to design spec), or because it is distorted in a pleasing way (to my ears). I'm not really sure how I could assess such a thing. Is it possible to do so by looking at tube data sheets, if so, what info about the amp is needed?


I am not sure I answered this very well or if I entirely understood the question but I tend to focus on amps designed around a specific driver and power tube. I want as little as I can in the path between input and output. A straight wire with gain is the best amp, but no such amp exists. Think of a receiver, many things built together but oftentimes one or more sections might not be very good. Ever hear anyone rave about the headphone out portion of a receiver? Or the pre-amp, or power amp portion? My belief is you design the best headphone amp you can, best power amp you can, best pre-amp you can etc. Keep them as pure and direct as possible and you can have something amazing. I strive for specifics, not versatility. I only look at data sheets to determine if a 7A4 or 6j5 pair meets up to a circuit built around a 6sn7, and they certainly do. Never have a weak link in the chain or it can take away from other devices. A thousand dollar turntable with a cheap cartridge can affect the entire chain. I could tell my amp was limited by my current headphones so I acquired some Focal Utopias with a cable that costs more than many amplifiers. Now things match to my satisfaction other than possibly a DAC upgrade down the road, my group chose one from Italy as the top rated DAC in a group of 20 and it is one of my goals.

I must say I am impressed with your tube collection and I will have to see if my group has 6j5's on the same level as some of yours. We are doing a 52 tube blind listen and dealing with 6sn7 equivalents as well as double triode tubes and an effort has been made to select the best 52 in existence. Four of my amps and HD 800's will be used and the same signal will go to each amp.


----------



## chrisdrop

Paladin79 said:


> I am not sure I answered this very well or if I entirely understood the question but I tend to focus on amps designed around a specific driver and power tube. I want as little as I can in the path between input and output. A straight wire with gain is the best amp, but no such amp exists. Think of a receiver, many things built together but oftentimes one or more sections might not be very good. Ever hear anyone rave about the headphone out portion of a receiver? Or the pre-amp, or power amp portion? My belief is you design the best headphone amp you can, best power amp you can, best pre-amp you can etc. Keep them as pure and direct as possible and you can have something amazing. I strive for specifics, not versatility. I only look at data sheets to determine if a 7A4 or 6j5 pair meets up to a circuit built around a 6sn7, and they certainly do. Never have a weak link in the chain or it can take away from other devices. A thousand dollar turntable with a cheap cartridge can affect the entire chain. I could tell my amp was limited by my current headphones so I acquired some Focal Utopias with a cable that costs more than many amplifiers. Now things match to my satisfaction other than possibly a DAC upgrade down the road, my group chose one from Italy as the top rated DAC in a group of 20 and it is one of my goals.
> 
> I must say I am impressed with your tube collection and I will have to see if my group has 6j5's on the same level as some of yours. We are doing a 52 tube blind listen and dealing with 6sn7 equivalents as well as double triode tubes and an effort has been made to select the best 52 in existence. Four of my amps and HD 800's will be used and the same signal will go to each amp.


I admire your scientific approach. Double-blind randomised controlled trials are the way to go if you can! I am sure there are all kinds of setup, kit, tools and considerations to conduct your experiments with a large # of people as you have. In my day to day life, we conduct experiments of sorts and being involved in such activities where randomness runs rampant - it is quite clear how much cognitive bias there is, and how fragile beliefs can be. Only a solid process can tease out the signal from the noise of experimentation. I also don't mind enjoying a non-scientific approach in this hobby. 

There are certainly some folks in the US with lots of 6J5s (and related tubes). As you know they are just a 1/2 6SN7. Amps designed around the 6SN7 input handle them. Consistently, albeit anecdotally, people have preferred the 2x 6J5 to 1x 6SN7. Although I am born in America, I've been in the UK for ~a dozen years. They do have an easy to acquire set of European tubes over here 

Good luck with your DAC. I had a bit of a DAC journey earlier this year and came across a builder that I liked here in the UK. Before the DAC hunt, I didn't appreciate how much real variety there was in DACs. 

I am, of course, interested in amps! That said, I am not very knowledgable about the workings of them. I set out to start to learn the general area by building some cables, and a Bottlehead kit this year. You clearly know how these things work and I am sure you have made many lovely amps. Certainly you have nice woodwork going. It sounds like others are enjoying them. It must be nice to produce something like that - which gives others direct enjoyment as only these musical devices can. As I have time, I'll keep learning more about the workings of tube amps. 

Finally, I've still been enjoying those 2x Marconi/Osram 6J5 Grey Glass posted recently. I have, however swapped from 2x Bendix 6080 to 6x Sylvania 6BX7s as outputs.


----------



## Paladin79 (Aug 9, 2020)

chrisdrop said:


> I admire your scientific approach. Double-blind randomised controlled trials are the way to go if you can! I am sure there are all kinds of setup, kit, tools and considerations to conduct your experiments with a large # of people as you have. In my day to day life, we conduct experiments of sorts and being involved in such activities where randomness runs rampant - it is quite clear how much cognitive bias there is, and how fragile beliefs can be. Only a solid process can tease out the signal from the noise of experimentation. I also don't mind enjoying a non-scientific approach in this hobby.
> 
> There are certainly some folks in the US with lots of 6J5s (and related tubes). As you know they are just a 1/2 6SN7. Amps designed around the 6SN7 input handle them. Consistently, albeit anecdotally, people have preferred the 2x 6J5 to 1x 6SN7. Although I am born in America, I've been in the UK for ~a dozen years. They do have an easy to acquire set of European tubes over here
> 
> ...


Very nice, oh and I put together a few kits in my day including cracks but I knew before I touched one what I would change on it.


Naturally I have access to most any wire made and have done some headphone cables, headphone racks, headphone mods.

I studied tube theory in college  so yeah I have a pretty good idea  about tubes and own quite a few.
Friends asked me to build an amp to allow the 6sn7 to be the star as well as the 6080 to some extent. I wanted more power than the Crack but did not want a lot of other tubes.@bcowen can let you know if I succeeded in my endeavor, or Ripper, or Jedi. Now I made a few refinements to SQ and so far folks like it but few have the experience with tubes like Cowen so maybe one day he will hear the new version. Oh yeah I no longer run the local audiophile group but they are even blind testing candidates for the final 52 before the serious testing begins.
The 6j5's in the third photo I call Naughty Girls since a lot of their characteristics resemble Bad Boys. I had to come up with something after Bill came up with Frankies lol.


----------



## bcowen

Paladin79 said:


> Very nice, oh and I put together a few kits in my day including cracks but I knew before I touched one what I would change on it.
> 
> 
> Naturally I have access to most any wire made and have done some headphone cables, headphone racks, headphone mods.
> ...



You succeeded. Mightily.

But they really had colleges back then?


----------



## Paladin79

bcowen said:


> You succeeded. Mightily.
> 
> But they really had colleges back then?


Sort of but we only had wax tablets and styli. You just killed your chances of hearing the new Incubus Elegan you know lol. I tend to get even. Ripper can hold his headphones up to the phone I suppose.


----------



## CAJames

Paladin79 said:


> ...I studied tube theory in college  so yeah I have a pretty good idea  about tubes...



My favorite uncle was an E.E./physicist at Los Alamos who was retired in early 90's when I got seriously into tube audio. So I asked him if he ever came across tube testers for sale. He paused, gave me 'the look,' and said, you know, solid state is here to stay.  I got another look later when I told him that I bought a tube tester "on the internet."


----------



## Paladin79

CAJames said:


> My favorite uncle was an E.E./physicist at Los Alamos who was retired in early 90's when I got seriously into tube audio. So I asked him if he ever came across tube testers for sale. He paused, gave me 'the look,' and said, you know, solid state is here to stay.  I got another look later when I told him that I bought a tube tester "on the internet."


I kept being pulled into other areas but finally I can get back into design. I kept being promoted and sent back for more and more education. I worked a lot with solid state out of college but now I am going back to learn what some of my forebearers knew. All my life’s a circle.


----------



## CAJames (Aug 9, 2020)

Paladin79 said:


> I kept being pulled into other areas but finally I can get back into design. I kept being promoted and sent back for more and more education. I worked a lot with solid state out of college but now I am going back to learn what some of my forebearers knew. All my life’s a circle.



I was a physics major myself, but much more inclined to the mathematical than the practical. The head of the department however was a frustrated E.E. and I wound up taking a lot more electronics classes than I wanted to. More then he wanted me to as well after I burned up a couple high dollar power transistors because I'm color blind and struggle with the resistor color codes. Turns out the difference between ohms and megaohm matters


----------



## chrisdrop

I've been really enjoying these same Marconi/Osram 6J5G/L63s. I have a guess on the date...

The tubes have very faded writing on them. On one side there is the 6J5G with the "up arrow" (which I think is just a military designation?). There is also text reading "ZA 4138" (or "7A..."). On the other side there is the oval "made & patented in England" oval text around "L63". Above the L63, hard to see, I believe is an "H". Below the L63 I believe is a "38". 

So I am guessing this is 41st week of 1938? 

I was wondering if there are other telltale signs of when tubes were likely made? Smoked glass? Black bakelite, non-metal base? You can't see the getters due to the smoked glass and silvery flash. Is there a sequence of these features?


----------



## leftside

Good guess. You might be right. I've spoken to a few tube collectors and sellers from the UK the last few years talking about GEC tubes, and no one really seems to be able to make sense of the GEC numbering system before 1945. I have quite a few rare GEC KT66 with the older shoulder (ST) type glass, and the people who I've purchased them from either had no idea of the date scheme used or at best could provide some rough guesses. All we really know is they were made sometime between 1939 and 1945.

When it comes to GEC: black base, black plates, smoked glass, foil getter = early tubes. Same with the ECCxx Mullards. A friend of mine swears Mullard and GEC sourced the black plate material from the same source, but I can't find any documented evidence to back that up. It would explain why the early GEC and Mullards with these characteristics (black base, black plates, smoked glass, foil getter) fetch such a pretty penny. I've managed to snag a few off eBay that weren't really advertised very well, but by taking a good look at the photos I could see these early materials being used.


----------



## leftside

August 1938 was the first appearance of the L63 tube:
https://www.radiomuseum.org/tubes/tube_l63.html


----------



## GDuss

chrisdrop said:


> I've been really enjoying these same Marconi/Osram 6J5G/L63s. I have a guess on the date...
> 
> The tubes have very faded writing on them. On one side there is the 6J5G with the "up arrow" (which I think is just a military designation?). There is also text reading "ZA 4138" (or "7A..."). On the other side there is the oval "made & patented in England" oval text around "L63". Above the L63, hard to see, I believe is an "H". Below the L63 I believe is a "38".
> 
> ...



I can't contribute to this tube date discussion but how do they sound?  Specifically, do they sound similar to any of your other tubes, maybe the GEC 6J5G's?  Or are they more distinct from anything else?


----------



## chrisdrop (Aug 17, 2020)

GDuss said:


> I can't contribute to this tube date discussion but how do they sound?  Specifically, do they sound similar to any of your other tubes, maybe the GEC 6J5G's?  Or are they more distinct from anything else?


I think they are similar to the other early 40s GEC 6J5Gs that I have. I tend to think they are my favourite inputs, but I am also fickle! I've had these in the amp for the most part since they arrived. I prefer them with the 6BX7s outputs as they can be too much low end w/ any of the 6080s. I'll need to rotate in the other GECs to compare, I haven't done that. I prefer these to the GEC 6J5GTs (which I really do like a lot too). Also, I put in 2x Mullard 6J5Gs today and the Mullards were a bit brighter and not quite as spacious sounding. I the Mullards are also worth rotating in, I just need to sort which outputs support them best. The Mullards are impossible to date, they have no markings on them at all that I can discern  I am most pleased with these pic'd tubes also as they were 50GBP, used, but silent and sound great.

EDIT: They are certainly working on a position in my "top drivers".


----------



## Velozity

Got a package in from my buddy Billington today.  New to the collection are the three pairs of tubes on the left:  Mullard 6J5G, Brimar 6C5G, and GEC 6J5G.  The Sylvania 6J5G I've had for a few weeks already.  Listening to the Brimars first.  Very, very, enjoyable and dead quiet!  Nothing is really standing out with them.  They just sound damn good.  Maybe the high end is rolled off slightly compared to the Sylvania, but it's a very pleasing tone.  I will be evaluating all these with Chatham 6AS7G powers and GEC U18/20 rectifier in my GOTL.


----------



## GDuss

Velozity said:


> Got a package in from my buddy Billington today.  New to the collection are the three pairs of tubes on the left:  Mullard 6J5G, Brimar 6C5G, and GEC 6J5G.  The Sylvania 6J5G I've had for a few weeks already.  Listening to the Brimars first.  Very, very, enjoyable and dead quiet!  Nothing is really standing out with them.  They just sound damn good.  Maybe the high end is rolled off slightly compared to the Sylvania, but it's a very pleasing tone.  I will be evaluating all these with Chatham 6AS7G powers and GEC U18/20 rectifier in my GOTL.



I'm happy to hear this on the Brimar's, I have a pair on the way from Langrex.


----------



## leftside

Velozity said:


> Got a package in from my buddy Billington today.  New to the collection are the three pairs of tubes on the left:  Mullard 6J5G, Brimar 6C5G, and GEC 6J5G.  The Sylvania 6J5G I've had for a few weeks already.  Listening to the Brimars first.  Very, very, enjoyable and dead quiet!  Nothing is really standing out with them.  They just sound damn good.  Maybe the high end is rolled off slightly compared to the Sylvania, but it's a very pleasing tone.  I will be evaluating all these with Chatham 6AS7G powers and GEC U18/20 rectifier in my GOTL.


Great haul. You must have loved opening that package from Martin.


----------



## chrisdrop

Velozity said:


> Got a package in from my buddy Billington today.  New to the collection are the three pairs of tubes on the left:  Mullard 6J5G, Brimar 6C5G, and GEC 6J5G.  The Sylvania 6J5G I've had for a few weeks already.  Listening to the Brimars first.  Very, very, enjoyable and dead quiet!  Nothing is really standing out with them.  They just sound damn good.  Maybe the high end is rolled off slightly compared to the Sylvania, but it's a very pleasing tone.  I will be evaluating all these with Chatham 6AS7G powers and GEC U18/20 rectifier in my GOTL.


I'm away in the countryside presently and missing my headphones!

Those are great, pristine looking tubes (and love the wooden amp!). That is going to be weeks or months of good fun rolling around. Just good photos 

Those Brimar 6C5Gs do look a good bit like some 6J7Gs we've been speculating about on the Glenn thread.

I think the Mullards took more time to settle/burn in. The Mullards are still changing for me. Also, I don't have any Sylvania 6J5*G*s, I'll need to grab some eventually.

I look forward to hearing how you get on with all of these; if you have any faves/preferences, output pairings, etc.


----------



## whirlwind

Velozity said:


> Got a package in from my buddy Billington today.  New to the collection are the three pairs of tubes on the left:  Mullard 6J5G, Brimar 6C5G, and GEC 6J5G.  The Sylvania 6J5G I've had for a few weeks already.  Listening to the Brimars first.  Very, very, enjoyable and dead quiet!  Nothing is really standing out with them.  They just sound damn good.  Maybe the high end is rolled off slightly compared to the Sylvania, but it's a very pleasing tone.  I will be evaluating all these with Chatham 6AS7G powers and GEC U18/20 rectifier in my GOTL.




Nice tubes!


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## CAJames

Here are my latest, also c/o BB (Buddy Billington). Continental brand 6P5GTs, they look like Sylvania round plates. They sound really nice, although much more like 6J5s than other 6P5s in my experience. A little on the soft side, and natural (not exaggerated) bass.  Long time residents of this thread might notice my upgraded adapters. They are very nice indeed, a huge upgrade over the ebay stuff, and definitely helped with the hum problem I was having. 

Could it be that I have enough single triodes (for now)? I ordered a couple new CDs for the first time in months.


----------



## chrisdrop

Velozity said:


> Got a package in from my buddy Billington today.  New to the collection are the three pairs of tubes on the left:  Mullard 6J5G, Brimar 6C5G, and GEC 6J5G.  The Sylvania 6J5G I've had for a few weeks already.  Listening to the Brimars first.  Very, very, enjoyable and dead quiet!  Nothing is really standing out with them.  They just sound damn good.  Maybe the high end is rolled off slightly compared to the Sylvania, but it's a very pleasing tone.  I will be evaluating all these with Chatham 6AS7G powers and GEC U18/20 rectifier in my GOTL.


Do you see how those Brimars have writing on the inside? What is that all about? The AnM 6J7s that I have look very similar as mentioned and also have writing on the inside. I haven't seen other tubes with that before. Is it a Brimar thing? Has anyone seen that on other valves?


----------



## GDuss

chrisdrop said:


> Do you see how those Brimars have writing on the inside? What is that all about? The AnM 6J7s that I have look very similar as mentioned and also have writing on the inside. I haven't seen other tubes with that before. Is it a Brimar thing? Has anyone seen that on other valves?



I got the Brimar 6C5G's from Langrex yesterday.  I can't tell that they have any writing on the inside, but they also have no markings on the base like the ones from @Velozity .  They otherwise look the same though.


----------



## CAJames (Aug 21, 2020)

Did you guys buy all the 6C5Gs from Langrex? I just went to their web site (purely for education reasons, no intention of buying anything ) and the only 6C5s I see are metal GEs.


----------



## GDuss

CAJames said:


> Did you guys buy all the 6C5Gs from Langrex? I just went to their web site (pure for education reasons, no intention of buying anything ) and the only 6C5s I see are metal GEs.



I noticed this too.  When the tubes came in yesterday, I went to the site to check how these compared to the photo they had listed.  And they were all gone.  I know when I ordered them about 2 weeks ago there were at least 50 of them listed on their site (I can't remember but there may have been more than that).  I only bought 2.  So I have no idea what happened.


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## CAJames

I blame @chrisdrop , again.


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## GDuss

CAJames said:


> I blame @chrisdrop , again.



LOL.  It is usually his fault, so this is probably reasonable  .

I also ordered a pair of GEC L63's from Langrex at the same time.  When I ordered them they had over 80 listed in stock, and they still have 83 listed.  So it's not like my order did something strange to their stocks, someone just bought all the Brimars.  If you start seeing some Brimar 6C5G's show up in the sales forum, we'll know where they came from.


----------



## chrisdrop

CAJames said:


> I blame @chrisdrop , again.


OK ... I admit it -I have more tubes coming ... Fivre 6C5s next week. I may have a problem, but it is a fun one.

For the minute I am sticking on these (what I think are 1938) M-OV 6J5Gs and really enjoying them.

I picked up a NOS ECC32 this week - double triode driver - almost a sin! He will have to get some airtime soon.

This past Tuesday, I also got to meet Martin in person and see the warehouse, meet some of the staff, etc. Sorry - no photos I was just hanging out and it didn't seem the thing to do. Guess what - he has a lot of tubes! If only he knew what a fan-club he has in us, it'd make him blush I'm sure.

Also, any 6J5-family blame that comes my way, I redirect to @L0rdGwyn. Another GOTL has just gone 6J5-native thanks to his explorations down this path.


----------



## GDuss

chrisdrop said:


> This past Tuesday, I also got to meet Martin in person and see the warehouse, meet some of the staff, etc. Sorry - no photos I was just hanging out and it didn't seem the thing to do. Guess what - he has a lot of tubes! If only he knew what a fan-club he has in us, it'd make him blush I'm sure.



Get him signed up on Head-Fi !!!


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## CAJames (Aug 21, 2020)

chrisdrop said:


> ...This past Tuesday, I also got to meet Martin in person and see the warehouse, meet some of the staff, etc. Sorry - no photos I was just hanging out and it didn't seem the thing to do. Guess what - he has a lot of tubes! If only he knew what a fan-club he has in us, it'd make him blush I'm sure....



Now that is cool. Forget the British Museum  and tea with the queen, that's how I want to spend my next afternoon in London. I would imagine though that when you sell exotic tubes all day for work when you come home you listen to music on a 70's Aiwa receiver.


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## GDuss

CAJames said:


> I would imagine though that when you sell exotic tubes all day for work when you come home you listen to music on a 70's Aiwa receiver.



Or straight out of your phone on speaker.


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## JazzVinyl

GDuss said:


> Or straight out of your phone on speaker.



Oh my! I hope not!


----------



## JazzVinyl (Aug 21, 2020)

GDuss said:


> I like the Sylvania 6J5/12J5 tubes I have, as well as the Tung Sol's.  I haven't had much luck with Ken Rad's of this type for some reason.  They're ok, but not among my top 5.  I have some National Union 12J5GT's from the early 50's that are also good.



Anyone here with the Glenn OTL do the 'driver triplet' setup?

I like all my 12J5 and 6J5's...and I find that stage and mid-range; enhancement is welcomed, via use of the Mullard straight bottle EL32's, adapted to the C3g sockets.

Right now I have in the NOS 1940's Tung Sol 12J5's the EL32's and a quad of Sylvania 6BL7's (not BX) Flat Plates and I dunno, gang, seems to me the EL32 really adds to the setup.

I know @GDuss  have "EL32'd" and pretty sure @chrisdrop has too...you guys still triplet-ing?

Anyone else?


----------



## chrisdrop

JazzVinyl said:


> Anyone here with the Glenn OTL do the 'driver triplet' setup?
> 
> I like all my 12J5 and 6J5's...and I find that stage and mid-range; enhancement is welcomed, via use of the Mullard straight bottle EL32's, adapted to the C3g sockets.
> 
> ...


I have certainly done a load of dual-driver-ing (probably inspired by you!). I have a few pairs of EL32 that I have run w/ mostly 6J5s and 6N7s. I have also experimented with 6J7 dual drivers. I am on a bit of an either/or run for the past few months however. I have a pair of 6J7Gs (which I think @GDuss also has now), which I really like solo with a certain output pairing (6BX7s - offer a crispness compliment). Sadly, EL32s are never good solo drivers (IMO), but make excellent seconds. 

Landing the right outputs has been critical to get solo drivers as nice as duals can be. I had a spell (~6mos) of only Bendix 6080s for outputs and lately I have been more flexible. I did land few more outputs that I like as of late. So - long story short, I've been more recently just 1 driver type and more flexible output rolling. 

I am sure I'll get back to dual-driver-ing soon enough . Perhaps your post is already sufficient inspiration!

N.B.; JV - you always have great pictures  Here is my less-elegant photo offering... Nice glow over here!


----------



## whirlwind (Aug 21, 2020)

chrisdrop said:


> OK ... I admit it -I have more tubes coming ... Fivre 6C5s next week. I may have a problem, but it is a fun one.
> 
> For the minute I am sticking on these (what I think are 1938) M-OV 6J5Gs and really enjoying them.
> 
> ...






chrisdrop said:


> OK ... I admit it -I have more tubes coming ... Fivre 6C5s next week. I may have a problem, but it is a fun one.
> 
> For the minute I am sticking on these (what I think are 1938) M-OV 6J5Gs and really enjoying them.
> 
> ...



The ECC32 is a wonderful tube, congrats on that.

I have had my amp back for a couple of days...a very nice head-fier did some surgery to my amp, put some 6/12J5 sockets in to replace the C3g sockets.
I am quite enjoying listening to these tubes I have collected but not really listed to, as I did not buy an adapter to use in my SN7 socket.
I only have planar headphones on hand for the time being, but the GOTL is powering the LCD-4 just fine so I am listening to the tubes.

The Belton sockets are of pretty good quality for the price, nice snug fit.
Currently listening to a pair of National Union VT-94 6J5GT


----------



## JazzVinyl

chrisdrop said:


> I have certainly done a load of dual-driver-ing (probably inspired by you!). I have a few pairs of EL32 that I have run w/ mostly 6J5s and 6N7s. I have also experimented with 6J7 dual drivers. I am on a bit of an either/or run for the past few months however. I have a pair of 6J7Gs (which I think @GDuss also has now), which I really like solo with a certain output pairing (6BX7s - offer a crispness compliment). Sadly, EL32s are never good solo drivers (IMO), but make excellent seconds.
> 
> Landing the right outputs has been critical to get solo drivers as nice as duals can be. I had a spell (~6mos) of only Bendix 6080s for outputs and lately I have been more flexible. I did land few more outputs that I like as of late. So - long story short, I've been more recently just 1 driver type and more flexible output rolling.
> 
> ...



Hello Chrisdrop...

Agree that the 6J7's adapted to the C3g sockets make for very nice sounding drivers, all by themselves.
And also agree the EL32's do not make good solo drivers, but are *the ones *for driver triplet-ing.

Hope you will give the EL32's another go, following some of your elegant 6J5's.

Hear ya on getting stuck on powers.  I was stuck on 4x 6080's for a few months, but am also venturing out, again.   I always loved the 6BL7's...they have a deep and gritty grunt...keeps things fun.

Cheers!!


----------



## JazzVinyl

whirlwind said:


> The ECC32 is a wonderful tube, congrats on that.
> 
> I have had my amp back for a couple of days...a very nice head-fier did some surgery to my amp, put some 6/12J5 sockets in to replace the C3g sockets.
> I am quite enjoying listening to these tubes I have collected but not really listed to, as I did not buy an adapter to use in my SN7 socket.
> ...



What a nice job your friend did, @whirlwind!!  
I take it you were not a fan of driver triplet-ing with the EL32?


----------



## bcowen

CAJames said:


> Could it be that I have enough single triodes (for now)?



No.


----------



## GDuss

chrisdrop said:


> I have certainly done a load of dual-driver-ing (probably inspired by you!). I have a few pairs of EL32 that I have run w/ mostly 6J5s and 6N7s. I have also experimented with 6J7 dual drivers. I am on a bit of an either/or run for the past few months however. I have a pair of 6J7Gs (which I think @GDuss also has now), which I really like solo with a certain output pairing (6BX7s - offer a crispness compliment). Sadly, EL32s are never good solo drivers (IMO), but make excellent seconds.
> 
> Landing the right outputs has been critical to get solo drivers as nice as duals can be. I had a spell (~6mos) of only Bendix 6080s for outputs and lately I have been more flexible. I did land few more outputs that I like as of late. So - long story short, I've been more recently just 1 driver type and more flexible output rolling.
> 
> ...



I'm not sure what it's technically considered if I run 2 tubes in the SN7 slot (dual 6J5's on an adapter, although currently dual GEC L63's) and 2 tubes in the C3g slots (currently those AnM 6J7's that @chrisdrop recommended).  Driver quad'ing?  Or is it still driver triplet-ing since the 6J5 is really half a 6SN7?  Either way, I haven't used an SN7 in probably 6 months because it's all been dual 6J5/6C5/12J5/L63's.  And yes @JazzVinyl , I did use the EL32's in the C3g slots for a while after your suggestion to try it, but it's been 6J7's in those slots for a while now.  I'll go back to the EL32's at some point, but I'm enjoying the 6J7's currently.


----------



## GDuss

whirlwind said:


> The ECC32 is a wonderful tube, congrats on that.
> 
> I have had my amp back for a couple of days...a very nice head-fier did some surgery to my amp, put some 6/12J5 sockets in to replace the C3g sockets.
> I am quite enjoying listening to these tubes I have collected but not really listed to, as I did not buy an adapter to use in my SN7 socket.
> ...



Keep us all posted on which 6J5-type tubes you like the best and in what combinations.

I think you mentioned you were looking at the Brimar 6C5G's from Langrex, but now they are all gone.  Did you buy any before they disappeared?  Or did you buy all of them?


----------



## JazzVinyl

GDuss said:


> I'm not sure what it's technically considered if I run 2 tubes in the SN7 slot (dual 6J5's on an adapter, although currently dual GEC L63's) and 2 tubes in the C3g slots (currently those AnM 6J7's that @chrisdrop recommended).  Driver quad'ing?  Or is it still driver triplet-ing since the 6J5 is really half a 6SN7?  Either way, I haven't used an SN7 in probably 6 months because it's all been dual 6J5/6C5/12J5/L63's.  And yes @JazzVinyl , I did use the EL32's in the C3g slots for a while after your suggestion to try it, but it's been 6J7's in those slots for a while now.  I'll go back to the EL32's at some point, but I'm enjoying the 6J7's currently.



LOL....Good point!  Driver QUAD-ing! 

Maybe @chrisdrop's saying that you are "following the SN7 slot" is the most correct way to say it.  

 I have the Ken-Rad 6J7's.  I prefer the EL32's following the SN7 socket.  I like the K-R 6J7's all by themselves.  
What is an "AnM 6J7"?  Not familiar....

.


----------



## GDuss

JazzVinyl said:


> What is an "AnM 6J7"? Not familiar....



Well I was going to post a link to the eBay listing where we bought them... but they're all gone.  I think that seller had a bunch of them too.  We need to stop talking about tubes on this forum, I think someone is reading and buying up everything we talk about.

Anyway, @chrisdrop started a discussion on those tubes here:

https://www.head-fi.org/threads/2359glenn-studio.600110/page-2476

The explanation of what AnM means is still a debate.  As is the NAPL 101 label on the base of the tubes.  Chris even recruited Martin Billington into the discussion, and he didn't really know either.


----------



## JazzVinyl

GDuss said:


> Well I was going to post a link to the eBay listing where we bought them... but they're all gone.  I think that seller had a bunch of them too.  We need to stop talking about tubes on this forum, I think someone is reading and buying up everything we talk about.
> 
> Anyway, @chrisdrop started a discussion on those tubes here:
> 
> ...



I see...so the AnM 6J7 is unobtanium at the moment!  Dang it!


----------



## GDuss

JazzVinyl said:


> I see...so the AnM 6J7 is unobtanium at the moment!  Dang it!



Hopefully the mysterious buyer of all these tubes wasn't BangyBang.  If it was, they will really be unobtanium


----------



## cddc

GDuss said:


> Hopefully the mysterious buyer of all these tubes wasn't BangyBang.  If it was, they will really be unobtanium




LOL, happened to read posts here. 

I'm 100% sure some tube vendors follow discussions on head-fi closely. Last time a few head-fi members were discussing TS BGRP and it price suddenly jumped up.

Thread like this definitely makes vendors much easier to track info and buy out tubes in hot spot. Since most folks here seem to be GOTL owners, I suggest close this thread and move discussions to the GOTL thread. This way all info is mixed in a larger pot, which hopefully will make it more difficult for vendors to track. 🤣🤣🤣


----------



## whirlwind

JazzVinyl said:


> What a nice job your friend did, @whirlwind!!
> I take it you were not a fan of driver triplet-ing with the EL32?



Thanks, yes sir he did a fantastic job.
I did try the driver triplet-ing for a brief time, but never with the EL32 as I do not own any of these tubes.
I know many like it however. 
I can not use the driver triplets or any 6SL7 or 6N7 in my amp now, because my amp has had CCS installed.
I own a very nice Mullard ECC35 tube that I will be posting in the classifieds soon as I can not use it anymore.





GDuss said:


> Keep us all posted on which 6J5-type tubes you like the best and in what combinations.
> 
> I think you mentioned you were looking at the Brimar 6C5G's from Langrex, but now they are all gone.  Did you buy any before they disappeared?  Or did you buy all of them?



No I did not buy any of them, let alone all of them. at some point I will get a pair of them to try.
I did see these at Langrex when browsing not long ago and it seemed they had plenty in stock.
I guess you never know.


----------



## bcowen (Aug 22, 2020)

GDuss said:


> Hopefully the mysterious buyer of all these tubes wasn't BangyBang.  If it was, they will really be unobtanium



ROFL!  The genuine ones would end up on his Menifee Audio site for $1k a pop, and he'd re-silkscreen some $2 Chinese tubes to match the logo and sell those on BangyBang.  But no worries -- everything sold on both sites is "100% guaranteed to work excellent in your gear's"(sic).


----------



## chrisdrop

bcowen said:


> ROFL!  The genuine ones would end up on his Menifee Audio site for $1k a pop, and he'd re-silkscreen some $2 Chinese tubes to match the logo and sell those on BangyBang.  But no worries -- everything sold on both sites is "100% guaranteed to work excellent in your gear's"(sic).


No worse than Wege in Italy. Marconi 6J7s for  $4,350.00 + $50.00 postage anyone?


----------



## bcowen

chrisdrop said:


> No worse than Wege in Italy. Marconi 6J7s for  $4,350.00 + $50.00 postage anyone?



  Holy ridiculousness, batman! I _might_ pay that for a (truly) NOS 40's or '50's Western Electric 300B. But a 6J7?  I've never spent more than $1k for a pair of tubes (and that for KR 300BXLS's), and it's doubtful I'll _ever _spend more than $1k for a pair of tubes.  

There's a seller from Vietnam posting a lot on Ebay of late with silly-stupid prices. Haven't followed any of his ads to see if the stuff is actually selling...


----------



## chrisdrop

Here are some sales for Menifee Audio


----------



## CAJames

Wait.... what ?!?!?! Crazy over priced stuff for sale on Ebay? That doesn't sound right....

Regardless, I just recieved an email from the barrister for the disposed oil minister of Nigeria who has promised me a considerable sum just for letting him use my American checking acct to recover his client's stolen fortune. So I'm going shoppin! Maybe a nice pair of metal base Mullard GZ34s for only US$ 3745...


----------



## Velozity

cddc said:


> LOL, happened to read posts here.
> 
> I'm 100% sure some tube vendors follow discussions on head-fi closely. Last time a few head-fi members were discussing TS BGRP and it price suddenly jumped up.
> 
> Thread like this definitely makes vendors much easier to track info and buy out tubes in hot spot. Since most folks here seem to be GOTL owners, I suggest close this thread and move discussions to the GOTL thread. This way all info is mixed in a larger pot, which hopefully will make it more difficult for vendors to track. 🤣🤣🤣





Or....

We organize and start a private Facebook group dedicated to Head-fi tube deals.  That way we can share our finds privately and even organize group buys with our favorite vendors, who would also be invited to the group.


----------



## JazzVinyl

cddc said:


> LOL, happened to read posts here.
> 
> I'm 100% sure some tube vendors follow discussions on head-fi closely. Last time a few head-fi members were discussing TS BGRP and it price suddenly jumped up.
> 
> Thread like this definitely makes vendors much easier to track info and buy out tubes in hot spot. Since most folks here seem to be GOTL owners, I suggest close this thread and move discussions to the GOTL thread. This way all info is mixed in a larger pot, which hopefully will make it more difficult for vendors to track. 🤣🤣🤣



Does not matter where the info is located, imo.  
If your intention is to corner the market on popular tubes, they are probably surfing all tube oriented threads.

What we need to do is behave like John D Rockafellar, and issue a code word book, for his remote business buyers to use, in communicating with the home office.

flower = '1940's era tube'
skunk = 'Sounds Great'
meat = 'Wide Sound Stage'
orange = 'silky highs'

...etc...

Let 'em try and break the code!


----------



## JazzVinyl

Velozity said:


> Or....
> 
> We organize and start a private Facebook group dedicated to Head-fi tube deals.  That way we can share our finds privately and even organize group buys with our favorite vendors, who would also be invited to the group.



I suggest you read the 'Terms of Service Agreement' very carefully, before posting anything on FB.


----------



## CAJames (Aug 22, 2020)

What makes you think FB (or Google) isn't behind the tube buying in the first place? What we need is our own website. I suggest:

^(6|12){1}(J|C|P){1}5(G|GT|MG){0,1}$ .com


----------



## GDuss

whirlwind said:


> No I did not buy any of them, let alone all of them. at some point I will get a pair of them to try.
> I did see these at Langrex when browsing not long ago and it seemed they had plenty in stock.
> I guess you never know.



Let me know if/when you are interested in trying them and I'll send you the pair.  Based on the comments from others who have used them, they sound promising, but I haven't tried them yet.  Currently going with the GEC L63's that were in the same order.  I spent an hour or so with those last night and initial impressions are very positive.  This is with the AnM 6J7G's and 4x Tung Sol 6BX7's.


----------



## GDuss

JazzVinyl said:


> Does not matter where the info is located, imo.
> If your intention is to corner the market on popular tubes, they are probably surfing all tube oriented threads.
> 
> What we need to do is behave like John D Rockafellar, and issue a code word book, for his remote business buyers to use, in communicating with the home office.
> ...



That's what I was thinking, although your suggested code words sound like they could be describing something that is not currently legal in the state of Texas


----------



## bcowen

CAJames said:


> Wait.... what ?!?!?! Crazy over priced stuff for sale on Ebay? That doesn't sound right....
> 
> Regardless, I just recieved an email from the barrister for the disposed oil minister of Nigeria who has promised me a considerable sum just for letting him use my American checking acct to recover his client's stolen fortune. So I'm going shoppin! Maybe a nice pair of metal base Mullard GZ34s for only US$ 3745...



ROFL!!   Did they really *dispose* of that guy?  I mean, probably justified and all, but seems a bit harsh just the same.  

I'll post some pics later of  what I bought in anticipation of  my share of his fortune...


----------



## CAJames (Aug 22, 2020)

bcowen said:


> ... *dispose...*



Ha! I blame spell check.  Of course deposed-disposed, its tomato-tomahto  🤡


----------



## JazzVinyl

GDuss said:


> That's what I was thinking, although your suggested code words sound like they could be describing something that is not currently legal in the state of Texas



Knock Knock.  Who's there?  It's Dave man, let me in.  Dave's not here, man....(repeat)...

This is Colorado, after all


----------



## CAJames

JazzVinyl said:


> Knock Knock.  Who's there?  It's Dave man, let me in.  Dave's not here, man....(repeat)...
> 
> This is Colorado, after all



Dude....


----------



## bcowen (Aug 22, 2020)

CAJames said:


> Ha! I blame spell check.  Of course deposed-disposed, its tomato-tomahto  🤡



LOL!  My first part of the Nigerian fortune spending arrived today.  2.5 weeks from Langrex.  Not bad at all considering how long stuff is taking these days.

Both test nicely and decently matched for GM. But although the exterior markings are identical and the plates/micas look the same, the one on the left has a D getter that's perpendicular to the bottle (so most of the getter material is flashed down in the base), and the one on the right has an O getter that's parallel to the bottle causing the getter material to be flashed on the bottle.  Somebody at GEC changed the getter holder and didn't update the drawing.  I'd fire him...except he's probably dead.


----------



## GDuss

bcowen said:


> LOL!  My first part of the Nigerian fortune spending arrived today.  2.5 weeks from Langrex.  Not bad at all considering how long stuff is taking these days.
> 
> Both test nicely and decently matched for GM. But although the exterior markings are identical and the plates/micas look the same, the one on the left has a D getter that's perpendicular to the bottle (so most of the getter material is flashed down in the base), and the one on the right has an O getter that's parallel to the bottle causing the getter material to be flashed on the bottle.  Somebody at GEC changed the getter holder and didn't update the drawing.  I'd fire him...except he's probably dead.



We must have ordered these at about the same time, mine got here Thursday.  They both look the same though (can't see the getter in this photo but they are similar to each other).


----------



## CAJames

Interesting. I hadn't noticed (I was too busy listening) but mine are like that too. Same labels different getters, and mine are from Billington. They sound great regardless, I'm thinking I need to get some more before they go all 6C5G.


----------



## Velozity

chrisdrop said:


> Do you see how those Brimars have writing on the inside? What is that all about? The AnM 6J7s that I have look very similar as mentioned and also have writing on the inside. I haven't seen other tubes with that before. Is it a Brimar thing? Has anyone seen that on other valves?




Yeah, now that you mention it I do.  The one with the markings on the base has writing inside the tube on the glass base.  Looks like 17425 and a last character that looks like ^ but it's hard to make out exactly.  The other tube has no writing inside.


----------



## GDuss

Velozity said:


> Yeah, now that you mention it I do.  The one with the markings on the base has writing inside the tube on the glass base.  Looks like 17425 and a last character that looks like ^ but it's hard to make out exactly.  The other tube has no writing inside.



So one of yours has no writing on the base and no markings on the inside?  If so, that one is like both of mine.  The internal construction appears to be the same on all of them though, at least to my admittedly uneducated eyes.


----------



## bcowen

CAJames said:


> Interesting. I hadn't noticed (I was too busy listening) but mine are like that too. Same labels different getters, and mine are from Billington. They sound great regardless, I'm thinking I need to get some more before they go all 6C5G.



I have to hurry up and try mine and see if I want some more before the vultures like @JKDJedi catch on.  After that the 6C5G's will seem comparatively plentiful.      

What output tube(s) do you like with the L63's?


----------



## JKDJedi

bcowen said:


> I have to hurry up and try mine and see if I want some more before the vultures like @JKDJedi catch on.  After that the 6C5G's will seem comparatively plentiful.
> 
> What output tube(s) do you like with the L63's?


I'm not waiting!!!


----------



## CAJames

bcowen said:


> ....What output tube(s) do you like with the L63's?



They make every output tube I've tried sound its best. I've mostly been using 6BX7s, Either Tung-Sol or Raytheon, but they sound good with e.g RCA 6AS7s or Sylvania  JAN 6080s. I don't really have any designer label output tubes.

The better question is which rectifier, and the answer is a Nation Union JAN 5Z3. For me the rectifier sets the tone for the rest of the system.


----------



## whirlwind

JazzVinyl said:


> Does not matter where the info is located, imo.
> If your intention is to corner the market on popular tubes, they are probably surfing all tube oriented threads.
> 
> What we need to do is behave like John D Rockafellar, and issue a code word book, for his remote business buyers to use, in communicating with the home office.
> ...



Ha!


----------



## GDuss

CAJames said:


> They make every output tube I've tried sound its best. I've mostly been using 6BX7s, Either Tung-Sol or Raytheon, but they sound good with e.g RCA 6AS7s or Sylvania  JAN 6080s. I don't really have any designer label output tubes.
> 
> The better question is which rectifier, and the answer is a Nation Union JAN 5Z3. For me the rectifier sets the tone for the rest of the system.



I've only used the TS 6BX7's with the GEC L63 thus far, but will change out to some 6080's soon.  Maybe they will only work well with 6BX7's, which would really only be of much benefit to GOTL owners, and these tubes then wouldn't have mass appeal, and thus they wouldn't be of much value.  So people shouldn't really be that interested in buying them.  Or something like that.

So far they sound like skunk


----------



## JKDJedi

GDuss said:


> I've only used the TS 6BX7's with the GEC L63 thus far, but will change out to some 6080's soon.  Maybe they will only work well with 6BX7's, which would really only be of much benefit to GOTL owners, and these tubes then wouldn't have mass appeal, and thus they wouldn't be of much value.  So people shouldn't really be that interested in buying them.  Or something like that.
> 
> So far they sound like skunk


NoooOOOoooOOOo!!


----------



## CAJames

GDuss said:


> So far they sound like skunk



How do you like the meat


----------



## bcowen (Aug 22, 2020)

GDuss said:


> Hopefully the mysterious buyer of all these tubes wasn't BangyBang.  If it was, they will really be unobtanium



Newsflash:  It appears there are new qualifications to meet before you can pay BangyBang $670 for a $150 tube.  I'm a hoarder, not a collector so I don't meet that requirement.   And I thought a buyer was a buyer??  If I frown or give my laptop a stern look when I log on to PayPal, does that qualify as serious?  I have 516 positive feedbacks on Ebay, so I'm toast on the 10 requirement too. Crap.  Hopefully one of you guys can meet at least one of the requirements and take a hosing on this tube.    





https://www.ebay.com/itm/RARE-6080-...692158?hash=item2aef41c83e:g:GSAAAOSwA~5fN10K


----------



## CAJames

bcowen said:


> Newsflash:  It appears there are new qualifications to meet before you can pay BangyBang $670 for a $150 tube.  I'm a hoarder, not a collector so I don't meet that requirement.   And I thought a buyer was a buyer??  If I frown or give my laptop a stern look when I log on to PayPal, does that qualify as serious?  I have 516 positive feedbacks on Ebay, so I'm toast on the 10 requirement too. Crap.  Hopefully one of you guys can meet at least one of the requirements and take a hosing on this tube.
> 
> 
> 
> https://www.ebay.com/itm/RARE-6080-...692158?hash=item2aef41c83e:g:GSAAAOSwA~5fN10K



Two comments. First is maybe you missed the part in the listing where is says it was just reduced 33%, from $1000. So this is obviously a bargain. The other is it reminds me of a game my parents used to play with me: Are you sure you're ready to eat avocado, it's grownup food? Of course I was 8.


----------



## bcowen

CAJames said:


> Two comments. First is maybe you missed the part in the listing where is says it was just reduced 33%, from $1000. So this is obviously a bargain. The other is it reminds me of a game my parents used to play with me: Are you sure you're ready to eat avocado, it's grownup food? Of course I was 8.



LOL!  I failed to mention the free shipping too, so even _more_ of a bargain. Perhaps my love for BangyBang needs a rekindling.


----------



## GDuss

CAJames said:


> How do you like the meat



Well done!!!!


----------



## GDuss

bcowen said:


> LOL!  I failed to mention the free shipping too, so even _more_ of a bargain. Perhaps my love for BangyBang needs a rekindling.



Bangylove 😁. 

Folks, you can’t make this stuff up. Especially in a tube thread.


----------



## CAJames

GDuss said:


> Bangylove 😁.



Awesome! We should make t-shirts.


----------



## GDuss

CAJames said:


> Awesome! We should make t-shirts.



Silk screened!!!


----------



## bcowen

GDuss said:


> Silk screened!!!



Counterfeit silk screens!!


----------



## JKDJedi (Aug 22, 2020)

bcowen said:


> Newsflash:  It appears there are new qualifications to meet before you can pay BangyBang $670 for a $150 tube.  I'm a hoarder, not a collector so I don't meet that requirement.   And I thought a buyer was a buyer??  If I frown or give my laptop a stern look when I log on to PayPal, does that qualify as serious?  I have 516 positive feedbacks on Ebay, so I'm toast on the 10 requirement too. Crap.  Hopefully one of you guys can meet at least one of the requirements and take a hosing on this tube.
> 
> 
> 
> https://www.ebay.com/itm/RARE-6080-...692158?hash=item2aef41c83e:g:GSAAAOSwA~5fN10K


Lol.. I talked to him for a bit about that tube . Some guy dropped it off and mentioned it was the 6th tube manufactured with the letters "enginneer sample" printed on it. How many was made who knows? I have the 7th tube made. ( Lettering hardly legible on mine) The story sounds a little stretched but you wonder with that "engineer sample" on the tube


----------



## CAJames

bcowen said:


> Counterfeit silk screens!!



And we sell them for US$ 300, just reduced from US$ 400.


----------



## bcowen

CAJames said:


> And we sell them for US$ 300, just reduced from US$ 400.



Free shipping?


----------



## CAJames

bcowen said:


> Free shipping?



But of course!


----------



## bcowen

JKDJedi said:


> Lol.. I talked to him for a bit about that tube . Some guy dropped it off and mentioned it was the 6th tube manufactured with the letters "enginneer sample" printed on it. How many was made who knows? I have the 7th tube made. ( Lettering hardly legible on mine) The story sounds a little stretched but you wonder with that "engineer sample" on the tube



He also has this in the description:





I'm guessing there's a reason they didn't.  Like maybe they sucked?


----------



## CAJames

JKDJedi said:


> Lol.. I talked to him for a bit about that tube . Some guy dropped it off and mentioned it was the 6th tube manufactured with the letters "enginneer sample" printed on it. How many was made who knows? I have the 7th tube made. ( Lettering hardly legible on mine) The story sounds a little stretched but you wonder with that "engineer sample" on the tube



If you're saying this is possibly a highly collectible tube I guess I can't argue. Still pretty ridiculous IMO.


----------



## JKDJedi

CAJames said:


> If you're saying this is possibly a highly collectible tube I guess I can't argue. Still pretty ridiculous IMO.


the price yes... now if only a very few of these were made... then that's a horse of a different color..


----------



## CAJames

@chrisdrop is going to wake up and wonder what the !@&&# happened to his thread....


----------



## JKDJedi

CAJames said:


> @chrisdrop is going to wake up and wonder what the !@&&# happened to his thread....


🤣😂🤣 I'm rolling it with Pinnacle, Tung Sol, Sylvania, 6J5GT/G ... I swear!! And maybe with that GEC that sucks as well later on... Or hope it doesn't  ....you guys were joking.   Right? 😒


----------



## bcowen (Aug 22, 2020)

JKDJedi said:


> 🤣😂🤣 I'm rolling it with Pinnacle, Tung Sol, Sylvania, 6J5GT/G ... I swear!! And maybe with that GEC that sucks as well later on... Or hope it doesn't  ....you guys were joking.   Right? 😒



I listened...I ordered (another pair). So now that I have some backups coming, I'm pretty sure they were joking.


----------



## CAJames

JKDJedi said:


> 🤣😂🤣 I'm rolling it with Pinnacle, Tung Sol, Sylvania, 6J5GT/G ... I swear!! And maybe with that GEC that sucks as well later on... Or hope it doesn't  ....you guys were joking.   Right? 😒



Its the code. And apparently it is almost unbreakable.  

At least I think its the code...


----------



## JKDJedi

CAJames said:


> Its the code. And apparently it is almost unbreakable.
> 
> At least I think its the code...


All I know is that @bcowen said he's buying everyone here a set of the GECs.... 
#truelies 🙂


----------



## CAJames

Make mine a double (cuz I need a quad)!


----------



## bcowen

JKDJedi said:


> All I know is that @bcowen said he's buying everyone here a set of the GECs....
> #truelies 🙂



That was supposed to be a surprise, you jerk.  But with shipping at only $125/pair (I never said _free _shipping), it's still pretty nice of me.


----------



## JKDJedi (Aug 23, 2020)

I'm gonna refrain from further posts guys....just to be safe...😁 #ILoveYouMan...


----------



## bcowen

JKDJedi said:


> I'm gonna refrain from further posts guys....just to be safe...😁 #ILoveYouMan...



LOL!!  Yeah, you're going to be in the bathroom the rest of the night.


----------



## CAJames

JKDJedi said:


> I'm gonna refrain from further posts guys....just to be safe...😁 #ILoveYouMan...



Cheers to that!


----------



## JKDJedi




----------



## JKDJedi (Aug 23, 2020)

bcowen said:


> That was supposed to be a surprise, you jerk.  But with shipping at only $125/pair (I never said _free _shipping), it's still pretty nice of me.


💸


----------



## bcowen

JKDJedi said:


>




I'm finding this combination to be extremely fatiguing....it's making me stay up waaaaaay past my bedtime, not get enough sleep, and end up very tired the next day.    

I don't know who first put the spotlight on these L63's (so can't give the proper credit due), but a big thanks to whoever it was!!


----------



## CAJames

bcowen said:


> ....I don't know who first put the spotlight on these L63's (so can't give the proper credit due), but a big thanks to whoever it was!!



For completeness I have to blame @chrisdrop, yet again. They are brilliant tubes, and also the the bus we took frequently when we visited Minneapolis IIRC.


----------



## GDuss

bcowen said:


> I'm finding this combination to be extremely fatiguing....it's making me stay up waaaaaay past my bedtime, not get enough sleep, and end up very tired the next day.
> 
> I don't know who first put the spotlight on these L63's (so can't give the proper credit due), but a big thanks to whoever it was!!



What you mean to say is thanks to whomever made you spend money on these tubes (twice!!!) when they don't really sound that great.  And the only reason you ordered another pair is to try to get matching getters.  Because otherwise they are not that interesting.

Right?

Less than 80 of them left now.


----------



## chrisdrop

GDuss said:


> Less than 80 of them left now.


----------



## CAJames

GDuss said:


> What you mean to say is thanks to whomever made you spend money on these tubes (twice!!!) when they don't really sound that great.  And the only reason you ordered another pair is to try to get matching getters.  Because otherwise they are not that interesting.
> 
> Right?
> 
> Less than 80 of them left now.



Skunk Skunk Skunk.


----------



## bcowen (Aug 23, 2020)

GDuss said:


> What you mean to say is thanks to whomever made you spend money on these tubes (twice!!!) when they don't really sound that great.  And the only reason you ordered another pair is to try to get matching getters.  Because otherwise they are not that interesting.
> 
> Right?
> 
> Less than 80 of them left now.



Um, kinda sorta.   @JKDJedi was eavesdropping and already ordered his hoard, so what's left is probably somewhat marginally safe. And too, I'm pretty much getter-blind. Unless of course they're D getters. Big D-getters. And two of them, making for great, big huge Double D's.


----------



## bcowen

chrisdrop said:


>


----------



## CAJames

bcowen said:


> Um, kinda sorta.   @JKDJedi was eavesdropping and already ordered his hoard, so what's left is probably somewhat marginally safe. And too, I'm pretty much getter-blind. Unless of course they're D getters. Big D-getters. And two of them, making for great, big huge Double D's.



OMG, did I really just read that? LOL. 👿 I'm trying really hard not make a comment about rings and flashing...  I'll go put together an order for Martin instead...


----------



## GDuss

Sorry @chrisdrop .  I know you titled this thread "Reference" but I'm not sure that term still applies


----------



## bcowen

CAJames said:


> OMG, did I really just read that? LOL. 👿 I'm trying really hard not make a comment about rings and flashing...  I'll go put together an order for Martin instead...



LOL!  But I didn't write that. Somebody hijacked my user ID.  I much prefer round getters. Or more specifically _halo_ getters, as most everyone that doesn't know me thinks I'm angelic.  

More seriously, you've been hoarding sourcing from Billington, yes?  Just wondering what they're charging in case I want to add some more garbage to my collection.    Langrex is at 35/each (GBP)....


----------



## CAJames

Billington is 32 GBP if your order is at least 240 GBP, which is annoyingly easy for me to do. And Martin is truly a delight to deal with. This thread has been really hard on my Scottish Heritage.


----------



## CAJames

GDuss said:


> Sorry @chrisdrop .  I know you titled this thread "Reference" but I'm not sure that term still applies



Yep. Let the Americans in and they ruin everything!  🌭


----------



## chrisdrop

.. you guys have lost the plot 

After a full day of listening to a dual-triode, I needed to try some pre-sleep sound swap. First time using them without 6080s driving and ... these things rock. 

Good night:


----------



## bcowen

chrisdrop said:


> .. you guys have lost the plot
> 
> After a full day of listening to a dual-triode, I needed to try some pre-sleep sound swap. First time using them without 6080s driving and ... these things rock.
> 
> Good night:



Sweet!  If they sound as good as they look....

But wait. There was a plot?


----------



## GDuss

chrisdrop said:


> .. you guys have lost the plot
> 
> After a full day of listening to a dual-triode, I needed to try some pre-sleep sound swap. First time using them without 6080s driving and ... these things rock.
> 
> Good night:



OP getting us back on track!!!  Those tubes are still on my list, but too many things arrived recently that I need to try out first.  I get a little too excited with ordering, then they all show up at the same time and I don't know where to start.  Problems.


----------



## CAJames

It's funny with all this talk about L63s and 6C5Gs, I've been digging 6P5GTs since about page 19 of this thread and I have 76 tubes on deck.


----------



## GDuss

I'm doing the opposite of @chrisdrop this evening, I just went back to 6080's from a two-week run with 6BX7s.  So it's GEC L63's, AnM 6J7's (which may or may not actually be GEC's), and some NOS Mullard 6080's that came in this week.  I'm going all British and it sounds great!!!

Maybe this is a reaction to us Americans ruining this thread


----------



## wenbinbin2010

wenbinbin2010 said:


> I was going to hold off a few days before listening to my GEC L63s until I got used to these RCA 12J5GTs, but ended up putting them in today just to make sure there weren't any technical issues (or let's be honest, we're all terrible at delayed gratification). And.....they are the real deal. I will still have to make more comparisons with the other 12J5/6J5 tubes I have, but they are certainly very pleasing to listen to. Early impression, but they sound just as "natural" as the RCAs with a slight increase in detail and forwardness. EDIT: Maybe even a little too bass-heavy. Are they worth 5x more than the RCAs? Definitely diminishing returns, but it's nice to have a premium tube option as a comparison for all the cheaper ones.
> 
> All that being said, I just ordered another of the 1940s RCA 12J5GTs, along with some metal RCA 6J5/6C5s for comparison. I think I'll be set for now in exploring these types of tubes. Even though I said earlier that these 6J5/12J5 tubes seem to be the best, I know for certain some of my other tube types are still pretty good, with different qualities. I can see myself still rotating between tubes like my Amperex 7308s, WE396As, and 12**7 variants.



Finally got a chance to sit down and roll through some metal RCA 6J5s, 6C5s, and a new pair of 12J5GTs. All are dated from the 1940s. While the metal 6J5 and 6C5s sounded pretty good, I rolled the 12J5GTs last, and yep those are the winners for me. They just add another layer of depth and "realness" to every song, it gets me every time I put them back in. I really don't even feel like I need the GEC L63s, but I'll keep them around as a reference I suppose.


----------



## wenbinbin2010

Does anyone know much about these 12J5G tubes? I can't seem to find any background info, and I'm not sure if these are compatible, or if they're actually more like 1626 tubes? https://www.ebay.com/itm/12J5-G-162...944257?hash=item217088f3c1:g:ysIAAOSwhCle1rD4


----------



## GDuss

wenbinbin2010 said:


> Finally got a chance to sit down and roll through some metal RCA 6J5s, 6C5s, and a new pair of 12J5GTs. All are dated from the 1940s. While the metal 6J5 and 6C5s sounded pretty good, I rolled the 12J5GTs last, and yep those are the winners for me. They just add another layer of depth and "realness" to every song, it gets me every time I put them back in. I really don't even feel like I need the GEC L63s, but I'll keep them around as a reference I suppose.



Totally agree about the 1940's RCA's and your assessment that they are all excellent (I upped your pretty good rating a bit because I like these a lot), with the 12J5GT's adding more of what I like about these tubes.


----------



## wenbinbin2010

GDuss said:


> Totally agree about the 1940's RCA's and your assessment that they are all excellent (I upped your pretty good rating a bit because I like these a lot), with the 12J5GT's adding more of what I like about these tubes.



Did you buy the last pair of the RCA 12J5GTs for Bendix on eBay? I was going to add them to my cart and then it was sold out! There's still a good number of the same type of tubes for Western Electric available. I have pairs of both, and they sound identically excellent.


----------



## GDuss

wenbinbin2010 said:


> Did you buy the last pair of the RCA 12J5GTs for Bendix on eBay? I was going to add them to my cart and then it was sold out! There's still a good number of the same type of tubes for Western Electric available. I have pairs of both, and they sound identically excellent.



No, did they disappear?  Have you read the last few pages of this thread?  Tubes we talk about are disappearing mysteriously.  The biggest one was the large numbers of Brimar 6C5G's from Langrex that were gone after we talked about them a few weeks ago (I only ordered 1 pair of those, they had more than 50 of them).  We really need to make some code words.

Stan from ESRC had a lot of those Western RCA's.  @JazzVinyl got some of them.  Unfortunately Stan died recently and now the status of his inventory is unclear.  His websites are gone.  Maybe they will show up for sale at some point.


----------



## chrisdrop

Well folks, I've gone n done it. I've killed some nice tubes.

RIP






... Goodbye new friends ...

Quite the shame really. I was enjoying these things. One of them was making some occasional noise. Gave it a bit of a tap-tap-tap and it seemed to quiet down. I swapped tubes and when I put them back a few days later, no tap-tap-tapping would really silence the tube. When I took them out, I noticed that one tube had a bit of a rattle when I moved it around. It sounded like a loose part inside. I think that was the noisy tube. 

I decided to heat the pins a bit with a soldering iron. I grabbed the soldering iron and gave each of the pins ~10-15 sec of heat with a tiny dab of solder at the bottom of the pin. All seemed to go as usual and I put them back in the queue for use. 

Today I popped them in after returning from work. Within a few seconds, one of the tubes had a faint white flash and stopped glowing  It wasn't even the tube with the shakey bit on the inside! Quite the shame really. It is plausible that they are 1938 valves within a few months of the very first tubes of this type! I am of course very glad this happened before plugging my headphones in. Old tubes - can't live with 'em, can't live without 'em.

Now, I got the pair for £50, knowing they weren't NOS, etc, but willing to chance it. No regrets really, you have to give things like that a go!

Perhaps this weekend I'll tear them down and see what is inside, thus, trying to learn something for my cack-handed tube destructive crime! 

... thankfully, I've got more tubes!


----------



## GDuss

chrisdrop said:


> Well folks, I've gone n done it. I've killed some nice tubes.
> 
> RIP
> 
> ...



Seems as though it's a dangerous time to be a tube right now:

https://www.head-fi.org/threads/for-6as7g-tube-rollers-here.410326/post-15820389


----------



## Monsterzero

chrisdrop said:


> Well folks, I've gone n done it. I've killed some nice tubes.
> 
> RIP
> 
> ...


Ouch! That sucks.


----------



## JazzVinyl

GDuss said:


> Stan from ESRC had a lot of those Western RCA's.  @JazzVinyl got some of them.  Unfortunately Stan died recently and now the status of his inventory is unclear.  His websites are gone.  Maybe they will show up for sale at some point.



He had a LOT of them, and they were all BNIB...would be shame if they do not find their way back on the market.


----------



## JazzVinyl

chrisdrop said:


> Today I popped them in after returning from work. Within a few seconds, one of the tubes had a faint white flash and stopped glowing  It wasn't even the tube with the shakey bit on the inside! Quite the shame really. It is plausible that they are 1938 valves within a few months of the very first tubes of this type! I am of course very glad this happened before plugging my headphones in. Old tubes - can't live with 'em, can't live without 'em.
> 
> Now, I got the pair for £50, knowing they weren't NOS, etc, but willing to chance it. No regrets really, you have to give things like that a go!
> 
> ...



Sorry Chris!!

I have been pitching some 'hopelessly noisy" 6SN7's lately.  Hate to them go...but...


----------



## CAJames

chrisdrop said:


> Well folks, I've gone n done it. I've killed some nice tubes.
> 
> RIP
> 
> ...



Sorry for your loss. It would be very interesting to crack one open though, silver linings and all.


----------



## bcowen

chrisdrop said:


> Well folks, I've gone n done it. I've killed some nice tubes.
> 
> RIP
> 
> ...



Supreme bummer.       Things like this only lead to more people testing positive for Stashid-19.  

Ugh, sorry.  I'll quit.


----------



## chrisdrop

chrisdrop said:


> Well folks, I've gone n done it. I've killed some nice tubes.
> 
> RIP
> 
> ...



Here are some autopsy photos of the victim. I had to hit it pretty hard with a hammer 2x before the glass broke. It was more rugged than I guessed. A sad passing, but - we must move on.


----------



## GDuss

chrisdrop said:


> Here are some autopsy photos of the victim. I had to hit it pretty hard with a hammer 2x before the glass broke. It was more rugged than I guessed. A sad passing, but - we must move on.



Excellent work, in the name of science!!!


----------



## chrisdrop

GDuss said:


> Excellent work, in the name of science!!!


Now that we can see the getter, what kind it is? Does that do anything to refute/corroborate my age guesses? By the way, this is the only getter types link I could find. It is not comprehensive. Any other refs warmly welcomed!


----------



## chrisdrop

At some point this weekend, I'll give these a go. The boxes look like they've been sealed since they were tax stamped. I've been keen to take a peek at them since the package arrived. 

Doing a bit of reading here, it seems the tax labels are exemptions applied to tubes made for the military.

"A.M." I believe is the "Aeronautica Militare" (the Italian air force).

FWIW - I did get 4 of them in the end (cheaper per tube), so if anyone is keen for 2, feel free to PM me. Happy to pass on at cost to any other Fivre-fans.


----------



## whirlwind

chrisdrop said:


> Here are some autopsy photos of the victim. I had to hit it pretty hard with a hammer 2x before the glass broke. It was more rugged than I guessed. A sad passing, but - we must move on.



Nice pics....thanks for the autopsy.
Sorry for your loss.


----------



## bcowen

chrisdrop said:


> Here are some autopsy photos of the victim. I had to hit it pretty hard with a hammer 2x before the glass broke. It was more rugged than I guessed. A sad passing, but - we must move on.



It's all bent up on the inside.  No wonder it failed.


----------



## GDuss

whirlwind said:


> Nice pics....thanks for the autopsy.
> Sorry for your loss.



It didn't take him long to move on, he already has replacements .


----------



## GDuss

bcowen said:


> It's all bent up on the inside.  No wonder it failed.



That's the real reason why they smoke the glass.  To hide the defects on the inside!!!  Great way to salvage B-stock tubes.


----------



## bcowen

GDuss said:


> That's the real reason why they smoke the glass.  To hide the defects on the inside!!!  Great way to salvage B-stock tubes.



ROFL!  Those dastardly deeders.


----------



## CAJames

chrisdrop said:


> At some point this weekend, I'll give these a go. The boxes look like they've been sealed since they were tax stamped. I've been keen to take a peek at them since the package arrived.
> 
> Doing a bit of reading here, it seems the tax labels are exemptions applied to tubes made for the military.
> 
> ...



Fivres always look like they should be full of spumante, not cathodes and anodes.


----------



## GDuss

CAJames said:


> Fivres always look like they should be full of spumante, not cathodes and anodes.



They’re usually priced like Brunello.


----------



## CAJames

GDuss said:


> They’re usually priced like Brunello.



Cheers to that!


----------



## bcowen

GDuss said:


> They’re usually priced like Brunello.



   Or a Ferrari, which was the only other good thing to come from Italy.


----------



## CAJames

I'd also love to hear how each of us pronounces "Fivre."


----------



## bcowen

CAJames said:


> I'd also love to hear how each of us pronounces "Fivre."



"Expensive."  




Or "feev - reh" too.


----------



## CAJames (Aug 29, 2020)

I'd go with "feev-ray", but I'll admit in my head I think "fiver." Which may be off  by a couple orders of magnitude.


----------



## bcowen

CAJames said:


> I'd go with "feev-ray", but I'll admit in my head I think "fiver." Which may be off  by a couple orders of magnitude.



I cheated.  

https://forvo.com/languages/it/


----------



## chrisdrop (Aug 29, 2020)

I haven't gotten to the Fivres yet (correct pronunciation TBD. Video submissions welcome!).  I guess I'd pronounce Fivre like I'd say either of these:




I killed those other 6J5Gs last week and managed to get these L63s to replace 'em. It was an arbitrary criteria, but I wanted those vertical clear bits in the grey glass. They are quite similar in sound to the other ones that I killed. The sound is a little thumpier in the lower end than my "usually compared to" GEC 6J5Gs. They are controlled and solid all around. They are silent and look great. I have no logic for why they sound different than the other ones mentioned...

Date-wise - the markings are CE 2 and CG 2. I'm not sure what the "2" is. Factory code? I imagine the E and G are May and July. The "C", is probably 1947 (ref'ing @leftside logic)?









Listening to and very much enjoying:


----------



## GDuss

bcowen said:


> Or a Ferrari, which was the only other good thing to come from Italy.



Too harsh   . They invented espresso, which depending on how you look at it, is either the reason I ever get anything done or the reason I have less money to spend on tubes. Probably both.


----------



## chrisdrop (Aug 29, 2020)

GDuss said:


> Too harsh   . They invented espresso, which depending on how you look at it, is either the reason I ever get anything done or the reason I have less money to spend on tubes. Probably both.


Plus, if you haven't been - GO (post insanity). Amazingly beautiful. For years we said "we'll go somewhere else this summer". Guess where we wound up; Italy.  Not so bad! The Fivre tubes came from very near to where this pic was taken actually, in Sardinia. I had a small chat with the seller. He lives somewhere not too bad!


----------



## GDuss

chrisdrop said:


> I haven't gotten to the Fivres yet (correct pronunciation TBD. Video submissions welcome!).  I guess I'd pronounce Fivre like I'd say either of these:
> 
> 
> 
> ...




So there are straight glass L63's and bottle-shaped L63's, and apparently no difference in the naming based on the shape (like 6J5GT vs 6J5G).  Or is there?


----------



## leftside (Aug 29, 2020)

chrisdrop said:


> I haven't gotten to the Fivres yet (correct pronunciation TBD. Video submissions welcome!).  I guess I'd pronounce Fivre like I'd say either of these:
> 
> Date-wise - the markings are CE 2 and CG 2. I'm not sure what the "2" is. Factory code? I imagine the E and G are May and July. The "C", is probably 1948 (ref'ing @leftside logic)?


Not my logic  It's just the way it is...
https://dalmura.com.au/static/MOV GEC date coding.pdf

Now if someone can figure out the date codes on GEC tubes prior to 1945 I'd very much appreciate it. I have quite a few grey glass/black base coke bottle GEC KT66's. Everyone I've spoken to say they were made sometime between 1939 and 1945, but good luck guessing the actual date. It's like some form of wartime cryptic secret code.


----------



## CAJames

For the weekend I rolled in some (cheap, used, mis-matched) metal based 6J5GTs. A couple GE (not clear if GE actually made them) , one looks like rebranded Sylvania and the other might be rebranded RCA.





I'm amazed how good they sound. Better, probably much better, than my "pretty good" 6SN7s or 7N7s.


----------



## leftside

CAJames said:


> For the weekend I rolled in some (cheap, used, mis-matched) metal based 6J5GTs. A couple GE (not clear if GE actually made them) , one looks like rebranded Sylvania and the other might be rebranded RCA.
> 
> 
> 
> I'm amazed how good they sound. Better, probably much better, than my "pretty good" 6SN7s or 7N7s.


I think those early metal base 6J5's are the best bang for the buck glass tubes around. No matter the brand. Also liked them in my WA22 as well.


----------



## bcowen

leftside said:


> I think those early metal base 6J5's are the best bang for the buck glass tubes around. No matter the brand. Also liked them in my WA22 as well.



I sure like these. Round plate versus the flat plate version @CAJames is sporting. Not sure how they compare, as I don't have any flat plates. But as of now, they're my second favorite to the GEC L63's.





These are my favorite cheapies.  Russian, but not sure what factory they came out of. They have that Russian bass-groove thing going on, making them a quite enjoyable with metal and hard rock:


----------



## CAJames

bcowen said:


> I sure like these. Round plate versus the flat plate version @CAJames is sporting. Not sure how they compare, as I don't have any flat plates. But as of now, they're my second favorite to the GEC L63's.
> 
> 
> 
> These are my favorite cheapies.  Russian, but not sure what factory they came out of. They have that Russian bass-groove thing going on, making them a quite enjoyable with metal and hard rock:



Can't go wrong with Tung Sol IMO. Not so sure about Russian, but I've seen the Pinnacles around and might pick them anyway if price is right. My Scottish Heritage is seriously questioning why I just spent long green on L63s when I got the 6J5GTs basically out of a dumpster. I just went and bought some more on ebay.


----------



## bcowen

CAJames said:


> Can't go wrong with Tung Sol IMO. Not so sure about Russian, but I've seen the Pinnacles around and might pick them anyway if price is right. My Scottish Heritage is seriously questioning why I just spent long green on L63s when I got the 6J5GTs basically out of a dumpster. I just went and bought some more on ebay.



I've seen 3 different versions of these Pinnacle-labeled 6J5's, and all with different internal construction.  The ones I have look pretty much identical to a Russian 6C2C (or 6S2S, depending on your preference of alphabet). Then there's a shiny metal base version and another that appears to be a painted metal base.  The Russkies are cheap, and the ads for the metal base ones are pretty sparse with the tubes being, well, _not _cheap comparatively. I've only heard the cheap ones and haven't ventured into the metal base versions...at least yet.  

These are Novosibirsk, but there are no markings on my Pinnacles to know for sure if they came from there.




Big O getters on these:




Can't see the getter shape on this one:


----------



## leftside (Sep 2, 2020)

Don't get involved in bidding wars. Lamberto from Spain had the same tubes (with boxes) listed very recently for $150:
https://www.ebay.co.uk/itm/2-x-L63-Osram-Valves-Tubes-Metal-Skirt-NOS-Tested-/164354392397

Use Auction Sniper. Later tubes by 10 years with different getters and different labels, but are the ones from above worth double?
https://www.ebay.co.uk/itm/2-x-L63-GEC-Valves-Tubes-Black-Plate-Brass-Skirt-NOS-Tested-/164354369402


----------



## leftside

Same tubes as the Osram, but with black base instead of metal. Same year and getters:
https://www.ebay.co.uk/itm/3-x-MWT-...es-Tubes-All-Tested-Super-Strong/184417709000


----------



## CAJames (Sep 3, 2020)

YAOT (Yet Another Obscure Tube), I give you the Type 76






I had a plan to make my own 76 -> 6J5 adapters but it was a complete bust. The sockets I bought were too deep to fit in the octal base so I punted the whole project and got adapters from ebay, which realistically I should have done in the first place.

As for the tubes, they are fine. Softer than the 6J5 variants, both tonally and gainwise. They have by far the least gain of any tube I've tried. If this was the first single triode I heard I would be pretty excited about the sound relative to the dual triodes I'd been using. But as much as I want to like them, for the looks if nothing else, I just don't find them competitive with others, e.g. 6J5GTs or L63s or even the metal Tung Sol 6C5s. FWIW I tried them with a Type 83 rectifier, to keep it period correct, but it didn't help.


----------



## Xcalibur255

If I can stop being so wishywashy about the details of what I want, it seems I may be in need of some 6J5 tubes in the future.  Maybe it's my imagination but it seems like there is a lot less to choose from compared to when talk of this first sprang up in the Glenn thread a couple of years ago.  I remember doing a quick eBay search and thinking it was like going to the supermarket...... you could find a nice example of just about every brand and plate style you wanted to try.

Today another look shows somewhat slimmer pickings, but I'm sure the right things will come along in due time.  Ideally I would like to get my hands on at least once nice pair of the ST glass style L63 so I have reference tube.  I suppose it wasn't going to be as easy as just placing an order at Langrex, though I suppose the straight glass version they still have in stock would be a find substitute for a while.

Any general impressions/guidelines on sound differences between the different glass and plate styles would be very much appreciated!  I should have been paying attention more closely to posts in the Glenn thread, but when one doesn't intend to go buy the tubes themselves after reading the info tends to not stick.  Or I'm just getting old......... (actually both can be true).


----------



## whirlwind (Sep 3, 2020)

Xcalibur255 said:


> If I can stop being so wishywashy about the details of what I want, it seems I may be in need of some 6J5 tubes in the future.  Maybe it's my imagination but it seems like there is a lot less to choose from compared to when talk of this first sprang up in the Glenn thread a couple of years ago.  I remember doing a quick eBay search and thinking it was like going to the supermarket...... you could find a nice example of just about every brand and plate style you wanted to try.
> 
> Today another look shows somewhat slimmer pickings, but I'm sure the right things will come along in due time.  Ideally I would like to get my hands on at least once nice pair of the ST glass style L63 so I have reference tube.  I suppose it wasn't going to be as easy as just placing an order at Langrex, though I suppose the straight glass version they still have in stock would be a find substitute for a while.
> 
> Any general impressions/guidelines on sound differences between the different glass and plate styles would be very much appreciated!  I should have been paying attention more closely to posts in the Glenn thread, but when one doesn't intend to go buy the tubes themselves after reading the info tends to not stick.  Or I'm just getting old......... (actually both can be true).



For what it is worth...I pretty much agree with @leftside  that the 6J5 metal base tubes are the best bang for the buck...they all sound great to my ears and especially at the price point.

There may be a tad better sound with the GEC shoulder type tubes...but the price is nearly 10 fold in some cases   

Even some 12J5 sound pretty darn good! There are no metal base 12J5 tubes that I have found.


----------



## JazzVinyl

whirlwind said:


> For what it is worth...I pretty much agree with @leftside  that the 6J5 metal plate tubes are the best bang for the buck...they all sound great to my ears and especially at the price point.
> 
> There may be a tad better sound with the GEC shoulder type tubes...but the price is nearly 10 fold in some cases
> 
> Even some 12J5 sound pretty darn good! There are no metal plate 12J5 tubes that I have found.



Joe when you say "metal plate" - you mean "metal envelope"?


----------



## whirlwind

JazzVinyl said:


> Joe when you say "metal plate" - you mean "metal envelope"?





JazzVinyl said:


> Joe when you say "metal plate" - you mean "metal envelope"?



Yes sir I do...thanks much for that catch!      
I have edited my post to say metal base tubes.


----------



## CAJames (Sep 3, 2020)

Another vote for the metal base 6J5GT. The best input tubes I own are the straight bottle GEC L63, but my used, cheap, mis-matched 6J5GTs get me 98, maybe 99% of the way there at a fraction of the cost. They only miss out on the final measure of high end sparkle and imaging compared to the GECs.

But, speaking of the metal envelope, the all metal 6[J|C]5 sound great and are cheap as [dirt|chips] as well. They might not be as sexy as the glass bottles but I could happily live with my Tung Sol 6C5 forever and they were only a few [bucks|quid] each.


----------



## leftside (Sep 3, 2020)

CAJames said:


> YAOT (Yet Another Obscure Tube), I give you the Type 76
> 
> 
> 
> ...


I thought exactly the same in the WA22. Really like them in my 1101 amp though - especially Fivre and Mazda. Give the amp a little extra airiness, with a slight loss of bass which is fine by me with certain moods/music.


----------



## JazzVinyl

CAJames said:


> Another vote for the metal base 6J5GT. The best input tubes I own are the straight bottle GEC L63, but my used, cheap, mis-matched 6J5GTs get me 98, maybe 99% of the way there at a fraction of the cost. They only miss out on the final measure of high end sparkle and imaging compared to the GECs.
> 
> But, speaking of the metal envelope, the all metal 6[J|C]5 sound great and are cheap as [dirt|chips] as well. They might not be as sexy as the glass bottles but I could happily live with my Tung Sol 6C5 forever and they were only a few [bucks|quid] each.



Big fan of the metal envelope 6C5 tubes, as well.  Cheap, and sound really really nice!!


----------



## Xcalibur255

Unfortunately using the 6C5 and a couple of the other variations won't be an option for me really because of their lower gain.  It would have too much of an impact on output power in the amp these will be going into, so I need to keep the driver stage gain at 20.


----------



## GDuss

I figured that people were getting tired of me saying how much I liked the metal RCA 6C5/6J5 tubes (with meatballs of course).  So I gave it up.  They're still great though.

Lately I've been listening to a tube that I can't discuss on this thread because it's not in the title   . A Visseaux 6N7GT from 1952. @JazzVinyl tried to get me to buy one for like 6 months and I finally listened to him. Excellent tube. I didn't think I could enjoy single driver tubes anymore, but this is changing my mind.


----------



## Xcalibur255

I'm listening.  

In the metal base G tubes I've noticed there are grey and black plate variations for some of the round plate tubes.  Do you guys feel there is a meaningful sonic difference there, or is a round plate a round plate when it comes to these tubes?


----------



## chrisdrop (Sep 4, 2020)

My 2p; For 6J5*s (_YMMV, and all other acronym based caveats/disclaimers appear here_)

_Good Economy class_; KenRad 6J5 or RCA 6J5 (only the older ones with the "beachball logo", the more modern RCA logo ones I have, I dislike). Cheap as chips. I think I am the odd man out on these - I have a slew, but don't really prefer any of them. Amazing value, however, and I'd prefer pairs of these to many 6SN7 tubes still. I tried hard/wanted very much for the metal case tubes to be my favourites!
_Premium Economy _(aka "Bang for buck award"): Sylvania metal base 6J5GTs. I've not found material differences between plate/getter types for these tubes. I'll check my Sylvania 12J5GTs, which I like a touch than the 6s to see if there are plate/getter differences. 
_Business Class;_ GEC Brown-base L63 straight glass (not as expensive as first-class, but very solid performers at some premium). I think mine are 1960s FWIW and still very nice.
_First Class;_ (aka "Reference") M-OV/GEC  (coke bottle types) L63/6J5G. Expensive. Perhaps my biases, but the grey-glass, older variants - I prefer them. Hard to see the getter/plate types/ dates for older versions of these tubes due to the grey glass.
I dislike that I sort of like them in "price order". It does make me feel like there is some bias involved, but I can't hear my way out of it. As others have said, the differences get smaller as you go "up".

_EDIT: My 12J5GTs (like a touch less) have black bases & light-coloured plates. The 6J5Gs (which I prefer) have black plates and metal bases. I can't see the getters in photos I have to-hand. Of course, I don't' know if these are meaningful to the sound or if it is nothing/something else!_


----------



## CAJames (Sep 4, 2020)

chrisdrop said:


> ...I dislike that I sort of like them in "price order". It does make me feel like there is some bias involved, but I can't hear my way out of it. As others have said, the differences get smaller as you go "up".



I hear you. But, I think it is fair to say I/we have spent a lot more tubes we like less than our economy choices, so it isn't _all _about the money. My list would be very similair.

Tung Sol 6C5

Sylvania(ish) 6J5GT metal base

GEC BBSG L63.

(Someday I hope to be allowed into first class, but it hasn't happened yet.)

I really hoped to like the 6P5 types more, but it is what it is.


----------



## GDuss

CAJames said:


> I hear you. But, I think it is fair to say I/we have spent a lot more tubes we like less than our economy choices, so it isn't _all _about the money. My list would be very similair.
> 
> Tung Sol 6C5
> 
> ...



Always a tricky discussion when factoring in price (and also looks) to how much you enjoy something.  But enjoyment of music is subjective right?  Do I enjoy my purple ZMF 2K cable more because it's purple?  Probably.  But I'm ok with it.  I also think the lighting at concerts enhances the experience (remember in-person concerts?) even though the lights have no influence on the sound.  I don't fault the user for getting more enjoyment out of something that costs more or looks great.  They are getting more enjoyment which is what they are after.  The seller of overpriced gear for no reason is another discussion.  Maybe they are just enhancing the users' experience by charging more, but that's the tricky part.

Back to the tubes, I must have gotten unlucky on the Tung Sol metal tubes I have.  The Tung Sol 6J5GT and 12J5GT are great tubes, but the metal Tung Sol 6J5's I have are nowhere near them.  I haven't had good luck with the metal GE 6J5 tubes either.  Maybe I just like metal RCA's too much.


----------



## Xcalibur255

I nabbed a pair of Sylvania metal base GT with round plates last night.  Intended to stop there but I also spotted some ladder plate Ken-Rads that were labeled Firestone Air Boss and I couldn't resist because that is a pretty cool thing to have stamped on the base of your tubes!  

That seemed like a good place to start since they're inexpensive.  For L63 and any of the older G tubes I'll probably wait unless the perfect pair happens to come along.


----------



## CAJames

GDuss said:


> Always a tricky discussion when factoring in price (and also looks) ...



Yes, I was thinking about the looks aspect as well. A whole different kind of bias...


----------



## bcowen (Sep 4, 2020)

chrisdrop said:


> _Business Class;_ GEC Brown-base L63 straight glass (not as expensive as first-class, but very solid performers at some premium). I think mine are 1960s FWIW and still very nice.



I received my 2nd pair of these today from Langrex, and just like the first order one has an O-getter and the other a D-getter. So now I have a pair of O-getters and a pair of D-getters. 

Interestingly, both O-getters measure at 2900 GM and both D-getters at 2500. So I now have not only 2 pairs with matching getters, but 2 pairs with nicely matching output. All by accident. I think. I definitely _*feel*_ more balanced to boot.


----------



## GDuss

bcowen said:


> I received my 2nd pair of these today from Langrex, and just like the first order one has an O-getter and the other a D-getter. So now I have a pair of O-getters and a pair of D-getters.
> 
> Interestingly, both O-getters measure at 2900 GM and both D-getters at 2500. So I now have not only 2 pairs with matching getters, but 2 pairs with nicely matching output. All by accident. I think. I definitely _*feel*_ more balanced to boot.



Nice work.  And you only had to pay double to get matching tubes  . Now you can begin the painstaking work of determining whether your matched pair of O-getters sounds different from your matched pair of D-getters. But it's a holiday weekend, so you have some extra time right?


----------



## bcowen

GDuss said:


> Nice work.  And you only had to pay double to get matching tubes  . Now you can begin the painstaking work of determining whether your matched pair of O-getters sounds different from your matched pair of D-getters. But it's a holiday weekend, so you have some extra time right?



LOL!  Yeah, I had to pay double, but I also got a pair for free.     I'm guessing the O-getters are later production, so if there is a meaningful difference the D-getters will sound better.  That's my usual scientific approach anyway, and I strive for consistency.


----------



## GDuss

bcowen said:


> LOL!  Yeah, I had to pay double, but I also got a pair for free.   I'm guessing the O-getters are later production, so if there is a meaningful difference the D-getters will sound better. That's my usual scientific approach anyway, and I strive for consistency.



The "older is better" concept is yet another one of those biases but in that specific case I've actually done the blind testing several times, because I didn't know which was older at the time I decided which was better (I'm a novice tube identifier).


----------



## bcowen

GDuss said:


> The "older is better" concept is yet another one of those biases but in that specific case I've actually done the blind testing several times, because I didn't know which was older at the time I decided which was better (I'm a novice tube identifier).



It's not so much bias as it is identifying with. When you're old (like me), older is always better.


----------



## Velozity

chrisdrop said:


> My 2p; For 6J5*s (_YMMV, and all other acronym based caveats/disclaimers appear here_)
> 
> _Good Economy class_; KenRad 6J5 or RCA 6J5 (only the older ones with the "beachball logo", the more modern RCA logo ones I have, I dislike). Cheap as chips. I think I am the odd man out on these - I have a slew, but don't really prefer any of them. Amazing value, however, and I'd prefer pairs of these to many 6SN7 tubes still. I tried hard/wanted very much for the metal case tubes to be my favourites!
> _Premium Economy _(aka "Bang for buck award"): Sylvania metal base 6J5GTs. I've not found material differences between plate/getter types for these tubes. I'll check my Sylvania 12J5GTs, which I like a touch than the 6s to see if there are plate/getter differences.
> ...




I'm curious to know where the Mullard 6J5G sits on your plane??  It's in Business Class on mine (joining the L63 straight glass), but YAMV (your airline may vary).  Quite surprisingly, the Brimar 6C5G bought out the whole First Class section so the GEC 6J5G gray glass hasn't even taken a flight yet.  It's hard to get the Brimars out of their seats!


----------



## GDuss

Velozity said:


> I'm curious to know where the Mullard 6J5G sits on your plane??  It's in Business Class on mine (joining the L63 straight glass), but YAMV (your airline may vary).  Quite surprisingly, the Brimar 6C5G bought out the whole First Class section so the GEC 6J5G gray glass hasn't even taken a flight yet.  It's hard to get the Brimars out of their seats!



I'm not sure how I feel about my tubes with respect to where they go in class rankings.  I can put them in classes based on how much they cost, but it doesn't match the value I put on them.  Like yeah, the GEC L63's are very nice, and demand business class pricing, but are you ever sitting in business class wondering why you paid for business class?  Should have used miles to upgrade.  It's nice to be up there occasionally, but I'm actually happy in economy with the RCA metal 6J5's.  Maybe I've just gotten lucky with the cheap economy seats I've chosen.  In fact, they are so cheap they may not even be flying.  They're on the bus.  Workingman's tubes!!!  

Or maybe I don't mind being in economy because the plane is so nice.  Makes all the seats comfortable.

I've been running the Brimar 6C5G's the last few nights as well.  I like them.  If they're in first class, they snuck up there.  And nobody has noticed yet.


----------



## Velozity

GDuss said:


> Or maybe I don't mind being in economy because the plane is so nice.  Makes all the seats comfortable.




Spoken like a true GOTL owner.  This is truth!


----------



## Velozity

In case any of you guys are interested I posted Sylvania VT-94D and GEC L63 straight-glass for sale in the classifieds.


----------



## chrisdrop

Thanks to @Deyan 

First time with some KenRad 6J5s at the office today.






I think even these humble metal guys nicely outpace the Brimar 12au7 I was using before.

The date code is C5 which I will guess is march 1945?

Anyhow - now I can bring more or these tubes to use at work too. As the tubes accumulate my coworker puzzlement will increase.


----------



## CAJames (Sep 11, 2020)

That's funny, even though we work mostly remote now a couple of my coworkers have tube powered desktop systems.Although it is safe to say that aren't really "into" tubes.


----------



## JKDJedi

Anybody here jump on the 7a4? 

 7A4 - loctal 6J5 (1/2 of a 6SN7GT)


----------



## JKDJedi

chrisdrop said:


> At some point this weekend, I'll give these a go. The boxes look like they've been sealed since they were tax stamped. I've been keen to take a peek at them since the package arrived.
> 
> Doing a bit of reading here, it seems the tax labels are exemptions applied to tubes made for the military.
> 
> ...


Something tells me these are not your ordinary 6j5 type tubes. ... (If you have to ask ....) 💸


----------



## bcowen

JKDJedi said:


> Anybody here jump on the 7a4?
> 
> 7A4 - loctal 6J5 (1/2 of a 6SN7GT)



@Paladin79 has.  I have a couple, but since I only have a Chinese adapter and lack a proper one from @Deyan I figured they were compromised from the start.


----------



## JKDJedi

bcowen said:


> @Paladin79 has.  I have a couple, but since I only have a Chinese adapter and lack a proper one from @Deyan I figured they were compromised from the start.


Imagaine asking Deyan,... could you make me a 8 pin loctal to 6j5 adapter, and I'll need two of them. o.O ;D


----------



## GDuss

Flight status update:  the Brimar 6C5G's still haven't been kicked out of first class. They are doing such a great job of entertaining the rest of the passengers (and flight attendants) they may get to stay for the remainder of the flight.

Seriously though, these tubes continue to impress.  Too bad Langrex sold their remaining stock of 50+ of them (seemingly overnight).


----------



## CAJames

GDuss said:


> Flight status update:  the Brimar 6C5G's still haven't been kicked out of first class. They are doing such a great job of entertaining the rest of the passengers (and flight attendants) they may get to stay for the remainder of the flight.
> 
> Seriously though, these tubes continue to impress.  Too bad Langrex sold their remaining stock of 50+ of them (seemingly overnight).



I'm still having a great time in economy+ with the Sylvania 6J5GTs. Maybe only a coincidence that I saved enough money to buy a whole mess of drinks...


----------



## CAJames

JKDJedi said:


> Anybody here jump on the 7a4?
> 
> 7A4 - loctal 6J5 (1/2 of a 6SN7GT)



The 7N7  (aka loctal 6SN7) was my daily driver until I was seduced by the Siren Song of the Single Triode (SSST). But a 7A4 seems like an adapter too far for me.


----------



## Deyan

JKDJedi said:


> Imagaine asking Deyan,... could you make me a 8 pin loctal to 6j5 adapter, and I'll need two of them. o.O ;D



I've already got the parts


----------



## JKDJedi

CAJames said:


> I'm still having a great time in economy+ with the Sylvania 6J5GTs. Maybe only a coincidence that I saved enough money to buy a whole mess of drinks...


Those are phenomenal, love mine. Have yet to listen to the GEC version, lost in da mail, seems to be the pattern here, but when they do I'm sure I'll have a tough time figuring out which ones I'd prefer....and that's a good thing. 😁


----------



## JKDJedi

Deyan said:


> I've already got the parts


Deyan!!! Lol... I'm tempted too... Not sure it's worth the 7a4s .


----------



## Deyan

JKDJedi said:


> Deyan!!! Lol... I'm tempted too... Not sure it's worth the 7a4s .



Me and my big mouth


----------



## CAJames

JKDJedi said:


> Those are phenomenal, love mine. Have yet to listen to the GEC version, lost in da mail, seems to be the pattern here, but when they do I'm sure I'll have a tough time figuring out which ones I'd prefer....and that's a good thing. 😁



For me the GEC L63s are clearly better, but the difference isn’t very big.


----------



## JKDJedi

Deyan said:


> Me and my big mouth


Your Love is King around here. Thanks for the excellent job with the adapters. 👍


----------



## bcowen

GDuss said:


> Flight status update:  the Brimar 6C5G's still haven't been kicked out of first class. They are doing such a great job of entertaining the rest of the passengers (and flight attendants) they may get to stay for the remainder of the flight.



I hope they're wearing masks.  Can't be too careful.


----------



## bcowen

CAJames said:


> I'm still having a great time in economy+ with the Sylvania 6J5GTs. Maybe only a coincidence that I saved enough money to buy a whole mess of drinks...



I've rolled quite a few different tubes both single and dual triodes through the 6SN7 socket in the last couple weeks, and put the Tung Sol round plate 6J5's back in last night for a sanity check (well, _aural_ anyway).   Dang.  Much as I like the L63's, the Tung Sols have an addicting rhythm and thump in the upper bass that the L63's just don't have. The mids are the L63's sacred territory where the Tung Sols take a step back. I only wish Tung Sol had made an L63.


----------



## bcowen

CAJames said:


> The 7N7  (aka loctal 6SN7) was my daily driver until I was seduced by the Siren Song of the Single Triode (SSST). But a 7A4 seems like an adapter too far for me.



The Frankentube 7N7 is my favorite without any qualification in the Vali 2.  In the Incubus amp it sounds quite nice, but isn't my favorite compared to some single triode tubes.  Synergy thing, obviously.

Configured properly with a custom (1 piece) @Deyan adapter:


----------



## chrisdrop

Velozity said:


> I'm curious to know where the Mullard 6J5G sits on your plane??  It's in Business Class on mine (joining the L63 straight glass), but YAMV (your airline may vary).  Quite surprisingly, the Brimar 6C5G bought out the whole First Class section so the GEC 6J5G gray glass hasn't even taken a flight yet.  It's hard to get the Brimars out of their seats!


In short, I'm not sure. I've not spent enough time with them yet. I've got a new amp (with native 6J5 sockets) coming this week to join my crazy amp party. I've been trying to save some new valves to try on the new amp; the Mullards among them (along with some new pairs of 6N7s which it will take natively too). I'll let you know how we get on. I've also been saving some pretty Fivres.

I guess I should have grabbed some Brimar 6C5Gs, which seem not to be around now!


----------



## Paladin79 (Sep 12, 2020)

bcowen said:


> @Paladin79 has.  I have a couple, but since I only have a Chinese adapter and lack a proper one from @Deyan I figured they were compromised from the start.


Bill is correct, I found the 7A4 mentioned in tube manuals a couple years ago and got a Chinese adapter. I have had no issues with it, nothing against the @Deyan adapters. There are plenty of industrial related 7a4's out there made by Sylvania as NOS as well as military versions as I recall, VT-192's, I have some of those as well.


These will not fit in my current amp but I will finish this one later today and give them a listen then.


----------



## bcowen

Paladin79 said:


> Bill is correct, I found the 7A4 mentioned in tube manuals a couple years ago and got a Chinese adapter. I have had no issues with it, nothing against the @Deyan adapters. There are plenty of industrial related 7a4's out there made by Sylvania as NOS as well as military versions as I recall, VT-192's, I have some of those as well.
> 
> These will not fit in my current amp but I will finish this one later today and give them a listen then.



Too bad you don't have an amp like mine.  LOL!!!


----------



## bcowen

Paladin79 said:


> Bill is correct, I found the 7A4 mentioned in tube manuals a couple years ago and got a Chinese adapter. I have had no issues with it, nothing against the @Deyan adapters. There are plenty of industrial related 7a4's out there made by Sylvania as NOS as well as military versions as I recall, VT-192's, I have some of those as well.
> 
> These will not fit in my current amp but I will finish this one later today and give them a listen then.



I have a couple Sylvanias, a few CBS, and I think some Tung Sols.  I think they're all in tube bin #4 which will take some planning and preparation to get to. Proper hoard collection organization is important.


----------



## Paladin79

bcowen said:


> Too bad you don't have an amp like mine.  LOL!!!


I will have a workable solution in about an hour lol. Maybe two hours, depending on how many times I have to chase Finnegan out of my chair at the work bench. And that amp is the only one of that style I will build so it is unique, just like you, and everybody else.


----------



## bcowen

Paladin79 said:


> And that amp is the only one of that style I will build so it is unique, just like you...



I think that's the nicest title you've ever bestowed on me.  

You feeling OK, I hope?


----------



## Paladin79

bcowen said:


> I think that's the nicest title you've ever bestowed on me.
> 
> You feeling OK, I hope?


I was ok till I tried plugging the adapter into my Incubus and it will not fit. Looks like I will be building a second one for myself one day. Oh and I believe you mentioned the VT-192's to me, some were called XXL I believe as well. One has to be careful on Ebay, folks use every term they can think of like adding VT-192 in the listing when they are not.


----------



## bcowen (Sep 12, 2020)

Paladin79 said:


> One has to be careful on Ebay, folks use every term they can think of like adding VT-192 in the listing when they are not.



Too true.  Pretty amazing how most every 6SN7 ever made is now a Bad Boy on Ebay. And I continue to crack up at the seller 'Peace Love and Music' that lists every tube they sell as testing great, and then show the test readings as (for instance) "47, where 65 is minimum good."   Huh?  I guess their test interpretation is that any tube that reads above 0 is "great."  What's amazing is that their ads for any particular tube don't stay there for long, so either people are buying the worn out crap or they're removing the listing (and sadly, it's probably the former).


----------



## Paladin79

bcowen said:


> Too true.  Pretty amazing how most every 6SN7 ever made is now a Bad Boy on Ebay. And I continue to crack up at the seller 'Peace Love and Music' that lists every tube they sell as testing great, and then show the test readings as (for instance) "47, where 65 is minimum good."   Huh?  I guess their test interpretation is that any tube that reads above 0 is "great."  What's amazing is that their ads for any particular tube don't stay there for long, so either people are buying the worn out crap or they're removing the listing (and sadly, it's probably the former).


 Ok I now have an amp in place for the VT-192's, the bass is much better than I recalled. 

Listening with a Gungnir and Utopias and a version 2 Incubus.


----------



## CAJames

bcowen said:


> ... I think they're all in tube bin #4 which will take some planning and preparation to get to. Proper hoard collection organization is important.



Indeed. I say store your tubes like a pro:





You guys are killing me with all the 7A4 talk BTW. I guess this is the peer pressure my parents always warned me about.


----------



## bcowen

CAJames said:


> Indeed. I say store your tubes like a pro:



Love it!  Hard to find those in awesome shape like that any more, and when you do the price is obnoxious.  I picked up the one below unopened in its factory shipping carton about 10 years ago....for $25.   

Tube _caddy_ porn now. LOL!


----------



## bcowen

Paladin79 said:


> Ok I now have an amp in place for the VT-192's, the bass is much better than I recalled.
> 
> Listening with a Gungnir and Utopias and a version 2 Incubus.



If clearance above the jet turbines in your main amp is the issue, you could always do something like this:


----------



## Paladin79

bcowen said:


> If clearance above the jet turbines in your main amp is the issue, you could always do something like this:


Now there's a bad idea!  It is easier to just build another amp. That grey and black cable looks kinda familiar. Some kind person must have gifted you that.


----------



## GDuss

chrisdrop said:


> I guess I should have grabbed some Brimar 6C5Gs, which seem not to be around now!



I'm not sure this is a tube that would end up high on your list (in the premium seats).  In my opinion, they don't sound like the GEC L63.  Based on my experience with other GEC's (6J7, 6AS7G), I think I have a decent sense of what their house sound is, and the Brimar 6C5G is different.  At least the version of this tube that I have (from Langrex, looks identical to the others posted in this thread but has no markings on the base).  For the past several nights of listening to them, I've been trying to figure out what they sound most like.  I don't have other Brimar tubes so this could be their house sound and I would have no idea.  They are definitely not the most detailed tube I have, but their tone is just extremely attractive.  They have great bass, not bright at all, midrange is not too forward, and the staging is about average.  But the textures of instruments are very interesting. They just seem to present the sound in a distinct way to the other driver tubes I have.  It's actually been quite challenging to figure them out.  But I could easily see someone saying they are too warm and not liking them at all.  Remember that I'm a big RCA fan, so these are closer to what I like anyway, while still differing from the RCA sound.

I'd be curious to hear what others who have this tube think about the way it sounds.  It may be different in other amps.


----------



## bcowen

Paladin79 said:


> Now there's a bad idea!  It is easier to just build another amp. That grey and black cable looks kinda familiar. Some kind person must have gifted you that.



Yeah, IIRC it was another ultra-cool, super-awesome fellow Headfi'er.


----------



## leftside

CAJames said:


> Indeed. I say store your tubes like a pro:
> 
> 
> 
> You guys are killing me with all the 7A4 talk BTW. I guess this is the peer pressure my parents always warned me about.


Nice solid wide open (for tube rolling) wooden shelves there. I'm currently looking for something similar. I may end up getting a set made if I can't find what I want.


----------



## Xcalibur255

GDuss said:


> I'm not sure this is a tube that would end up high on your list (in the premium seats).  In my opinion, they don't sound like the GEC L63.  Based on my experience with other GEC's (6J7, 6AS7G), I think I have a decent sense of what their house sound is, and the Brimar 6C5G is different.  At least the version of this tube that I have (from Langrex, looks identical to the others posted in this thread but has no markings on the base).  For the past several nights of listening to them, I've been trying to figure out what they sound most like.  I don't have other Brimar tubes so this could be their house sound and I would have no idea.  They are definitely not the most detailed tube I have, but their tone is just extremely attractive.  They have great bass, not bright at all, midrange is not too forward, and the staging is about average.  But the textures of instruments are very interesting. They just seem to present the sound in a distinct way to the other driver tubes I have.  It's actually been quite challenging to figure them out.  But I could easily see someone saying they are too warm and not liking them at all.  Remember that I'm a big RCA fan, so these are closer to what I like anyway, while still differing from the RCA sound.
> 
> I'd be curious to hear what others who have this tube think about the way it sounds.  It may be different in other amps.



Your description is very consistent with how I'd describe a Brimar 13D1 as well.  It's the only tube I know that completely takes the bite out of the DT880 top end without making everything else sound veiled.


----------



## whirlwind (Sep 12, 2020)

CAJames said:


> Indeed. I say store your tubes like a pro:
> 
> 
> 
> You guys are killing me with all the 7A4 talk BTW. I guess this is the peer pressure my parents always warned me about.



I have one of those tube caddies. It was from my fathers tv shop...a lot of nice memories it brings.
I lugged that thing around all over town running service calls for my father.


----------



## CAJames (Sep 12, 2020)

leftside said:


> Nice solid wide open (for tube rolling) wooden shelves there. I'm currently looking for something similar. I may end up getting a set made if I can't find what I want.



Thanks. I'm useless with power tools and the like but a buddy of mine is an excellent woodworker and he made the shelves for me to mostly my specs. Also the CD shelves in the background.


----------



## leftside

CAJames said:


> Thanks. I'm useless with power tools and the like but a buddy of mine is an excellent woodworker and he made the shelves for me to mostly my specs. Also the CD shelves in the background.


As with my amps... I think I'm also going to need to go custom with my shelves.


----------



## Monsterzero

I tried a proper vertical audio rack,but the cables became a waterfall of vipers and working on the system was quite difficult,so i repurposed some pallets,slapped 4 wheels on each and now I have easy access to the rear,venting both up and down and its ghetto fab.


----------



## leftside

Monsterzero said:


> I tried a proper vertical audio rack,but the cables became a waterfall of vipers and working on the system was quite difficult,so i repurposed some pallets,slapped 4 wheels on each and now I have easy access to the rear,venting both up and down and its ghetto fab.


Looks good!


----------



## CAJames

Monsterzero said:


> I tried a proper vertical audio rack,but the cables became a waterfall of vipers and working on the system was quite difficult,so i repurposed some pallets,slapped 4 wheels on each and now I have easy access to the rear,venting both up and down and its ghetto fab.



Sweet!


----------



## whirlwind

Monsterzero said:


> I tried a proper vertical audio rack,but the cables became a waterfall of vipers and working on the system was quite difficult,so i repurposed some pallets,slapped 4 wheels on each and now I have easy access to the rear,venting both up and down and its ghetto fab.



Awesome...I am about everything being much easier to get it...very practical.

I used some old counter-top that I bought off of our lumber company's  clearance rack for my table top and attached  some 4x4 for legs


----------



## JKDJedi

CAJames said:


> For me the GEC L63s are clearly better, but the difference isn’t very big.


Well, my Gecs are Lost In Space..aka  Da MAil..  They're sending me another pair with tracking this time..  Ho Hum.. Maybe by October?


----------



## JKDJedi (Sep 15, 2020)

bcowen said:


> Love it!  Hard to find those in awesome shape like that any more, and when you do the price is obnoxious.  I picked up the one below unopened in its factory shipping carton about 10 years ago....for $25.
> 
> Tube _caddy_ porn now. LOL!


I want one now...best ole buddy pal of mine...


----------



## bcowen (Sep 15, 2020)

JKDJedi said:


> I want one now...best ole buddy pal of mine...



LOL!!!  My stash of tube caddies numbers exactly 1.      Just have to keep an eye out on Ebay.  Very difficult to find one in absolute pristine condition, but I've seen them in very good condition pop up every now and then.

https://www.ebay.com/itm/Large-Blac...4f2b87d501dc0a89163f|ampid:PL_CLK|clp:2334524






Better hurry if you want this one though...I think @Ripper2860 has a $100 bid in on it.


----------



## JKDJedi

bcowen said:


> LOL!!!  My stash of tube caddies numbers exactly 1.      Just have to keep an eye out on Ebay.  Very difficult to find one in absolute pristine condition, but I've seen them in very good condition pop up every now and then.
> 
> https://www.ebay.com/itm/Large-Black-Sylvania-Vintage-Radio-TV-Vacuum-Tube-Caddy-Carrying-Case/153440453614?_trkparms=ispr=1&hash=item23b9c383ee:g:UFYAAOSwI5FbagSo&amdata=enc:AQAFAAACYBaobrjLl8XobRIiIML1V4Imu%2Fn%2BzU5L90Z278x5ickkxGz2ccqatkEnoeekHqhLkQoFzicpdMESQi6IOXmYKw6qvWhpRcXHDD460it7rrX2X0BID0%2BikkbuE%2BxxskHSUgAYHisuGUm3nvCsXAEfMfU5uVFyu4VqCu%2B%2BehtCzv%2FVY1oiIEze7aSwTXEOr3vU7zzF9T0%2F2PRJY2GvGcM6NZTjbZnFgbBjIIDfW2HgPGFv5HVlp1zq7tHgP%2BJ5NtIAFcZD4CXxQLu2hx3eFv6ukx%2Fqi2T95q3t%2FhrGK7GOdEJ76lqcOKzeRsGlpoihWnCq4r5oPdAsOgAxmq9uKiEHI4A7D7X1nPy2vQyy2OfC658SyeK%2B%2BlNYb3cKS2uSS2ky%2BJXgCIcxKVTj57Q6FpN71GMqHEW322VCVVONImx6f64T2MkdiD5QXZE4ZGyUXE%2F5vRqTIM%2FhKOcW4LdD%2BVzq5TnNKHgyrCJkZP2ER%2BZ6%2BxLX1SUV%2BvWVXOZf3hN55P%2Fwx18X2I2ix3fDO1I09%2BPZdw1BiDmcD%2BVoHo9rFzT1HdbixUS6KnTxW3JwoYpr5nyw1ONe%2F6VBvzTZheiFwZPiE0S6G6SIUUg1Suk22O%2Fifu2FjnZ51lA%2FfoSHRcv57LFjFUzKEu6eIeWnPtOJc1SEXC9b0LuAYqmj%2BRSS48oG41EPEgcxbpmLCeWVhx7yU4pBpal7JHGsqJziYXpXfdzSgEuNlbBwAqpF4cVxSOEe3iTghIm1qRRRN6IHwpACGryHMo%2B7Lz9VMxqE0mr9cI7uwnCngxXmjv1qKJtlk22dwHAZ|cksum:153440453614df8759e6646a4f2b87d501dc0a89163f|ampidL_CLK|clp:2334524
> 
> ...


You guys are a bad (good?) Influence... Grabbed some of them XXL tubes ... (7A4) see how they roll.


----------



## Ripper2860

bcowen said:


> Better hurry if you want this one though...I think @Ripper2860 has a $100 bid in on it.



100 pesos.  Not dollars.   🙄


----------



## CAJames

bcowen said:


> LOL!!!  My stash of tube caddies numbers exactly 1.      Just have to keep an eye out on Ebay.  Very difficult to find one in absolute pristine condition, but I've seen them in very good condition pop up every now and then.
> 
> https://www.ebay.com/itm/Large-Black-Sylvania-Vintage-Radio-TV-Vacuum-Tube-Caddy-Carrying-Case/153440453614?_trkparms=ispr=1&hash=item23b9c383ee:g:UFYAAOSwI5FbagSo&amdata=enc:AQAFAAACYBaobrjLl8XobRIiIML1V4Imu%2Fn%2BzU5L90Z278x5ickkxGz2ccqatkEnoeekHqhLkQoFzicpdMESQi6IOXmYKw6qvWhpRcXHDD460it7rrX2X0BID0%2BikkbuE%2BxxskHSUgAYHisuGUm3nvCsXAEfMfU5uVFyu4VqCu%2B%2BehtCzv%2FVY1oiIEze7aSwTXEOr3vU7zzF9T0%2F2PRJY2GvGcM6NZTjbZnFgbBjIIDfW2HgPGFv5HVlp1zq7tHgP%2BJ5NtIAFcZD4CXxQLu2hx3eFv6ukx%2Fqi2T95q3t%2FhrGK7GOdEJ76lqcOKzeRsGlpoihWnCq4r5oPdAsOgAxmq9uKiEHI4A7D7X1nPy2vQyy2OfC658SyeK%2B%2BlNYb3cKS2uSS2ky%2BJXgCIcxKVTj57Q6FpN71GMqHEW322VCVVONImx6f64T2MkdiD5QXZE4ZGyUXE%2F5vRqTIM%2FhKOcW4LdD%2BVzq5TnNKHgyrCJkZP2ER%2BZ6%2BxLX1SUV%2BvWVXOZf3hN55P%2Fwx18X2I2ix3fDO1I09%2BPZdw1BiDmcD%2BVoHo9rFzT1HdbixUS6KnTxW3JwoYpr5nyw1ONe%2F6VBvzTZheiFwZPiE0S6G6SIUUg1Suk22O%2Fifu2FjnZ51lA%2FfoSHRcv57LFjFUzKEu6eIeWnPtOJc1SEXC9b0LuAYqmj%2BRSS48oG41EPEgcxbpmLCeWVhx7yU4pBpal7JHGsqJziYXpXfdzSgEuNlbBwAqpF4cVxSOEe3iTghIm1qRRRN6IHwpACGryHMo%2B7Lz9VMxqE0mr9cI7uwnCngxXmjv1qKJtlk22dwHAZ|cksum:153440453614df8759e6646a4f2b87d501dc0a89163f|ampidL_CLK|clp:2334524
> 
> ...



For me, I prefer RCA caddies to Sylvania. YMMV of course.

Yes, I'm talking tube caddie rolling....


----------



## bcowen

CAJames said:


> For me, I prefer RCA caddies to Sylvania. YMMV of course.
> 
> Yes, I'm talking tube caddie rolling....



I do too, but then this is for @JKDJedi .


----------



## Xcalibur255

A seller in India dumped a bunch of 6J5 listings on eBay, mostly Mullard and Brimar with a few GEC and Ken-Rad.  I took a chance on a pair with the Mullard plate style and hope it works out.  They are proud of the fact that they have amplitrex test results, but if you look closely the test sheets are self-dating and they are dated 2015 in most of the photos.  Maybe they just sat around in somebody's collection for the last 5 years?


----------



## Xcalibur255

The listings all seem to be gone now.  I wonder if somebody made an oops and turned a bunch of private listings public for a short period of time?


----------



## JKDJedi

Xcalibur255 said:


> The listings all seem to be gone now.  I wonder if somebody made an oops and turned a bunch of private listings public for a short period of time?


Did a quick look and didn't see it either... unless @bcowen  snagged them all....


----------



## bcowen

JKDJedi said:


> Did a quick look and didn't see it either... unless @bcowen  snagged them all....



Wasn't me.  Promise.  Did you check with the Hoardeus Supremus, @Ripper2860 ?


----------



## GDuss

Xcalibur255 said:


> The listings all seem to be gone now.  I wonder if somebody made an oops and turned a bunch of private listings public for a short period of time?



It was probably on purpose, to create more craziness for when they reappear.  Then people will feel like they need to hurry up and buy them before they disappear again.


----------



## Xcalibur255

Most of the seller's feedback is also private, so I'm thinking they didn't meant to list all of that and I just happened to be in the right place at the right time.  Or maybe I wasn't..... I guess we'll see when they show up.


----------



## Ripper2860

bcowen said:


> Wasn't me.  Promise.  Did you check with the Hoardeus Supremus, @Ripper2860 ?



Will neither confirm nor deny.


----------



## JKDJedi (Sep 19, 2020)

Well, the 7A4 are interesting... Was thinking I got a bad batch with broken pins but quickly realized these are single triode tubes so the pin configuration should be different. 2 of the 8 are missing on all of them. Total of 6 pins... How do they sound? Well my luck for getting the wrong item has doubled these past two weeks.... I got some 5 pin to 4 pin adapters instead of the 7a4 to 6j5...🤣. Oh well. eBay is like a box of chocolates...you never know what your gonna get..


----------



## bcowen

JKDJedi said:


> Well, the 7A4 are interesting... Was thinking I got a bad batch with broken pins but quickly realized these are single triode tubes so the pin configuration should be different. 2 of the 8 are missing on all of them. Total of 6 pins... How do they sound? Well my luck for getting the wrong item has doubled these past two weeks.... I got some 5 pin to 4 pin adapters instead of the 7a4 to 6j5...🤣. Oh well. eBay is like a box of chocolates...you never know what your gonna get..



Geeez.  Kids these days.    

Yoohoo @Deyan :  Jedi needs a 6SN7 to 7A4's adapter....


----------



## JKDJedi

bcowen said:


> Geeez.  Kids these days.
> 
> Yoohoo @Deyan :  Jedi needs a 6SN7 to 7A4's adapter....


Nope... they're sending me the right ones Monday. He apologized and told me to keep what I had, and that the 7a4 to 6j5 will be sent Monday.


----------



## bcowen

JKDJedi said:


> Nope... they're sending me the right ones Monday. He apologized and told me to keep what I had, and that the 7a4 to 6j5 will be sent Monday.



But then you'll be double-adaptering.  That's illegal in many states, and California was probably the first.


----------



## JKDJedi

bcowen said:


> But then you'll be double-adaptering.  That's illegal in many states, and California was probably the first.


They kinda made up for it with the pot dispensaries on every corner here..


----------



## bcowen

JKDJedi said:


> They kinda made up for it with the pot dispensaries on every corner here..



LOL!  But do they have free Prime Delivery like in Amsterdam?     Double-adaptering was legal too, at least back when I was there...


----------



## JKDJedi (Sep 20, 2020)

bcowen said:


> LOL!  But do they have free Prime Delivery like in Amsterdam?     Double-adaptering was legal too, at least back when I was there...


Not like that.. they do deliver, incognito style.. unmarked vehicle. I sampled some special gummies awhile back, for municipal purposes! No kittens were harmed during experiments.. ;D Which reminds me.. I'm past due!!  #Truelies..


----------



## CAJames

bcowen said:


> But then you'll be double-adaptering.  That's illegal in many states, and California was probably the first.



No problem in Cali as long as you add a side of avocado. I think the Beach Boys actually started out writing songs about double-adaptering, but eventually realized songs about girls and cars sold better. Go figure.


----------



## Xcalibur255

I meant to post something about the tubes I mentioned buying from India last week, but like a dullard I posted it in the (kind of) wrong place by accident.  So I'll just drop a link to that post here instead.....

https://www.head-fi.org/threads/1101-audio-custom-crafted-headphone-amps.919425/post-15879281


----------



## JKDJedi (Sep 23, 2020)

Xcalibur255 said:


> I meant to post something about the tubes I mentioned buying from India last week, but like a dullard I posted it in the (kind of) wrong place by accident.  So I'll just drop a link to that post here instead.....
> 
> https://www.head-fi.org/threads/1101-audio-custom-crafted-headphone-amps.919425/post-15879281


Are we supposed to respond there too??  Wow..nIce tubes there..Brimars are tempting..  Grabbed the link for ya to repost here.. thanks for the headsup!
https://www.ebay.com/sch/m.html?_ssn=totempole_999&_armrs=1&_from=R40&_sacat=0&_nkw=6j5&rt=nc


----------



## CAJames

I will live vicariously through you guys as you chase your hundred dollar Mullards and GECs around the world.

For me, I tried spicing up my humble RCA 76 tubes with French power tubes and a 83 rectifier. And Sacré bleu! they sound fantastic now. A little more lush and laid back compared to the 6J5GTs and L63s but very nice indeed. I need to roll the L63s back to compare, but its hard because I'm loving the sound. So for me it is

R-C-A!
R-C-A!
R-C-A!

(Feel free to join in and do the wave)


----------



## JKDJedi

CAJames said:


> I will live vicariously through you guys as you chase your hundred dollar Mullards and GECs around the world.
> 
> For me, I tried spicing up my humble RCA 76 tubes with French power tubes and a 83 rectifier. And Sacré bleu! they sound fantastic now. A little more lush and laid back compared to the 6J5GTs and L63s but very nice indeed. I need to roll the L63s back to compare, but its hard because I'm loving the sound. So for me it is
> 
> ...


Radiotron RCA?


----------



## GDuss

CAJames said:


> I will live vicariously through you guys as you chase your hundred dollar Mullards and GECs around the world.
> 
> For me, I tried spicing up my humble RCA 76 tubes with French power tubes and a 83 rectifier. And Sacré bleu! they sound fantastic now. A little more lush and laid back compared to the 6J5GTs and L63s but very nice indeed. I need to roll the L63s back to compare, but its hard because I'm loving the sound. So for me it is
> 
> ...



I like mine with meatballs!!!


----------



## L0rdGwyn (Sep 24, 2020)

I think I may have accidentally unsubbed from this thread!  Looks like I have some catching up to do.



Xcalibur255 said:


> I meant to post something about the tubes I mentioned buying from India last week, but like a dullard I posted it in the (kind of) wrong place by accident.  So I'll just drop a link to that post here instead.....
> 
> https://www.head-fi.org/threads/1101-audio-custom-crafted-headphone-amps.919425/post-15879281



I've purchased tubes from that seller a few times, his prices are usually high, but the quality is very good and his international shipping is lightning fast from India, typically 2-3 days FedEx International to the USA.

Just a warning - those Ferranti tubes he has on sale are rebranded Raytheon 6J5G.  They are nice tubes, but they are not British-made as advertised.


----------



## CAJames

JKDJedi said:


> Radiotron RCA?



At least some of them. I got a lot of 6 used and some of the labels are hard to read. Some of them say Radiotron and others say RCA Victor which I assume is different because I don't see any that say both. The internal construction is similar in all of them, but not identical.


----------



## GDuss

CAJames said:


> At least some of them. I got a lot of 6 used and some of the labels are hard to read. Some of them say Radiotron and others say RCA Victor which I assume is different because I don't see any that say both. The internal construction is similar in all of them, but not identical.



I have some Radiotron and some Victor, and they're not typically found together in my experience.

Currently I am running a pair of RCA 6J7 (I know, not the focus of this thread, but I'm also running 6J5's with them) and they are Radiotron.  Matching date codes of R4, which I think is 1940.  Great sounding tubes.  So are the Tung Sol 6J5's that are running with them.  Interesting combination between their sounds.


----------



## CAJames

GDuss said:


> I have some Radiotron and some Victor, and they're not typically found together in my experience.
> 
> Currently I am running a pair of RCA 6J7 (I know, not the focus of this thread, but I'm also running 6J5's with them) and they are Radiotron.  Matching date codes of R4, which I think is 1940.  Great sounding tubes.  So are the Tung Sol 6J5's that are running with them.  Interesting combination between their sounds.



Yes, I got mine cheap to see if they were worth further investigation and the answer is definitely yes. I'm going to try to track down some NOS 76s, perhaps TS or NU if I can find them.


----------



## Xcalibur255

L0rdGwyn said:


> I think I may have accidentally unrubbed from this thread!  Looks like I have some catching up to do.
> 
> 
> 
> ...



I think part of the prices are the original boxes.  He had a couple of pairs that were listed for a lower price because they were in generic brown military surplus boxes instead of "real" Mullard or Brimar boxes, and I nabbed one of those.  Somebody else in some part of the world got the other ones right around the same time it seems.  I do think it's cool when the original box survives (and the artwork is always great), but what matters is the sound so I was happy to get a deal in exchange for having ugly boxes.


----------



## JKDJedi

And I'm still waiting for my GECs 😒😞


----------



## Xcalibur255

JKDJedi said:


> And I'm still waiting for my GECs 😒😞



I hope you find a nice pair!  If you're referring to the smoked glass coke bottle GEC L63s I would love to land a pair too at some point.  Sooner or later the unicorn you're looking for always comes along.

Unless I've misunderstood and you're experiencing shipping delays on something you already bought.  That can be frustrating too.


----------



## JKDJedi

Xcalibur255 said:


> I hope you find a nice pair!  If you're referring to the smoked glass coke bottle GEC L63s I would love to land a pair too at some point.  Sooner or later the unicorn you're looking for always comes along.
> 
> Unless I've misunderstood and you're experiencing shipping delays on something you already bought.  That can be frustrating too.


Smoked glass coke bottles GECs....oh....that's intriguing.. no mine are the boring straight bottles...😂.. or the ones I ordered...yet to receive them. Curious about the RCA... I'm sorry my day has been discombobulated... Did you receive your RCA? Pics!!


----------



## L0rdGwyn

Xcalibur255 said:


> I think part of the prices are the original boxes.  He had a couple of pairs that were listed for a lower price because they were in generic brown military surplus boxes instead of "real" Mullard or Brimar boxes, and I nabbed one of those.  Somebody else in some part of the world got the other ones right around the same time it seems.  I do think it's cool when the original box survives (and the artwork is always great), but what matters is the sound so I was happy to get a deal in exchange for having ugly boxes.



I like having the original boxes too, and some of the artwork is phenomenal.  My sister is a graphic designer, I send her pictures of my coolest tube boxes, she is all about what they were doing back then.  Breaks my heart though, as tube rolling eventually wears the boxes down, its inevitable that they eventually deteriorate no matter how careful you are.  Glad you got a good deal, I think I bought the same STC / Brimar tubes from him a while back, they sound great!  In fact they have been in my 45 amp for a while now, listening to them now


----------



## chrisdrop

L0rdGwyn said:


> I like having the original boxes too, and some of the artwork is phenomenal.  My sister is a graphic designer, I send her pictures of my coolest tube boxes, she is all about what they were doing back then.  Breaks my heart though, as tube rolling eventually wears the boxes down, its inevitable that they eventually deteriorate no matter how careful you are.  Glad you got a good deal, I think I bought the same STC / Brimar tubes from him a while back, they sound great!  In fact they have been in my 45 amp for a while now, listening to them now



I usually replace my nice original boxes with plain white boxes. Then, I keep the nice boxes untouched.



chrisdrop said:


> At some point this weekend, I'll give these a go. The boxes look like they've been sealed since they were tax stamped. I've been keen to take a peek at them since the package arrived.
> 
> Doing a bit of reading here, it seems the tax labels are exemptions applied to tubes made for the military.
> 
> ...


To report on these; super nice on the Blue Halo. I've not touched them since I put them in.


----------



## L0rdGwyn

chrisdrop said:


> I usually replace my nice original boxes with plain white boxes. Then, I keep the nice boxes untouched.



I've done the same in the past, I even have a label maker to put the tube names on all of my white boxes  but it becomes a burden to store numerous empty boxes, this is a very first-world problem.


----------



## bcowen

L0rdGwyn said:


> I've done the same in the past, I even have a label maker to put the tube names on all of my white boxes  but it becomes a burden to store numerous empty boxes, this is a very first-world problem.



I have a really inexpensive label maker called a Sharpie. Two, actually -- one black and one blue depending on my mood.    





Seriously, I used to use a Brother labelmaker until I got lazy about it, and more to record the test measurements than anything.  The Hytron boxes aren't technically white boxes obviously, but I picked up a lot of 500 small octal size for $5 at a hamfest a number of years ago, and if I sell the tube contained within it always helps to create confusion. Everybody knows Hytron made RCA tubes, right?


----------



## L0rdGwyn (Sep 24, 2020)

bcowen said:


> I have a really inexpensive label maker called a Sharpie. Two, actually -- one black and one blue depending on my mood.
> 
> 
> 
> Seriously, I used to use a Brother labelmaker until I got lazy about it, and more to record the test measurements than anything.  The Hytron boxes aren't technically white boxes obviously, but I picked up a lot of 500 small octal size for $5 at a hamfest a number of years ago, and if I sell the tube contained within it always helps to create confusion. Everybody knows Hytron made RCA tubes, right?



Lol!  The label maker seems like a good idea at the time, until you realize what a PITA it is!  My tube collection is in a state of chaos right now, I just fumble around in drawers until I find the one I am looking for


----------



## CAJames

chrisdrop said:


> I usually replace my nice original boxes with plain white boxes. Then, I keep the nice boxes untouched...



So, tube box rolling?


----------



## GDuss

bcowen said:


> I have a really inexpensive label maker called a Sharpie. Two, actually -- one black and one blue depending on my mood.



These are all located alphabetically in the "F" section of your library?


----------



## JKDJedi (Sep 24, 2020)

The Gods Of @bcowen have smiled on me!!! Holy Shipments!! Three sides and a bottom getter.... Squeaky wheel gets the oil folks... 😁


----------



## JKDJedi

GDuss said:


> These are all located alphabetically in the "F" section of your library?


That's just the basement.... 😁 We haven't even seen the main floor yet..


----------



## JKDJedi (Sep 24, 2020)

The double X adapters arrived today as well . The L63 can wait... I've been wanting to roll these 7a4 badly... And love a genuine surprise...wow, for pennies these sound great.  And I just have an RCA back there, what would a 5998 do to these guys... The 7a4 have a signature of their own, Deep Hall like. Might just grab a proper adapter after all.


----------



## CAJames

Glad the International Parcel Gods finally came through. I look forward to your thoughts on the L63s, I finally rolled in my second quint and they just kicked all my other tubes back into economy. For me they are the Baskin-Robbins Chocolate Fudge of tubes: cost a little more, but worth it.


----------



## JKDJedi

CAJames said:


> Glad the International Parcel Gods finally came through. I look forward to your thoughts on the L63s, I finally rolled in my second quint and they just kicked all my other tubes back into economy. For me they are the Baskin-Robbins Chocolate Fudge of tubes: cost a little more, but worth it.


Baskin-Robbins Chocolate Fudge of tubes...😂😂😂😂 Love it!!! May I use that?


----------



## CAJames

JKDJedi said:


> Baskin-Robbins Chocolate Fudge of tubes...😂😂😂😂 Love it!!! May I use that?



Sure. Like the man says, "the first one is free..."


----------



## Xcalibur255 (Sep 25, 2020)

Could anybody tell me who the most likely manufacturer was for 6J5G tubes that have round black plates and the cross style top mica support?  My gut feeling is that they would be Raytheon made but that's just intuition on my part.  I have most recently seen this style on a pair of Philcos but my suspicion is Philco was re-branding here (as they often did).

I'm enjoying the journey of learning who makes what in the 6J5 world based on plate and mica details, but the going has been a bit slower than it was learning about 45 tubes was.  As usual Sylvanias are the easiest to identify.  They always seem to be.  The Ken-Rads seem easy too.  All the other American brands have been harder to nail down.  In particular I'm trying to figure out if Tung-Sol made both ladder plate and round plate 6J5s, or if it was just one of those styles.  Knowing that much would make identifying re-brands for them easier too.


----------



## bcowen

JKDJedi said:


> That's just the basement.... 😁 We haven't even seen the main floor yet..



Or the storage building out back.


----------



## gleanfont

bcowen said:


> I have a really inexpensive label maker called a Sharpie. Two, actually -- one black and one blue depending on my mood.
> 
> 
> 
> Seriously, I used to use a Brother labelmaker until I got lazy about it, and more to record the test measurements than anything.  The Hytron boxes aren't technically white boxes obviously, but I picked up a lot of 500 small octal size for $5 at a hamfest a number of years ago, and if I sell the tube contained within it always helps to create confusion. Everybody knows Hytron made RCA tubes, right?



 collection indeed. nice!


----------



## bcowen

GDuss said:


> These are all located alphabetically in the "F" section of your library?



Dang...never noticed that.  I have a very organized storage system -- whenever I get a new (to me) tube, I put it wherever there's a void in the tub.  Organized is a subjective term, right?


----------



## bcowen

JKDJedi said:


> The Gods Of @bcowen have smiled on me!!! Holy Shipments!! Three sides and a bottom getter.... Squeaky wheel gets the oil folks... 😁



Sweet!  And no double-adaptering required.  Always best to stay off the radar of the tube police.


----------



## GDuss

bcowen said:


> Dang...never noticed that.  I have a very organized storage system -- whenever I get a new (to me) tube, I put it wherever there's a void in the tub.  Organized is a subjective term, right?



Uh, whatever your storage method is, it has to be better than mine.  For example, one of my tube boxes...




I have no idea what's at the bottom of it.  I also have no idea what's at the top, without unwrapping plastic.  All I know is that they are all power tubes.

In case you're wondering, there is no organized search function for this inventory


----------



## bcowen

GDuss said:


> Uh, whatever your storage method is, it has to be better than mine.  For example, one of my tube boxes...
> 
> 
> 
> ...



That actually looks pretty nicely organized compared to @Ripper2860 's storage system.


----------



## GDuss

bcowen said:


> That actually looks pretty nicely organized compared to @Ripper2860 's storage system.



The only thing separating me from that organizational system is some minimal use of bubble wrap and foam.


----------



## Ripper2860 (Sep 25, 2020)

bcowen said:


> That actually looks pretty nicely organized compared to @Ripper2860 's storage system.




It seems that I've been a bit negligent.  I've been meaning to spray them down with the garden hose to knock the dust off, but just haven't gotten around to it yet.  Sorry.

Besides -- those are my tube-fondling castaways.  I've moved on.


----------



## JKDJedi (Sep 26, 2020)

I'll tell you what... I'm at odds between these two tubes... the *Sylvania 7a4* have this tubey bloom pass your shoulders kinda sound that's very different from most of my tubes (from memory) and I really enjoy them for that. Then .. the *GEC L63* reigns all that in, the vocal distinction is off the charts. Even with a loose sound of the RCA (Cunningham) 6AS7G the vocals are clear as f"c+.. 😁


----------



## bcowen

JKDJedi said:


> I'll tell you what... I'm at odds between these two tubes... the *Sylvania 7a4* have this tubey bloom pass your shoulders kinda sound that's very different from most of my tubes (from memory) and I really enjoy them for that. Then .. the *GEC L63* reigns all that in, the vocal distinction is off the charts. Even with a loose sound of the RCA (Cunningham) 6AS7G the vocals are as clear as f"c+.. 😁



Give those L63's about 20 hours of play time and they will re-blow your mind.


----------



## JKDJedi

bcowen said:


> Give those L63's about 20 hours of play time and they will re-blow your mind.


My big brother @bcowen tipped me on these guys.. huge thanks !


----------



## bcowen

JKDJedi said:


> My big brother @bcowen tipped me on these guys.. huge thanks !



I can't remember if it was @chrisdrop or @CAJames talking about these that first got me interested (maybe both), so I'll pass along the thanks to them. Not a tube I'd likely have stumbled across on my own.


----------



## GDuss

bcowen said:


> I can't remember if it was @chrisdrop or @CAJames talking about these that first got me interested (maybe both), so I'll pass along the thanks to them. Not a tube I'd likely have stumbled across on my own.



When in doubt, blame @chrisdrop . That's where I got the idea in any case. I need to revisit these tubes and put more hours on them. My thoughts on them are not as positive as many others, but it's probably because of the mix of tubes I tried them with. At that point, it was GEC L63, GEC 6J7, and GEC 6AS7G.  I think I overdosed on GEC, which I have learned is a thing.


----------



## JKDJedi

GDuss said:


> When in doubt, blame @chrisdrop . That's where I got the idea in any case. I need to revisit these tubes and put more hours on them. My thoughts on them are not as positive as many others, but it's probably because of the mix of tubes I tried them with. At that point, it was GEC L63, GEC 6J7, and GEC 6AS7G.  I think I overdosed on GEC, which I have learned is a thing.


These are true NOS (meaning never used, spanking brand new/old out of the box tubes) some burn in required..,,  mine are opening up quick. Like a date on prom night..


----------



## Ripper2860

Aren't you a little old for High School proms?  😒


----------



## JKDJedi

Ripper2860 said:


> Aren't you a little old for High School proms?  😒


The memory lives FOREVER!!  #Goodtimes


----------



## Ripper2860

Fyi - He's not reliving memories.  Checkout http://prom-predator-mugshots.com. 😯


----------



## chrisdrop

GDuss said:


> When in doubt, blame @chrisdrop . That's where I got the idea in any case. I need to revisit these tubes and put more hours on them. My thoughts on them are not as positive as many others, but it's probably because of the mix of tubes I tried them with. At that point, it was GEC L63, GEC 6J7, and GEC 6AS7G.  I think I overdosed on GEC, which I have learned is a thing.


#GECPusher - sorry @GDuss. I thought I'd get you hooked and then start selling you knock-off or old-dirty GECs to sate your new habit, but it seems I failed!


----------



## GDuss

chrisdrop said:


> #GECPusher - sorry @GDuss. I thought I'd get you hooked and then start selling you knock-off or old-dirty GECs to sate your new habit, but it seems I failed!



I'm easily influenced.  It's ok though, I'll figure out how to like the L63's.  And if not, there's always the sales forum.  So please keep building the interest in them so their value goes up   . Mine have matched getters, so doesn't that mean they're worth more? Or maybe I'm starting that rumor. Based on what I've seen on that auction site, I think you can say whatever you want and then use it to increase your prices.


----------



## JKDJedi

GDuss said:


> I'm easily influenced.  It's ok though, I'll figure out how to like the L63's.  And if not, there's always the sales forum.  So please keep building the interest in them so their value goes up   . Mine have matched getters, so doesn't that mean they're worth more? Or maybe I'm starting that rumor. Based on what I've seen on that auction site, I think you can say whatever you want and then use it to increase your prices.


He's not alone. These are phenomenal, yours will sell ASAP.


----------



## leftside

GDuss said:


> I'm easily influenced.  It's ok though, I'll figure out how to like the L63's.  And if not, there's always the sales forum.  So please keep building the interest in them so their value goes up   . Mine have matched getters, so doesn't that mean they're worth more? Or maybe I'm starting that rumor. Based on what I've seen on that auction site, I think you can say whatever you want and then use it to increase your prices.


The rectangle getters go for more than the halo getters, as the rectangle are earlier tubes.


----------



## L0rdGwyn

Xcalibur255 said:


> Could anybody tell me who the most likely manufacturer was for 6J5G tubes that have round black plates and the cross style top mica support?  My gut feeling is that they would be Raytheon made but that's just intuition on my part.  I have most recently seen this style on a pair of Philcos but my suspicion is Philco was re-branding here (as they often did).



Do you have a picture, @Xcalibur255 ?


----------



## Xcalibur255

https://www.ebay.com/itm/No-6J5G-au...745500?hash=item36694ad39c:g:XekAAOSwvLJfSLXD

The interesting thing is two of them are round plate and the other two ladder plate.  The markings and micas are all the same though which suggests the same manufacturer making two variants in plate style.  Any thoughts on who made these?


----------



## L0rdGwyn (Sep 27, 2020)

Xcalibur255 said:


> https://www.ebay.com/itm/No-6J5G-au...745500?hash=item36694ad39c:g:XekAAOSwvLJfSLXD
> 
> The interesting thing is two of them are round plate and the other two ladder plate.  The markings and micas are all the same though which suggests the same manufacturer making two variants in plate style.  Any thoughts on who made these?



Those are pretty odd.  The ladder plates and support rod are unmistakably Raytheon, however they did not typically have a crossed top mica, the Raytheon top mica looks like below, at least in later models.




But here is another example.  This listing is long over, so the image is from Google, Raytheon branding.



The crossed top mica is usually associated with Arcturus tubes.  Here is the top mica of an Arcturus 6C5G, as an example (the Arcturus tube itself is of odd construction, but that's an aside).



I can't really explain the round plate, typically a Sylvania feature in these tubes.  Sylvania was also often resold by Philco and Zenith, but I feel confident they are _mostly _Raytheon, perhaps Philco / Zenith received other OEM internals from different manufacturers and combined them during construction.  Sorry I can't give a definite answer!


----------



## CAJames

This thread continues to deliver. From refined erudition to high school locker room and back in 2 pages. For me, I have 37 tubes in the mail and should be reporting on them in a few days. That's Type 37, not quantity 37.


----------



## JKDJedi

CAJames said:


> This thread continues to deliver. From refined erudition to high school locker room and back in 2 pages. For me, I have 37 tubes in the mail and should be reporting on them in a few days. That's Type 37, not quantity 37.


Type 37... 🤔 Oh oh... Just when you thought it was safe to go back in the waters...


----------



## bcowen

JKDJedi said:


> Type 37... 🤔 Oh oh... Just when you thought it was safe to go back in the waters...



LOL!!   Seems appropriate (rude, but appropriate) to hack-edit @CAJames prior post:

'This thread continues to deliver...endless opportunities for bankruptcy.'


----------



## CAJames

If @chrisdrop can be #GECPusher then I want to be #UX5Pimp   .


----------



## Ripper2860 (Sep 27, 2020)

I wonder what a 36-24-36 combo would sound like. 🤔


----------



## JKDJedi

Ripper2860 said:


> I wonder what a 36-24-36 combo would sound like. 🤔


----------



## Monsterzero

Question for all but especially the GOTL owners, current or past.

About a year ago I bought up a ton of Sylvania 6 and 12J5s as I loved the sound but one was rather noisy....Anyways I had them organized so I could tell which were which. Unfortunately my "organizing" was disrupted by a mancave remodel we did awhile back. Now I cant tell which are the 6 volt and which are the 12 volt. Ive looked on the tubes and I dont see any markings one way or the other.

If I fire up my Glenn with incorrect voltage setting what will happen to amp and tubes? Better yet,are there any telltale markings that im unaware of so I can figure out the correct voltage?


----------



## L0rdGwyn

Monsterzero said:


> Question for all but especially the GOTL owners, current or past.
> 
> About a year ago I bought up a ton of Sylvania 6 and 12J5s as I loved the sound but one was rather noisy....Anyways I had them organized so I could tell which were which. Unfortunately my "organizing" was disrupted by a mancave remodel we did awhile back. Now I cant tell which are the 6 volt and which are the 12 volt. Ive looked on the tubes and I dont see any markings one way or the other.
> 
> If I fire up my Glenn with incorrect voltage setting what will happen to amp and tubes? Better yet,are there any telltale markings that im unaware of so I can figure out the correct voltage?



Hey @Monsterzero , without any markings on the tube to identify the model, you will be hard-pressed to differentiate a 6V from a 12V tube, they are often identical from a construction standpoint.  If you posted some pictures, I might be able to pick some out to say which is which, but can't guarantee it.

Another approach is to put the tubes in the GOTL with the driver voltage set to 6V, the 12V tubes will not operate correctly being run under voltage, but should not be damaged.  The damage comes from running the heaters over voltage, running a 6V tube with the switch set to 12V, for example.

Pop them in and see which ones work at 6V, the ones that don't are 12V.


----------



## GDuss

Monsterzero said:


> Question for all but especially the GOTL owners, current or past.
> 
> About a year ago I bought up a ton of Sylvania 6 and 12J5s as I loved the sound but one was rather noisy....Anyways I had them organized so I could tell which were which. Unfortunately my "organizing" was disrupted by a mancave remodel we did awhile back. Now I cant tell which are the 6 volt and which are the 12 volt. Ive looked on the tubes and I dont see any markings one way or the other.
> 
> If I fire up my Glenn with incorrect voltage setting what will happen to amp and tubes? Better yet,are there any telltale markings that im unaware of so I can figure out the correct voltage?



I'm sure there is a better way to do this, but I've had this problem before and the safest thing to do is to put the amp in 6V mode and try the tubes.  If they are 12V they will barely light up.  The 6V tubes will be bright.


----------



## Monsterzero

Thanks gentlemen!


----------



## L0rdGwyn

Monsterzero said:


> Thanks gentlemen!



Happy to help  always up for talking tubes.


----------



## L0rdGwyn (Sep 27, 2020)

Here are some tubes I don't think have been shown here yet, Italian-made Sicte 6J5GT, I like the Dr. Seuss-esque boxes.


 

Admittedly, they are not the most resolving of the 6J5 tubes, but they have a nice, slightly warm tonality that is very pleasing, much like Fivre tubes.


----------



## GDuss

L0rdGwyn said:


> Here are some tubes I don't think have been shown here yet, Italian-made Sicte 6J5GT, I like the Dr. Seuss-esque boxes.
> 
> 
> 
> Admittedly, they are not the most resolving of the 6J5 tubes, but they have a nice, slightly warm tonality that is very pleasing, much like Fivre tubes.



This requires the obligatory question of how to pronounce Sicte  . The discussion on how to pronounce Fivre is a few pages back. I don't think that one was settled, maybe this one won't be either.


----------



## L0rdGwyn

GDuss said:


> This requires the obligatory question of how to pronounce Sicte  . The discussion on how to pronounce Fivre is a few pages back. I don't think that one was settled, maybe this one won't be either.



Lol I typed it into Google translate, sounds like "seek-tay", who knows if that's right but I'm going with it!

Doing the same with Fivre results in "feev-ray" with a slightly rolled R.


----------



## CAJames

They are beautiful tubes, regardless.

As for pronunciation, I drew a first round bye this time.


----------



## Ripper2860

I have a Fivre and Sicte 6SN7GT tubes on their way to me from a HF friend.  Granted they're not single triode, but I'm anxious to see how they sound.


----------



## L0rdGwyn

@Ripper2860 you are in for a treat, they are up there with some of the best!  Think I still have some gray and black plate Fivre 6SN7GT hiding somewhere...but no amp for them


----------



## whirlwind

Monsterzero said:


> Question for all but especially the GOTL owners, current or past.
> 
> About a year ago I bought up a ton of Sylvania 6 and 12J5s as I loved the sound but one was rather noisy....Anyways I had them organized so I could tell which were which. Unfortunately my "organizing" was disrupted by a mancave remodel we did awhile back. Now I cant tell which are the 6 volt and which are the 12 volt. Ive looked on the tubes and I dont see any markings one way or the other.
> 
> If I fire up my Glenn with incorrect voltage setting what will happen to amp and tubes? Better yet,are there any telltale markings that im unaware of so I can figure out the correct voltage?




I agree that the Sylvania 6J5/12J5 tubes sound great.
All of the 12J5 tubes that I own have the plastic base.
As already stated as long as you leave your setting at 6 volt  I think you can figure it out just don't use 12 volt setting while testing


----------



## Velozity

NOS Brimar 6C5G popped up today.  Get them while you can...

https://www.ebay.com/itm/313236390777


----------



## GDuss

Velozity said:


> NOS Brimar 6C5G popped up today.  Get them while you can...
> 
> https://www.ebay.com/itm/313236390777



Wow, only 1 left already.  And less than I paid from Langrex.  Hopefully they went to people in this thread and not to BangyBang who will charge way more for them later.


----------



## chrisdrop

GDuss said:


> Wow, only 1 left already.  And less than I paid from Langrex.  Hopefully they went to people in this thread and not to BangyBang who will charge way more for them later.


I've been wanting a pair, so I got 2. Tx @Velozity.


----------



## GDuss

chrisdrop said:


> I've been wanting a pair, so I got 2. Tx @Velozity.



Great to hear, I hope you like them.  Those are the only Brimar tubes I have so I can't say if they sound like Brimars.  They sound great though.  And no, I'm not yet a #BrimarPusher


----------



## Velozity

GDuss said:


> Wow, only 1 left already.  And less than I paid from Langrex.  Hopefully they went to people in this thread and not to BangyBang who will charge way more for them later.




There were none sold when I posted this, so I imagine we got them all.  I bought the first six, hoping to be able to make two closely matched pairs.  I didn't know they only had 13 though.


----------



## raindownthunda

Velozity said:


> There were none sold when I posted this, so I imagine we got them all.  I bought the first six, hoping to be able to make two closely matched pairs.  I didn't know they only had 13 though.


Thanks for posting the listing here. I just snagged the last one  I have a pair of these on the way already from Martin... I couldn't resist getting the last one as a "backup" at that price.


----------



## GDuss

Glad to hear it sounds like most/all of those tubes went to people in this thread.  I still wonder what happened to the 50+ of them that Langrex had that disappeared.  I doubt the seller from today got them, unless he/she is selling them for less than Langrex (or maybe he/she got a bulk deal).  In any case, we can have a Brimar 6C5G party soon  .

As an aside, but this is kind of on topic, I bought a Crack kit from the recent sale Bottlehead had.  I figured I need to work on my amp building and mod skills, which currently don't exist, so any skills gained are more than I have now.  But I don't have any 12AU7 tubes, and I don't really want to go into the rabbit hole of those tubes.  So I'm thinking I should just build it with a 6SN7 socket (you can do that right?) and just use dual 6J5 tubes in it with an adapter.  Has anyone else done this?  I think several people on this thread have Cracks.  Is it a reasonable idea?  Is there something I am not considering?


----------



## raindownthunda (Oct 1, 2020)

GDuss said:


> As an aside, but this is kind of on topic, I bought a Crack kit from the recent sale Bottlehead had.  I figured I need to work on my amp building and mod skills, which currently don't exist, so any skills gained are more than I have now.  But I don't have any 12AU7 tubes, and I don't really want to go into the rabbit hole of those tubes.  So I'm thinking I should just build it with a 6SN7 socket (you can do that right?) and just use dual 6J5 tubes in it with an adapter.  Has anyone else done this?  I think several people on this thread have Cracks.  Is it a reasonable idea?  Is there something I am not considering?



First of all, great choice with the Bottlehead Crack! I built my crack almost a year ago and was my first real soldering project and went through the process of learning everything as well. Feel free to PM me if you have any questions. It's a fantastic sounding amp, even if it wasn't a kit!

Regarding the 6j5 adapter: YES!! I am using this and would highly recommend it. I don't think there are any gotcha's. I believe the 12au7 runs at 6V in the crack, so it's plug and play. I started out down the 12au7 rabbit hole for the first ~6 months and ended up with some very nice tubes that were a huge upgrade from stock. Then I put a deposit down for a GOTL and started researching and collecting 6j5 tubes. My strategy was to skip the 6sn7 rabbit hole altogether as my GOTL will have 2x 6j5 sockets. I got my dual 6j5 -> 12au7 adapter from @Deyan and have been using it (almost) exclusively in my Bottlehead Crack for the past several months. The results have been outstanding!! I'm currently running the 2x Sylvania 6j5g tubes with the WE421a and am in heaven.

The other day I tried putting my favorite 12au7 back in ('58 Amperex 7316 long plate foil D getter) and it didn't last very long before I was back to 6j5 land. I don't think the adapter will be leaving my amp anytime soon. Personally, I'm glad I started with the 12au7 because otherwise I wouldn't have been able to appreciate the difference. If you already have 6j5 and 6sn7 tubes I would personally not feel the need to go down the 12au7 rabbit hole, but others may disagree.

I can't speak to how much work a built-in 6sn7 socket mod would be, or if it is even possible with the stock chasis/plate dimensions. Minimally you would need to modify the aluminum top plate - even then it might not fit. Everyone I have seen who goes the 6sn7 route get an adapter. Again would recommend @Deyan due to QC issues reported with other adapters.

Here's the Deyan adapter in the 12au7 socket (please ignore the Schitt sandwich sitting next to it). It looks comically top heavy. I was honestly afraid it might be too top heavy and damage the socket, but Deyan thought it would be fine. It's turned out to be manageable as long as you're careful. As I'm typing this I'm realizing adding a socket saver might be a good idea.


----------



## GDuss

raindownthunda said:


> First of all, great choice with the Bottlehead Crack! I built my crack almost a year ago and was my first real soldering project and went through the process of learning everything as well. Feel free to PM me if you have any questions.
> 
> Regarding the 6j5 adapter: YES!! I am using this and would highly recommend it. I don't think there are any gotcha's. I believe the 12au7 runs at 6V in the crack, so it's plug and play. I started out down the 12au7 rabbit hole for the first ~6 months and ended up with some very nice tubes that were a huge upgrade from stock. Then I put a deposit down for a GOTL and started researching and collecting 6j5 tubes. My strategy was to skip the 6sn7 rabbit hole altogether as my GOTL will have 2x 6j5 sockets. I got my dual 6j5 -> 12au7 adapter from @Deyan and have been using it (almost) exclusively in my Bottlehead Crack for the past several months. The results have been outstanding!! I'm currently running the 2x Sylvania 6j5g tubes with the WE421a and am in heaven.
> 
> ...



Wow, super helpful information!!!  Thanks. I have several Deyan adapters right now, including 2 dual 6J5 to 6SN7 adapters. So I figured by using a 6SN7 socket that one of my current adapters could just go in the Crack. But maybe that’s more trouble to make it fit than its worth. I ordered on the last day of the sale and am probably at the end of the queue, so I should still have plenty of time to look into this. But it’s great to hear that dual 6J5s sound good in this amp. 

I have way more 6J5-type tubes than 6SN7 actually because almost all my SN7 tubes are 12V versions. So there really isn’t even a need for the 6SN7 socket In the Crack other than to use my current adapters. This probably just means I need to give Deyan some more business and stick to the 12AU7 socket.


----------



## chrisdrop

GDuss said:


> Wow, super helpful information!!!  Thanks. I have several Deyan adapters right now, including 2 dual 6J5 to 6SN7 adapters. So I figured by using a 6SN7 socket that one of my current adapters could just go in the Crack. But maybe that’s more trouble to make it fit than its worth. I ordered on the last day of the sale and am probably at the end of the queue, so I should still have plenty of time to look into this. But it’s great to hear that dual 6J5s sound good in this amp.
> 
> I have way more 6J5-type tubes than 6SN7 actually because almost all my SN7 tubes are 12V versions. So there really isn’t even a need for the 6SN7 socket In the Crack other than to use my current adapters. This probably just means I need to give Deyan some more business and stick to the 12AU7 socket.


I did the same thing - Deyan adapter for 6j5s
Do that 
I enjoyed making it and I like the crack 
Here it is at the office


----------



## GDuss

chrisdrop said:


> I did the same thing - Deyan adapter for 6j5s
> Do that
> I enjoyed making it and I like the crack
> Here it is at the office



Excellent laptop stickers!!!


----------



## bcowen

raindownthunda said:


> First of all, great choice with the Bottlehead Crack! I built my crack almost a year ago and was my first real soldering project and went through the process of learning everything as well. Feel free to PM me if you have any questions. It's a fantastic sounding amp, even if it wasn't a kit!
> 
> Regarding the 6j5 adapter: YES!! I am using this and would highly recommend it. I don't think there are any gotcha's. I believe the 12au7 runs at 6V in the crack, so it's plug and play. I started out down the 12au7 rabbit hole for the first ~6 months and ended up with some very nice tubes that were a huge upgrade from stock. Then I put a deposit down for a GOTL and started researching and collecting 6j5 tubes. My strategy was to skip the 6sn7 rabbit hole altogether as my GOTL will have 2x 6j5 sockets. I got my dual 6j5 -> 12au7 adapter from @Deyan and have been using it (almost) exclusively in my Bottlehead Crack for the past several months. The results have been outstanding!! I'm currently running the 2x Sylvania 6j5g tubes with the WE421a and am in heaven.
> 
> ...



My experience with 12AU7's versus 6SN7's is very similar. I have a whole tub full of 12AU7's (and subs) including Mullards, CIFTE's, Telefunkens, Brimars, Amperex 7316's (but mine are all the later 60's short plates) and a number of US makes, and none of them sound as good as the upper tier 6SN7's.  And my favorite 6SN7 right now is a pair of GEC L63's.    So to @GDuss I'll chime in with the same: skip the 12AU7 rabbit hole and go directly to the single triode of your choice. 

And on the @Deyan adapters, beyond the *much* higher quality level what I love most is his willingness to customize an adapter to whatever you want if it's at all possible.  Below is a 6922 -> 7N7 adapter he made for me that is one piece and fits perfectly into the recessed socket of the Vali 2 without having to add a socket saver.  So if you need that 12AU7 -> 6*5 adapter to be a little taller or shorter, just ask.


----------



## L0rdGwyn (Oct 1, 2020)

GDuss said:


> As an aside, but this is kind of on topic, I bought a Crack kit from the recent sale Bottlehead had.  I figured I need to work on my amp building and mod skills, which currently don't exist, so any skills gained are more than I have now.  But I don't have any 12AU7 tubes, and I don't really want to go into the rabbit hole of those tubes.  So I'm thinking I should just build it with a 6SN7 socket (you can do that right?) and just use dual 6J5 tubes in it with an adapter.  Has anyone else done this?  I think several people on this thread have Cracks.  Is it a reasonable idea?  Is there something I am not considering?



Hey @GDuss congrats on the BHC kit, it is a great entry to DIY, I think you'll be very pleased with it!

As far as building it with an octal socket rather than a 9-pin noval (12AU7 socket), it isn't a simple 1:1 switch.  The octal socket has larger dimensions and different mounting hole centers, so building the BHC to take the 6SN7 would require either modifying the stock BHC top plate or having a custom one made.

If you decide to go for it, you could potentially send the BHC top plate to Dave at Landfall and have him machine you a copy of it with the appropriate sized cutout / mounting holes for an octal socket.

If you were feeling really adventurous, you could even investigate having a pair of octal socket cutouts machined into the top plate to run 6J5 natively, but note they definitely would not fit in the position of the 9-pin socket, would likely need to be positioned on the sides of the ventilation holes in the center of the top plate. Some other layout / wiring changes might need to be made too.

This would add cost and complexity, so the other choice is to build it natively and just use 12AU7 to octal / dual octal adapters, definitely the simplest approach, just throwing some ideas out there


----------



## GDuss

Thanks Everyone.  This is all super helpful.  @L0rdGwyn , I thought about doing the dual 6J5 socket approach, but had that question about whether it would fit with the location of components under the top plate.  That is probably a level I won't go to, but I may actually consider having the top plate made with the cutout for an octal socket.  I agree with others that the adapters from @Deyan are awesome, but it looks like the dual 6J5 to 12AU7 adapter sits a bit precariously in the front of the amp (right next to the volume control, and easy to hit it, especially after a glass of wine, or a few).  I'm used to his adapters in the octal 6SN7 socket (and the C3g socket also) and those are quite sturdy in that socket.  All this said, others have used the dual 6J5 to 12AU7 adapter and not had problems, so this may just be the easiest thing to do.  Plus, who needs wine when you have Crack 

@bcowen , I totally agree, all my favorite 6SN7's are dual 6J5/6C5/L63's.  Hard to go back to the single tubes.  The only time I do these days is with a 6N7 to 6SN7 adapter, to use the Visseaux 6N7GT.


----------



## L0rdGwyn

@GDuss no problem, happy to help if you have any questions along the way.  If you end up going for the octal top plate through Landfall, Dave may even be able to powder coat it for you  he is working on getting a powder coating booth up-and-running.


----------



## raindownthunda

Wow - that was fast! Looks like someone just modded their crack to include 2x built-in 6j5 Compatible sockets:
https://www.head-fi.org/threads/crack-bottlehead-otl.476650/post-15895679


----------



## GDuss

raindownthunda said:


> Wow - that was fast! Looks like someone just modded their crack to include 2x built-in 6j5 Compatible sockets:
> https://www.head-fi.org/threads/crack-bottlehead-otl.476650/post-15895679



I just saw that too.  I like it.


----------



## L0rdGwyn

raindownthunda said:


> Wow - that was fast! Looks like someone just modded their crack to include 2x built-in 6j5 Compatible sockets:
> https://www.head-fi.org/threads/crack-bottlehead-otl.476650/post-15895679



Well there you have it!  What are the chances?  Talking about it hours apart.


----------



## CAJames (Oct 3, 2020)

TotD: The Type 37. I got a grab bag of the usual suspects, RCA (Radiotron), Philco, Hytron, Raytheon that all look nice enough, though basically indistinguishable from the Type 76s I posted about earlier. Then the last box I opened was this mesh plate beauty:







Easily the most beautiful tube I've ever seen (in real life, not counting the pictures in this thread). I had to go through a few to find 4 that weren't noisy, and they sound promising on first listen but certainly need more time to cook before I'll pass judgement.

#FoxyTube #DoubleAdapterWeekend #UX5Pimp


----------



## chrisdrop

CAJames said:


> TotD: The Type 37. I got a grab bag of the usual suspects, RCA (Radiotron), Philco, Hytron, Raytheon that all look nice enough, though basically indistinguishable from the Type 76s I posted about earlier. Then the last box I opened was this mesh plate beauty:
> 
> 
> 
> ...


Beautiful tube. These are 6.3v with the same pinout as 76s? Are they drop-in replacements for 76s? I briefly checked radiomuseum and they don't seem in the same lineage (predecessor, successor) as each other?


----------



## L0rdGwyn (Oct 3, 2020)

@CAJames beautiful tubes!  I am a sucker for globes.



chrisdrop said:


> Beautiful tube. These are 6.3v with the same pinout as 76s? Are they drop-in replacements for 76s? I briefly checked radiomuseum and they don't seem in the same lineage (predecessor, successor) as each other?



They are similar to the 76 but not an exact equivalent, likely will work fine in an amplifier made for the 76.  The 37 is the 6.3V version of the 27 (essentially), whereas the 76 is the 6.3V version of the 56.  The 76 has higher gain and transconductance than the 27/37, mu for the 76 is 13.8 whereas mu for the 37 is 9.2.

37 datasheet: https://frank.pocnet.net/sheets/021/3/37.pdf
76 datasheet: https://frank.pocnet.net/sheets/021/7/76.pdf

I may pick up a pair of 37, I think they would be nice in a very simple line preamp, don't have to deal with the wonky heater specs of the 27 or the direct-heating of the 26, thanks for the idea @CAJames .


----------



## CAJames (Oct 3, 2020)

Yes, what @L0rdGwyn said. Works fine in my WA22, but even lower gain than the 76 which is lower gain than the 6J5/L63/6SN7s. I like the sound, kinda tubey like the 76 but more spacious like the 6J5GTs. Keepers for sure and recommended with the caveat you either need to buy them from someone (you trust) who has listened to them first or buy spares because they have by far the highest ratio of noisy to good tubes of any in my experience.


----------



## chrisdrop

chrisdrop said:


> And now, a first post. *Mullard 6J5G*
> 
> I heard from another head-fier that these "brown base" Mullards are an uncommon variety. I did a bit of googling and it seems the same is true of other Mullard tubes too, brown base seems rarer. That is, a happy accident for me, not any of my tube-smarts. These came via Billington here in the UK. I highly recommend them. Always top quality and excellent service.
> 
> ...


Of note, I am on these today, on the Blue Halo. I like them a lot more on this amp than I did on the GOTL. I liked them, but on the other amp, they are among the best I've rolled in. Oddly, for several tubes my "favourites" on the Glenn are not my favourites on the Blue Halo. Mysteries of valves I guess...


----------



## leftside

chrisdrop said:


> Of note, I am on these today, on the Blue Halo. I like them a lot more on this amp than I did on the GOTL. I liked them, but on the other amp, they are among the best I've rolled in. Oddly, for several tubes my "favourites" on the Glenn are not my favourites on the Blue Halo. Mysteries of valves I guess...


I too like the 76 in Mischa's amp. I'm not sure about you, but they give the amp a lightier/airy sound which can be good for some recordings. I also find them similar to the 6C5. As per usual, and in different amps, this might not be the same for everyone.


----------



## whirlwind (Oct 3, 2020)

chrisdrop said:


> Of note, I am on these today, on the Blue Halo. I like them a lot more on this amp than I did on the GOTL. I liked them, but on the other amp, they are among the best I've rolled in. Oddly, for several tubes my "favourites" on the Glenn are not my favourites on the Blue Halo. Mysteries of valves I guess...



Yeah, different tubes and different amps...pretty cool actually   

I have been burning in the VC on the same tubes, I rolled power tubes tonight and put in the Arcturus 6J5G tubes (RCA)...great stuff with the VC ...listening to John Fogerty - Centerfield album.


----------



## tintinsnowydog

Hi all, looking into this family of tubes and having a custom amp come in soon for them. I love the warmth of British tubes so am looking at the GEC L63 and black glass shoulder shaped tubes of course; what is a good going rate for them at the moment? I'm finding them for around 60 and 140 a pair respectively. Not tooo bad but certainly not cheap!


----------



## chrisdrop

tintinsnowydog said:


> Hi all, looking into this family of tubes and having a custom amp come in soon for them. I love the warmth of British tubes so am looking at the GEC L63 and black glass shoulder shaped tubes of course; what is a good going rate for them at the moment? I'm finding them for around 60 and 140 a pair respectively. Not tooo bad but certainly not cheap!


That sounds (in GBP) not too bad. You can find them for more than that. Those rates are around market price IMO.


----------



## L0rdGwyn (Oct 4, 2020)

These are the two pairs of 37 tubes I bought, not sure when I will use them, but they were super cheap $15-20 USD a pair.  They will go in my stockpile of unused tubes lol would love to build a preamp with them.  That Silvertone engraving is pretty fancy.


----------



## CAJames

L0rdGwyn said:


> These are the two pairs of 37 tubes I bought, not sure when I will use them, but they were super cheap $15-20 USD a pair.  They will go in my stockpile of unused tubes lol would love to build a preamp with them.  That Silvertone engraving is pretty fancy.



Fancy indeed, and mesh plate to boot.

I'm not going to back over 40 pages but does anyone else remember other mesh plate tubes? Fivre perhaps? Maybe my next quest will be to find 3 more mesh plate globe 37s, I've never heard a mesh plate tube.


----------



## Tom-s (Oct 4, 2020)

@CAJames Your mesh globe is probably made by Sylvania. You can find them as SY237 or Y237 sometimes on resellers list, so have a look..
They have special glow. Nice to look at.




Here's my post about them in the Crack: https://www.head-fi.org/threads/crack-bottlehead-otl.476650/page-663#post-15582020
And in this post i discus their ancestor, the mesh plate 227. https://www.head-fi.org/threads/crack-bottlehead-otl.476650/page-676#post-15689425
@L0rdGwyn I'll put that Sylvertone on my wanted list! It's a beauty! And do build a preamp for these. They easily switch out with type 76. From my experience with them, they're worth it!


----------



## CAJames (Oct 4, 2020)

Tom-s said:


> @CAJames Your mesh globe is probably made by Sylvania. You can find them as SY237 or Y237 sometimes on resellers list, so have a look..
> They have special glow. Nice to look at.
> 
> 
> ...



Thank you! The hum issue gives me pause about going all in on this tube. Perhaps I'll just get a nice display base for the one I have.


----------



## L0rdGwyn

Tom-s said:


> @L0rdGwyn I'll put that Sylvertone on my wanted list! It's a beauty! And do build a preamp for these. They easily switch out with type 76. From my experience with them, they're worth it!



They really are!  Hope the sound matches, sounds like it will  and I am liking the preamp idea, not sure when, but type 27 line preamps are quite popular builds, the 37 is a natural replacement since it has more favorable heater specs and they are so cheap.  And should be quite easy to find a happy medium bias point to use 76 as drop-ins as well for a little more gain!  A build with these tubes should be quite compact with a low part count (and low cost), think battery grid bias would be well-suited to only have a single film cap in the signal path for ultimate clarity, would CCS load the 37, so power supply would be very simple...anyway, I am getting ahead of myself, probably wouldn't be until sometime next year.


----------



## leftside

tintinsnowydog said:


> Hi all, looking into this family of tubes and having a custom amp come in soon for them. I love the warmth of British tubes so am looking at the GEC L63 and black glass shoulder shaped tubes of course; what is a good going rate for them at the moment? I'm finding them for around 60 and 140 a pair respectively. Not tooo bad but certainly not cheap!


If you want warm, go with RCA. I don't consider GEC warm, but maybe that's just me. You won't go wrong with a nice pair anyway  

60 pounds for a pair would be very cheap. 140 seems closer to the "going rate" for a pair that test strong or maybe even NOS.


----------



## L0rdGwyn

CAJames said:


> I'm not going to back over 40 pages but does anyone else remember other mesh plate tubes? Fivre perhaps? Maybe my next quest will be to find 3 more mesh plate globe 37s, I've never heard a mesh plate tube.



The going theory is that mesh plate tubes sound more "organic" or "lifelike" compared to their solid plate counterparts, the reason why new-production tube manufacturers make mesh variants of their popular tubes and charge a premium (Emission Labs, for example).  I have a few mesh plate MH4 and MHL4 tubes, I remember early on when experimenting with these tubes I bought into the idea, but haven't done a head-to-head in a long time.  Interestingly, like @Tom-s experienced with his mesh 37, my mesh plate MHL4 also have a 60Hz hum issue, I never looked deeply into the cause, not sure if it is external coupling or leakage from the heater.  If the mesh 37 hum I'll have to try and troubleshoot it.


----------



## bcowen

CAJames said:


> Thank you! The hum issue gives me pause about going all in on this tube. Perhaps I'll just get a nice display base for the one I have.



Cut off just enough of the bottom of the center pin to open up a hole, and stick an orange LED in there.


----------



## Xcalibur255

The mechanical damping properties of the plates themselves is superior with mesh, which eliminates some kinds of microphonics and can help keep very fine low level details from getting lost.


----------



## maxpudding (Oct 7, 2020)

Glad I found this thread, thank you CD!

Could anyone help me identify the date code of this fivre 6c5g tube? I see D9, struggling to find info on this one.


----------



## chrisdrop

maxpudding said:


> Glad I found this thread, thank you CD!
> 
> Could anyone help me identify the date code of this fivre 6c5g tube? I see D9, struggling to find info on this one.


I'd guess D (Apr) as the month, 9 as year. Which "9" is unknown. I don't have any good source for Fivre date codes. The FIvre 6C5Gs that I have - their inner cylinder (grid?) is smooth, whereas this one is mesh. Mine are marked '52, so perhaps these are 49?? VERY guess-driven here!


----------



## maxpudding

chrisdrop said:


> I'd guess D (Apr) as the month, 9 as year. Which "9" is unknown. I don't have any good source for Fivre date codes. The FIvre 6C5Gs that I have - their inner cylinder (grid?) is smooth, whereas this one is mesh. Mine are marked '52, so perhaps these are 49?? VERY guess-driven here!



Thanks CD! Yeah, there’s not a lot of info for fivre tubes that I can find, it could be ‘59, or 69?? But it’s a black base so maybe between the 50s or 60s? Need more opinion from the valve gurus around here 

I have three more fivre tubes coming in from Italy, I’ll share more photos once they have arrived.


----------



## L0rdGwyn

I haven't come across a reliable source for Fivre date codes either, sometimes it is obvious on the tax exemption decals but more often than not it isn't!  If the 9 does signify the year based on the construction it is more likely 1949, the shouldered 6C5G are quite old, black bases are even older than brown.  By the late 50s/60s, straight bottle "GT" tubes were pretty standard.  The mesh thing on the inside is a electrostatic shield grounded via pin 1.


----------



## maxpudding

L0rdGwyn said:


> I haven't come across a reliable source for Fivre date codes either, sometimes it is obvious on the tax exemption decals but more often than not it isn't!  If the 9 does signify the year based on the construction it is more likely 1949, the shouldered 6C5G are quite old, black bases are even older than brown.  By the late 50s/60s, straight bottle "GT" tubes were pretty standard.  The mesh thing on the inside is a electrostatic shield grounded via pin 1.



Appreciate your reply, LG. So it is probably a very old tube then. Is the mesh unique for 6C5G tubes? I have only seen the mesh thing in this tube type, wonder if there’re other tubes that have similar structure in their tube design.


----------



## L0rdGwyn

maxpudding said:


> Appreciate your reply, LG. So it is probably a very old tube then. Is the mesh unique for 6C5G tubes? I have only seen the mesh thing in this tube type, wonder if there’re other tubes that have similar structure in their tube design.



No problem  the internal shield isn't really unique to the 6C5, there are other tubes that had internal shielding too.  The shield serves the same function as the metal envelope of the American-made metal 6J5 / 6C5, it will shunt some noise to ground rather than it being picked up by the internal elements of the tube.  The 6C5G is sort of a converted 6J7G pentode, the same guts are used, including the internal shield, but the pentode is strapped internally to function as a triode.  I showed an example of this in the post here: https://www.head-fi.org/threads/the-reference-6j5-thread-l63-6c5-12j5-6p5-etc.934653/post-15771791


----------



## maxpudding

L0rdGwyn said:


> No problem  the internal shield isn't really unique to the 6C5, there are other tubes that had internal shielding too.  The shield serves the same function as the metal envelope of the American-made metal 6J5 / 6C5, it will shunt some noise to ground rather than it being picked up by the internal elements of the tube.  The 6C5G is sort of a converted 6J7G pentode, the same guts are used, including the internal shield, but the pentode is strapped internally to function as a triode.  I showed an example of this in the post here: https://www.head-fi.org/threads/the-reference-6j5-thread-l63-6c5-12j5-6p5-etc.934653/post-15771791



Fascinating, thank you very much for all the informative posts sir


----------



## JKDJedi

maxpudding said:


> Glad I found this thread, thank you CD!
> 
> Could anyone help me identify the date code of this fivre 6c5g tube? I see D9, struggling to find info on this one.


That looks like a museum piece. ...very nice


----------



## tintinsnowydog (Oct 10, 2020)

Just scored a single GEC grey glass 6J5G and an Osram A1834 for $5 each amongst a small lot of other used tubes. Fingers crossed they'll test ok when they arrive. Have a bunch of L63/6J5s coming in from Martin Billington too, shipping to Aus will take a while though. They will work for sure  Excited to roll them when they arrive!

Checking tester manuals and different settings are specified for 6J5/6C5; are their characteristics slightly different?


----------



## L0rdGwyn

@tintinsnowydog nice find!  That's a steal, especially for the A1834.  The curves for the 6J5 / 6C5 are slightly different, with the 6J5 having a lower plate resistance and higher transconductance, close enough to be interchangeable though.

6J5 datasheet: https://frank.pocnet.net/sheets/049/6/6J5.pdf

6C5 datasheet: https://frank.pocnet.net/sheets/127/6/6C5.pdf


----------



## tintinsnowydog

L0rdGwyn said:


> @tintinsnowydog nice find!  That's a steal, especially for the A1834.  The curves for the 6J5 / 6C5 are slightly different, with the 6J5 having a lower plate resistance and higher transconductance, close enough to be interchangeable though.
> 
> 6J5 datasheet: https://frank.pocnet.net/sheets/049/6/6J5.pdf
> 
> 6C5 datasheet: https://frank.pocnet.net/sheets/127/6/6C5.pdf



Ah interesting, thanks for that info! The hickok manuals have the 6C5 at 2000 and 6J5 at 2600 transconductance with all same settings except for suppressor. I assume the difference is due to the pentode vs triode internals mentioned above?


----------



## bcowen

tintinsnowydog said:


> Ah interesting, thanks for that info! The hickok manuals have the 6C5 at 2000 and 6J5 at 2600 transconductance with all same settings except for suppressor. I assume the difference is due to the pentode vs triode internals mentioned above?



Interesting. My 752A has the same socket settings for both tubes with no difference in the suppressor. The 6C5 has a bias setting of 21, uses the x2 multiplier and a min good of 625 versus 23, x4, and 400 for the 6J5 (same as the 6SN7).  But doing the math, the multiplied bogey value would mimic what you're seeing of 2000 and 2600 respectively, noting that all the min good values for the 752A are listed in increments of 25 which is probably to correspond with the meter markings rather than going after pure mathematical accuracy.


----------



## CAJames (Oct 10, 2020)

tintinsnowydog said:


> Ah interesting, thanks for that info! The hickok manuals have the 6C5 at 2000 and 6J5 at 2600 transconductance with all same settings except for suppressor. I assume the difference is due to the pentode vs triode internals mentioned above?



6C5 is a triode, not a pentode,  at least in all the datasheets I've seen so I don't know where the suppressor comes in, unless it is just based on the pinout. My TV-7 shows test settings exactly the same as 6J5 except bias is 21 for C and 23 J.


----------



## JKDJedi (Oct 10, 2020)

Anyone else rockn these *Zenith 6J5G*? @therremans led me to these guys and they're quickly growing on me. Seems like they are either you love em or hate em kinda tube.


----------



## chrisdrop

Brimar 6C5Gs arrived and in use. Good recommendation. Nice right away, dead silent and sounding all-around happy.






Here are some reference songs that I use when benchmarking new valves, components. 

Here are non-electronic references that I use 1) for guests, 2) benchmarking.

Radiohead - Everything in its right place [Tidal, Spotify, Youtube]
Barbara Lynn - You'll Lose A Good Thing [Tidal, Spotify, Youtube]
Diana Krall - Temptation [Tidal, Spotify, Youtube]
Mats Norrefalk - Longe Pode Estar Muito Perto [Tidal, Spotify, Youtube]
Feist - The Limit to Your Love [Tidal, Spotify, Youtube]
Electronic - by far most of my listening (this evolves faster than the non-electronic list):

Liam Back - Vapor Mountain [Tidal, Spotify, Youtube]
Martin Nonstatic - Ligand  [Tidal, Spotify, Youtube]
edapollo - Undercurrents (ft. Koresma) [Tidal, Spotify, Youtube] 
Molife - Spark [Tidal, Spotify, Youtube]
State Azure - Peninsula [Tidal, Spotify, Youtube]


----------



## CAJames

I've been thinking about posting demo tracks myself. Some of mine are:

Rebecca Pidgeon - Spanish Harlem (anyone really need/want a link for this?, its a cliche I know but it was on a demo disc that came with my amps back in the 90's and I've been listening to it for a long long time)

Dave Grusin Lee Ritenour  - Harlequin [YouTube]

Herbie Hancock - Cameleon [YouTube]

von Karajan - Bruckner -  Symphony Nr. 5 (4th Movement)   [YouTube]

John Eliot Gardiner - Bach - Mass in B Minor (Cum Sancto Spiritu) [YouTube]

Fritz Reiner - Rimsky-Korsakov - Scheherazade (4th Movement) [YouTube]

Dire Straits - Telegraph Road [YouTube]

Zep - In the Light [YouTube]

I'm generally not into "electronic" but I had your tracks on while I was working on this post and enjoyed it a lot.


----------



## CAJames

JKDJedi said:


> Anyone else rockn these *Zenith 6J5G*? @therremans led me to these guys and they're quickly growing on me. Seems like they are either you love em or hate em kinda tube.



I have some Zenith 6J5Gs, but they don't look like that, and I don't have 4 of them so I can't tell you how they sound specifically. I was just starting to listen to 6J5Gs when my GEC L63s showed up and I got side tracked. The 6J5Gs are actually queued up to go in next, but I can't stop stop listening to the 37s  .

#UX5Pimp


----------



## leftside (Oct 11, 2020)

chrisdrop said:


> Brimar 6C5Gs arrived and in use. Good recommendation. Nice right away, dead silent and sounding all-around happy.
> 
> 
> 
> ...


Does it drive anyone else nuts when the instruments are all in the left speaker and the vocals are in the right speaker? I tend to like my vocals centered. Yeah it's probably just me... I thought the track afterwards "Heartbreaking Years" was better.

When I have friends come over to listen, I ask them what they would like to listen to - and then do a search with Roon/Tidal. Music is so diverse with so many different tastes. But, it does seem "Telegraph Road" appears on a lot of "reference" lists. Yes even mine.

That Diana Krall track is nice on "HiFi" on Tidal. I can see why she comes up on a lot of audiophile lists. Great voice and production. With vocals and instruments separated where they should be


----------



## CAJames

leftside said:


> Does it drive anyone else nuts when the instruments are all in the left speaker and the vocals are in the right speaker?



Ha! "Beatles Stereo." I wouldn't say it drives me nuts, but I'm not a fan. My Audio Research preamps had a mono switch that I found to be a good solution but I lost that when I moved to the WA22.


----------



## Velozity

chrisdrop said:


> Brimar 6C5Gs arrived and in use. Good recommendation. Nice right away, dead silent and sounding all-around happy.
> 
> 
> 
> ...





Yep, the Brimar 6C5G is just all-around kick-ass.  Last week I received my 6 piece order from that eBay listing as well.  Unfortunately one tube tested low, but the seller refunded me so still a smooth transaction all around.  The other 5 test NOS as advertised.  I'll keep that seller on my radar.


----------



## bcowen

leftside said:


> Does it drive anyone else nuts when the instruments are all in the left speaker and the vocals are in the right speaker? I tend to like my vocals centered. Yeah it's probably just me... I thought the track afterwards "Heartbreaking Years" was better.
> 
> When I have friends come over to listen, I ask them what they would like to listen to - and then do a search with Roon/Tidal. Music is so diverse with so many different tastes. But, it does seem "Telegraph Road" appears on a lot of "reference" lists. Yes even mine.
> 
> That Diana Krall track is nice on "HiFi" on Tidal. I can see why she comes up on a lot of audiophile lists. Great voice and production. With vocals and instruments separated where they should be



This is another Dire Straits favorite. The LP is an absolutely superb recording, and it sounds quite good on Tidal too. Just happy nobody has screwed it up with a remaster...yet.


----------



## bcowen (Oct 12, 2020)

My first 6C5, and my first tin can too. Measures nicely at 2400 GM on the Hickok (minimum is 1350).  I was pretty disappointed at first -- no reading at all on the 2nd triode.  Duh. Pushing that 2nd triode button becomes an ingrained habit after testing a few thousand 6SN7's I guess.    Now all I need is a partner for it...


----------



## GDuss

bcowen said:


> My first 6C5, and my first tin can too. Measures nicely at 2400 GM on the Hickok (minimum is 1350).  I was pretty disappointed at first -- no reading at all on the 2nd triode.  Duh. Pushing that 2nd triode button becomes an ingrained habit after testing a few thousand 6SN7's I guess.    Now all I need is a partner for it...



1944 Ken Rad.  Nice.  Back when they were the real Ken Rad, not the GE Ken Rad.


----------



## bcowen

GDuss said:


> 1944 Ken Rad.  Nice.  Back when they were the real Ken Rad, not the GE Ken Rad.



Totally.  I figure anything 1944 or earlier is completely safe from GE ruination. Probably most of '45 as well, as I don't think even GE could totally wreck things in less than a year.


----------



## GDuss

bcowen said:


> Totally.  I figure anything 1944 or earlier is completely safe from GE ruination. Probably most of '45 as well, as I don't think even GE could totally wreck things in less than a year.



I've had good luck with '45 Ken Rad.

Regarding GE, I recently got a pair of 6AS7GA's, from 1959/1960 and labeled as Hewlett Packard, they were less expensive than those ones from parts express.  I actually like them.  Surprising.  But maybe it's because they are older.


----------



## GDuss

I should also note that I am coming around on the GEC L63 tubes.  I haven't been a fan thus far.  Not that they are unlistenable, far from it.  Just not my favorites.  But they're growing on me as I've been making an effort to spend more time with them.  Maybe I'm just getting used to them.  Or maybe they are burning in.  Or both.  I'm definitely not ready to buy any more to have backups, so don't worry about them disappearing.  At least not because of me.


----------



## JKDJedi

@bcowen lifted my tester from the grave .  Huge thanks partner.  On call today and nothing better than rolling and testing new and old tubes ... (Kinda wish I had that glass of wine)


----------



## bcowen

JKDJedi said:


> @bcowen lifted my tester from the grave .  Huge thanks partner.  On call today and nothing better than rolling and testing new and old tubes ... (Kinda wish I had that glass of wine)



My pleasure. Always fun to give a good tester a new lease on life.    

Now test those L63's and tell @GDuss they measure like crap.  Quick.  Before he changes his mind and starts hoarding what's left.


----------



## GDuss

bcowen said:


> My pleasure. Always fun to give a good tester a new lease on life.
> 
> Now test those L63's and tell @GDuss they measure like crap.  Quick.  Before he changes his mind and starts hoarding what's left.



I'm not buying any more tubes.  

I've move on to "spring rolling"


----------



## bcowen

GDuss said:


> I'm not buying any more tubes.


----------



## bcowen

GDuss said:


> I've move on to "spring rolling"



Do they make a significant difference?  I've played with a lot of different footers in my day, but never tried springs.


----------



## GDuss

bcowen said:


>



This forum needs a dedicated emoji for the statement "I'm not buying any more tubes" and another emoji for the response to that statement.


----------



## GDuss

bcowen said:


> Do they make a significant difference?  I've played with a lot of different footers in my day, but never tried springs.



I think they do, but it's hard to A-B them quickly given the weight of the amp and how awkward it would be to swap them out.  But since they were only $35, why not just keep them under the amp.

Also, I blame @chrisdrop for the idea, as usual .


----------



## CAJames

GDuss said:


> I should also note that I am coming around on the GEC L63 tubes.  I haven't been a fan thus far.  Not that they are unlistenable, far from it.  Just not my favorites.  But they're growing on me as I've been making an effort to spend more time with them.  Maybe I'm just getting used to them.  Or maybe they are burning in.  Or both.  I'm definitely not ready to buy any more to have backups, so don't worry about them disappearing.  At least not because of me.



FWIW my first batch of L63s sounded fantastic right out of the box. The second, not so much. Probably took 20 hours before they sounded like I expected.


----------



## leftside

Cheap metal base Sylvania:
https://www.ebay.co.uk/itm/2-SYLVANIA-6J5-RADIO-VACUUM-TUBES-TESTED/293782559688


----------



## Xcalibur255

I wish sellers would post more top-down pictures.  I've gotten too many pairs with mismatched grid post material (copper and steel) so now I won't buy anything unless I can clearly confirm in the photos that the construction is actually identical.


----------



## JKDJedi

Xcalibur255 said:


> I wish sellers would post more top-down pictures.  I've gotten too many pairs with mismatched grid post material (copper and steel) so now I won't buy anything unless I can clearly confirm in the photos that the construction is actually identical.


$10 was worth a roll of the dice for me...In Da Mail!!


----------



## chrisdrop (Oct 15, 2020)

Fivre 6J5GTs - not a bad price. He also has Visseaux 6J5G (more expensive) and Silvertone (Sylvania)  6P5Gs not a bad price.


----------



## JKDJedi

chrisdrop said:


> Fivre 6J5GTs - not a bad price. He also has Visseaux 6J5G (more expensive) and Silvertone (Sylvania)  6P5Gs not a bad price.


I was told Silvertone were National Unions ? And thanks for the links!


----------



## chrisdrop

JKDJedi said:


> I was told Silvertone were National Unions ? And thanks for the links!


Maybe Silvertone has rebranded many.
I  have some Silvertone branded tubes that have Sylvania manufacturing codes on them.
I was probably presumptuous to assume all Silvertones are Sylvania just because some are.


----------



## Velozity

Did you see those 6J5MGT Visseaux tubes he has?  Sick!  I want those just to display.  They look like silver bullets.  Sadly he doesn't ship to the US though


----------



## CAJames (Oct 15, 2020)

Yes, Silvertone rebrands many. I have Silvertone branded Sylvanias as well and probably RCAs.


----------



## GDuss

Velozity said:


> Did you see those 6J5MGT Visseaux tubes he has?  Sick!  I want those just to display.  They look like silver bullets.  Sadly he doesn't ship to the US though



Do 6J7MG's count?



These came sealed in the original plastic bag.


----------



## bcowen

Velozity said:


> Did you see those 6J5MGT Visseaux tubes he has?  Sick!  I want those just to display.  They look like silver bullets.  Sadly he doesn't ship to the US though



You might send him a message through Ebay.  He doesn't have calculated rates for US shipping set up in the listing, but he might still be willing to ship across the pond.


----------



## JKDJedi

chrisdrop said:


> Maybe Silvertone has rebranded many.
> I  have some Silvertone branded tubes that have Sylvania manufacturing codes on them.
> I was probably presumptuous to assume all Silvertones are Sylvania just because some are.


I don't know for sure myself, and if it has Sylvania codes...it's a Sylvania. 😁


----------



## tintinsnowydog

chrisdrop said:


> Fivre 6J5GTs - not a bad price. He also has Visseaux 6J5G (more expensive) and Silvertone (Sylvania)  6P5Gs not a bad price.



Damn, really beautiful tubes but can't even send the seller a message. Seems like they have blocked international offers completely. Wonder if there's a way to ship it forward via ebay..


----------



## chrisdrop

tintinsnowydog said:


> Damn, really beautiful tubes but can't even send the seller a message. Seems like they have blocked international offers completely. Wonder if there's a way to ship it forward via ebay..


If among we head-fiers, we want several of his tubes, I can make him a bulk offer and ship on to wherever in the world you'd like. I don't mind. If anyone is keen, just PM me. I don't think I'm going to get any but there is a post office right across from my office so it is easy to receive there/ship across the st.


----------



## tintinsnowydog

chrisdrop said:


> If among we head-fiers, we want several of his tubes, I can make him a bulk offer and ship on to wherever in the world you'd like. I don't mind. If anyone is keen, just PM me. I don't think I'm going to get any but there is a post office right across from my office so it is easy to receive there/ship across the st.



That is super generous! I can't see what other offerings that seller has but I'm definitely interested in those fivres, love their look and your description of their sound matches what I like to hear. Possibly the visseaux as well but can't make an offer from overseas. Any other takers?


----------



## chrisdrop

tintinsnowydog said:


> That is super generous! I can't see what other offerings that seller has but I'm definitely interested in those fivres, love their look and your description of their sound matches what I like to hear. Possibly the visseaux as well but can't make an offer from overseas. Any other takers?


These are the direct links to his other relevant valves in the spirit of the thread; Visseaux-6J5MGT,  Brimar-6C5G 
(He also has a Mullard ECC31 which are harder to come by and this is a good price)

if there is enough interest I'll just offer on the batch and we might get a reasonable deal. 
(I think it is implied, but to be clear, I'll just pass them on at whatever the end cost with shipping appropriate to wherever the valves go )


----------



## tintinsnowydog

chrisdrop said:


> These are the direct links to his other relevant valves in the spirit of the thread; Visseaux-6J5MGT,  Brimar-6C5G
> (He also has a Mullard ECC31 which are harder to come by and this is a good price)
> 
> if there is enough interest I'll just offer on the batch and we might get a reasonable deal.
> (I think it is implied, but to be clear, I'll just pass them on at whatever the end cost with shipping appropriate to wherever the valves go )



I'm in for the ECC31 and the 6J5MGT pair. Possibly the lot if no other takers


----------



## maxpudding

Those brimar 6c5g tubes are beautiful, but I’ll have to pass the generous offer this time around. Thank you CD!

BTW, can the 6P5 directly replace the 6J5 tubes without using another adapter? I am waiting for a couple of adapters to arrive (thanks @Deyan), one of the adapters is specifically made for 6J5/L63 tubes, wondering if the same adapter can be used for 6p5 tubes.


----------



## Deyan

maxpudding said:


> Those brimar 6c5g tubes are beautiful, but I’ll have to pass the generous offer this time around. Thank you CD!
> 
> BTW, can the 6P5 directly replace the 6J5 tubes without using another adapter? I am waiting for a couple of adapters to arrive (thanks @Deyan), one of the adapters is specifically made for 6J5/L63 tubes, wondering if the same adapter can be used for 6p5 tubes.



You don't need another adapter.


----------



## whirlwind

I would be in for the Fivre 6J5GT


----------



## Velozity

I wanted the Visseaux but I guess I was sniped.


----------



## chrisdrop

Velozity said:


> I wanted the Visseaux but I guess I was sniped.


Sorry. After a few PMs, we negotiated most of his tubes. I'm sending them on to a few users who asked. I'll keep my eyes open for *moar toobz* !!


----------



## maxpudding

chrisdrop said:


> Sorry. After a few PMs, we negotiated most of his tubes. I'm sending them on to a few users who asked. I'll keep my eyes open for *moar toobz* !!



Thank you CD


----------



## tintinsnowydog

chrisdrop said:


> Sorry. After a few PMs, we negotiated most of his tubes. I'm sending them on to a few users who asked. I'll keep my eyes open for *moar toobz* !!


Absolute legend


----------



## GDuss

Velozity said:


> I wanted the Visseaux but I guess I was sniped.



Can you use 6J7's in your amp, maybe with an adapter to C3g sockets?  If so I'll send you my Visseaux 6J7MG's so you can try them.  Unfortunately I don't have any Visseaux 6J5MG's so I can't help with those.


----------



## JKDJedi

I played it safe with this acquisition and grabbed an econo pair of RCA 6C5G(from separate vendors) and got lucky with them matching really close. Don't know what year these are and they sound golden to my ears, kinda the same flow as the Zenith 6J5G, very close, I don't think I could tell them apart in a blind test. As good as all these 6J5 variants are ..may never roll a 6SN7 on this amp again. 😏


----------



## bcowen

JKDJedi said:


> I played it safe with this acquisition and grabbed an econo pair of RCA 6C5G(from separate vendors) and got lucky with them matching really close. Don't know what year these are and they sound golden to my ears, kinda the same flow as the Zenith 6J5G, very close, I don't think I could tell them apart in a blind test. As good as all these 6J5 variants are ..may never roll a 6SN7 on this amp again. 😏



Feel free to send all those useless and newly unloved 6SN7's to me.  Just trying to be helpful (of course) and assure you aren't featured on the next episode of 'Hoarders'.


----------



## JKDJedi

bcowen said:


> Feel free to send all those useless and newly unloved 6SN7's to me.  Just trying to be helpful (of course) and assure you aren't featured on the next episode of 'Hoarders'.


I already sent you a little something something and it's not a 6Sn7.. 😏


----------



## whirlwind

Giving the GEC L63 a spin tonight and these definitely live up to their reputation, really nice sounding tubes.


----------



## JKDJedi

whirlwind said:


> Giving the GEC L63 a spin tonight and these definitely live up to their reputation, really nice sounding tubes.


The one that started this whole thread... Watching a pair. Just waiting .. wondering if I'll ever hit the buy button. 😏


----------



## leftside

whirlwind said:


> Giving the GEC L63 a spin tonight and these definitely live up to their reputation, really nice sounding tubes.


XF2's as well (or is that another amp)? Currently running a pair in my DAC. Very, very nice tubes. Hopefully I'll also be running the L63/EL34(XF2) combi in an amp by the end of the year. Also came across EL34 Mullard metal base for a good price (for those tubes anyway). They are going in for the first time very shortly......


----------



## whirlwind

leftside said:


> XF2's as well (or is that another amp)? Currently running a pair in my DAC. Very, very nice tubes. Hopefully I'll also be running the L63/EL34(XF2) combi in an amp by the end of the year. Also came across EL34 Mullard metal base for a good price (for those tubes anyway). They are going in for the first time very shortly......



The XF2's are in a different amp. 
Nice , the metal base EL34 are the holy grail of EL34 tubes!
The XF2's are very nice in their own right.


----------



## JKDJedi

So what's with the metal cage around the plates with the 6C5 tubes? Early grid design?


----------



## Velozity

GDuss said:


> Can you use 6J7's in your amp, maybe with an adapter to C3g sockets?  If so I'll send you my Visseaux 6J7MG's so you can try them.  Unfortunately I don't have any Visseaux 6J5MG's so I can't help with those.



Actually no, my amp doesn’t have C3g sockets.  It’s fine though, thanks for offering!  I’ve got plenty of drivers now anyway.


----------



## maxpudding (Oct 18, 2020)

JKDJedi said:


> So what's with the metal cage around the plates with the 6C5 tubes? Early grid design?



Hi JKDJedi, did you mean the metal mesh thing?

LG was very kind to offer some answers when I asked about it, hopefully this would help.

https://www.head-fi.org/threads/the-reference-6j5-thread-l63-6c5-12j5-6p5-etc.934653/post-15907517


----------



## JKDJedi

maxpudding said:


> Hi JKDJedi, did you mean the metal mesh thing?
> 
> LG was very kind to offer some answers when I asked about it, hopefully this would help.
> 
> https://www.head-fi.org/threads/the-reference-6j5-thread-l63-6c5-12j5-6p5-etc.934653/post-15907517


Thanks..I think it even confused me even more..which isn't hard to do. I'm gonna google this over my coffee roll tomorrow morning. Started to _read_ this interesting thread from page 1 (made it to page15 so far)


----------



## leftside (Oct 18, 2020)

Here’s a tube worth checking out. It’s a widely used tube: E188CC/7308/6DJ8. Brent Jessee has lots of details on his website. Beware - this tube has many variations and is a total rabbit hole. But, if you have some lying around - perhaps from another piece of equipment - they are worth a try. The Siemens I’m running seem very smooth.

6J5 adapters are available. Deyan, eBay, etc.


----------



## JKDJedi

JazzVinyl said:


> Does not matter where the info is located, imo.
> If your intention is to corner the market on popular tubes, they are probably surfing all tube oriented threads.
> 
> What we need to do is behave like John D Rockafellar, and issue a code word book, for his remote business buyers to use, in communicating with the home office.
> ...


The Rabbit Has Fur...


----------



## tintinsnowydog

My city has finally come out of hard lockdown after more than 2 months. First thing I did today was go and collect some bulk boxes of tubes. Have gone through only one so far, and inside of note were these; 2 Tung Sol 6C5G, 1 Osram L63, 1 Osram A1834/6AS7 and 2 Radiotron Australia 6J5GT. These are the first of this family of tube I've got my hands on, and they both look and feel beautiful. Really digging the mesh plates on the 6C5Gs. All test NOS as well, super stoked. The L63 just needs a friend now!

I havent been able to find much info on the Radiotron Australia tubes at all. The printing is very faded but they're marked VT-94, D 'uparrow' D military designation and have support rods, no date codes as far as I can see. I'm not too familiar still with all the 6J5 constructions but wonder if any other brands are similar? I assume these were around WWII era but if anyone has a better idea would love to learn more.

As for the sound.. am waiting on a custom amp to use them, and the 2x-->6SN7 adapters I've ordered are travelling somewhere on this planet right now. Need to give the glass a bit of a cleanup but the 6AS7 sounds great right now. More photos to come hopefully


----------



## JKDJedi

tintinsnowydog said:


> My city has finally come out of hard lockdown after more than 2 months. First thing I did today was go and collect some bulk boxes of tubes. Have gone through only one so far, and inside of note were these; 2 Tung Sol 6C5G, 1 Osram L63, 1 Osram A1834/6AS7 and 2 Radiotron Australia 6J5GT. These are the first of this family of tube I've got my hands on, and they both look and feel beautiful. Really digging the mesh plates on the 6C5Gs. All test NOS as well, super stoked. The L63 just needs a friend now!
> 
> I havent been able to find much info on the Radiotron Australia tubes at all. The printing is very faded but they're marked VT-94, D 'uparrow' D military designation and have support rods, no date codes as far as I can see. I'm not too familiar still with all the 6J5 constructions but wonder if any other brands are similar? I assume these were around WWII era but if anyone has a better idea would love to learn more.
> 
> As for the sound.. am waiting on a custom amp to use them, and the 2x-->6SN7 adapters I've ordered are travelling somewhere on this planet right now. Need to give the glass a bit of a cleanup but the 6AS7 sounds great right now. More photos to come hopefully


Where did you collect this box from? Santa's Village? Nice Grab!


----------



## JKDJedi

Is it just me or do the GEC (straight bottle) L63 sound more _SolidState_ compared to Zenith, RCA, 6C5G tubes?


----------



## leftside

tintinsnowydog said:


> My city has finally come out of hard lockdown after more than 2 months. First thing I did today was go and collect some bulk boxes of tubes. Have gone through only one so far, and inside of note were these; 2 Tung Sol 6C5G, 1 Osram L63, 1 Osram A1834/6AS7 and 2 Radiotron Australia 6J5GT. These are the first of this family of tube I've got my hands on, and they both look and feel beautiful. Really digging the mesh plates on the 6C5Gs. All test NOS as well, super stoked. The L63 just needs a friend now!
> 
> I havent been able to find much info on the Radiotron Australia tubes at all. The printing is very faded but they're marked VT-94, D 'uparrow' D military designation and have support rods, no date codes as far as I can see. I'm not too familiar still with all the 6J5 constructions but wonder if any other brands are similar? I assume these were around WWII era but if anyone has a better idea would love to learn more.
> 
> As for the sound.. am waiting on a custom amp to use them, and the 2x-->6SN7 adapters I've ordered are travelling somewhere on this planet right now. Need to give the glass a bit of a cleanup but the 6AS7 sounds great right now. More photos to come hopefully


I bet those TungSols are nice.


----------



## bcowen

JKDJedi said:


> Is it just me or do the GEC (straight bottle) L63 sound more _SolidState_ compared to Zenith, RCA, 6C5G tubes?



Probably just you.

Although I don't have any Zenith or RCA 6C5's so I'm just assuming.


----------



## mordy

I don't have the L63, but there are tubes that are described as sounding more solid state, such as the Tung Sol 7236.
Possibly with certain tube combinations there might be such an effect.


----------



## L0rdGwyn

Tung-Sol 7802 fall into that category as well, great air and well-defined bass in an OTL, but definitely fall more toward the stereotypical "solid state" sound quality.


----------



## JKDJedi

mordy said:


> I don't have the L63, but there are tubes that are described as sounding more solid state, such as the Tung Sol 7236.
> Possibly with certain tube combinations there might be such an effect.


I was gonna mention the 7236, not a complaint,( that's for @bcowen to do), 😁. Just an observation, with RCA out it does loosen up, when we get to Chatham and Winged C is when the solid state comparison comes. (6as7g)


----------



## tintinsnowydog

JKDJedi said:


> Where did you collect this box from? Santa's Village? Nice Grab!


Found a guy who fixes radios and didn’t need these triode tubes. Said he bought them by the hundreds in the 70s- dont we all wish we had started collecting back then! This was his last box of triodes. Sure did feel like Christmas


----------



## JKDJedi

tintinsnowydog said:


> Found a guy who fixes radios and didn’t need these triode tubes. Said he bought them by the hundreds in the 70s- dont we all wish we had started collecting back then! This was his last box of triodes. Sure did feel like Christmas


You scored big time!


----------



## L0rdGwyn (Oct 23, 2020)

Have to stay up all night in preparation for a series of night shifts, so I am here to rant, deliriously.

I have not listened to my 45 amp in what feels like a very long time, so we need to spend some quality time together.  This amp is getting an overhaul soon, it has been buried in a pile of electronics components / tubes on my desk since there has been a flurry of activity lately, I excavated it for a listen.

Thought I would pop in some uncommon 6J5 tubes, Tung-Sol 6J5G.  I have one pair of these tubes, for whatever reason they do not show up often.  They have ladder plates and foil getters.  The ladder plates are the same in construction to a very rare version of the Tung-Sol 6SN7GT, a tube I used to have in my collection.  Last year, I did a comparison of the 6J5G tubes to the Tung-Sol 6SN7GT BGRP, and Tung-Sol 6SN7GT ladder plate.  As you might expect, the 6J5G took the blue ribbon.  This was early on in 6J5 experimentation times.

Here is the post: https://www.head-fi.org/threads/2359glenn-studio.600110/post-15152863

And here are the tubes.




So what to listen to tonight?!  I have an idea...

The other day, I went to the Rock and Roll Hall of Fame.  Despite it being in my home town, I hadn't been there in at least a decade, but some family were in town so I had to show them the sites.  In the main exhibit, they have a pretty sizable chunk dedicated to Hendrix, with many of his guitars, artwork, scribbled song lyrics, etc.  Of course I have listened to his music a ton over the years, but I was again reminded of what a virtuosic legend he was performing live...

So I am listening to some JH, my favorite performance of his being "Machine Gun" on his live album _Band of Gypsys_.  What a monster!  Terrible that his life was cut short, but amazing what he accomplished in such a short period of time.



The Tung-Sols are sounding very nice in the 45 amp, up there with some of the best in this family.  Listening to the HD650, more and more I am having these recurring "the HD650 is all I really need" thoughts, we'll see if I act on them.



Have many more hours to kill, I'll stick to the usual activities to stave off the specter of sleep: poring over tube datasheets, transformer specifications, making plans to build tube amps I absolutely should not build, mouse cursor hovering over the "Buy It Now" button for the tube flavor of the day...

The Thin White Duke is next on my stroll down classic rock memory lane


----------



## JKDJedi

L0rdGwyn said:


> Have to stay up all night in preparation for a series of night shifts, so I am here to rant, deliriously.
> 
> I have not listened to my 45 amp in what feels like a very long time, so we need to spend some quality time together.  This amp is getting an overhaul soon, it has been buried in a pile of electronics components / tubes on my desk since there has been a flurry of activity lately, I excavated it for a listen.
> 
> ...


Just when I was gonna rest my laurels the Tung Sol 6J5 gets this praise.. With Jimi at that.


----------



## GDuss

L0rdGwyn said:


> Have to stay up all night in preparation for a series of night shifts, so I am here to rant, deliriously.
> 
> I have not listened to my 45 amp in what feels like a very long time, so we need to spend some quality time together.  This amp is getting an overhaul soon, it has been buried in a pile of electronics components / tubes on my desk since there has been a flurry of activity lately, I excavated it for a listen.
> 
> ...



How do I vote Like for this post more than once?


----------



## L0rdGwyn

JKDJedi said:


> Just when I was gonna rest my laurels the Tung Sol 6J5 gets this praise.. With Jimi at that.



They don't show up often!  Especially these days, keep your eyes peeled


----------



## Xcalibur255

The Tung-Sol 6J5G is the one tube I really want to find in a clean NOS pair like you've got there.  There are other interesting ones out there of course, but this and a really nice pair of GECs in the grey glass are the only "must haves" for me.


----------



## chrisdrop (Oct 24, 2020)

I've had a few parcels come in the past 2w. Some 76s - 1 pair Wards, 1 pair Ken Rad (for which @Deyan is making some adapters), some NU 6P5GTs, and another pair of Silvertone branded 6P5Gs in. I've not yet had any 6P5s, 76s or National Union tubes, so all exploration.

I'm not sure who actually made the Silvertones.
I'm not sure how to date the NUs (the only possible code on the 6P5GTs is "KU").
76s & 6P5Gs have no clear markings to date them. Perhaps I bust out the headlamp & magnifying glass...
On Blue Halo, I've had my 1st National Union tubes in.




FWIW on GOTL I've been unable to roll out the Osram L63s I've had in since I busted broke/dismantled the one of a pair. A different angle, with the same roll. I tried to roll out from the 6BX7s to 6BL7s this week, but went back...




Here is what the Silverone 6P5Gs look like:




and here are the 76s with the NUs in their boxes.





Fun times continuing to explore this most interesting family of tubes...

EDIT: why not add what is currently happening musically:


----------



## bcowen (Oct 24, 2020)

chrisdrop said:


> I've had a few parcels come in the past 2w. Some 76s - 1 pair Wards, 1 pair Ken Rad (for which @Deyan is making some adapters), some NU 6P5GTs, and another pair of Silvertone branded 6P5Gs in. I've not yet had any 6P5s, 76s or National Union tubes, so all exploration.
> 
> I'm not sure who actually made the Silvertones.
> I'm not sure how to date the NUs (the only possible code on the 6P5GTs is "KU").
> ...




Nice!  Great pics too.  Very interested to hear your take on the 6P5's once you get a handle on them.

Found a mate for the KR 6C5 I got a couple weeks ago, and got quite lucky as its GM is within 5% of the other one.  Not sure what date the 2nd one (left) is, but since I can't see the plates, micas or getters I'm going to assume they're close enough...mostly because that makes me feel good.   These are my first tin cans, and while first listen last night didn't get me all whoopin' and hollerin' about them, they need some time to play _and_ find the best power tube to partner with to see what they're capable of.


----------



## whirlwind

L0rdGwyn said:


> Have to stay up all night in preparation for a series of night shifts, so I am here to rant, deliriously.
> 
> I have not listened to my 45 amp in what feels like a very long time, so we need to spend some quality time together.  This amp is getting an overhaul soon, it has been buried in a pile of electronics components / tubes on my desk since there has been a flurry of activity lately, I excavated it for a listen.
> 
> ...



Great post Keenan. Cool that the family got to visit the Rock & Roll Hall Of Fame. The wife and I have fallen in love with going to the East Side Market, Great Lakes Brewery and visiting the Playhouse Square area. Cleveland has quite a lot to offer and gets a bad rap, that is not deserving as far as entertainment and the like.

I think those are the same Tung Sol 6J5G that I got to listen to and I liked them a whole lot, I never chased a pair because I had a few of the 6/12 volt SN7 versions.
I will need to keep my eyes open as I know these are rare.  Killer looking amp and I bet Hendrix sounds sublime with that and HD650. 
You have just made me put some Hendrix on my to do list...maybe get to him tonight with a couple of cocktails.
We sure did lose him way to early, he could bend strings like no other.

How long have you owned the HD650 ?  I have owned one on two or three different occasions. It has a fantastic tone and is never harsh to the ears.
I know most headphones scale with better gear, but this one maybe better than most. It sure has stood the test of time which is about the best compliment you can give it.


----------



## CAJames (Oct 24, 2020)

L0rdGwyn said:


> Have to stay up all night in preparation for a series of night shifts, so I am here to rant, deliriously.
> 
> I have not listened to my 45 amp in what feels like a very long time, so we need to spend some quality time together.  This amp is getting an overhaul soon, it has been buried in a pile of electronics components / tubes on my desk since there has been a flurry of activity lately, I excavated it for a listen.
> 
> ...



Great Post! You should stay up late more often. Hendrix, Tung-Sol and the HD-650 are three great tastes that taste great together.

My name is James and the HD-650 is all I need. Pass the candle.


----------



## bcowen

CAJames said:


> Great Post! You should stay up late more often. Hendrix, Tung-Sol and the HD-650 are three great tastes that taste great together.
> 
> My name is James and the HD-650 is all I need. Pass the candle.



Apologies for going off-topic here, but have any of you HD-650 owners listened to the Drop HD-6XX as well?  I have the 6XX's but have never heard the 650's...just wondering if there is a substantial difference.


----------



## CAJames

bcowen said:


> Apologies for going off-topic here, but have any of you HD-650 owners listened to the Drop HD-6XX as well?  I have the 6XX's but have never heard the 650's...just wondering if there is a substantial difference.



Short answer is I have not. Longer answer is a few months ago I was wondering if I was missing something not having an HD-600 so I bought one on Amazon. After I week I decided I wasn't so I sent it back and got a refund.


----------



## A2029

bcowen said:


> Apologies for going off-topic here, but have any of you HD-650 owners listened to the Drop HD-6XX as well?  I have the 6XX's but have never heard the 650's...just wondering if there is a substantial difference.



I owned both at the same time. For the most part almost the same other than driver to driver differences (my HD-6XX had a very very slight dip in the treble that my HD-650s didn't have). HD-650 and HD-6XX use the same HD-650 drivers, just with a different headband, so I think the main thing to expect is normal headphone to headphone differences that would show up in the HD-650 line anyways.


----------



## L0rdGwyn

Xcalibur255 said:


> The Tung-Sol 6J5G is the one tube I really want to find in a clean NOS pair like you've got there.  There are other interesting ones out there of course, but this and a really nice pair of GECs in the grey glass are the only "must haves" for me.



Well I hope you spot a pair!  Otherwise making a pair from two singles is probably very doable...



whirlwind said:


> Great post Keenan. Cool that the family got to visit the Rock & Roll Hall Of Fame. The wife and I have fallen in love with going to the East Side Market, Great Lakes Brewery and visiting the Playhouse Square area. Cleveland has quite a lot to offer and gets a bad rap, that is not deserving as far as entertainment and the like.
> 
> I think those are the same Tung Sol 6J5G that I got to listen to and I liked them a whole lot, I never chased a pair because I had a few of the 6/12 volt SN7 versions.
> I will need to keep my eyes open as I know these are rare.  Killer looking amp and I bet Hendrix sounds sublime with that and HD650.
> ...



Thanks, Joe!  Cleveland still gets a bad rap, probably the weather has something to do with it, but it has a lot going for it from an arts and culture perspective, most people who visit the city are shocked by how it has been portrayed nationally.  Oh and it is cheap to live here, which helps if you have a bunch of expensive hobbies, not that I would know.

Those are the same Tung-Sols I sent over to you!  I've had the HD650...five years maybe?  I have bought and sold a lot of headphone in that time, but it has endured.  At this point I really only own two, the HD650 and my cocobolo Auteur.  I have found the whole "HD650 scales well" stereotype to be very true.  Moreso than other headphones I have owned, including the Auteur, the HD650 is very revealing of upstream improvements.  When making iterative changes to the amplifiers I have designed, I could pretty easily say whether or not things are trending in the right direction using the HD650.  I have found the sound translates to speakers as well, so if it sounds good on the HD650, it is going to sound good in my stereo, so it is a great amplifier design tool for me.



bcowen said:


> Apologies for going off-topic here, but have any of you HD-650 owners listened to the Drop HD-6XX as well?  I have the 6XX's but have never heard the 650's...just wondering if there is a substantial difference.





CAJames said:


> Short answer is I have not. Longer answer is a few months ago I was wondering if I was missing something not having an HD-600 so I bought one on Amazon. After I week I decided I wasn't so I sent it back and got a refund.



They are the same headphone, the difference is really aesthetic, but the sound should be identical.  I have owned every headphone in the Sennheiser HD6XX lineup up to this point (HD580, HD58X, HD600, HD650, HD660S).  The HD650, IMO, is the best of the bunch.  The HD660S is a nice headphone, but it lacks the scalability of the HD650, which also beats it out on tonality, IMO.  I came to the same conclusion on the HD600, the HD650 is a little more nuanced, and some people don't care for the more forward upper midrange of the HD600.


----------



## whirlwind (Oct 24, 2020)

> Thanks, Joe!  Cleveland still gets a bad rap, probably the weather has something to do with it, but it has a lot going for it from an arts and culture perspective, most people who visit the city are shocked by how it has been portrayed nationally.  Oh and it is cheap to live here, which helps if you have a bunch of expensive hobbies, not that I would know.
> 
> Those are the same Tung-Sols I sent over to you!  I've had the HD650...five years maybe?  I have bought and sold a lot of headphone in that time, but it has endured.  At this point I really only own two, the HD650 and my cocobolo Auteur.  I have found the whole "HD650 scales well" stereotype to be very true.  Moreso than other headphones I have owned, including the Auteur, the HD650 is very revealing of upstream improvements.  When making iterative changes to the amplifiers I have designed, I could pretty easily say whether or not things are trending in the right direction using the HD650.  I have found the sound translates to speakers as well, so if it sounds good on the HD650, it is going to sound good in my stereo, so it is a great amplifier design tool for me.
> 
> ...



Very nice, that indeed makes it a nice design tool.
The HD650 and those Tung Sol's shall make for a wonderful warm and cozy evening...I bet it will be cold there tonight.


----------



## Xcalibur255

Keenan what is the output impedance on your 45 headphone amp?  Since it apparently drives the HD650 well which is either 250 or 300 ohm (I can't remember which is correct atm).  I tried my Beyer DT880 600ohm on my 45 once and it sounded bad.  Like bedroom clock radio bad.  Ever since I have considered the amp a low impedance headphone only affair, but maybe there was something else at play instead.  The HD650 probably has the tonal balance I want, no need to go off buying 2-3K headphones when everything I need would be right there but I've been afraid they won't play nice with the amp.

Apparently the new 3rd generation Beyer T1 went all the way down to 32 ohm and people are saying it sounds similar or even more mellow than the HD650 which is very interesting to say the least.  That would be a major departure from traditional Beyer tuning, but it's something I've had my eye on and you might be interested as well.


----------



## bcowen (Oct 24, 2020)

L0rdGwyn said:


> They are the same headphone, the difference is really aesthetic, but the sound should be identical.  I have owned every headphone in the Sennheiser HD6XX lineup up to this point (HD580, HD58X, HD600, HD650, HD660S).  The HD650, IMO, is the best of the bunch.  The HD660S is a nice headphone, but it lacks the scalability of the HD650, which also beats it out on tonality, IMO.  I came to the same conclusion on the HD600, the HD650 is a little more nuanced, and some people don't care for the more forward upper midrange of the HD600.



Thanks much (and to @A2029 and @CAJames ) for the input.  I was reasonably impressed with the 6XX's out of the box, and more so after about 50 hours of loud volume "exercise."  Didn't like the stock pads very much so swapped them for some Dekoni Hybrid pads (through Drop) that I'm much happier with. Then a DIY cable with braided Neotech PCOCC copper wire, a ViaBlue 1/4" plug and Cardas cup connectors, and for a total spend of less than $300 they're a superb value to me.  But there's that stinkin' audiophile devil always perched on my shoulder whining that they can't sound this good for that little.  I need to shoot the little jerk...


----------



## L0rdGwyn (Oct 25, 2020)

Xcalibur255 said:


> Keenan what is the output impedance on your 45 headphone amp?  Since it apparently drives the HD650 well which is either 250 or 300 ohm (I can't remember which is correct atm).  I tried my Beyer DT880 600ohm on my 45 once and it sounded bad.  Like bedroom clock radio bad.  Ever since I have considered the amp a low impedance headphone only affair, but maybe there was something else at play instead.  The HD650 probably has the tonal balance I want, no need to go off buying 2-3K headphones when everything I need would be right there but I've been afraid they won't play nice with the amp.
> 
> Apparently the new 3rd generation Beyer T1 went all the way down to 32 ohm and people are saying it sounds similar or even more mellow than the HD650 which is very interesting to say the least.  That would be a major departure from traditional Beyer tuning, but it's something I've had my eye on and you might be interested as well.



I haven't measured it directly, but given typical plate resistance of the 45 is around 1.6K, with a 5K:8ohm OPT, it should be around 2-3 ohm, sort of typical for a SET amp.  Now I have a pair of 8 ohm resistors in parallel with the headphone output in my amp, such that the 45 gets its 5K load on the primary at all times.  If I remember correctly, Glenn usually runs the headphones directly off the OPT secondary.  Assuming a 5K:8 turns ratio as an example (can't remember what OPT are used in your amp, I'm sorry!), if you attach a 600 ohm load to the secondary, that _theoretically_ translates to a reflected 375K load to the primary in the ideal transformer (impedance transformation is 5000ohm / 8ohm = 625; 625*600ohm = 375K reflected primary impedance).  But real-world transformers are different from the ideal, they have limitations.  As such, with a 600 ohm load, the OPT is unlikely to actually show the 45 a 375K load, and the load will likely vary with frequency.

Not sure where this image originated, but it has been linked to me on two different occasions from different DIY folks.  It essentially illustrates the real-world limitations of an OPT.  The 6ohm load is the intended load for this particular OPT, and as you can see, the impedance is relatively flat across the audio band.  Also graphed are an open secondary (can be read as infinite secondary impedance / load), and a shorted secondary.  With the open circuit, the impedance is no longer flat across the audio band, far from it!  The maximum primary impedance the transformer is capable of is around 300K, and that is only at around 1kHz, falling rapidly at the frequency extremes.

So, my best guess as to why it sounded bad isn't so much related to the output impedance, but could be that the very high load impedance of a 600ohm headphone is pushing the OPT to their design limits, meaning the 45 is seeing an uneven load at varying frequencies.  Decreasing the load may bring the OPT back to a relatively flat impedance curve.  My guesstimation assuming the headphone is connected directly the the secondary with no parallel resistance.


----------



## L0rdGwyn (Oct 25, 2020)

@Xcalibur255 one more thing - at one point, I did measure the frequency response of the Lundahl LL1620 60mA with 8 / 16ohms in parallel with a 300ohm load, and with no parallel load, just a 300ohm secondary.  I saw no difference in the frequency response.  That would translate to a 124K primary in that transformer without any parallel resistance, but I never did try increasing the load beyond 300ohms, so I can't say for sure increasing it to 600 would have affected the FR or pushed the OPT to their limits, they seemed okay with a 300ohm secondary, so maybe your OPT would be too!  Sorry, ranting again, hope that helps somewhat.

Edit: okay last thing really, an advantage of not using parallel resistance on the output is lower THD as the higher reflected impedance flattens the load line for the output tube, so if the OPT can handle it, the second harmonic distortion will be lower.  I saw this in the measurements I mentioned above.


----------



## mordy

chrisdrop said:


> I've had a few parcels come in the past 2w. Some 76s - 1 pair Wards, 1 pair Ken Rad (for which @Deyan is making some adapters), some NU 6P5GTs, and another pair of Silvertone branded 6P5Gs in. I've not yet had any 6P5s, 76s or National Union tubes, so all exploration.
> 
> I'm not sure who actually made the Silvertones.
> I'm not sure how to date the NUs (the only possible code on the 6P5GTs is "KU").
> ...



Silvertone was the brand name used by the Sears department store for vacuum tubes. In the 30's the tubes were mainly made by National Union; later tubes mainly by Sylvania, but there may be a few other brands as well.
Perhaps the easiest way to identify who made the Silvertones is to go on eBay and compare pictures of offerings; the other way is to go to Google Images and type in the designation och look at the pictures there.
National Union date codes: I made my own list based on what I have, boxes and pictures. It is a tentative list.
 K should stand for 1947.
U could mean a four month period: U is March April / June July. It is possible that the month symbol changes with the year. Here is my little list:












*First letter:
G 1943
H 1944
I 1945
J 1946
K 1947*
GU is July 1943
HU is June 1944
HC is Oct 44
IN is May 1945
IU June 1945
IU April 45
IU March 45
Maybe somebody can make sense out of the monthly sequence?


----------



## mordy

A2029 said:


> I owned both at the same time. For the most part almost the same other than driver to driver differences (my HD-6XX had a very very slight dip in the treble that my HD-650s didn't have). HD-650 and HD-6XX use the same HD-650 drivers, just with a different headband, so I think the main thing to expect is normal headphone to headphone differences that would show up in the HD-650 line anyways.


I have the HD6XX from Drop (formerly Massdrop). It is supposed to be identical to the HD650 but with a different color, shorter cable and a 3.5mm plug. Had the HD600 a long time ago but could not get myself to like it. 
I like the HD650 and I am not alone in this - to date Drop has sold over 113,000 of them; today's price is $220. (Looks like there is hope for hi-fi after all...)
But I have an old pair from 1997 (on M0's recommendation) that I like even better - the HD250II. Better bass extension and more comfortable. Funny, the HD650 came out in 2003, and the HD 250 in 1987. 
Talk about staying power....


----------



## JKDJedi

mordy said:


> I have the HD6XX from Drop (formerly Massdrop). It is supposed to be identical to the HD650 but with a different color, shorter cable and a 3.5mm plug. Had the HD600 a long time ago but could not get myself to like it.
> I like the HD650 and I am not alone in this - to date Drop has sold over 113,000 of them; today's price is $220. (Looks like there is hope for hi-fi after all...)
> But I have an old pair from 1997 (on M0's recommendation) that I like even better - the HD250II. Better bass extension and more comfortable. Funny, the HD650 came out in 2003, and the HD 250 in 1987.
> Talk about staying power....


You wonder will all these "_new headphones" _ (this decade even) could stand the test of time like the HD650 has had. We might still be talking about these (another) 20 years from now. They do reveal the slightest nuances of said 6J5 (any tube really), can't say the same for the few (headphones) that I have on me.


----------



## Xcalibur255

@L0rdGwyn 

I'm pretty sure the output is connected directly to the OPT secondary.  My amp has LL1664 3K OPTs, and the the 16 ohm secondary tap is the one connected to the output.  Since I have no way of being sure it will work I've just never entertained the idea of getting the HD650.  They would certainly work with the OTL, but I have the Beyer and AKG for that amp.

Thanks for the explainer!


----------



## L0rdGwyn

@Xcalibur255 no worries!  Given your traffos are wired for 3K:16, what I described is less likely since the impedance transformation isn't quite so large.  Maybe it was just that famous Beyer treble  I'd be happy to lend you my HD650 if you wanna give them a test run, just let me know.


----------



## Xcalibur255

It's definitely more than elevated treble.  It just sounds........ I guess pathetic would be the word?  Which is no biggie because I didn't buy those headphones for this amp, but it had the effect of scaring me off any high Z phones for said amp which mean passing on some really attractive options sometimes including all the ZMF stuff you guys are always hyping.


----------



## Xcalibur255

Actually....... maybe I should be looking at the HD660S...... I had forgotten it existed.  Anyway this is rather off-topic for this thread so I'll "can" it.

What I should be doing instead is posting pictures of all the shiny clean pins on the 6J5Gs I spent hours cleaning the other day, but in my zeal I put them back in their boxes without taking a photo and now the effort barrier of unboxing exists.  

It's going to be a long wait for the amp these were bought for.  I'm already lined up for a fun experiment in that I was able to get my hands on Raytheon 6J5G in both the ladder plate and round plate style from the same manufacturing year (1937) so I will know exactly what contribution the plate style itself may be contributing to the sound through direct comparison.  Assuming all these tubes are actually good anyway, that's the risk of buying ahead of time.


----------



## mordy

Does anybody have experience with 6J7G? 
Also KTW 61 and KTW63?

Using a little pen knife under a large magnifying glass it usually takes me not more than a couple of minutes to clean off the oxidation off the pins.


----------



## bcowen

mordy said:


> *Using a little pen knife* under a large magnifying glass it usually takes me not more than a couple of minutes to clean off the oxidation off the pins.



How bourgeois.  * *


----------



## mordy

bcowen said:


> How bourgeois.  * *


I have a Dremel that I can rev up to 5000 RPM, but the setup time is faster for my Swiss made precision pocket knife.
What kind of bit do you use in the Dremel?


----------



## mordy

mordy said:


> I have a Dremel that I can rev up to 5000 RPM, but the setup time is faster for my Swiss made precision pocket knife.
> What kind of bit do you use in the Dremel?


And speaking of different pin cleaning methods, i once raided a children's playground and escaped with a scoopful of sand. Then I put the sand in a schnapps glass and stuck in the tube pins and twirled the tube around in the sand. A little messy until I made a cardboard shield with holes for the pins to prevent the sand from splashing out. Worked pretty well, but I had to make sure that no sand particles stuck to the pins. But I digress.....


----------



## bcowen

mordy said:


> I have a Dremel that I can rev up to 5000 RPM, but the setup time is faster for my Swiss made precision pocket knife.
> What kind of bit do you use in the Dremel?



The one pictured has a 4mm diameter hard wool felt tip. Works well on an octal base tube. It's a bit too large in diameter initially to get between the center guide pin and the (metal) tube pins, but goes between the metal pins just fine.  After it wears down a little it fits between the center guide pin as well. They make these in a 3mm diameter version that would probably work even better, but I haven't tried them as I already had a stash of the 4mm size.

https://www.amazon.com/uxcell-Mount...lja1JlZGlyZWN0JmRvTm90TG9nQ2xpY2s9dHJ1ZQ&th=1


----------



## mordy

Thanks for the answer and the link. I have more problems with oxidation on Noval 9 pin miniature tubes with the B9A base than the octal base tubes, and here the small knife blade fits between the little pins.


----------



## bcowen

mordy said:


> Thanks for the answer and the link. I have more problems with oxidation on Noval 9 pin miniature tubes with the B9A base than the octal base tubes, and here the small knife blade fits between the little pins.



Yeah, these Dremel bits are way too big for noval pins, plus you need to apply some pressure for them to be effective. Octal pins are robust enough to handle it, but I'd be worried about bending a noval pin.

Anybody ever tried an ultrasonic cleaner for a noval tube?  My wife has a small one made for cleaning jewelry....I might try a Philips ECG in it and see what happens. Worst case is it ruins the tube which would end up being a gift to humanity.


----------



## Xcalibur255

I've always used ultra fine steel wool for cleaning.  It is, of course, extremely important that no strands are left afterward because technically it could make an unintentional electrical connection between pins, but the steel wool is just the first in a multi-step proces and I'm thorough about checking them afterward.  Tearing off a chunk and rolling it into a bit of a "rope" in your palms lets you loop it around the pin then you can work it back and forth.  I wouldn't call it the easiest method, but it has the advantage of leaving a pin that is SUPER smooth with no grain.  They glide in and out of sockets beautifully without any rough feeling metal on metal contact and they shine like silver too.

I'd say it took me 2-3 hours to do seven pairs of tubes, which isn't bad considering I was also applying deoxit D100 with a Q-tip and then finishing with an alcohol cleaning to remove residue.

I also had to affix a couple of loose bases this time around so I had to bust out my now 10 year old jar of clear nail polish.  A couple of carefully applied drops works like a charm.


----------



## maxpudding

mordy said:


> Does anybody have experience with 6J7G?
> Also KTW 61 and KTW63?
> 
> Using a little pen knife under a large magnifying glass it usually takes me not more than a couple of minutes to clean off the oxidation off the pins.



I’d like to know too if someone have experience with 6J7G tubes


----------



## leftside

bcowen said:


> The one pictured has a 4mm diameter hard wool felt tip. Works well on an octal base tube. It's a bit too large in diameter initially to get between the center guide pin and the (metal) tube pins, but goes between the metal pins just fine.  After it wears down a little it fits between the center guide pin as well. They make these in a 3mm diameter version that would probably work even better, but I haven't tried them as I already had a stash of the 4mm size.
> 
> https://www.amazon.com/uxcell-Mounted-Cylinder-Polishing-Buffing/dp/B07PLJFSDV/ref=sr_1_3_sspa?dchild=1&keywords=dremel+wool+felt+4mm&qid=1603750266&s=industrial&sr=1-3-spons&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUE5Nk80MUpFTEtQTjQmZW5jcnlwdGVkSWQ9QTAxNjY3MTcxU0ZWS1JZU01YNU1MJmVuY3J5cHRlZEFkSWQ9QTA5Mjc3MjIyQ0JaUUg3QTRIM1RXJndpZGdldE5hbWU9c3BfbXRmJmFjdGlvbj1jbGlja1JlZGlyZWN0JmRvTm90TG9nQ2xpY2s9dHJ1ZQ&th=1


Ordered


----------



## mordy

A long time ago I read a scientific research paper written in the 40's on various methods of cleaning tube pins, including chemical methods (don't think ultrasonic cleaning was invented then).
The authors concluded that mechanical cleaning was the best method since it lead to metal to metal contact for best conductivity - apparently chemical methods could leave an undesirable residue.
This is the simple reason i stick to the simple method of gently scraping off the pins with my little knife - obviously any other suitable somewhat sharp instrument is equally effective.

Can't find the link now, but found another method for people who have access to guns(!):

"The easiest method I've found is to cut a small section of an ultra-fine Scotchbrite pad (the gray ones), and insert into a small section of tubing or an expended pistol cartridge case. It takes a little fiddling to find just the right size to fill the inside periphery of the case. Once you do, though, all it takes is inserting the individual pins in the center of the Scotchbrite insert- a few quick twists and the pin is polished. .357 Magnum cases work just right for octal pins, .22 Magnum for nine-pins and other smaller diameters."

Also found a link to cleaning an entire tube amp ultrasonically by dunking it in a special bath but it sounds too scary to me, and too pricey too:
http://aeaaudio.com/ultrasonic-cleaning/


----------



## GDuss

mordy said:


> Does anybody have experience with 6J7G?



I have a pair of these, so does @chrisdrop


----------



## bcowen

mordy said:


> A long time ago I read a scientific research paper written in the 40's on various methods of cleaning tube pins, including chemical methods (don't think ultrasonic cleaning was invented then).
> The authors concluded that mechanical cleaning was the best method since it lead to metal to metal contact for best conductivity - apparently chemical methods could leave an undesirable residue.
> This is the simple reason i stick to the simple method of gently scraping off the pins with my little knife - obviously any other suitable somewhat sharp instrument is equally effective.
> 
> ...



The scotchbrite/shell casing idea is pretty neat. Hadn't heard of that before, but might give it a try!  Good excuse to go "empty out" some .44 mag rounds. 

I use an ultrasonic cleaner for my LP's, but tossing an entire electronic component into an ultrasonic bath sounds like a Halloween story to me. Thinking of vintage wax-impregnated cloth wire insulation that would be destroyed with ultrasonics, old capacitors that weren't fully sealed like modern ones, etc etc.  Presumably those guys know what they're doing, but I'm not going to personally verify that.


----------



## leftside

bcowen said:


> The scotchbrite/shell casing idea is pretty neat. Hadn't heard of that before, but might give it a try!  Good excuse to go "empty out" some .44 mag rounds.
> 
> I use an ultrasonic cleaner for my LP's, but tossing an entire electronic component into an ultrasonic bath sounds like a Halloween story to me. Thinking of vintage wax-impregnated cloth wire insulation that would be destroyed with ultrasonics, old capacitors that weren't fully sealed like modern ones, etc etc.  Presumably those guys know what they're doing, but I'm not going to personally verify that.


I too use an US for my LP's and have thought about US for tube pins, but I wouldn't want any of the water to go up the pins. This is the best thread I've found on US cleaning btw:
http://vpiforum.com/viewtopic.php?f=9&t=2289

My process is fairly simple. Clean on the US 40 Hz and rinse on the VPI HW-17. If a record is particularly dirty I'll give it a pre-clean on the HW-17 as well. It's the "cleaning formulas" where people seem to complicate matters. I just put 2.5ml of Ilfotol into the tank. Also thought of adding a US 132 Hz for a second round of cleaning. Maybe one day. I go the DIY route with my US machine (cheap version from China/Amazon) and an earlier/cheaper system from cleanervinyl.


----------



## bcowen

leftside said:


> I too use an US for my LP's and have thought about US for tube pins, but I wouldn't want any of the water to go up the pins. This is the best thread I've found on US cleaning btw:
> http://vpiforum.com/viewtopic.php?f=9&t=2289
> 
> My process is fairly simple. Clean on the US 40 Hz and rinse on the VPI HW-17. If a record is particularly dirty I'll give it a pre-clean on the HW-17 as well. It's the "cleaning formulas" where people seem to complicate matters. I just put 2.5ml of Ilfotol into the tank. Also thought of adding a US 132 Hz for a second round of cleaning. Maybe one day. I go the DIY route with my US machine (cheap version from China/Amazon) and an earlier/cheaper system from cleanervinyl.



That's an excellent thread...will take a while to get through it, but thanks!

Here's another thread (even longer) that was quite helpful to me when I started. I use a solution of distilled water, Triton X-100, isopropyl alcohol and Hepastat. Simplifying things audio has never been my forte'.   And I also do a distilled water rinse/vacuum after the US cleaning (with a 20 year old VPI 16.5 that's still going strong).

https://audiokarma.org/forums/index...-developing-the-best-possible-methods.689430/


----------



## leftside

bcowen said:


> That's an excellent thread...will take a while to get through it, but thanks!
> 
> Here's another thread (even longer) that was quite helpful to me when I started. I use a solution of distilled water, Triton X-100, isopropyl alcohol and Hepastat. Simplifying things audio has never been my forte'.   And I also do a distilled water rinse/vacuum after the US cleaning (with a 20 year old VPI 16.5 that's still going strong).
> 
> https://audiokarma.org/forums/index...-developing-the-best-possible-methods.689430/


Your process is very similar to mine then. I'm also on Audiokarma occasionally. The thread I posted get's quite interesting once a guy called Neil/theeng starts posting (around page 60 I think). I too use distilled water in the US tank and some sort of "ultra pure" water for the final rinse/vacuum on the VPI. All my records have been cleaned, but some get a second/third clean if there is something new I ever want to change with the process


----------



## maxpudding

Interesting, thanks for the share guys


----------



## CAJames (Oct 30, 2020)

I'm a little late to the rusty pin discussion, but I use a thing called a "rust eraser." You can google it. I originally got one to deal with rust spots on our carbon steel kitchen knives, but it works great on corroded tube pins too, especially with a drop of DeoxIT on it.


----------



## tintinsnowydog

Had some time over the weekend and decided to go through this thread, while it was still small, and make a reference doc for all the tube types we've collectively seen/heard/owned thus far. I started it for my own benefit but decided to format it a little so it might be legible for others too. Feel free to request access and add to the doc as well, still missing many things  

Reference 6J5 doc (View --> uncheck print layout for continuous scrolling)


----------



## maxpudding

tintinsnowydog said:


> Had some time over the weekend and decided to go through this thread, while it was still small, and make a reference doc for all the tube types we've collectively seen/heard/owned thus far. I started it for my own benefit but decided to format it a little so it might be legible for others too. Feel free to request access and add to the doc as well, still missing many things
> 
> Reference 6J5 doc (View --> uncheck print layout for continuous scrolling)



Thank you!


----------



## Xcalibur255

@tintinsnowydog 

Very nice reference doc!  I think this should be stickied to the first page of this thread actually.  Maybe a mod could help with that.


----------



## chrisdrop

Xcalibur255 said:


> @tintinsnowydog
> 
> Very nice reference doc!  I think this should be stickied to the first page of this thread actually.  Maybe a mod could help with that.


I've added this to the initial post, right at the top. Tx v much


----------



## bcowen

tintinsnowydog said:


> Had some time over the weekend and decided to go through this thread, while it was still small, and make a reference doc for all the tube types we've collectively seen/heard/owned thus far. I started it for my own benefit but decided to format it a little so it might be legible for others too. Feel free to request access and add to the doc as well, still missing many things
> 
> Reference 6J5 doc (View --> uncheck print layout for continuous scrolling)



Man, that's awesome!  Many thanks for putting it all together.

Here's a couple KenRad 6C5's to add:


----------



## GDuss

tintinsnowydog said:


> Had some time over the weekend and decided to go through this thread, while it was still small, and make a reference doc for all the tube types we've collectively seen/heard/owned thus far. I started it for my own benefit but decided to format it a little so it might be legible for others too. Feel free to request access and add to the doc as well, still missing many things
> 
> Reference 6J5 doc (View --> uncheck print layout for continuous scrolling)



Nice work!!!  You need a column now that puts each of the tubes in their appropriate section on the plane:  first class, business, economy...  But remember the metal RCA 6J5's are not on the plane, they couldn't afford it, so they took the bus .


----------



## Velozity

tintinsnowydog said:


> Had some time over the weekend and decided to go through this thread, while it was still small, and make a reference doc for all the tube types we've collectively seen/heard/owned thus far. I started it for my own benefit but decided to format it a little so it might be legible for others too. Feel free to request access and add to the doc as well, still missing many things
> 
> Reference 6J5 doc (View --> uncheck print layout for continuous scrolling)




Vedddy niiiicee!


----------



## bcowen (Nov 1, 2020)

GDuss said:


> Nice work!!!  You need a column now that puts each of the tubes in their appropriate section on the plane:  first class, business, economy...  But remember the metal RCA 6J5's are not on the plane, they couldn't afford it, so they took the bus .



LOL!  You could at least grant them a seat in the lavatory so they're on the same plane. Family members should always fly together, even if they're the cousin Eddie's of the family.


----------



## GDuss

bcowen said:


> LOL!  You could at least grant them a seat in the lavatory so they're on the same plane. Family members should always fly together, even if they're the cousin Eddie's of the family.



I kept trying to get them on the plane but TSA always wants to take off their metal jackets, and they refuse to comply.  I think they would rather be in the RV with cousin Eddie anyway


----------



## GDuss

In other news, the last 3 days I've had the dual Brimar 6C5G's from Langrex in the GOTL with a pair of TS 5998's.  This combo is really working.  The 5998's are quite balanced from top to bottom with great space and detail.  Importantly, they aren't really midrange-focused to my ears.  I think this blends well with the more lush sound of the mids on the 6C5G's.  In the past I've run these Brimars with Mullard 6080's and that was too much midrange.  I think this is a better balance between the sounds of the driver and power tubes.  Maybe the Brimars would work with something like Sylvania 6080's also.


----------



## chrisdrop

GDuss said:


> In other news, the last 3 days I've had the dual Brimar 6C5G's from Langrex in the GOTL with a pair of TS 5998's.  This combo is really working.  The 5998's are quite balanced from top to bottom with great space and detail.  Importantly, they aren't really midrange-focused to my ears.  I think this blends well with the more lush sound of the mids on the 6C5G's.  In the past I've run these Brimars with Mullard 6080's and that was too much midrange.  I think this is a better balance between the sounds of the driver and power tubes.  Maybe the Brimars would work with something like Sylvania 6080's also.


I've been using Brimar 6C5Gs too in the BH for a few days, and _really_ enjoying them. 

I've not rolled them into the GOTL yet. There, I'm currently violating my tubey raison d'etre and using ... a dual triode input; Mullard ECC32 !! I'd like to hear @whirlwind's GOTL with the single input socket re-biased accordingly...


----------



## GDuss

chrisdrop said:


> I've been using Brimar 6C5Gs too in the BH for a few days, and _really_ enjoying them.
> 
> I've not rolled them into the GOTL yet. There, I'm currently violating my tubey raison d'etre and using ... a dual triode input; Mullard ECC32 !! I'd like to hear @whirlwind's GOTL with the single input socket re-biased accordingly...



Didn't you get the Brimar 6C5G's from an eBay seller fairly recently?  I think several people on this thread got them too, but I haven't heard much feedback from those purchases.


----------



## chrisdrop

GDuss said:


> Didn't you get the Brimar 6C5G's from an eBay seller fairly recently?  I think several people on this thread got them too, but I haven't heard much feedback from those purchases.


I did. Yes. I'm a fan. They are currently one of my top inputs for the BH . Currently enjoying these Brimars with:


----------



## CAJames

GDuss said:


> In other news, the last 3 days I've had the dual Brimar 6C5G's from Langrex in the GOTL with a pair of TS 5998's.  This combo is really working.  The 5998's are quite balanced from top to bottom with great space and detail.  Importantly, they aren't really midrange-focused to my ears.  I think this blends well with the more lush sound of the mids on the 6C5G's.  In the past I've run these Brimars with Mullard 6080's and that was too much midrange.  I think this is a better balance between the sounds of the driver and power tubes.  Maybe the Brimars would work with something like Sylvania 6080's also.



Just FWIW I like the Thomson (French) 6080s when I need less lush from my power tubes.


----------



## GDuss

CAJames said:


> Just FWIW I like the Thomson (French) 6080s when I need less lush from my power tubes.



Those are on my list of "almost ordered several times but haven't for some reason" tubes.  It's not like I'm a rational tube buyer (is there such a thing?) so I'm not sure why there aren't already some of them here.  But good to know for future reference.


----------



## tintinsnowydog

bcowen said:


> Man, that's awesome!  Many thanks for putting it all together.
> 
> Here's a couple KenRad 6C5's to add:


added, thanks! I have just opened up a box from a garage sale full of tubes, a couple of interesting 6J5s but they may well be rebrand, will have a closer look later and post some pictures too 

Watch out for fakes on the Thomson 6080s, there was a plague of them recently. Had one pair at one point, they are 'bright' and well detailed, but can be thin on the midrange. Sold them off as I prefer warm tubes myself.


----------



## Ollie the bear

Hi folks, I’m very new to tubes. Would you recommend me a good source to buy a pair of GEC L63 please.


----------



## chrisdrop

Ollie the bear said:


> Hi folks, I’m very new to tubes. Would you recommend me a good source to buy a pair of GEC L63 please.


These are UK tubes. My favourite UK tube seller is Billington. Of course, there is eBay - YMMV.


----------



## bcowen (Nov 2, 2020)

Ollie the bear said:


> Hi folks, I’m very new to tubes. Would you recommend me a good source to buy a pair of GEC L63 please.



In addition to Billington (with a good reputation) that @chrisdrop noted, there is Langrex who sells on Ebay as well as an internet storefront. He's also based in the UK, and I've found him to be a reliable seller over the years and responsive to problems if one occurs.

https://www.langrex.co.uk/?s=L63&post_type=product

https://www.ebay.com/itm/L63-CV1067...785746?hash=item48a5d41812:g:BK8AAOSwH7ZdeoEt


----------



## maxpudding

Apart from Billington and Langrex, I've also dealt with Brent Jessee at https://www.audiotubes.com/

Good luck!


----------



## Velozity

Great deal here, especially if the seller accepts an offer.  I'm not buying GT types anymore so passing this along:

https://www.ebay.com/itm/Qty-4-NOS-...700815?hash=item1aa879bf4f:g:VBwAAOSwFe1foBeE


----------



## whirlwind

Velozity said:


> Great deal here, especially if the seller accepts an offer.  I'm not buying GT types anymore so passing this along:
> 
> https://www.ebay.com/itm/Qty-4-NOS-...700815?hash=item1aa879bf4f:g:VBwAAOSwFe1foBeE



Great deal, these tubes sound fantastic.


----------



## tintinsnowydog (Nov 2, 2020)

Some interesting specimens I came across yesterday in the garage sale box. Unfortunately they’re all singles as far as I can find so I’ll have to keep looking for a pair to hear how they sound.
First is a philips miniwatt WM and K30 marking. K seems to be one of two unknown factory marking in the Philips date code list. 30= February 1953? Bottom open D getter marked 'made in great Britain'. Wonder if anyone has come across another?

2nd is Haltron England (but not necessarily = made in England). 3 hole plate, bottom foil getter. Top U/horseshoe shaped heater shield. No date markings as far as I can see. The internal construction seems to have similarities to 40's Sylvanias listed here https://tubeworldexpress.com/collections/preamp/6j5gt if anyone can confirm.

And since we have some resident 6J7 experts here too, I found a Radiotron Australia 6J7G, D up arrow D Australian defence force military markings. If I can find a pair and they test ok I'm happy to send them to someone here to try as I don't have any amps that use these. I have a pair of MOV Z63 too that I can include. Shipping may be a shocker...


----------



## L0rdGwyn

tintinsnowydog said:


> Some interesting specimens I came across yesterday in the garage sale box. Unfortunately they’re all singles as far as I can find so I’ll have to keep looking for a pair to hear how they sound.
> First is a philips miniwatt WM and K30 marking. K seems to be one of two unknown factory marking in the Philips date code list. 30= February 1953? Bottom open D getter marked 'made in great Britain'. Wonder if anyone has come across another?
> 
> 2nd is Haltron England (but not necessarily = made in England). 3 hole plate, bottom foil getter. Top U/horseshoe shaped heater shield. No date markings as far as I can see. The internal construction seems to have similarities to 40's Sylvanias listed here https://tubeworldexpress.com/collections/preamp/6j5gt if anyone can confirm.
> ...



Hi @tintinsnowydog, the Philips-branded tube is the same as the Mullard-branded Tottenham factory 6J5GT.  Haltron was a rebrander of many different companies, USA and European.  That black round plate with the three holes on each side is characteristic of Sylvania 6J5GT.


----------



## tintinsnowydog

L0rdGwyn said:


> Hi @tintinsnowydog, the Philips-branded tube is the same as the Mullard-branded Tottenham factory 6J5GT.  Haltron was a rebrander of many different companies, USA and European.  That black round plate with the three holes on each side is characteristic of Sylvania 6J5GT.


Awesome, thanks for the info as always! Just wondering how you determined the Tottenham factory; was it based on construction or code? Thanks


----------



## L0rdGwyn

tintinsnowydog said:


> Awesome, thanks for the info as always! Just wondering how you determined the Tottenham factory; was it based on construction or code? Thanks



Based on the construction.  Philips/Mullard acquired British Tungsram in 1952, Tungsram's factory was in Tottenham, London.  The Mullard Branded 6J5GT were made there and have some features of Tungsram made tubes because of it, particularly the top mica with the ridged edges.  With a lot of this stuff, you pick up the construction patterns after buying / shopping for lots and lots of tubes, then during some reading you come across that bit of information that confirms your suspicion and ties it all together


----------



## tintinsnowydog

L0rdGwyn said:


> Based on the construction.  Philips/Mullard acquired British Tungsram in 1952, Tungsram's factory was in Tottenham, London.  The Mullard Branded 6J5GT were made there and have some features of Tungsram made tubes because of it, particularly the top mica with the ridged edges.  With a lot of this stuff, you pick up the construction patterns after buying / shopping for lots and lots of tubes, then during some reading you come across that bit of information that confirms your suspicion and ties it all together


Got it thanks! I'm pretty confident on my constructions and dates for 6AS7 and 6SN7 but still learning for the 6J5 family so this is great knowledge


----------



## KillerQ

Hey, All,

Forgive my ignorance, but i appreciate your help in advance. 

I have rolled many 6SN7 tubes on my ember 2, and never had an issue. It’s amazing. Today, I got an adapter that goes from 2 6J5 tubes to a single 6SN7 connector that Incan plug right into my ember 2. I have two “ Matched Pair RCA 6P5 6P5G Foil Getters Shoulder ST Shape” tubes in it. 

Here are detailed pics of the adapter and the tubes: imgur.com/a/PMkfZqU

The problem is that, even through the volume level seems just the same as my other tubes, when I use the adapter, the bass seems distorted. Not overly loud and distorting, but like it can’t recreate the sound properly and it is distorted. 

Could it be that since I am using the double adapter than I now have to change some jumpers because the ember can’t drive the tubes properly or something like that?

I hope these end up working out. 

Thank you!!’


----------



## chrisdrop

KillerQ said:


> Hey, All,
> 
> Forgive my ignorance, but i appreciate your help in advance.
> 
> ...


Have you ever used these tubes? Are they NOS? Any chance the tubes themselves are noisy? Do you have 2x other tubes to try in the adapter?


----------



## KillerQ

chrisdrop said:


> Have you ever used these tubes? Are they NOS? Any chance the tubes themselves are noisy? Do you have 2x other tubes to try in the adapter?


Hi.
the tubes have more background hum Than other tubes, but that’s not the part that bothers me, it’s the distorted bass that’s annoying. I don’t have two other tubes that would fit this. I can ask the seller to send two more to test. They are nos in the sense that they are old, but I’m sure they have been used.

here’s the manual:http://www.garage1217.com/MANUALS/EMBER MANUALS/EMBER 2.1 MANUAL 5-15-16.pdf

there are lots of possible jumper settings so I wasn’t sure if there were some thingI had set wrong. I’ll ask for another set and keep you posted. Unless you have some for sale, lol. Thanks!


----------



## chrisdrop

KillerQ said:


> Hi.
> the tubes have more background hum Than other tubes, but that’s not the part that bothers me, it’s the distorted bass that’s annoying. I don’t have two other tubes that would fit this. I can ask the seller to send two more to test. They are nos in the sense that they are old, but I’m sure they have been used.
> 
> here’s the manual:http://www.garage1217.com/MANUALS/EMBER MANUALS/EMBER 2.1 MANUAL 5-15-16.pdf
> ...


I'd imagine the jumper settings to be the same for your 6SN7s, but I've not had an Ember so best not listen to me much on that.

The sources of noise are either 1) the adapter, 2) the tubes, 3) the Ember. If you swap the tubes left/right, does the bass distortion move? If it is across both channels it is probably not 1 tube. Chinese adapters can go wrong, although I'd not assume that right off. It is possible both tubes are noisy but both being noisy in a way that distorts the bass would be surprising. You could remove/reseat both tubes. Ensure pins on both tubes are clean. 

Not much more I can advise; with hope for your success/apologies!


----------



## CAJames (Nov 8, 2020)

In addition to everything @chrisdrop said, I would suggest getting several cheap metal 6J5 tubes for testing, at least. If you have the same problems with them you can  rule out  your pretty 6P5P tubes as the problem. And the metal tubes usually sound great as a bonus. I'll also point out that the 6P5 has different electrical characteristics than a 6J5/6SN7 so it is possible you might need to change a setting on your amp, although I know nothing about your Ember. The 6J5 is much closer to a 6SN7  than a 6P5.


----------



## KillerQ

Thanks!

the seller also has these RCA NOS 6J5 metal tubes for sale - maybe I should get them for testing:https://imgur.com/a/wtBNr38

In my ignorance, I figured that glass tubes are sexy and Would sound better than metal ones, haha. 


this amp has a lot of jumpers and settings available which makes it great for tube rollers. Here’s a link to the manual and specs
http://www.garage1217.com/MANUALS/EMBER MANUALS/EMBER 2.1 MANUAL 5-15-16.pdf

http://garage1217.com/garage1217_diy_tube_headphone_amplifiers_004.htm

Thanks again.


----------



## CAJames (Nov 8, 2020)

Yes, the glass tubes are sexy indeed, and often sound great. But you tend to pay for it. Don't underestimate the plain metal tubes though, they are often a great bargain. I shan't pull that thread any further, I'll leave that to @bcowen, aka "Getter Man."  

Anyway,  my 2 cents is get the metal tubes if the price is right and try them and take it from there.


----------



## KillerQ

Great. One more quick question.

This jumper on the adapter is set for 6.3V. Should it be 12.6V , or is it that way because there’s two tubes that it’s sit across on the adapter ?


----------



## CAJames

No, 6.3V is the right setting for all the tubes we're talking about. It is cool that you have the option for using 12V tubes, but that is a different discussion.


----------



## maxpudding

6J5 tubes are half of 6SN7, so you need 2 6J5's for 1 6SN7 (6.3V)


----------



## mordy

KillerQ said:


> Thanks!
> 
> the seller also has these RCA NOS 6J5 metal tubes for sale - maybe I should get them for testing:https://imgur.com/a/wtBNr38
> 
> ...


The RCA 6J5 are very good sounding tubes and should be very inexpensive. From what I read people like the 6C5/6J5 better than the 6P5 but I am not familiar with your amp.


----------



## bcowen

CAJames said:


> Yes, the glass tubes are sexy indeed, and often sound great. But you tend to pay for it. Don't underestimate the plain metal tubes though, they are often a great bargain. I shan't pull that thread any further, I'll leave that to @bcowen, aka "Getter Man."
> 
> Anyway,  my 2 cents is get the metal tubes if the price is right and try them and take it from there.



At times I've been a real go-getter.  

More often a go-pher though.


----------



## dpump

@KillerQ: you need to plug your 2-tube adaptor into the Ember 6SN7 adaptor and then plug the complete assembly into the Ember. The same way you plug a 6SN7 into the Ember 6SN7 adaptor and then plug it into the Ember.


----------



## KillerQ (Nov 8, 2020)

dpump said:


> @KillerQ: you need to plug your 2-tube adaptor into the Ember 6SN7 adaptor and then plug the complete assembly into the Ember. The same way you plug a 6SN7 into the Ember 6SN7 adaptor and then plug it into the Ember.



yes, that’s exactly how I am doing it.

https://imgur.com/a/mNkE8Uo


----------



## JKDJedi

Were the 6J5 (grey plated) Sylvania an exclusive 1951 production? (center)


----------



## KillerQ (Nov 8, 2020)

I just tried one of these ground eliminators just to test that possibility. The hum did not go away. When I unplugged the rca cables so that nothing was connected, the him actually got worse.



Buuuuuut, I solved it!!!!

The ONLY thing I found was to touch BOTH rca cables connectors with one end of the foil and then touch the other end of the foil to the tops or both tubes. The hum is 99.95 % gone. As a matter of fact, I really have to concentrate to even hear it. Here’s the image https://imgur.com/a/mZSWy2K

So, I suppose I can experiment with how little of foil I actually need to accomplish this - I just wanted to mention it right away since I was so excited.

Any thoughts on a better solution? A new, discreet ground wire somewhere on the unit instead ?


----------



## Xcalibur255

KillerQ said:


> Thanks!
> 
> the seller also has these RCA NOS 6J5 metal tubes for sale - maybe I should get them for testing:https://imgur.com/a/wtBNr38
> 
> ...


The secret of the metal can tubes is they sound just as good as the glass ones, they just cost less.  The only actual downside is you cannot see the plate/mica style so you don't if the indicated manufacturer was the actual maker or a re-brand which is something you can find out if you can see the guts of the tube.  Really, though, what matters is if they sound good to you and the metal tubes are so cheap you can buy lots of them and experiment.


----------



## mordy

Xcalibur255 said:


> The secret of the metal can tubes is they sound just as good as the glass ones, they just cost less.  The only actual downside is you cannot see the plate/mica style so you don't if the indicated manufacturer was the actual maker or a re-brand which is something you can find out if you can see the guts of the tube.  Really, though, what matters is if they sound good to you and the metal tubes are so cheap you can buy lots of them and experiment.


Some (but not all) of the all metal tubes have symbols and numbers embossed in the metal rim which also can help to identify them. Tubes like the 6J5 first came out in the mid 30's and I have seen such tubes with mid 50's dates - wonder if they were still made then or it was just old stock with newer markings.
But if the same tubes were made over a 20 year year period it is quite remarkable given all the changes.


----------



## tintinsnowydog (Nov 9, 2020)

Have just returned home today after a week out in the Australian countryside to a plethora of packages, including the tubes @chrisdrop generously forward to some of us. The custom amp I have coming in with 6J5 sockets is complete and somewhere in the mail.. In the meantime, adapters have finally arrived so I can listen! Will be playing around with what I have in the next couple of days in the crack.

First tubes I am getting to know are these Fivre 6J5GT. Was very excited for these after reading about their sound profile, as they seemed like exactly what I would enjoy. As expected, they pair perfectly with my HD800, and a Tung Sol 6080, which I find is a touch more neutral than the 5998 without being bright like the 7236, and the best for hearing what the driver tube has to offer in my setup. The Fivres have a generous touch of warmth with a killer tone, just the right amount of clean punchy bass while still being quite spacious sounding. Treble is gently rolled off but I am hearing all the technicalities, partners beautifully with a brighter headphone/setup. If this is the Fivre house sound, I'm really digging it and will certainly be on the lookout for more Fivre tubes. Not to mention they are some of the prettiest tubes and boxes I have seen! I am already convinced by this family of tubes, they are better than any 6SN7 I have tried to date.

Excuse the stack of adapters and socket savers- they are of great quality though, absolutely no hum to my great surprise and relief! I ought to rewire the input to 6SN7 some time..12AU7s are all but ignored in my storage now. 2x tubes in the input socket now also make for 2x better glow photos 

Many more tubes to try in the coming days, some expensive, some from garage sales. Exciting times!


----------



## tintinsnowydog (Nov 10, 2020)

Trying out Australian made AWV Radiotron 6J5GT today. I have 2 pairs and each individual tube seems to be slightly different in construction.. They all have in common etched D *↑* D Australian defence force marking, double metal support rods and smooth black plates which I believe is unique. Can't see inside for the getter. 2 have a wire above the top mica connecting the plate to a support gridpost, two do not. The glass bottles are a little shorter than the Fivre 6J5GT, and look very cute 


Sound is very clean, accurate and a little forward without being bright- likely due to a slight emphasis to the upper-mids but not necessarily the treble. The overall presentation is quite neutral, on the leaner side and definitely not warm, possibly due to a small recess in the upper-bass→ bass frequencies. Treble is never fatiguing,  midrange tonality as well as microdetails are excellent and musical. Soundstage is quite intimate but imaging and layering of sound is not sacrificed; complex orchestral passages are never congested. It is very comparable to a Sylvania 1940’s 6SN7 in frequency response, tonality and overall presentation.

I think this tube is ideally paired with a warmer-than-neutral power tube or system to give it a bit more bass and warmth in tonality; I preferred the 5998, RCA 6AS7G or graphite plate 6080 (in that order) over the TS6080. Graphite plate 6080 + Radiotron 6J5 was a little too emphatic in the upper mid→ treble region for my ears+setup. Overall a very pleasing tube which I managed to pick up for $10 a pair, one of which was still in original military boxes and I tested to be over 110% gm.

Edit: I'm going to leave these in to burn for a bit seeing as they are NOS and possibly unused. I can't imagine them changing too much, they are already very pleasant, but perhaps hoping for a bit more refinement in the lower frequencies.


----------



## mordy

tintinsnowydog said:


> Trying out Australian made AWV Radiotron 6J5GT today. I have 2 pairs and each individual tube seems to be slightly different in construction.. They all have in common etched D *↑* D Australian defence force marking, double metal support rods and smooth black plates which I believe is unique. Can't see inside for the getter. 2 have a wire above the top mica connecting the plate to a support gridpost, two do not. The glass bottles are a little shorter than the Fivre 6J5GT, and look very cute
> 
> 
> Sound is very clean, accurate and a little forward without being bright- likely due to a slight emphasis to the upper-mids but not necessarily the treble. The overall presentation is quite neutral, on the leaner side and definitely not warm, possibly due to a small recess in the upper-bass→ bass frequencies. Treble is never fatiguing,  midrange tonality as well as microdetails are excellent and musical. Soundstage is quite intimate but imaging and layering of sound is not sacrificed; complex orchestral passages are never congested. It is very comparable to a Sylvania 1940’s 6SN7 in frequency response, tonality and overall presentation.
> ...


----------



## tintinsnowydog (Nov 10, 2020)

For sure! Giving the amp a rest right now, hot summer days incoming down here. Will leave them in to burn for the night with a cheap GE power tube and see how they sound tomorrow. I do like buying slightly used tubes for cheaper as someone has already done the burn-in job for me, but it does feel special being the first to crack open an old box!


----------



## bcowen

tintinsnowydog said:


> For sure! Giving the amp a rest right now, hot summer days incoming down here. Will leave them in to burn for the night with a cheap GE power tube and see how they sound tomorrow. I do like buying slightly used tubes for cheaper as someone has already done the burn-in job for me, but it does feel special being the first to crack open an old box!



Nice pics!  Thanks for sharing.

And I'm impressed that you've found a good use for a GE.  I mean other than trash can ballast.


----------



## mordy

bcowen said:


> Nice pics!  Thanks for sharing.
> 
> And I'm impressed that you've found a good use for a GE.  I mean other than trash can ballast.


There are always exceptions to every rule  - although I agree with you re the GE tubes, I have found that some sound very good, notably late 30's-early 40's metal 6C5 and the 5687 tubes.


----------



## tintinsnowydog

bcowen said:


> Nice pics!  Thanks for sharing.
> 
> And I'm impressed that you've found a good use for a GE.  I mean other than trash can ballast.


GE had one other good use; being relabelled as Telefunkens so they can at least pretend to be pretty and collectible


----------



## mordy

tintinsnowydog said:


> GE had one other good use; being relabelled as Telefunkens so they can at least pretend to be pretty and collectible


And expensive.
There are Sylvania 6080 tubes that are relabeled Mullard that also go for crazy prices but at least they are very good sounding tubes.
Not to speak about the fake 6AS7 tubes made by Svetlana that regularly pop up with a authentic looking boxes under various expensive brand names.
The giveaway is always the double inverted “flying saucer” getters but some sellers know how to take pictures that hide them from sight.


----------



## bcowen

tintinsnowydog said:


> GE had one other good use; being relabelled as Telefunkens so they can at least pretend to be pretty and collectible



LOL!  I have one of those.  Makes ass sound good.


----------



## bcowen

mordy said:


> And expensive.
> There are Sylvania 6080 tubes that are relabeled Mullard that also go for crazy prices but at least they are very good sounding tubes.
> Not to speak about the fake 6AS7 tubes made by Svetlana that regularly pop up with a authentic looking boxes under various expensive brand names.
> The giveaway is always the double inverted “flying saucer” getters but some sellers know how to take pictures that hide them from sight.



I have a couple of those too. LOL!  These were made at the Svetlana plant in England.


----------



## maxpudding

bcowen said:


> I have a couple of those too. LOL!  These were made at the Svetlana plant in England.



Thanks to @mordy, whenever searching for these tubes I'll keep an eye out looking for the saucers to spot fakes lol


----------



## mordy

bcowen said:


> I have a couple of those too. LOL!  These were made at the Svetlana plant in England.


Sorry you fell in - hope you did not pay too much for the super rare Amperex tubes. In any case, the Svetlana tubes are quite good and usually very quiet.
Couldn't find any fakes on eBay today - wait, here is one from here-we-go-again Wege tubes:




You CAN sometimes (but very rarely) find GEC 1834A/6AS7G rebranded Haltron, but not these - a mere $500 incl shipping will land you these $30 Svetlanas. TELEFUNKEN (BRANDED HALTRON) #AI834 according to this price gouger and dishonest seller.

https://www.ebay.com/itm/6AS7G-TUBE...142499&hash=item3b2f3cb70e:g:ZTEAAOSwdSRZ-5XN


----------



## bcowen

mordy said:


> Sorry you fell in - hope you did not pay too much for the super rare Amperex tubes. In any case, the Svetlana tubes are quite good and usually very quiet.
> Couldn't find any fakes on eBay today - wait, here is one from here-we-go-again Wege tubes:
> 
> You CAN sometimes (but very rarely) find GEC 1834A/6AS7G rebranded Haltron, but not these - a mere $500 incl shipping will land you these $30 Svetlanas. TELEFUNKEN (BRANDED HALTRON) #AI834 according to this price gouger and dishonest seller.
> ...



I was totally ignorant when I bought those...they were one of my first purchases when I started rolling this family of tubes. Fortunately I only paid $40 delivered for the pair, so not a great deal by any means, but with the usual shipping charges from Russia for Svetlana-labeled Svetlana's not a terrible beating either.  Both test beautifully and they _are _decent sounding, so a cheap lesson. 

That wege_high_tubes guy needs to seriously consider changing his seller name to i'm_high_tubes.  He's the Italian Bangy Bang. 

Then I run across this one this morning. The C3g is not a triode, and it's not a dual...anything.  It's a single pentode. Sent the seller a message, and his response was basically to go screw myself because I didn't know what I was talking about.  I should probably send an email to Ebay about the false advertising and misrepresentation (especially with a seller that doesn't accept returns), but that's probably a total waste of time.


----------



## GDuss

bcowen said:


> I was totally ignorant when I bought those...they were one of my first purchases when I started rolling this family of tubes. Fortunately I only paid $40 delivered for the pair, so not a great deal by any means, but with the usual shipping charges from Russia for Svetlana-labeled Svetlana's not a terrible beating either.  Both test beautifully and they _are _decent sounding, so a cheap lesson.
> 
> That wege_high_tubes guy needs to seriously consider changing his seller name to i'm_high_tubes.  He's the Italian Bangy Bang.
> 
> Then I run across this one this morning. The C3g is not a triode, and it's not a dual...anything.  It's a single pentode. Sent the seller a message, and his response was basically to go screw myself because I didn't know what I was talking about.  I should probably send an email to Ebay about the false advertising and misrepresentation (especially with a seller that doesn't accept returns), but that's probably a total waste of time.



The amusing part is that's not a terrible price for Lorenz C3g tubes.  But someone is in for a surprise if they try to use them as 300B's.  There really should be some easier way to contact eBay about this and to warn buyers, but that's another discussion.


----------



## maxpudding

mordy said:


> Sorry you fell in - hope you did not pay too much for the super rare Amperex tubes. In any case, the Svetlana tubes are quite good and usually very quiet.
> Couldn't find any fakes on eBay today - wait, here is one from here-we-go-again Wege tubes:
> 
> You CAN sometimes (but very rarely) find GEC 1834A/6AS7G rebranded Haltron, but not these - a mere $500 incl shipping will land you these $30 Svetlanas. TELEFUNKEN (BRANDED HALTRON) #AI834 according to this price gouger and dishonest seller.
> ...



Found another one

https://ebay.us/TxlQ5k


----------



## mordy

bcowen said:


> I was totally ignorant when I bought those...they were one of my first purchases when I started rolling this family of tubes. Fortunately I only paid $40 delivered for the pair, so not a great deal by any means, but with the usual shipping charges from Russia for Svetlana-labeled Svetlana's not a terrible beating either.  Both test beautifully and they _are _decent sounding, so a cheap lesson.
> 
> That wege_high_tubes guy needs to seriously consider changing his seller name to i'm_high_tubes.  He's the Italian Bangy Bang.
> 
> Then I run across this one this morning. The C3g is not a triode, and it's not a dual...anything.  It's a single pentode. Sent the seller a message, and his response was basically to go screw myself because I didn't know what I was talking about.  I should probably send an email to Ebay about the false advertising and misrepresentation (especially with a seller that doesn't accept returns), but that's probably a total waste of time.


Looked at the ad - it actually says metal pentode in the description as well. Strangely enough $95/pair is less than the prices German sellers are asking for the same pair.


----------



## JKDJedi

Are these a horse of a different color or can they roll well with 6J5 amps with no compromise? 

https://www.etsy.com/listing/877701...P7uKZkxDNwxEHWl4ERR0wXsWVGpleGFBoClsUQAvD_BwE


----------



## mordy

JKDJedi said:


> Are these a horse of a different color or can they roll well with 6J5 amps with no compromise?
> 
> https://www.etsy.com/listing/877701...P7uKZkxDNwxEHWl4ERR0wXsWVGpleGFBoClsUQAvD_BwE


I have a weak spot for red tubes, but these pentode tubes do have a different pinout than the 6J5 family. Presumably they could be used with the correct adapters.


----------



## JKDJedi

mordy said:


> I have a weak spot for red tubes, but these pentode tubes do have a different pinout than the 6J5 family. Presumably they could be used with the correct adapters.


That's what I'm kinda hoping for, La Figaro 339i seems promising and within reach, might grab one on the next Drop. Now if I could get one of them 339i custom built for me with 6J5 sockets in place..  @tintinsnowydog has a really nice build done for him form the Figaro man himself (did he post about it here already?)


----------



## leftside

JKDJedi said:


> Are these a horse of a different color or can they roll well with 6J5 amps with no compromise?
> 
> https://www.etsy.com/listing/877701...P7uKZkxDNwxEHWl4ERR0wXsWVGpleGFBoClsUQAvD_BwE


Get a 6J5 adapter and these are good to go. I really like those tubes.


----------



## tintinsnowydog

tintinsnowydog said:


> Edit: I'm going to leave these in to burn for a bit seeing as they are NOS and possibly unused. I can't imagine them changing too much, they are already very pleasant, but perhaps hoping for a bit more refinement in the lower frequencies.


Reporting back after a solid 20 hours of burn-in on the Radiotron 6J5GT. Just plugged in headphones and they have definitely opened up! The previously lean bass is better; soundstage and decay is more realistic, definition and quality of lower frequencies is much improved. On its way to sounding more like a Sylvania 6SN7GTA or short bottle 6SN7W. These tubes definitely pair better with my HD650 than HD800; clean and slightly forward presentation should benefit warmer headphones/systems. 

I'm really enjoying the separation and imaging by the 6J5 family so far; placebo or not, splitting the triodes apart both look and _sound _like there are improvements over 6SN7s in spatial representation.


----------



## tintinsnowydog

So I'm reading that 6J5 is a drop in replacement for 6N7 sockets, but is the converse true too? I understand the plate and grid of 6N7 on pins 4 and 6 would be unused. Would it be appropriate to simply connect 4-5 and 3-6 on the 6J5 socket, or would the 6N7 work the same using only one plate, or are some other entirely different considerations appropriate?


----------



## chrisdrop

tintinsnowydog said:


> So I'm reading that 6J5 is a drop in replacement for 6N7 sockets, but is the converse true too? I understand the plate and grid of 6N7 on pins 4 and 6 would be unused. Would it be appropriate to simply connect 4-5 and 3-6 on the 6J5 socket, or would the 6N7 work the same using only one plate, or are some other entirely different considerations appropriate?


@A2029 wired the sockets in a few of his amps to take both 6j5 and 6n7 tubes. Seems like he can authoritatively answer your query.


----------



## CAJames (Nov 11, 2020)

tintinsnowydog said:


> So I'm reading that 6J5 is a drop in replacement for 6N7 sockets, but is the converse true too?



My reading of the data sheet says even that isn't true. 6J5 is a single triode with plate and grid on pins 3 and 5. 6N7 is a dual triode with plate(2) and grid(1) on 3 and 5. That doesn't seem like "drop in" compatible to me.


----------



## tintinsnowydog

CAJames said:


> My reading of the data sheet says even that isn't true. 6J5 is a single triode with plate and grid on pins 3 and 5. 6N7 is a dual triode with plate(2) and grid(1) on 3 and 5. That doesn't seem like "drop in" compatible to me.


I was imaging it would work fine if the two triodes of the 6N7 were wired in parallel, then the only substantial difference would be in gain. Of course I could be very wrong..


----------



## A2029 (Nov 11, 2020)

If you wire an 8 pin socket to run the 6N7 sections in parallel (I.e. strap it as a pseudo-single triode), then the 6J5 can more-or-less drop in to the same socket and bias up close(ish) to what the 6J5 bias at.

If the 6N7 is run as a dual triode, then 6J5 is not a drop in.

To wire up the socket so that it takes both 6N7 and 6J5, use a ~1K resistor between pins 4 & 5, then a separate grid stopper resistor connecting your signal to grid 5. Then also connect pins 3 & 6 together. When looking at the tube curves for the 6N7, approx 50% of the current will go through each plate, so if the overall tube is biased at say 5mA, then you would look at the 2.5mA bias point. Note that the cathode will have the full 5mA current through it in this case thereby setting the cathode bias voltage.


----------



## CAJames

tintinsnowydog said:


> I was imaging it would work fine if the two triodes of the 6N7 were wired in parallel, then the only substantial difference would be in gain. Of course I could be very wrong..



I agree, but this is a specific situation, not "drop in compatible" IMO.


----------



## A2029

tintinsnowydog said:


> So I'm reading that 6J5 is a drop in replacement for 6N7 sockets, but is the converse true too? I understand the plate and grid of 6N7 on pins 4 and 6 would be unused. Would it be appropriate to simply connect 4-5 and 3-6 on the 6J5 socket, or would the 6N7 work the same using only one plate, or are some other entirely different considerations appropriate?



6N7 normally cannot drop in to a 6J5 wired socket, wouldn't bias correctly. But this depends on if you have an anode resistor or a CCS. If you have a CCS with sufficient headroom the 6N7 could potentially be put in, but in general it's not a great idea to have floating sections within a tube (some sensitive tubes don't like this, I'm not sure about the 6N7).


----------



## tintinsnowydog

A2029 said:


> If you wire an 8 pin socket to run the 6N7 sections in parallel (I.e. strap it as a pseudo-single triode), then the 6J5 can more-or-less drop in to the same socket and bias up close(ish) to what the 6J5 bias at.
> 
> If the 6N7 is run as a dual triode, then 6J5 is not a drop in.
> 
> To wire up the socket so that it takes both 6N7 and 6J5, use a ~1K resistor between pins 4 & 5, then a separate grid stopper resistor connecting your signal to grid 5. Then also connect pins 3 & 6 together. When looking at the tube curves for the 6N7, approx 50% of the current will go through each plate, so if the overall tube is biased at say 5mA, then you would look at the 2.5mA bias point. Note that the cathode will have the full 5mA current through it in this case.


Awesome, thank you so much for the detailed explanation! Hadn’t even checked the bias problem yet, was more concerned about the floating sections of the 6N7. Will avoid that all together 


CAJames said:


> I agree, but this is a specific situation, not "drop in compatible" IMO.


Definitely should have specified. Not drop in or interchangeable without very specific parameters for sure.


----------



## KillerQ

Solved.


----------



## bcowen

KillerQ said:


> Solved.




Faraday would be proud of you.  Nice!


----------



## leftside

bcowen said:


> The one pictured has a 4mm diameter hard wool felt tip. Works well on an octal base tube. It's a bit too large in diameter initially to get between the center guide pin and the (metal) tube pins, but goes between the metal pins just fine.  After it wears down a little it fits between the center guide pin as well. They make these in a 3mm diameter version that would probably work even better, but I haven't tried them as I already had a stash of the 4mm size.
> 
> https://www.amazon.com/uxcell-Mounted-Cylinder-Polishing-Buffing/dp/B07PLJFSDV/ref=sr_1_3_sspa?dchild=1&keywords=dremel+wool+felt+4mm&qid=1603750266&s=industrial&sr=1-3-spons&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUE5Nk80MUpFTEtQTjQmZW5jcnlwdGVkSWQ9QTAxNjY3MTcxU0ZWS1JZU01YNU1MJmVuY3J5cHRlZEFkSWQ9QTA5Mjc3MjIyQ0JaUUg3QTRIM1RXJndpZGdldE5hbWU9c3BfbXRmJmFjdGlvbj1jbGlja1JlZGlyZWN0JmRvTm90TG9nQ2xpY2s9dHJ1ZQ&th=1


Works very well with "regular" dirty pins. For the really dirty pins I like to bring out the heavy duty grinder. I tried cleaning these pins with the wool felt tip, but it wasn't getting off as much gunk as I hoped. Here is a before and after using the grinder:


----------



## JKDJedi

KillerQ said:


> Solved.



I bet a Deyan adapter would help here and stoked you solved that.. sick lighting.


----------



## bcowen

leftside said:


> Works very well with "regular" dirty pins. For the really dirty pins I like to bring out the heavy duty grinder. I tried cleaning these pins with the wool felt tip, but it wasn't getting off as much gunk as I hoped. Here is a before and after using the grinder:



What tube is that?  Has to be old, old.      I have a 7-pin socket in the tester for a similar base, but not an 8 pin.


----------



## leftside

bcowen said:


> What tube is that?  Has to be old, old.      I have a 7-pin socket in the tester for a similar base, but not an 8 pin.


EL3N. The grinder works very well on those pins, but not sure I'd want to use the grinder on the "regular" pins such as those on a 6J5.


----------



## tintinsnowydog (Nov 13, 2020)

Yesterday I found a TS VT-99 flat plate, top square mica in one of the garage sale boxes I've been slowly sifting through. Tested used but strong- every seller's favourite term. I like to define that as 90%+. Along with the  a BGRP  that just arrived and a pair of TS 6C5G (both very used)I finally get to compare the construction differences for myself and see if there is a difference at all! Spent some time comparing them, gave the TS6080 a workout with all the on-off heating cycles, and finished up some impressions today. There may have been some slight bias- was my first time hearing the much-hyped BGRP after finally finding a working one for less than 3 digits- but the results seemed to inversely reflect this anyway.. *Short verdict*; there are definitely noticeable sonic difference between these tubes. Is it simply due to them being at various stages of life? The differences to me are clear enough that I don't think so, but only paying a lot more to get some NOS specimens would confirm it I guess 

Listening notes:

*TS BGRP*:
-Huge, visceral and resonant bass that is  well extended, and is sustained into the lower mids.
-Dynamic, punchy, amazing technicalities and micro-details. Airy, well weighted, engaging, highly musical sound.
-Treble is pleasant, a little rolled off at the very top, and never too bright even at high volume.
-Mids sweet and realistic. All the refinements KR 6SN7 was missing. Probably does not need more description, it is very well documented and liked. This is the most musical and fun tube of the 3.

*TS flat plate 6F8G: *
-Compared to BGRP, it has noticeably more extended, cleaner and more quantity of treble. This makes the overall presentation airier, but leaner. The enhanced treble gets a bit fatiguing over a longer period; was sometimes reaching to lower volume in heavy treble sections.
-There is a slightly wider as well as noticeably deeper soundstage.
-It conveys even sweeter and addictive mids, and has much tighter bass but with slightly less overall weight/body.
-It is more balanced and linear sounding IMO than the BGRP which feels bass-boosted and more diffuse and euphonic in comparison- that may have been due to the BGRP bass bleeding a little into the mids. The bass is certainly just as well extended, if not more so into the sub-bass, but is less diffuse, less bloom, less overall less body and weight. For an analogy, it sounds like applying CCS to the BGRP.
-It sounds faster, cleaner and there is more overall micro-detail, likely due to more enhanced and refined treble. The overall presentation is slightly further back; while the BGRP surrounds immerses you in sound from all directions, the 6F8G places the sound on the stage in front of you with you in the front row.
-It is slightly more airy, noticeably more refined, leaner, and a bit drier in presentation than the BGRP.
-It is far more prone to noise and interference, but tended to quieten down after some hours of burn-in- noise was present again after changing tubes and then back to it.
-Differences were still apparent even at -3dB lower volume apart. BGRP: fun, euphonic and musical. 6F8G flat plate: accurate, hyper-realistic and controlled.

*-TS 6C5G: *
-ever so slightly attenuated treble compared to 6F8G but still amazingly extended. Treble is still on the leaner side but certainly not thin. Both are inevitably fatiguing over long periods at high volumes on a bright system, 6C5G less so (6F8G calmed down a bit after some burn-in and on additional rounds of listening, less harshness). No perceivable loss of detail; if anything, slightly less treble helps reveal more in mids.
-Bass sits perfectly between BGRP and 6F8G. It is well extended, textured and appropriately impactful without bringing any excess attention to itself or colouring the rest of the presentation. The result is better weight and texture than the 6F8G, but not as diffuse and visceral as the BGRP.
-Slightly wider but possibly shallower soundstage. 6F8G still certainly has the largest soundstage. Imaging and layering of sound is about equal and superb across all 3.
-I am hearing better spatial separation+definition than both dual triode options especially in orchestral recordings. About the same amount of air between notes/musicians.
-all the good qualities of the 6F8G mentioned above, but with slightly better linearity and overall, and an even more realistic presentation.
-My favourite of the 3.

Concluding thoughts:
-Both 6F8G and 6C5G share the same beautifully natural, transparent and clean presentation. Both exhibit less bloom and warmth than the BGRP, but are instead very musical and faithful across all registers. Superb articulation and details.
-Their best strength is their super-realistic midrange and treble. Light and delicate sounding extending to the very top of treble register.  Sound reproduction feels more effortless, the sonic equivalent of looking through a polished tube envelope. Vocals are some of the best I’ve heard, and they shine on acoustic/live recordings and genres.
-Overall, the main differences between the 3 lie in amount of treble, and bass quality.  The 6C5G seems to combine the 'best of both worlds' for a highly enjoyable presentation.
-The BGRP is the most fun, and least fatiguing tube that still maintains great technicalities. I get the hype, but separated triodes come out on top for me 


Now to hunt for a round plate 6F8G and 6J5G pair  to complete the family!


----------



## bcowen

tintinsnowydog said:


> Yesterday I found a TS VT-99 flat plate, top square mica in one of the garage sale boxes I've been slowly sifting through. Tested used but strong- every seller's favourite term. I like to define that as 90%+. Along with the  a BGRP  that just arrived and a pair of TS 6C5G (both very used)I finally get to compare the construction differences for myself and see if there is a difference at all! Spent some time comparing them, gave the TS6080 a workout with all the on-off heating cycles, and finished up some impressions today. There may have been some slight bias- was my first time hearing the much-hyped BGRP after finally finding a working one for less than 3 digits- but the results seemed to inversely reflect this anyway.. *Short verdict*; there are definitely noticeable sonic difference between these tubes. Is it simply due to them being at various stages of life? The differences to me are clear enough that I don't think so, but only paying a lot more to get some NOS specimens would confirm it I guess
> 
> Listening notes:
> 
> ...



Awesome info.  Thanks for sharing your eloquent and detailed impressions!


----------



## chrisdrop

tintinsnowydog said:


> Yesterday I found a TS VT-99 flat plate, top square mica in one of the garage sale boxes I've been slowly sifting through. Tested used but strong- every seller's favourite term. I like to define that as 90%+. Along with the  a BGRP  that just arrived and a pair of TS 6C5G (both very used)I finally get to compare the construction differences for myself and see if there is a difference at all! Spent some time comparing them, gave the TS6080 a workout with all the on-off heating cycles, and finished up some impressions today. There may have been some slight bias- was my first time hearing the much-hyped BGRP after finally finding a working one for less than 3 digits- but the results seemed to inversely reflect this anyway.. *Short verdict*; there are definitely noticeable sonic difference between these tubes. Is it simply due to them being at various stages of life? The differences to me are clear enough that I don't think so, but only paying a lot more to get some NOS specimens would confirm it I guess
> 
> Listening notes:
> 
> ...


Can I ask, what amp are you using for these tube experiences? Perhaps you've said before, sorry if so.


----------



## tintinsnowydog (Nov 13, 2020)

chrisdrop said:


> Can I ask, what amp are you using for these tube experiences? Perhaps you've said before, sorry if so.


That is definitely very important info to include going forward! The full chain is Tidal--> Singxer SU-1 USB bridge --> Gustard X20 Pro DAC --> Bottlehead Crack with Speedball (took out some film caps actually to keep impressions more relatable) --> HD800. TS 6080 is my favourite power tube to review with, very neutral and especially with my brighter setup tells me when the treble is not up to scratch.

Edit: and provided shipping and customs don't mess with it, this should also be arriving some time in the future


----------



## tintinsnowydog

The 6C5Gs really are beautiful. So beautiful I got distracted by them on my desk after I took them out, and forgot to grab a photo of the TS dual triodes hard at work


----------



## Velozity

tintinsnowydog said:


> Yesterday I found a TS VT-99 flat plate, top square mica in one of the garage sale boxes I've been slowly sifting through. Tested used but strong- every seller's favourite term. I like to define that as 90%+. Along with the  a BGRP  that just arrived and a pair of TS 6C5G (both very used)I finally get to compare the construction differences for myself and see if there is a difference at all! Spent some time comparing them, gave the TS6080 a workout with all the on-off heating cycles, and finished up some impressions today. There may have been some slight bias- was my first time hearing the much-hyped BGRP after finally finding a working one for less than 3 digits- but the results seemed to inversely reflect this anyway.. *Short verdict*; there are definitely noticeable sonic difference between these tubes. Is it simply due to them being at various stages of life? The differences to me are clear enough that I don't think so, but only paying a lot more to get some NOS specimens would confirm it I guess
> 
> Listening notes:
> 
> ...




Good review.  For as awesome as the BGRP is, IMO it is noticeably trumped by many dual-6C5 or dual-6J5 sets I have tried.  Find a pair of TS VT-94D and you'll be golden.


----------



## GDuss

Velozity said:


> Good review.  For as awesome as the BGRP is, IMO it is noticeably trumped by many dual-6C5 or dual-6J5 sets I have tried.  Find a pair of TS VT-94D and you'll be golden.



Agreed, the TS VT-94D's are fantastic!!!


----------



## CAJames

Good stuff. Even my humble metal TS 6C5 (pics back at the start of the thread) sound great and are essentially free compared to e.g a BGRP.


----------



## chrisdrop

tintinsnowydog said:


> That is definitely very important info to include going forward! The full chain is Tidal--> Singxer SU-1 USB bridge --> Gustard X20 Pro DAC --> Bottlehead Crack with Speedball (took out some film caps actually to keep impressions more relatable) --> HD800. TS 6080 is my favourite power tube to review with, very neutral and especially with my brighter setup tells me when the treble is not up to scratch.


I'm fascinated by the effect of (what appears to be attributable to) CCS relative to how different tubes sound. The GOTL has no CCS and has bigger differences between tubes, Blue Halo has CCS and has smaller differences between tubes. I think Crack is also on the smaller differences side. I distinctly recall preferring the CCS in the Crack over the no CCS. Don't get me wrong, you can certainly hear the differences in the CCS amps. This has come up on this or other threads before, so no new info - just pondering "out loud". Is it "good" or "bad" to have more or less differences? That is for you to decide!


----------



## GDuss

I've been listening to these for the last 5 days or so and they're as good as any Sylvania 6J5/12J5/6SN7/12SN7 tubes I have heard.  These were NOS (in the original boxes) and date matched and were 4 tubes for $20.  You can't beat these metal tubes for price/performance ratio.


----------



## GDuss

chrisdrop said:


> I'm fascinated by the effect of (what appears to be attributable to) CCS relative to how different tubes sound. The GOTL has no CCS and has bigger differences between tubes, Blue Halo has CCS and has smaller differences between tubes. I think Crack is also on the smaller differences side. I distinctly recall preferring the CCS in the Crack over the no CCS. Don't get me wrong, you can certainly hear the differences in the CCS amps. This has come up on this or other threads before, so no new info - just pondering "out loud". Is it "good" or "bad" to have more or less differences? That is for you to decide!



I like having an amp where rolling tubes makes a large difference in sound.  I think part of what drives all of us in this psychological disorder hobby is the continual search for differences in how an amp, DAC, headphones etc make our favorite recordings sound.  To me this is one of the advantages of having a tube amp.  But this clearly also feeds the need to buy more tubes, and to create threads all about specific tube types.  But that's why we're all here right?

The Crack I ordered from the September sale finally arrived but I probably won't build it until the holidays at the end of the year.  I'm still debating whether to build it without the Speedball first and spend some time with it and then do the install later (or just do it all at once).  So this is an interesting point about what role the CCS has in differences in sound between tubes.


----------



## chrisdrop

GDuss said:


> I like having an amp where rolling tubes makes a large difference in sound.  I think part of what drives all of us in this psychological disorder hobby is the continual search for differences in how an amp, DAC, headphones etc make our favorite recordings sound.  To me this is one of the advantages of having a tube amp.  But this clearly also feeds the need to buy more tubes, and to create threads all about specific tube types.  But that's why we're all here right?
> 
> The Crack I ordered from the September sale finally arrived but I probably won't build it until the holidays at the end of the year.  I'm still debating whether to build it without the Speedball first and spend some time with it and then do the install later (or just do it all at once).  So this is an interesting point about what role the CCS has in differences in sound between tubes.


Even if you do put the Speedball in eventually - I certainly recommend building without it first, using it for a bit, and then putting the CCS in. I like the CCS in Crack. I certainly like the sound w/ CCS in Blue Halo and there is certainly a difference in tubes, but not as big within the same tube-type across brands as in the GOTL (as leftside has mentioned before).


----------



## CAJames

GDuss said:


> I like having an amp where rolling tubes makes a large difference in sound....



I believe that is what "they" refer to as a good amp. One that is able to resolve differences in e.g. tubes, headphones, recordings or (dare I say it) stuff like cables and power cords.


----------



## chrisdrop (Nov 13, 2020)

CAJames said:


> I believe that is what "they" refer to as a good amp. One that is able to resolve differences in e.g. tubes, headphones, recordings or (dare I say it) stuff like cables and power cords.


I think in the case of CCS, it is not necessarily less resolving. CCS might make an amp "_more_ resolving" (revealing of recording details, DAC quality, headphones, etc) - and more consistent. The variation is_ certainly_ an enjoyable aspect of the GOTL (a tube explorers amp). I think they are 2 different ways to do it, each with tradeoffs. Why is the speedball an "upgrade" to the Crack if it makes the amp "less of a good amp"? From the Bottlehead Speedbal page:



> So what does it do for the sound? The most immediate thing you will notice is a better sense of clarity. Things get tighter and quicker, bass and midrange get cleaner and more dynamic sounding, and the background gets more quiet. As with all of our upgrade kits, the improvement is easily heard.



I've really been enjoying having both around!

EDIT: entirely unrelated, to keep the post on the thread. Here is a recent (not today) pic of 2x Osram L63s that I really like.


----------



## leftside

Getting 6J5 “equivalents” of some of the classic tubes like TS BGRP and Sylvania metal base is a great way to save money. Another way, is to get their 12 volt equivalents. As many of us have DIY amps on here, this is a good option to have. I quite often use the TS BGRP 12 volt version.


----------



## Velozity

GDuss said:


> I've been listening to these for the last 5 days or so and they're as good as any Sylvania 6J5/12J5/6SN7/12SN7 tubes I have heard.  These were NOS (in the original boxes) and date matched and were 4 tubes for $20.  You can't beat these metal tubes for price/performance ratio.




Many others agree with you.  I will soon find out for myself.  Waiting for the postman to deliver a secret stash of these little rarities.  I've been on a Cossor kick lately (yes I know these were made by RCA):


----------



## tintinsnowydog

Velozity said:


> Good review.  For as awesome as the BGRP is, IMO it is noticeably trumped by many dual-6C5 or dual-6J5 sets I have tried.  Find a pair of TS VT-94D and you'll be golden.


Will certainly be on the lookout for a pair 


chrisdrop said:


> I'm fascinated by the effect of (what appears to be attributable to) CCS relative to how different tubes sound. The GOTL has no CCS and has bigger differences between tubes, Blue Halo has CCS and has smaller differences between tubes. I think Crack is also on the smaller differences side. I distinctly recall preferring the CCS in the Crack over the no CCS. Don't get me wrong, you can certainly hear the differences in the CCS amps. This has come up on this or other threads before, so no new info - just pondering "out loud". Is it "good" or "bad" to have more or less differences? That is for you to decide!


From a technical/electrical standpoint, CCS is undoubtedly better. As evident from my setup I really like detail, and I'm a big fan of classical music, so CCS works mostly in my favour. The way I like to see it, CCS raises the baseline performance of all tubes to an even playing field, and the differences we hear in non-CCS are mostly a result of the technical/electrical 'deficiencies' of tubes; but these do not necessarily mean bad, and can translate into more pleasant/warmer/differently tuned sound. Differences between tubes are considerably smaller, but to me are still immediately audible and alter the overall presentation of sound, to the extent that I will prefer certain combinations with certain recordings but not others. No tubes sound bad with CCS, some can sound questionable without it.



CAJames said:


> I believe that is what "they" refer to as a good amp. One that is able to resolve differences in e.g. tubes, headphones, recordings or (dare I say it) stuff like cables and power cords.


I strongly agree with this, and am in the camp that every piece of the audio chain makes an audible difference. The more revealing the main components, (headphones, amp and DAC) the more the recordings, cables and cords are revealed. I was a non-believer of cables making a difference until I was offered a trial of some nice silver interconnects. While I don't think exotic metals make a difference, I do personally believe build quality and shielding design up to a certain sane (???) extent can make a difference that cannot be explained by placebo (or psychological justification of money spent) alone.


----------



## leftside

Here another tube with similar pins to the EL3N that just had the grinding treatment. This time a Philips FDD20. You can buy FDD20 to 12SN7 adapters. First photo is with just the tube pins on the left having been cleaned. It looked the same as the tube on the right before the cleaning/grinding.


----------



## KillerQ

These Metal RCA 6J5 triodes are the best tubes I’ve heard to date. Wow.


----------



## leftside

Not sure if these will be too abrasive, but I'll give them a try on an old, cheap, very well used tube first:
https://www.amazon.ca/gp/product/B087RQXFZ7

Ok - no more cleaning pins posts from me. I promise to stay on track now  See if I can dig up some 6J5/related tubes that haven't been discussed so far...


----------



## chrisdrop

tintinsnowydog said:


> From a technical/electrical standpoint, CCS is undoubtedly better. As evident from my setup I really like detail, and I'm a big fan of classical music, so CCS works mostly in my favour. The way I like to see it, *CCS raises the baseline performance of all tubes to an even playing field,* and *the differences we hear in non-CCS are mostly a result of the technical/electrical 'deficiencies' of tubes; but these do not necessarily mean bad, and can translate into more pleasant/warmer/differently tuned sound. *Differences between tubes are considerably smaller, but to me are* still immediately audible and alter the overall presentation of sound*, to the extent that I will prefer certain combinations with certain recordings but not others. *No tubes sound bad with CCS, some can sound questionable without it.*


Thanks for your thoughts. I think you said that _very_ well, adding nuance and specificity. That all resonates with me and solidifies my thinking about it.


----------



## L0rdGwyn (Nov 15, 2020)

GDuss said:


> The Crack I ordered from the September sale finally arrived but I probably won't build it until the holidays at the end of the year.  I'm still debating whether to build it without the Speedball first and spend some time with it and then do the install later (or just do it all at once).  So this is an interesting point about what role the CCS has in differences in sound between tubes.



I don't know if people are interested in the technical type stuff, but from an amplifier design standpoint, the biggest difference between using a CCS load and a resistive load are going to be the degree of harmonic distortion in the output signal, 2nd harmonic being most affected, and power supply rejection.  I'll try to illustrate it with some thrown together load lines.

At a high level, a large portion of the distortion attributed a triode and its "linearity" are determined by the "evenness" of the spacing between the grid curves along the tube's load line.

Here is a L63 load line using a 400V B+ with a 50K resistive load and a.....220V plate voltage at roughly 3.6mA plate current (side note: what sadistic person thought using 8V per hash on the x-axis was a good idea?).  As you can see, as you move left to right across the load line, the grid curve spacing is not particularly even, especially when swinging to higher voltages, which will lead to more distortion.




Now compare that to a CCS load using the same 400V B+, 220V plate voltage, but setting the CCS to a 6mA plate current.  Compared to the 50K resistor, the CCS will effectively show the tube an "infinite" AC impedance (more on the order of tens of megaohms), such that the tube will see a "flat" load line (in reality, the CCS is in parallel with the grid leak resistor of the following stage, so the load will be approximately the value of the grid leak, typical would be around 500K, so slightly less flat than displayed).  Now you can see the grid spacing across the load line is much more even, which results in lower THD.



So lower distortion and less variation between grid spacing / curves between tubes is likely why there are less pronounced difference between tubes when using a CCS.  Restating it another way, differences between the characteristic curves of different makes of tubes will be less pronounced when using a CCS as it minimizes the degree of distortion created by those differences.  And as I mentioned, the CCS also affords very high power supply rejection, so ripple passed through from even a poorly filtered passive power supply will be squashed by the CCS.

Hope that makes sense.


----------



## chrisdrop

L0rdGwyn said:


> I don't know if people are interested in the technical type stuff, but from an amplifier design standpoint, the biggest difference between using a CCS load and a resistive load are going to be the degree of harmonic distortion in the output signal, 2nd harmonic being most affected, and power supply rejection.  I'll try to illustrate it with some thrown together load lines.
> 
> At a high level, a large portion of the distortion attributed a triode and its "linearity" are determined by the "evenness" of the spacing between the grid curves along the tube's load line.
> 
> ...


As always, clear and exceptionally helpful  Hope life is treating you well !


----------



## GDuss

L0rdGwyn said:


> I don't know if people are interested in the technical type stuff, but from an amplifier design standpoint, the biggest difference between using a CCS load and a resistive load are going to be the degree of harmonic distortion in the output signal, 2nd harmonic being most affected, and power supply rejection.



Definitely interesting, and thanks for the science behind the sound (graphs and data are always appreciated, even if the plots were created by sadists  ; this latter critique could be applied to much of the US unit system. Fortunately most scientific fields use metric).  

So then a CCS decreasing 2nd harmonics would minimize the "tube sound" that many people enjoy?  The tube sound is not only about 2nd harmonic distortion of course. Different people have different definitions of what the "tube sound" actually is (that's an interesting discussion on its own), but this distortion is commonly used in descriptions of tubes.  It seems that a CCS would minimize this distortion, as well as noise, and let the tubes do the other things that tubes are good at.


----------



## leftside

That's why I always say you can't beat modern tube gear with vintage tubes


----------



## JKDJedi

L0rdGwyn said:


> I don't know if people are interested in the technical type stuff, but from an amplifier design standpoint, the biggest difference between using a CCS load and a resistive load are going to be the degree of harmonic distortion in the output signal, 2nd harmonic being most affected, and power supply rejection.  I'll try to illustrate it with some thrown together load lines.
> 
> At a high level, a large portion of the distortion attributed a triode and its "linearity" are determined by the "evenness" of the spacing between the grid curves along the tube's load line.
> 
> ...


All that is alien to me... like reading a music sheet.(all I see is hieroglyphics ).please explain in Howdy Doody terms...


----------



## JKDJedi

KillerQ said:


> These Metal RCA 6J5 triodes are the best tubes I’ve heard to date. Wow.


I want that dac so bad.. beautiful set up/


----------



## KillerQ

JKDJedi said:


> All that is alien to me... like reading a music sheet.(all I see is hieroglyphics ).please explain in Howdy Doody terms...


Do they make all metal 6SN7 tubes like they do 6J5 tubes?


----------



## KillerQ

JKDJedi said:


> I want that dac so bad.. beautiful set up/


Thank you very much.


----------



## JKDJedi

KillerQ said:


> Do they make all metal 6SN7 tubes like they do 6J5 tubes?


Probably not


----------



## L0rdGwyn

GDuss said:


> Definitely interesting, and thanks for the science behind the sound (graphs and data are always appreciated, even if the plots were created by sadists  ; this latter critique could be applied to much of the US unit system. Fortunately most scientific fields use metric).
> 
> So then a CCS decreasing 2nd harmonics would minimize the "tube sound" that many people enjoy?  The tube sound is not only about 2nd harmonic distortion of course. Different people have different definitions of what the "tube sound" actually is (that's an interesting discussion on its own), but this distortion is commonly used in descriptions of tubes.  It seems that a CCS would minimize this distortion, as well as noise, and let the tubes do the other things that tubes are good at.



The "tube sound" is a hot topic, I might avoid that one  but yes the second harmonic would be reduced in the driver stage.  In a single-ended class A design, there will be more second harmonic added in the output stage.  The load for the output tube will not be so high as the driver (compare a 500K grid leak resistor in parallel with the CCS to a 300ohm headphone in an OTL, or a 5K output transformer in a SET design), so the load line will not be so flat and there will be significantly more second harmonic distortion added here with less contribution from the CCS loaded driver.



JKDJedi said:


> All that is alien to me... like reading a music sheet.(all I see is hieroglyphics ).please explain in Howdy Doody terms...



Basically, the CCS load allows the tube to operate such that the alternating current input signal (music signal) produces less distortion as the tube swings along its operating curve.

I forgot to mention, yet another advantage of a CCS is that it will maximize the gain of the stage.  It is the ideal load for a triode.


----------



## L0rdGwyn

chrisdrop said:


> As always, clear and exceptionally helpful  Hope life is treating you well !



Thanks, as good as it can at the moment!  New COVID surge is making work life a pain, but I am on vacation for over a week, need to find something to do to avoid going stir crazy.  I have a tube box shipment coming today, going to reorganize my collection, which is long overdue, so that's a start.  Too many rare tubes floating around in drawers, it's gotten out of hand!


----------



## JKDJedi

L0rdGwyn said:


> The "tube sound" is a hot topic, I might avoid that one  but yes the second harmonic would be reduced in the driver stage.  In a single-ended class A design, there will be more second harmonic added in the output stage.  The load for the output tube will not be so high as the driver (compare a 500K grid leak resistor in parallel with the CCS to a 300ohm headphone in an OTL, or a 5K output transformer in a SET design), so the load line will not be so flat and there will be significantly more second harmonic distortion added here with less contribution from the CCS loaded driver.
> 
> 
> 
> ...


CCS is? acronym for. ..


----------



## L0rdGwyn (Nov 14, 2020)

JKDJedi said:


> CCS is? acronym for. ..



Constant current source, or sink, depending on the application.  It sets a constant bias current through the tube while also applying a high impedance to the alternating current music signal.

For a basic overview of how a tube amplifier works, check out Uncle Doug's YouTube channel, he has lots of educational videos that go over the fundamentals in the context of guitar amplifiers.  Can also search, "Uncle Doug How Amplifiers Work".

https://www.youtube.com/user/Stratosaurus1/videos


----------



## bcowen

L0rdGwyn said:


> I have a tube box shipment coming today, going to reorganize my collection, which is long overdue, so that's a start.  Too many rare tubes floating around in drawers, it's gotten out of hand!



I was going to say something to you about that, but then bit my tongue in the nick of time. 

Ooops.


----------



## L0rdGwyn

bcowen said:


> I was going to say something to you about that, but then bit my tongue in the nick of time.
> 
> Ooops.



THE HORROR!  Avert your eyes!


But really all I am thinking is I would love to go through that stash


----------



## tintinsnowydog

bcowen said:


> I was going to say something to you about that, but then bit my tongue in the nick of time.
> 
> Ooops.


Bet there’s some good stuff in there! A similar situation here of messier proportions..


----------



## GDuss

GDuss said:


> I've been listening to these for the last 5 days or so and they're as good as any Sylvania 6J5/12J5/6SN7/12SN7 tubes I have heard.  These were NOS (in the original boxes) and date matched and were 4 tubes for $20.  You can't beat these metal tubes for price/performance ratio.



So I had been using these Sylvania 6C5's with a pair of TS 5998's and they were working really well together.  Tonight I took out the 5998's and replaced them with some Sylvania 6080's.  These are WC's from the mid-60's, so not the best 6080's ever, but I like them and come back to them often.  Problem is they don't work with the Sylvania 6C5's.  Maybe it's too much Sylvania? Something about the combo just doesn't work, it's boring. But this has been a theme for a while, that I don't typically like tubes from the same manufacturer as both driver and power tubes (in the GOTL).  This has been true for Tung Sol, GEC, RCA, GE, Sylvania.  After about an hour and a half, I replaced the Sylvania 6C5's with the trusty old RCA metal 6J5 VT-94's, and we're back in business.  I'm engaged by the sound again.  

I doubt this is explainable on any graph, but if anyone can do it, @L0rdGwyn can.  More likely it's because at the end of the chain, the human ears and brain are still required, and those are so far not fully explainable.


----------



## L0rdGwyn

GDuss said:


> So I had been using these Sylvania 6C5's with a pair of TS 5998's and they were working really well together.  Tonight I took out the 5998's and replaced them with some Sylvania 6080's.  These are WC's from the mid-60's, so not the best 6080's ever, but I like them and come back to them often.  Problem is they don't work with the Sylvania 6C5's.  Maybe it's too much Sylvania? Something about the combo just doesn't work, it's boring. But this has been a theme for a while, that I don't typically like tubes from the same manufacturer as both driver and power tubes (in the GOTL).  This has been true for Tung Sol, GEC, RCA, GE, Sylvania.  After about an hour and a half, I replaced the Sylvania 6C5's with the trusty old RCA metal 6J5 VT-94's, and we're back in business.  I'm engaged by the sound again.
> 
> I doubt this is explainable on any graph, but if anyone can do it, @L0rdGwyn can.  More likely it's because at the end of the chain, the human ears and brain are still required, and those are so far not fully explainable.



Hmmm assuming there isn't something functionally wrong with the tubes, I can only chalk it up to personal preference!  If the 6C5s are working well with the 5998s, I see no reason they wouldn't work well with the 6080s, so maybe just a bad combination for your taste.


----------



## GDuss

L0rdGwyn said:


> Hmmm assuming there isn't something functionally wrong with the tubes, I can only chalk it up to personal preference!  If the 6C5s are working well with the 5998s, I see no reason they wouldn't work well with the 6080s, so maybe just a bad combination for your taste.



Personal preference it is!!!  The combination clearly works from a functional perspective, I just don’t like the sound. And I have no idea how to explain why two perfectly functional sets of tubes just don’t sound good together (to me) but that’s the mystery of the human brain. Or maybe mine just doesn’t work correctly. That’s entirely possible.


----------



## tintinsnowydog

GDuss said:


> So I had been using these Sylvania 6C5's with a pair of TS 5998's and they were working really well together.  Tonight I took out the 5998's and replaced them with some Sylvania 6080's.  These are WC's from the mid-60's, so not the best 6080's ever, but I like them and come back to them often.  Problem is they don't work with the Sylvania 6C5's.  Maybe it's too much Sylvania? Something about the combo just doesn't work, it's boring. But this has been a theme for a while, that I don't typically like tubes from the same manufacturer as both driver and power tubes (in the GOTL).  This has been true for Tung Sol, GEC, RCA, GE, Sylvania.  After about an hour and a half, I replaced the Sylvania 6C5's with the trusty old RCA metal 6J5 VT-94's, and we're back in business.  I'm engaged by the sound again.
> 
> I doubt this is explainable on any graph, but if anyone can do it, @L0rdGwyn can.  More likely it's because at the end of the chain, the human ears and brain are still required, and those are so far not fully explainable.


I've always found the Sylvania 6080 to be severely lacking in treble quality and extension. The bass is quite rolled off too, but the overall tonality is very liquid and relaxing- possibly helped by the extension 'problem'. I haven't heard them myself, but if the Sylvania 6C5 don't perform amazingly outside of the midrange I can imagine the combo might sound a bit boring!


----------



## GDuss

tintinsnowydog said:


> I've always found the Sylvania 6080 to be severely lacking in treble quality and extension. The bass is quite rolled off too, but the overall tonality is very liquid and relaxing- possibly helped by the extension 'problem'. I haven't heard them myself, but if the Sylvania 6C5 don't perform amazingly outside of the midrange I can imagine the combo might sound a bit boring!



I don't think I can hear treble extension like most humans.  So you may be totally correct and I wouldn't be able to argue with you.  The bass rolloff is true.  If I'm listening to the 650 this is problematic, but on the ZMF Aeolus I don't mind it because they have more bass than the 650 anyway.  I just like the remainder of the tonality of these 6080's.  Don't get me wrong, they are not in the same league with the TS 5998, but like I said a few pages back, part of the fun of an OTL amp is changing up tubes all the time and finding combinations that work.


----------



## tintinsnowydog

GDuss said:


> I don't think I can hear treble extension like most humans.  So you may be totally correct and I wouldn't be able to argue with you.  The bass rolloff is true.  If I'm listening to the 650 this is problematic, but on the ZMF Aeolus I don't mind it because they have more bass than the 650 anyway.  I just like the remainder of the tonality of these 6080's.  Don't get me wrong, they are not in the same league with the TS 5998, but like I said a few pages back, part of the fun of an OTL amp is changing up tubes all the time and finding combinations that work.


I still hold on to a pair of Sylvania 6080 to roll when I want a real smooth and easy sound. It kind of negates most of the technical prowess on my HD800 but that's not always a bad thing  And I agree personal preference as you said above is what matters in the end. I still prefer the TS6080 over the 5998 for most applications, even though the 5998 is 'better' by consensus.


----------



## Marutks

Have you tried Sovtek 6J5GT tubes?   Are they any good?

https://www.vivatubes.com/search.php?search_query=Sovtek 6J5GT &section=product


----------



## GDuss

tintinsnowydog said:


> I still hold on to a pair of Sylvania 6080 to roll when I want a real smooth and easy sound. It kind of negates most of the technical prowess on my HD800 but that's not always a bad thing  And I agree personal preference as you said above is what matters in the end. I still prefer the TS6080 over the 5998 for most applications, even though the 5998 is 'better' by consensus.



I only have the TS 5998 so can't compare to the TS 6080.  And I also only have GEC 6AS7G's so can't compare those to the 6080 version either.  There are certainly worse problems to have in life, so I'm not complaining.

I just had a new set of Verite Closed show up today (which in theory have better technical prowess than the Aeolus), so all my tube preferences may be out the window with these new headphones.  Might have to start from scratch, but as above, there are worse problems to have.  

So if everyone in this thread hears me totally contradicting my earlier posts, you'll all know why  .


----------



## chrisdrop

GDuss said:


> I only have the TS 5998 so can't compare to the TS 6080.  And I also only have GEC 6AS7G's so can't compare those to the 6080 version either.  There are certainly worse problems to have in life, so I'm not complaining.
> 
> I just had a new set of Verite Closed show up today (which in theory have better technical prowess than the Aeolus), so all my tube preferences may be out the window with these new headphones.  Might have to start from scratch, but as above, there are worse problems to have.
> 
> So if everyone in this thread hears me totally contradicting my earlier posts, you'll all know why  .


Awesome !! Congratulations!!


----------



## tintinsnowydog (Nov 17, 2020)

Well after a long wait, my package from Martin arrived today! Lots of goodies inside, some British L63 and plenty of affordable American 6J5/6C5. Excited to try them all, but these Fivre 76 took precedence. Not too much time to listen tonight, however first impression is that these are extremely good sounding tubes- not to mention they are possibly the most beautiful tubes I now own! Plenty of warm yet well-controlled bass, singing mids, balanced treble. Good technique and detail wrapped in a really expansive, airy presentation. These give me a strong urge to look for more Fivre, as well as more type 76 tubes!


----------



## chrisdrop

tintinsnowydog said:


> Well after a long wait, my package from Martin arrived today! Lots of goodies inside, some British L63 and plenty of affordable American 6J5/6C5. Excited to try them all, but these Fivre 76 took precedence. Not too much time to listen tonight, however first impression is that these are extremely good sounding tubes- not to mention they are possibly the most beautiful tubes I now own! Plenty of warm yet well-controlled bass, singing mids, balanced treble. Good technique and detail wrapped in a really expansive, airy presentation. These give me a strong urge to look for more Fivre, as well as more type 76 tubes!


Those are beautiful 😍.

Thanks to a new pair of adapters from @Deyan I was able to pop in some 76s for the first time today. Kenrads. Not as pretty as those Fivres but lovely nonetheless. Silent and nice from the get go.


----------



## Slade01

chrisdrop said:


> Those are beautiful 😍.
> 
> Thanks to a new pair of adapters from @Deyan I was able to pop in some 76s for the first time today. Kenrads. Not as pretty as those Fivres but lovely nonetheless. Silent and nice from the get go.



Are the 76s a direct drop in replacement for 6j5 as well?  Sorry if this was answered already...


----------



## Xcalibur255

Slade01 said:


> Are the 76s a direct drop in replacement for 6j5 as well?  Sorry if this was answered already...



Physically you need an adapter as the pin configuration is different.  Electrically the general answer is yes, though the 76 is lower gain and has a different plate resistance so it may behave differently in the circuit depending on the amplifier.  It's not unsafe (you won't damage your amp), but it may sound substantially different for good or for bad.


----------



## leftside

The 76 gives a lighter and more airy sound in my amp. Same as 6C5 or 6P5 tubes in my amp. eBay has 76 to 6J5 adapters - these are the one I use.


----------



## tintinsnowydog (Nov 17, 2020)

chrisdrop said:


> Those are beautiful 😍.
> 
> Thanks to a new pair of adapters from @Deyan I was able to pop in some 76s for the first time today. Kenrads. Not as pretty as those Fivres but lovely nonetheless. Silent and nice from the get go.



was surprised how quiet the 76 were, with all the “older tubes better but noisier” talk. Possibly even quieter than a couple 6J/C5 I’ve tried so far!


Slade01 said:


> Are the 76s a direct drop in replacement for 6j5 as well?  Sorry if this was answered already...


This is the adapter I use, the 76 is the 5 pin version of the 6P5. The seller seems to have doubled the price after my purchase.. was quite an affordable option before! I’ve gotten most of my adapters from there and they’ve all been great quality and fast shipping to me here in Aus. Just wish there was cheaper shipping right now from Deyan/Europe..


----------



## Slade01

tintinsnowydog said:


> This is the adapter I use, the 76 is the 5 pin version of the 6P5. The seller seems to have doubled the price after my purchase.. was quite an affordable option before! I’ve gotten most of my adapters from there and they’ve all been great quality and fast shipping to me here in Aus. Just wish there was cheaper shipping right now from Deyan/Europe..



Thank you.  After realizing the Type 76 is a different pinout, became obvious that an adapter is needed.   I would need a dual 76 to 6sn7 myself.  I'm not in a rush as I actually just started rolling 6J5s in my amp, and just recently got my adapter from Deyan.  He does make great quality adapters.  I've also only sourced adapters from that vendor (xulingmrs) if i'm ordering from China, and I agree that they are pretty solid too.  Thank you everyone who chimed in about the compatibility and adapters info.  Something to think about and its nice to have the options.  Much appreciated!


----------



## KillerQ

Slade01 said:


> Thank you.  After realizing the Type 76 is a different pinout, became obvious that an adapter is needed.   I would need a dual 76 to 6sn7 myself.  I'm not in a rush as I actually just started rolling 6J5s in my amp, and just recently got my adapter from Deyan.  He does make great quality adapters.  I've also only sourced adapters from that vendor (xulingmrs) if i'm ordering from China, and I agree that they are pretty solid too.  Thank you everyone who chimed in about the compatibility and adapters info.  Something to think about and its nice to have the options.  Much appreciated!


I wish there was a good adapter seller in the US. I hate waiting - haha


----------



## tintinsnowydog

Who's up for a group buy  
https://www.ebay.com.au/itm/20x-6C5G-TUBE-GRAY-GLASS-BY-COSSOR-ENGLAND/284082200829
Incidentally, if anyone has any labelled similarly, are they identical to the L63?


----------



## CAJames

tintinsnowydog said:


> Who's up for a group buy
> https://www.ebay.com.au/itm/20x-6C5G-TUBE-GRAY-GLASS-BY-COSSOR-ENGLAND/284082200829
> Incidentally, if anyone has any labelled similarly, are they identical to the L63?



L63 is closer to a 6J5 than a 6C5. But these sure look nice regardless.


----------



## Marutks

Are these Mullard "Amerty" tubes any good?   I found them in an online shop.


----------



## chrisdrop

Marutks said:


> Are these Mullard "Amerty" tubes any good?   I found them in an online shop.


I think Amerty is made in America (by Mullard or rebranded by Mullard I don't know in this case). Did Mullard ever have North American manufacturing is unclear to me.

I have and like some Mullard 6J5Gs but they don't look like these. 

Depending on the cost might be worth a punt. They might really Sylvania or RCA made however (or another American manufacturer).


----------



## Slade01

chrisdrop said:


> I think Amerty is made in America (by Mullard or rebranded by Mullard I don't know in this case). Did Mullard ever have North American manufacturing is unclear to me.
> 
> I have and like some Mullard 6J5Gs but they don't look like these.
> 
> Depending on the cost might be worth a punt. They might really Sylvania or RCA made however (or another American manufacturer).



Amerty is american made tubes imported and sold under the Mullard name.  They typically sourced tubes from RCA and Sylvania -- @chrisdrop  is absolutely right.


----------



## Xcalibur255

The plate style is not consistent with any American made 6J5 from that manufacturing period, but it is consistent with STC/Brimar which would indeed make them English made.  By all accounts they are very nice tubes.  I have a pair just like them with different labeling but I haven't had the opportunity to listen to them yet.


----------



## Slade01

Xcalibur255 said:


> The plate style is not consistent with any American made 6J5 from that manufacturing period, but it is consistent with STC/Brimar which would indeed make them English made.  By all accounts they are very nice tubes.  I have a pair just like them with different labeling but I haven't had the opportunity to listen to them yet.



If it is indeed an STC/Brimar, it would be a great and fortunatus find.  But I wouldn't understand why then they would choose to label it as an Amerty tube if they are simply sourcing it from the neighboring region.  Also, wouldn't it be hard to to ascertain the true manufacturing period if they are completely scrubbing and rebranding tubes?  To me, they look similar to Sylvania 6J5G like pictured below but i could be/(probably) wrong. Lol.


----------



## Marutks

Amerty tubes are from https://www.nosaudiotubes.com/produ...ade-in-gt-britain-amplitrex-tested-163201620/ 

They have STC tubes as well https://www.nosaudiotubes.com/product/1mq-6j5g-stc-made-in-gt-britain-539066-539087-539099-539132/

Those tubes look similar to some STC/Brimar tubes I found on ebay  







There is Brimar tube too.
https://www.nosaudiotubes.com/produ...-nib-made-in-england-amplitrex-tested-819016/


----------



## Slade01 (Nov 19, 2020)

Marutks said:


> Amerty tubes are from https://www.nosaudiotubes.com/produ...ade-in-gt-britain-amplitrex-tested-163201620/
> 
> They have STC tubes as well https://www.nosaudiotubes.com/product/1mq-6j5g-stc-made-in-gt-britain-539066-539087-539099-539132/
> 
> ...



Were you specifically looking for Mullard 6J5G tubes?  Because the Brimars look nice and to get two of them - they are a bit cheaper.


----------



## Marutks

Slade01 said:


> Were you specifically looking for Mullard 6J5G tubes?  Because the Brimars look nice and to get two of them - they are a bit cheaper.



No, not specifically.  I don't know which sounds better.   I have just ordered the Blue Halo tube amplifier. 
I would like to get one or two pairs of nice, "high end" 6J5 tubes before my amp arrives. Some cheap-ish metal tubes (RCA) too.


----------



## Xcalibur255 (Nov 19, 2020)

Marutks said:


> Amerty tubes are from https://www.nosaudiotubes.com/produ...ade-in-gt-britain-amplitrex-tested-163201620/
> 
> They have STC tubes as well https://www.nosaudiotubes.com/product/1mq-6j5g-stc-made-in-gt-britain-539066-539087-539099-539132/
> 
> ...


Brimar is the true manufacturer in all of these cases.  This kind of relabeling was common.  Many Brimar tubes were manufactured with intent to export.

As to Slade01's question, there are meaningful differences in construction details here between the Brimar and the Sylvania if you look closely.  They look similar at first because they are both black plate ST tubes, have round plate middles and have a similar support system for the top mica.  However, the Brimar tubes have a larger diameter curve to the center of their plate, along with having a slightly wider plate overall, and the top mica and getter are different designs.


----------



## L0rdGwyn

tintinsnowydog said:


> Who's up for a group buy
> https://www.ebay.com.au/itm/20x-6C5G-TUBE-GRAY-GLASS-BY-COSSOR-ENGLAND/284082200829
> Incidentally, if anyone has any labelled similarly, are they identical to the L63?



Despite the 6C5G labeling, these are most definitely GEC L63.



Marutks said:


> Are these Mullard "Amerty" tubes any good?   I found them in an online shop.



As @Xcalibur255 already said, these are STC/Brimar 6J5G.  STC (Standard Telephones and Cables) was the parent company of Brimar, they are one and the same.


----------



## leftside

L0rdGwyn said:


> Despite the 6C5G labeling, these are most definitely GEC L63.


Cossor or really GEC?


----------



## L0rdGwyn

leftside said:


> Cossor or really GEC?



Very confident they are GEC manufactured, the gray glass coating was their style alone, Cossor did a lot of GEC rebranding!

If the seller provided a pic of the top mica, I'm certain it would be identical to a GEC L63.


----------



## L0rdGwyn

Here is another example, a Mullard-branded 6C5G, but it is really another GEC L63!


----------



## leftside

L0rdGwyn said:


> Very confident they are GEC manufactured, the gray glass coating was their style alone, Cossor did a lot of GEC rebranding!
> 
> If the seller provided a pic of the top mica, I'm certain it would be identical to a GEC L63.


That's what I thought.


----------



## L0rdGwyn (Nov 20, 2020)

I've seen this with other tubes models from the BVA manufacturers, where two tube models are "close enough" electrically that one will rebrand another as a tube from their company's portfolio.

Take these for example, Mazda AC/HL, but really these are MOV MH4.  The AC/HL and MH4 are very similar, but not identical, but that didn't stop them from rebranding and selling them as AC/HL!



Here is a real Mazda AC/HL.


----------



## tintinsnowydog

L0rdGwyn said:


> Very confident they are GEC manufactured, the gray glass coating was their style alone, Cossor did a lot of GEC rebranding!
> 
> If the seller provided a pic of the top mica, I'm certain it would be identical to a GEC L63.


This is what I suspected too, thanks for the confirmation! I guess the question now is why they were labelled 6C5G rather than 6J5G or L63. Were they always considered interchangeable? Or maybe these are of an earlier vintage before 6J5 superseded 6C5?


----------



## L0rdGwyn

tintinsnowydog said:


> This is what I suspected too, thanks for the confirmation! I guess the question now is why they were labelled 6C5G rather than 6J5G or L63. Were they always considered interchangeable? Or maybe these are of an earlier vintage before 6J5 superseded 6C5?



It's hard to say!  But that would be my guess, that this was near the transition period, late 1930s to early 1940s, these companies likely had customers buying 6C5G and it was simpler to keep supplying the "same" tube since they are very nearly identical electronically - same bias point, same amplification, just small differences in plate impedance and transconductance.  The 6C5G existed before the 6J5G as an internally triode-strapped 6J7G, the 6J5G replaced it as a true triode.


----------



## Slade01

L0rdGwyn said:


> It's hard to say!  But that would be my guess, that this was near the transition period, late 1930s to early 1940s, these companies likely had customers buying 6C5G and it was simpler to keep supplying the "same" tube since they are very nearly identical electronically - same bias point, same amplification, just small differences in plate impedance and transconductance.  The 6C5G existed before the 6J5G as an internally triode-strapped 6J7G, the 6J5G replaced it as a true triode.



That I could buy and understand.  But the whole Mullard -- taking STC/Brimar Tubes and rebranding them as such and specifically slapping the Amerty label on them i'd love to know the reasoning behind that.  I understand Brimar manufactured tubes based on American design, and so wildly, it could make some sense that Mullard sells it as an Amerty (to seemingly make it appear that those tubes were american import)?  But to what end.  Tube history is fascinating and frustrating.


----------



## Xcalibur255 (Nov 21, 2020)

I'm not sure where you read that Brimar tubes are based primarily on American design.  This might be true in a few specific cases, but you definitely can't apply it as a generalization to all Brimar tubes.  STC was a tube developer and manufacturer just like Mullard and the others and produced many tubes that were unique to them in design features.

My personal experience is the opposite of your assertion:  I've owned a number of different kinds of Brimar tubes over the years and I have never seen one whose design and construction details are the same as one of their USA made counterparts.  They're generally their own thing, and they're generally very good tubes too.  This all depends on the tube type of course.  I'm sure examples of Brimars being identical to an American counterpart exist like you say.  Logically they probably did some licensing of design for certain tubes they didn't want to R&D themselves for whatever reason.  If you've ever seen the words "Licensed to the extent indicated on carton" on a NOS tube still in it's original packaging that's often a clue that the tube is being either made to somebody else's design or is a rebrand.

Re-branding was done for many reasons.  In that era if a large government contract needed fulfilled by a certain date for example, a company would outsource part of the lot production to a second company to get the quantity fulfilled in time.  The customer generally doesn't care who made the tube as long as the quality was acceptable and the tube met proper specifications.


----------



## chrisdrop

Xcalibur255 said:


> I'm not sure where you read that Brimar tubes are based primarily on American design.  This might be true in a few specific cases, but you definitely can't apply it as a generalization to all Brimar tubes.  STC was a tube developer and manufacturer just like Mullard and the others and produced many tubes that were unique to them in design features.
> 
> My personal experience is the opposite of your assertion:  I've owned a number of different kinds of Brimar tubes over the years and I have never seen one whose design and construction details are the same as one of their USA made counterparts.  They're generally their own thing, and they're generally very good tubes too.  This all depends on the tube type of course.  I'm sure examples of Brimars being identical to an American counterpart exist like you say.  Logically they probably did some licensing of design for certain tubes they didn't want to R&D themselves for whatever reason.  If you've ever seen the words "Licensed to the extent indicated on carton" on a NOS tube still in it's original packaging that's often a clue that the tube is being either made to somebody else's design or is a rebrand.
> 
> Re-branding was done for many reasons.  In that era if a large government contract needed fulfilled by a certain date for example, a company would outsource part of the lot production to a second company to get the quantity fulfilled in time.  The customer generally doesn't care who made the tube as long as the quality was acceptable and the tube met proper specifications.


I had a similar impression, probably just due to the Brimar name (BRItish Made American Range). That is merely however a surface level observation and you actually know what you are talking about


----------



## tintinsnowydog (Nov 21, 2020)

Have been experimenting with British L63 tubes the past few days. Definitely need more time on the grey-glass ST shaped and brown based GT ones- both my ears and the tubes to burn in more. I have however spent a lot of time on these metal base Osram. These were united by chance and some hard searching, one piece from the UK, another from Western Australia.

To my ears, they are extremely picky regarding the power tube pairing. They were too forward, bright and dry paired with TS6080, and had a strange, muted tonality with bits of each register sticking out using warmer 6080s and 6AS7s (RCA, Mullard). They were nice with the 5998, but its treble was still overpowering for me. To be honest, I was quite confused by the demand, especially given their comparability to the B65, as the tonality and forward presentation of detail didn't make sense to my ears; that was until I paired them with the MOV power tubes. A GEC6080 was very pleasant, but still a tad dry, the 6AS7 just right for me.

Everything makes sense now. There is razor sharp micro-detail readily available, the soundstage is airy and expansive, midrange tonality is possibly the sweetest and most refined I've heard. I think through this pairing, the power tube filled in missing warmth and depth in the bass and smoothed out the treble, making the overall presentation musical and cohesive. Overall, this was a valuable refresher lesson for me on power/driver tube synergy.

I wonder if anyone here has both these tubes and the coveted B65 who could compare the two, or hear something similar to what I am hearing. I doubt I will ever get to hear a B65 at their current value, but if these are performing anywhere close for less than a tenth of the price there are much worse problems I should be worrying about 



With an Osram A1834, a rare opportunity for me to match up MOV brands!


----------



## maxpudding

@tintinsnowydog thanks for the write up, it’ll help me to choose which pairings I’ll do later, once my tubes and adapter arrived.

I wonder, do you have the Russian 6N13S that you could try with the 6J5 tubes?


----------



## tintinsnowydog

maxpudding said:


> @tintinsnowydog thanks for the write up, it’ll help me to choose which pairings I’ll do later, once my tubes and adapter arrived.
> 
> I wonder, do you have the Russian 6N13S that you could try with the 6J5 tubes?


I only had a pair of the Russian tubes briefly before I sold them off- should've kept them for reference in hindsight. The closest I have now is a Chinese 6N5P I use to burn in driver tubes but it is inferior and probably wouldn't give as accurate impressions as you or I would like! I do have at least one of most other well discussed power tubes though


----------



## maxpudding

tintinsnowydog said:


> I only had a pair of the Russian tubes briefly before I sold them off- should've kept them for reference in hindsight. The closest I have now is a Chinese 6N5P I use to burn in driver tubes but it is inferior and probably wouldn't give as accurate impressions as you or I would like! I do have at least one of most other well discussed power tubes though



Guess I’ll do the comparison and will report back, once those tubes are here 😅 I currently have the TS5998’s, various 6080’s, but no 6AS7’s.

The russian 6N13S tubes are on their way, along with a bunch of other tubes and a couple of adapters


----------



## tintinsnowydog

maxpudding said:


> Guess I’ll do the comparison and will report back, once those tubes are here 😅 I currently have the TS5998’s, various 6080’s, but no 6AS7’s.
> 
> The russian 6N13S tubes are on their way, along with a bunch of other tubes and a couple of adapters


The 5998 is a great reference tube! I would certainly be happy with them if I didn't own any MOV 6AS7s; to me they have very similar and enjoyable presentations, but I personally prefer the MOV. Also the fact that the 5998 price is approaching that of the MOV makes me want to save them! I think the 5998 will pair quite well with most if not all 6J5s


----------



## Slade01

Xcalibur255 said:


> I'm not sure where you read that Brimar tubes are based primarily on American design.  This might be true in a few specific cases, but you definitely can't apply it as a generalization to all Brimar tubes.  STC was a tube developer and manufacturer just like Mullard and the others and produced many tubes that were unique to them in design features.
> 
> My personal experience is the opposite of your assertion:  I've owned a number of different kinds of Brimar tubes over the years and I have never seen one whose design and construction details are the same as one of their USA made counterparts.  They're generally their own thing, and they're generally very good tubes too.



Totally agree with you - and I didn't mean to generalize on all Brimar tubes, insofar that I was merely suggesting the feasibility of Mullard Amerty tubes specifically (are on face value, supposed to be American imported tubes) but really, as you state re-branding occurred on so many levels - where then you do have to trust the internal construction to make that determination.  Obviously you are well experienced in this area, and I really do appreciate you straightening me out on the issue.  I'm always learning and I do find this all fascinating.  



chrisdrop said:


> I had a similar impression, probably just due to the Brimar name (BRItish Made American Range). That is merely however a surface level observation and you actually know what you are talking about



Yes - this exactly.  From researching, their name origin lends to that surface impression.  Even if they started out like that, i'm sure over time they evolved to make the designs better and their own.   Historically STC/Brimar was borne out of a divesture from Western Electric so there was always that inference for me.


----------



## Velozity

tintinsnowydog said:


> Have been experimenting with British L63 tubes the past few days. Definitely need more time on the grey-glass ST shaped and brown based GT ones- both my ears and the tubes to burn in more. I have however spent a lot of time on these metal base Osram. These were united by chance and some hard searching, one piece from the UK, another from Western Australia.
> 
> To my ears, they are extremely picky regarding the power tube pairing. They were too forward, bright and dry paired with TS6080, and had a strange, muted tonality with bits of each register sticking out using warmer 6080s and 6AS7s (RCA, Mullard). They were nice with the 5998, but its treble was still overpowering for me. To be honest, I was quite confused by the demand, especially given their comparability to the B65, as the tonality and forward presentation of detail didn't make sense to my ears; that was until I paired them with the MOV power tubes. A GEC6080 was very pleasant, but still a tad dry, the 6AS7 just right for me.
> 
> ...




I have found the MOV 6J5G / L63 pairs perfectly with the Chatham 6AS7G.  Likewise I have found the Brimar 6C5G pairs perfectly with the Bendix 6080WB.  I pretty much use these two rolls exclusively now, and alternate rectifiers every now and then.  NOW that I've settled on these pairings for my GOTL I can just focus on hoarding.._.er_, collecting multiple s of each.


----------



## tintinsnowydog

Velozity said:


> I have found the MOV 6J5G / L63 pairs perfectly with the Chatham 6AS7G.  Likewise I have found the Brimar 6C5G pairs perfectly with the Bendix 6080WB.  I pretty much use these two rolls exclusively now, and alternate rectifiers every now and then.  NOW that I've settled on these pairings for my GOTL I can just focus on hoarding.._.er_, collecting multiple s of each.


The Chatham 6AS7G is the one tube I’m still on the lookout for. The recent bidding fiascos on it make the search pretty unappetising.. would you say it is a more neutral 5998? I am on the lookout for some Brimar 6C5G. From the descriptions previously on the thread, I would imagine they pair very well with the Bendix


----------



## Velozity

tintinsnowydog said:


> The Chatham 6AS7G is the one tube I’m still on the lookout for. The recent bidding fiascos on it make the search pretty unappetising.. would you say it is a more neutral 5998? I am on the lookout for some Brimar 6C5G. From the descriptions previously on the thread, I would imagine they pair very well with the Bendix




Yes keep up the search, it’s well worth it.  I’ve only had one 5998 and I used it on a different amp, so I can’t compare it to the Chatham in the GOTL.  But I did use them both on my Audiotailor and I would definitely say the Chatham is more neutral, but not a “neutral 5998”.  It is its own tube.  The 5998 has a holographic presentation that is altogether different and adds flavor to the music.  I think this is why so many people love it.  The Chatham doesn’t do that but is a more pure power tube, just amplifying whatever is put into it without coloration.  Both tubes are great and have their places.


----------



## JKDJedi

Velozity said:


> Yes keep up the search, it’s well worth it.  I’ve only had one 5998 and I used it on a different amp, so I can’t compare it to the Chatham in the GOTL.  But I did use them both on my Audiotailor and I would definitely say the Chatham is more neutral, but not a “neutral 5998”.  It is its own tube.  The 5998 has a holographic presentation that is altogether different and adds flavor to the music.  I think this is why so many people love it.  The Chatham doesn’t do that but is a more pure power tube, just amplifying whatever is put into it without coloration.  Both tubes are great and have their places.


Excellent description on these two.


----------



## bcowen

Velozity said:


> Yes keep up the search, it’s well worth it.  I’ve only had one 5998 and I used it on a different amp, so I can’t compare it to the Chatham in the GOTL.  But I did use them both on my Audiotailor and I would definitely say the Chatham is more neutral, but not a “neutral 5998”.  It is its own tube.  The 5998 has a holographic presentation that is altogether different and adds flavor to the music.  I think this is why so many people love it.  The Chatham doesn’t do that but is a more pure power tube, just amplifying whatever is put into it without coloration.  Both tubes are great and have their places.



Well put.  My experience is very similar.  I love the midrange bloom and the bass heft and punch of the 5998.  The Chatham 6AS7 is more linear to my ears and can be almost sterile sounding with a similarly linear (or lean) driver tube. But paired with a driver that's on the warm/romantic side, the Chatham can be quite musically engaging.


----------



## Xcalibur255 (Nov 23, 2020)

Velozity said:


> I have found the MOV 6J5G / L63 pairs perfectly with the Chatham 6AS7G.  Likewise I have found the Brimar 6C5G pairs perfectly with the Bendix 6080WB.  I pretty much use these two rolls exclusively now, and alternate rectifiers every now and then.  NOW that I've settled on these pairings for my GOTL I can just focus on hoarding.._.er_, collecting multiple s of each.


If you can get your hands on some Tungsol/Chatham 6520 then the pairing is even better.  I think some people would contest my assertion that the 6520 sounds different than a 6AS7.  After all they're exactly the same tube with the 6520 having a section matching tolerance specified, but to my ears they present differently (and better) than regular 6AS7s.  Both B65 and TS BGRP produce a wonderfully three dimensional sound with the 6520 that just isn't there with a regular 6AS7 or 6080.


----------



## maxpudding

*notes down additional power tubes to hunt for


----------



## L0rdGwyn

Xcalibur255 said:


> If you can get your hands on some Tungsol/Chatham 6520 then the pairing is even better.  I think some people would contest my assertion that the 6520 sounds different than a 6AS7.  After all they're exactly the same tube with the 6520 having a section matching tolerance specified, but to my ears they present differently (and better) than regular 6AS7s.  Both B65 and TS BGRP produce a wonderfully three dimensional sound with the 6520 that just isn't there with a regular 6AS7 or 6080.



I never did try a pair of Chatham 6520, although I did once have a pair of 6AS7G.  What do have though is a bit of an oddity a pair of Japanese Nippon Electric 6520.  Reading what I wrote a ways back, seems I did think they were better than their 6AS7G equivalent, for what it's worth!


----------



## maxpudding

These unicorn tubes are really elusive. Kinda like playing pokemon, “gotta catch ‘em all!”


----------



## bcowen

L0rdGwyn said:


> I never did try a pair of Chatham 6520, although I did once have a pair of 6AS7G.  What do have though is a bit of an oddity a pair of Japanese Nippon Electric 6520.  Reading what I wrote a ways back, seems I did think they were better than their 6AS7G equivalent, for what it's worth!



Man, I forgot all about that tube.  Gave it a quick listen when I first got it, but got distracted before I gave it a chance to even break in.  Need to give it another listen. If nothing else, the Japanese text on the back makes it worthy.


----------



## JKDJedi

bcowen said:


> Man, I forgot all about that tube.  Gave it a quick listen when I first got it, but got distracted before I gave it a chance to even break in.  Need to give it another listen. If nothing else, the Japanese text on the back makes it worthy.


why..why is all this candy out.... must avoid temptation....must avoid....... temp......ta..... tion...... 🙄


----------



## bcowen

JKDJedi said:


> why..why is all this candy out.... must avoid temptation....must avoid....... temp......ta..... tion...... 🙄



Resistance is futile.  But you already know that.


----------



## raindownthunda (Nov 25, 2020)

What are folks favorite warmer 6j5/etc tube to add a bit more meat to the bones when using a leaner/neutral power tube?

My most recent haul is a pair of Ken-Rad 6J5GT. They sound surprisingly good for how cheap they were. They remind me of the metal RCA 6J5 with maybe a bit more detail.


----------



## GDuss

raindownthunda said:


> What are folks favorite warmer 6j5/etc tube to add a bit more meat to the bones when using a leaner/neutral power tube?
> 
> My most recent haul is a pair of Ken-Rad 6J5GT. They sound surprisingly good for how cheap they were. They remind me of the metal RCA 6J5 with maybe a bit more detail.



I can't remember if you ended up getting any Brimar 6C5's but those are on the list.  Between the RCA, Ken Rad, and Brimar, that pretty much covers it.  I have some National Unions but they are 12J5 and I haven't listened to those in many months.  They might be on this list but I need to go back and listen to them again.


----------



## Xcalibur255

A direct comparison between these and the black glass Ken-Rad 6SN7GT would be an enlightening experiment to see if they sound largely the same or not.


----------



## bcowen

raindownthunda said:


> What are folks favorite warmer 6j5/etc tube to add a bit more meat to the bones when using a leaner/neutral power tube?
> 
> My most recent haul is a pair of Ken-Rad 6J5GT. They sound surprisingly good for how cheap they were. They remind me of the metal RCA 6J5 with maybe a bit more detail.



I like the TungSol round plate 6J5's in that regard.  No wondering where the beef is with them.


----------



## chrisdrop

I really like these guys on both amps; Brimar 6C5Gs. Recommended !


----------



## Velozity

chrisdrop said:


> I really like these guys on both amps; Brimar 6C5Gs. Recommended !



Agreed, I've said this before.  Honestly to me it's a toss up between Brimar 6C5G and MOV L63 as the best drivers in my amp.


----------



## whirlwind

I have been enjoying a pair of Fivre 6C5G tubes in my SET amp for the last couple of days.
They are nice tubes. I have been listening to The Dirty Knobs - Wreckless Abandon album a lot this weekend.
If you are a Mike Campbell fan, this is his new band. Mike was with the Heartbreakers and the lead guitarist for 41 years with Tom Petty.
Good stuff!


----------



## maxpudding

My 6J5 adapter has finally arrived! Thanks, @Deyan! 

For the first roll, I chose to try the MOV CV1067's with the Mullard 6080 combo. With the VC, they have plenty of bass, nice clarity and overall good sounding tubes. Might change to 5998 and compare after 50 hours or so, but so far, I do love them.


----------



## JKDJedi

maxpudding said:


> My 6J5 adapter has finally arrived! Thanks, @Deyan!
> 
> For the first roll, I chose to try the MOV CV1067's with the Mullard 6080 combo. With the VC, they have plenty of bass, nice clarity and overall good sounding tubes. Might change to 5998 and compare after 50 hours or so, but so far, I do love them.


Just got my replacement adapter from @Deyan the same today, (last one..well, don't fix anything that aint broke.. )


----------



## maxpudding

JKDJedi said:


> Just got my replacement adapter from @Deyan the same today, (last one..well, don't fix anything that aint broke.. )



Did you try to peek inside the adapter?   @Deyan's adapters are great, they are not noisy at all compared to some Chinese adapters that I have used in the past


----------



## Tom-s (Dec 6, 2020)

How I sometimes "save" a tube.

This poor sucker had a loose, cracked base while testing >100%. It had to be rescued from the bin.

Step 1: Test it. Don't wiggle the base too much. As it will usually sit in it's natural non-shorted out position. If it's shorted; rotate it in the direction with the least resistance and test again.

Step 2: Glue it.
I use Bison Kombi rapide, a two component epoxy glue, as this stays a bit flexible when dry (you need this as the tube heats up).
Further, match-sticks; gloves and some paper to mix on.
Breaking a match will provide a very sharp point to get minimal amount of glue. A good alternative is a tooth-pick. Then place three or four minimal dots of glue around the base (really, an amount next to nothing will do).
Then use consecutive fingers/nails to distribute the glue exactly between the glass and base. With this example i also put a minimal amount in the crack that started this all to prevent it from going further. As a last stap, take a clean rag to remove any excess glue. The least amount of glue is the best in my experience.

Step 3: Leave it to dry for a bit. Check the match stick that you put in the blob you started with for movement. When it's very sticky after +-10-20 min. Retest the tube to make sure it's still functioning like it should.

Step 4: Before it's completely dry. Put it in the amp and fast dry it there. This will allow the glass to expend a little and the glue to dry with it in that position. Luckily an L63 or any 6J5G barely get warm. So not much of an issue here.

Step 5:  Re-unite with it's brother and enjoy!

Step 6: Post it on a forum. To get some critique and others advice on how to improve. 

Pictures.


After picture.


----------



## Velozity (Dec 7, 2020)

Finally got a chance to roll these Cossor-branded, Ken-Rad 6C5 in tonight.  I found a NOS lot of 12 on accident, some are Ken-Rad made, and some are RCA made (haven't listened to those yet).  Dayum, what nice midrange and bottom they have.  Their warmth warms me toes on this chilly evening.  Listening to a piano solo by one of my favorite pianists Hania Rani and I am lost in the clicks and clacks of the keys, the squeaks and creaks of the foot pedals, and the thoings and thungs of the reverberating strings.  Sounds freaking amazing!  Who knew these unassuming metal cans had all this packed inside!  The Chatham power tubes are really showcasing these puppies.  Going to try the Bendix next and see if I can add even more euphony to this spectacular performance.


----------



## therremans




----------



## Xcalibur255

I've often wondered about the danger of glass cracking or failure because a tube base was re-glued using a glue that cannot flex.  Maybe it's entirely dependent upon how hot that particular tube gets?  I've used clear nail polish in the past to secure loose bases and this has never come back to bite me, but I've never done it on a large power tube that gets hot.  Several of the 6J5G I purchased a little while back had loose bases and I secured all of them with that same nail polish so hopefully it doesn't bite me this time either!


----------



## therremans

Pretty sure I just snagged some early metal base Tung-Sol rebrands. The construction seems very similar to my 6j5g but in the straight bottle. Link


----------



## L0rdGwyn

therremans said:


> Pretty sure I just snagged some early metal base Tung-Sol rebrands. The construction seems very similar to my 6j5g but in the straight bottle. Link



Yep, those are Tung-Sols.  Rapsco, that's a new one for me, I like those boxes.


----------



## leftside

therremans said:


> Pretty sure I just snagged some early metal base Tung-Sol rebrands. The construction seems very similar to my 6j5g but in the straight bottle. Link


Look at that lovely early foil getter and black plates and then consider how much an equivalent 6SN7 will cost you


----------



## Velozity

therremans said:


> Pretty sure I just snagged some early metal base Tung-Sol rebrands. The construction seems very similar to my 6j5g but in the straight bottle. Link




Yes I saw that last night too, almost bought them myself.  Good eye!  You probably won't find that rebrand again for years so that's a good one to add to your collection.


----------



## whirlwind

leftside said:


> Look at that lovely early foil getter and black plates and then consider how much an equivalent 6SN7 will cost you




Yeah, that is the thing....you are going to drop some cash for some of the best 6SN7.....much more than 6J5 and at least for the time being, it is not hard to find NOS tubes and matched pairs.


----------



## Slade01

therremans said:


> Pretty sure I just snagged some early metal base Tung-Sol rebrands. The construction seems very similar to my 6j5g but in the straight bottle. Link



LOL. That's another one I had on my watchlist that you poached.


----------



## JKDJedi

leftside said:


> Look at that lovely early foil getter and black plates and then consider how much an equivalent 6SN7 will cost you


and that be the truth.  . 😏


----------



## Slade01

First dive into the 6C5G.  RCA and Raytheon mismatched twins (RCA Construction).  But wow - rich and smooth, nicely detailed, and very lively -- musical - with great punches on the low end in just the right amounts.  These are doing so much correctly.  Paired with Sylvania Gold Brand 6080.   These are another steal at this price.  Can listen to this all day long.  Wait...I have been listening to this all day long.  I totally dig the mesh cage look.  Character!


----------



## JKDJedi

Slade01 said:


> First dive into the 6C5G.  RCA and Raytheon mismatched twins (RCA Construction).  But wow - rich and smooth, nicely detailed, and very lively -- musical - with great punches on the low end in just the right amounts.  These are doing so much correctly.  Paired with Sylvania Gold Brand 6080.   These are another steal at this price.  Can listen to this all day long.  Wait...I have been listening to this all day long.  I totally dig the mesh cage look.  Character!


RCA 6C5 shielded tubes are a gem and one of my favorite all day tubes.  Excellent grab. 🙂


----------



## Velozity

Slade01 said:


> First dive into the 6C5G.  RCA and Raytheon mismatched twins (RCA Construction).  But wow - rich and smooth, nicely detailed, and very lively -- musical - with great punches on the low end in just the right amounts.  These are doing so much correctly.  Paired with Sylvania Gold Brand 6080.   These are another steal at this price.  Can listen to this all day long.  Wait...I have been listening to this all day long.  I totally dig the mesh cage look.  Character!





Nice pair there.  

The 6C5 is definitely a Pokemon tube...

...Gotta catch 'em all!


----------



## Xcalibur255

therremans said:


> Pretty sure I just snagged some early metal base Tung-Sol rebrands. The construction seems very similar to my 6j5g but in the straight bottle. Link


Congrats on the score.  Real glass Tung-Sols seem to be the least common 6J5 to begin with, and to find a pair in an interesting and uncommon re-brand makes these somewhat of a unicorn.


----------



## PsilocybinCube

@JKDJedi pointed me to this page as we were discussing adapters for the 6sn7 slot.  Using a 6sn7 to dual 7a4 adapter has me curious for other interesting combos.

So...a couple of quick questions:

What specific 6sn7 to 6j5 adapter would you use?  Or is this an @Deyan project?
Where do you start, which tubes are considered TOTL and maybe one step under with this tube?

Thanks!


----------



## Deyan

PsilocybinCube said:


> @JKDJedi pointed me to this page as we were discussing adapters for the 6sn7 slot.  Using a 6sn7 to dual 7a4 adapter has me curious for other interesting combos.
> 
> So...a couple of quick questions:
> 
> ...



The 7A4's use a different than the 6J5 adapter.


----------



## JKDJedi

PsilocybinCube said:


> @JKDJedi pointed me to this page as we were discussing adapters for the 6sn7 slot.  Using a 6sn7 to dual 7a4 adapter has me curious for other interesting combos.
> 
> So...a couple of quick questions:
> 
> ...


@Deyan has most of us covered with the 6J5 adapter here on this thread. And TOTL = $$$  with some of these tubes here, read back a few pages and check out the goodies available.


----------



## chrisdrop (Dec 8, 2020)

PsilocybinCube said:


> @JKDJedi pointed me to this page as we were discussing adapters for the 6sn7 slot.  Using a 6sn7 to dual 7a4 adapter has me curious for other interesting combos.
> 
> So...a couple of quick questions:
> 
> ...


+1 for @Deyan adapters. You can get lower quality (IMO) Chinese adapters via eBay, but Deyan's are always solid.

Thanks to @tintinsnowydog here is a consolidated list of tubes in this family. There are some comments on impressions/etc.

What amp are you using?


----------



## GDuss

chrisdrop said:


> +1 for @Deyan adapters. You can get lower quality (IMO) Chinese adapters via eBay, but Deyan's are always solid.
> 
> Thanks to @tintinsnowydog here is a consolidated list of tubes in this family. There are some comments on impressions/etc.
> 
> What amp are you using?



Another happy @Deyan 6J5 to 6SN7 adapter user here.  I liked the first one so much I bought a second one later  .

These 6J5/6C5 (and their 12V equivalents if your amp can use them) have been one of the greatest discoveries in my tube journey so far.

You know how you always hear these old-timer tube people (and I mean that in the best possible way ) talking about how much they paid for Tung Sol 5998's or GEC 6AS7G's back in the day?  I'm hoping to be one of those guys at some point, talking about how much I enjoy the metal 6J5 tubes I got for less than $5.


----------



## PsilocybinCube

chrisdrop said:


> +1 for @Deyan adapters. You can get lower quality (IMO) Chinese adapters via eBay, but Deyan's are always solid.
> 
> Thanks to @tintinsnowydog here is a consolidated list of tubes in this family. There are some comments on impressions/etc.
> 
> What amp are you using?


I use the Incubus Elegan amp.  It takes a 6as7g/6080 and 6sn7.  Designed by a fellow head fi tube enthusiast.  It's the same amp as a few other folks on this message board.

Thanks for linking to the list of the tubes.  Now to PM Deyan...


----------



## bcowen (Dec 8, 2020)

PsilocybinCube said:


> I use the Incubus Elegan amp.  It takes a 6as7g/6080 and 6sn7.  Designed by a fellow head fi tube enthusiast.  It's the same amp as a few other folks on this message board.
> 
> Thanks for linking to the list of the tubes.  Now to PM Deyan...



Might as well get both a 6SN7 -> 7A4 adapter along with the 6SN7 -> 6J5/6C5 adapter.  That way you only have to wait half as long for the other.  

The 6J5/6C5/L63 etc all have an octal base. The 7A4 has a loctal base, thus the need for two different adapters.  If you only want to get one to start with, I'd recommend the 6J5 adapter as there are lots more rolling opportunities with it than the loctal socket adapter.

Edit and PS:  grab a couple GEC L63's from Langrex while you're at it.


----------



## therremans

Tom-s said:


> Step 1: Test it. Don't wiggle the base too much. As it will usually sit in it's natural non-shorted out position. If it's shorted; rotate it in the direction with the least resistance and test again.
> 
> Step 2: Glue it.
> I use Bison Kombi rapide, a two component epoxy glue, as this stays a bit flexible when dry (you need this as the tube heats up).
> ...


Thanks for sharing this. I will look into Bison Kombi, but have you heard of using Furnace Cement? I want to reattach a Mullard 6080 metal collar.


----------



## wenbinbin2010

chrisdrop said:


> +1 for @Deyan adapters. You can get lower quality (IMO) Chinese adapters via eBay, but Deyan's are always solid.
> 
> Thanks to @tintinsnowydog here is a consolidated list of tubes in this family. There are some comments on impressions/etc.
> 
> What amp are you using?



When did that Google Doc become so fancy?? Going to browse through it again to check out the updates. Great work @tintinsnowydog


----------



## CAJames

Just wanted to throw out another +1 for @Deyan and his adapters. I've got them for 6J5 and also Type 37/76. First class for sure.


----------



## tintinsnowydog

Silence from me for the past week, was out in the Australian country again with no internet! Back home now with some new toys; new amp, and some new tubes. Still getting used to my new amp's sound signature.

Tonight I'm enjoying some nice Brimar 6J5G with RCA 6AS7G for a warm, full-bodied sound, with permanent sparkly top end detail provided by some silver/oil bypass caps. I chose these caps as I love detail, but wanted to use some of the warmer power tubes in my collection that didn't see much use as a result. Compared to just a few other combinations I've rolled on the amp so far, the Brimars have stellar bass control and a wonderful tone, at least as good all rounders in my setup as the MOV


----------



## PsilocybinCube

bcowen said:


> Might as well get both a 6SN7 -> 7A4 adapter along with the 6SN7 -> 6J5/6C5 adapter.  That way you only have to wait half as long for the other.
> 
> The 6J5/6C5/L63 etc all have an octal base. The 7A4 has a loctal base, thus the need for two different adapters.  If you only want to get one to start with, I'd recommend the 6J5 adapter as there are lots more rolling opportunities with it than the loctal socket adapter.
> 
> Edit and PS:  grab a couple GEC L63's from Langrex while you're at it.


I meant to say, I already purchased the 7a4 adapter from Deyan, that's what got me interested in additional adapters.

So...now I my addiction will have spread to buying the following tubes:

5998
421a
6080
6as7g
7a4
6j5 (and its variants)
6sn7

This is a serious problem.


----------



## bcowen (Dec 9, 2020)

PsilocybinCube said:


> I meant to say, I already purchased the 7a4 adapter from Deyan, that's what got me interested in additional adapters.
> 
> So...now I my addiction will have spread to buying the following tubes:
> 
> ...



Problem....opportunity....kind of the same thing.   LOL!!

Oh, and don't forget (with some different adapters) the 6F8G's, 7N7's, 7AF7's, 6CG7's, 2C51's, 396A's, 5670's, 12A*7 family, and a couple hundred dozen others.  Just want to be sure you don't feel limited.


----------



## maxpudding

PsilocybinCube said:


> I meant to say, I already purchased the 7a4 adapter from Deyan, that's what got me interested in additional adapters.
> 
> So...now I my addiction will have spread to buying the following tubes:
> 
> ...



welcome to the club 🤣


----------



## leftside

PsilocybinCube said:


> I meant to say, I already purchased the 7a4 adapter from Deyan, that's what got me interested in additional adapters.
> 
> So...now I my addiction will have spread to buying the following tubes:
> 
> ...


You'll have a "serious" problem when you need to increase your content insurance because of your tubes.


----------



## L0rdGwyn

PsilocybinCube said:


> I meant to say, I already purchased the 7a4 adapter from Deyan, that's what got me interested in additional adapters.
> 
> So...now I my addiction will have spread to buying the following tubes:
> 
> ...



I bought a pair of 5998s the other day from Japan, I don't even have an amp for them.  Being out of the OTL game for a little while, I "heard" they were going extinct.  A quick look at eBay and that seems to be true.  At $125 (in equivalent JPY), I had to do it.


----------



## GDuss

L0rdGwyn said:


> I bought a pair of 5998s the other day from Japan, I don't even have an amp for them.  Being out of the OTL game for a little while, I "heard" they were going extinct.  A quick look at eBay and that seems to be true.  At $125 (in equivalent JPY), I had to do it.



I think we have a winner of the "serious problem" contest  .  

Great find though.  I've had some Tung Sol 5998's stuck in my amp for a while.  Can't seem to get them out.  Whenever I think I'm ready to swap them out, I listen to them and change my mind.  They do almost everything well, so they work in combination with many different 6J5/6C5 driver tubes.


----------



## L0rdGwyn

GDuss said:


> I think we have a winner of the "serious problem" contest  .
> 
> Great find though.  I've had some Tung Sol 5998's stuck in my amp for a while.  Can't seem to get them out.  Whenever I think I'm ready to swap them out, I listen to them and change my mind.  They do almost everything well, so they work in combination with many different 6J5/6C5 driver tubes.



Yeah no kidding, they will go in my OTL tube stockpile  they are one of the best though, sad to see their numbers are dwindling.


----------



## maxpudding (Dec 10, 2020)

One of my tube suppliers said whenever he put the 5998’s up for sale, they sold out very quickly. I told him probably he’s selling them too cheaply and next time try to sell them through auctions 🤣 sadly he said the 5998’s are getting harder to find


----------



## tintinsnowydog (Dec 11, 2020)

The prices for the TS/Chatham 5998 and 6AS7G have been crazy lately.. I managed to pick up this guy recently for under 100AUD. It tests new but the guide pin had come so cleanly off that I had to orient the heaters with a multimeter.




To get the thread back on title, here are some interesting Tunsgram 6J5G. Their construction with the metal shields look more like 6C5G but they are clearly branded 6J5G. Perhaps this is another case of the Cossor 6C5G, rebranding to whatever was most recognised/convenient at the time. First impressions are that they sound good, but nothing tooo special. They are slightly warmer than neutral but lack a bit of bass impact. Mids are very smooth and treble is somewhat tame. Thinking of trying these later with some graphite 6080 to liven them up a bit


----------



## whirlwind

L0rdGwyn said:


> Yeah no kidding, they will go in my OTL tube stockpile  they are one of the best though, sad to see their numbers are dwindling.



Eventually, at some point ...you will get to an OTL amp...I just know it


----------



## bcowen

tintinsnowydog said:


> The prices for the TS/Chatham 5998 and 6AS7G have been crazy lately.. I managed to pick up this guy recently for under 100AUD. It tests new but the guide pin had come so cleanly off that I had to orient the heaters with a multimeter.
> 
> 
> To get the thread back on title, here are some interesting Tunsgram 6J5G. Their construction with the metal shields look more like 6C5G but they are clearly branded 6J5G. Perhaps this is another case of the Cossor 6C5G, rebranding to whatever was most recognised/convenient at the time. First impressions are that they sound good, but nothing tooo special. They are slightly warmer than neutral but lack a bit of bass impact. Mids are very smooth and treble is somewhat tame. Thinking of trying these later with some graphite 6080 to liven them up a bit



I'm surprised you don't have some of these in your toolbox.     

https://www.vivatubes.com/6-pieces-...X4vyiQ8vPuJq9TwropBRiJwT7dzyPGz8aAjL0EALw_wcB


----------



## bcowen

L0rdGwyn said:


> I bought a pair of 5998s the other day from Japan, I don't even have an amp for them.  Being out of the OTL game for a little while, I "heard" they were going extinct.  A quick look at eBay and that seems to be true.  At $125 (in equivalent JPY), I had to do it.



You know of course that tubes just sitting in a box will dry rot and get layers of oxidation on the cathodes (despite being in an oxygen-free vacuum) and will subsequently become totally worthless.  But with me being my usual helpful self, send them to me and I'll be happy play them occasionally for you to prevent that from happening.  No charge, of course.  

Seriously, that's a screaming bargain for a pair of those, at least at the prices being commanded these days. Hope they test well!


----------



## Xcalibur255 (Dec 11, 2020)

whirlwind said:


> Eventually, at some point ...you will get to an OTL amp...I just know it


It won't be "get" but rather "build" I'm thinking.  

edit:  Ohhhhh..... there was a "to" hiding in that sentence that I didn't see.  I'm dumb.


----------



## Xcalibur255

L0rdGwyn said:


> I bought a pair of 5998s the other day from Japan, I don't even have an amp for them.  Being out of the OTL game for a little while, I "heard" they were going extinct.  A quick look at eBay and that seems to be true.  At $125 (in equivalent JPY), I had to do it.


At that price I can't blame you for buying them without a usage case.  I paid more than that for the two pairs I bought 9 years ago.  Have thought about selling the backup pair a few times, but since the Glenn OTL sees 8 hours of operation a day at work now I'll probably wind up actually using them at some point.


----------



## L0rdGwyn

whirlwind said:


> Eventually, at some point ...you will get to an OTL amp...I just know it





Xcalibur255 said:


> It won't be "get" but rather "build" I'm thinking.
> 
> edit:  Ohhhhh..... there was a "to" hiding in that sentence that I didn't see.  I'm dumb.



Yes, at some point!  Not sure when that will be, have not spent much time designing one.  When the idea has come to mind, I have thought I would design an OTL that uses a single 6AS7G / 5998 output tube.  I have matched pairs of several, but they are getting so are, I am thinking I would rather have backups.  There are some other interesting lesser known OTL suitable tubes out there that have me curious, like the Telefunken ED8000 or the RFT EC360...

Anyway, sorry for going off topic, I should have some updated 6J5 amplifier pictures to share soon


----------



## chrisdrop

L0rdGwyn said:


> Yes, at some point!  Not sure when that will be, have not spent much time designing one.  When the idea has come to mind, I have thought I would design an OTL that uses a single 6AS7G / 5998 output tube.  I have matched pairs of several, but they are getting so are, I am thinking I would rather have backups.  There are some other interesting lesser known OTL suitable tubes out there that have me curious, like the Telefunken ED8000 or the RFT EC360...
> 
> Anyway, sorry for going off topic, I should have some updated 6J5 amplifier pictures to share soon


Your off topics are as good as or better than most on topics !


----------



## Tom-s

A bit more off-topic.

The Telefunken ED8000 is a fine tube. But i prefer my GEC CV4079's most off the time. They are fast and clean sounding.

I'm planning on a write up some day with most known and lesser known "half 6080". Unfortunately all need their own adapter so sometimes i rewire an adapter which makes rolling very hard.

Here's a pair ED8000 with ECC802s driver.


----------



## L0rdGwyn

Tom-s said:


> A bit more off-topic.
> 
> The Telefunken ED8000 is a fine tube. But i prefer my GEC CV4079's most off the time. They are fast and clean sounding.
> 
> ...



Very nice!  You are ahead of the curve @Tom-s .  I will keep that in mind, the GEC 4079 are still very plentiful and I have heard they compare favorably to the now unobtainium GEC 6AS7G.  Maybe I will buy 30 of them and build an OTL speaker amplifier / space heater


----------



## JKDJedi

Sylvania? (6L5)


----------



## bcowen

JKDJedi said:


> Sylvania? (6L5)



Not sure.  But these are RCA 6L5's.
(sorry, I'm killin' myself here)


----------



## JKDJedi

bcowen said:


> Not sure.  But these are RCA 6L5's.
> (sorry, I'm killin' myself here)


😂😂😂


----------



## therremans

bcowen said:


> Not sure.  But these are RCA 6L5's.
> (sorry, I'm killin' myself here)


*VT-213.. much better than those basic consumer versions some plebs have.


----------



## Slade01

JKDJedi said:


> Sylvania? (6L5)



Dude, why are you wasting your time on 6L5?  Jump straight to 6*P*5.  P is greater than L.  Must be better!


----------



## JKDJedi

Slade01 said:


> Dude, why are you wasting your time on 6L5?  Jump straight to 6*P*5.  P is greater than L.  Must be better!


I don't feel pretty anymore... 😒😞

😝🤣


----------



## Slade01

On a more serious note - has anyone seen a 6C5G (shouldered glass/coke bottle) style tube without the mesh plate at the top?  Coincidentally, on ebay, when looking to match some of my tubes, I saw a Super Silvertone 6C5G  without said mesh plate hat at the top.  Wondering if this is rare or not.


----------



## bcowen (Dec 11, 2020)

therremans said:


> *VT-213.. much better than those basic consumer versions some plebs have.



LOL!  Yes, the 'L' in 6L5 is for Loser.  VT denotes Victorious Treachery.  Not that I would ever do such a thing of course....heard about it from a friend.


----------



## leftside

L0rdGwyn said:


> I bought a pair of 5998s the other day from Japan, I don't even have an amp for them.  Being out of the OTL game for a little while, I "heard" they were going extinct.  A quick look at eBay and that seems to be true.  At $125 (in equivalent JPY), I had to do it.


Time to stock up on the quality Mullard Mitcham 6080's. I'm a big fan of these early power tubes:
https://www.ebay.ca/itm/4-x-NOS-608...d-Philips-Same-Codes-AJ1-R2J-NIB/264594487952


----------



## L0rdGwyn

leftside said:


> Time to stock up on the quality Mullard Mitcham 6080's. I'm a big fan of these early power tubes:
> https://www.ebay.ca/itm/4-x-NOS-608...d-Philips-Same-Codes-AJ1-R2J-NIB/264594487952



At one point Billington had these for a very reasonable price, still might!


----------



## JKDJedi

L0rdGwyn said:


> At one point Billington had these for a very reasonable price, still might!


he just got 4 @ $50 each...that's reasonable.


----------



## leftside

L0rdGwyn said:


> At one point Billington had these for a very reasonable price, still might!


Yes I've purchased a few from Martin in the past. Now that I'm getting better at identifying the Mullard/Philips codes, I'm going to have to check these tubes again. I think some are the very early types.

I see Langrex is also selling pairs for 85 pounds on eBay. I think these are the later ones though as he's not showing the codes (so I can't identify the factory or year), and the tubes appear to have the later shield symbol used by Mullard.


----------



## maxpudding

Slade01 said:


> On a more serious note - has anyone seen a 6C5G (shouldered glass/coke bottle) style tube without the mesh plate at the top?  Coincidentally, on ebay, when looking to match some of my tubes, I saw a Super Silvertone 6C5G  without said mesh plate hat at the top.  Wondering if this is rare or not.



The consolidated list shows a pair of ken rad 6C5G's without the mesh

From our own head-fier RoyGB:



> The key thing that stands out to me with this tube is how ‘soft’ it sounds. It retains a good amount of detail but is lacking microdetail of solidstate.
> 
> It can almost be psychoacoustically confused with soundstage because it does make music sound ‘further away’ in the sense that microdeail is equally gone from all ranges creating a soundstage-like sound. Contrast with many tubes where it seems like a certain range has certain characteristics like loss of microdetail.
> 
> ...


----------



## maxpudding

L0rdGwyn said:


> At one point Billington had these for a very reasonable price, still might!



Yes they still have a very reasonable pricing for 6080's, I bought 4 mullards 6080's from Martin at GBP33 each (wholesale price).


----------



## maxpudding

Sorry for another post, here's a picture of a pair of Fivre 6C5G's with TS 5998. I initially roll these 6C5G's with the Mullard 6080, the pairing sound wonderful, although it is a bit warm, like the CV1067's. Then, I replace the 6080 with 5998, the music is more balanced with tighter bass. The details in the music are more pronounced and the sound is slightly more spacious. The seller that I bought the Fivres from told me the 6C5Gs will sound their best after 500hrs, so I'm gonna leave these in and enjoy a plethora of music for the next month or two (hopefully ).


----------



## whirlwind

leftside said:


> Time to stock up on the quality Mullard Mitcham 6080's. I'm a big fan of these early power tubes:
> https://www.ebay.ca/itm/4-x-NOS-608...d-Philips-Same-Codes-AJ1-R2J-NIB/264594487952



I never met a Mullard that I didn't like


----------



## bcowen

whirlwind said:


> I never met a Mullard that I didn't like



I like the Mullard 6080 quite a lot. Don't think mine are the early-early versions, but I'm not versed well enough on them to know the difference. And Mullard EL-34's remain one of the hallmarks of that tube type (IMO), bettered only by GEC KT-77's.  OTOH, the CV4003 (12AU7) is a horse of a different color for my tastes. Glorious midrange, but the rest of _everything_ is a total train wreck. Bloated, mushy, roll off sharply (perceptually) at about 10khz, and bass that is not ill-defined but rather completely _not_ defined. I'm exaggerating of course, but let's just say it's one of the worst sounding 12AU7 types I've had roll through my system(s) over the years.


----------



## GDuss

I got these Mullard 6080's earlier this year for about $50 each.  I like them quite a bit, but they are warm, so they need to be paired with somewhat brighter and crisper driver tubes, like Tung Sol 6J5's.  That's a good combination actually.


----------



## leftside (Dec 12, 2020)

bcowen said:


> I like the Mullard 6080 quite a lot. Don't think mine are the early-early versions, but I'm not versed well enough on them to know the difference. And Mullard EL-34's remain one of the hallmarks of that tube type (IMO), bettered only by GEC KT-77's.  OTOH, the CV4003 (12AU7) is a horse of a different color for my tastes. Glorious midrange, but the rest of _everything_ is a total train wreck. Bloated, mushy, roll off sharply (perceptually) at about 10khz, and bass that is not ill-defined but rather completely _not_ defined. I'm exaggerating of course, but let's just say it's one of the worst sounding 12AU7 types I've had roll through my system(s) over the years.


Post up the codes and I'll see if I can identify them. I've been studying and I wouldn't mind some homework haha.

I've recently been buying some close ancestors of the EL34 and am looking forward to doing some comparisons. Also getting through a 365(!) page book on the history of the EL34, Philips and all the various variations. Fascinating book for someone interested in tubes and history. Also learning a lot.


----------



## leftside

GDuss said:


> I got these Mullard 6080's earlier this year for about $50 each.  I like them quite a bit, but they are warm, so they need to be paired with somewhat brighter and crisper driver tubes, like Tung Sol 6J5's.  That's a good combination actually.


I'm not sure those are Mullards (could be GEC), but they are from 1973 and 1970. I'll check the construction later. I do find the Mullard tubes tend to get a little warmer after the mid 50's in some amps.


----------



## GDuss

leftside said:


> I'm not sure those are Mullards (could be GEC), but they are from 1973 and 1970. I'll check the construction later. I do find the Mullard tubes tend to get a little warmer after the mid 50's in some amps.



I think the KB/D code designates them as Mullard Mitcham.  If they are GEC's the seller probably let them go for too low of a price!!!

https://mullard.org/blogs/news/83886851-cv-numbers-and-uk-military-date-and-factory-codes


----------



## Slade01

bcowen said:


> OTOH, the CV4003 (12AU7) is a horse of a different color for my tastes. Glorious midrange, but the rest of _everything_ is a total train wreck. Bloated, mushy, roll off sharply (perceptually) at about 10khz, and bass that is not ill-defined but rather completely _not_ defined. I'm exaggerating of course, but let's just say it's one of the worst sounding 12AU7 types I've had roll through my system(s) over the years.



I know this is off from the topic thread, but thanks for the heads up on the mullard CV4003.  I was about to give them a shot too.  I've got the Brimar CV4003 and that has glorious midrange, and the rest of that tube is solid - doing their thing right/correctly - in a concise manner.  At least i should really temper my expectations on the mullard...you ears a pro, so thanks for the pearl of wisdom.


----------



## L0rdGwyn

A very good 12AU7 is the Brimar CV4034, but it is a flying lead tube so needs to be soldered to a noval base...or if you really like it, hardwired directly into your amp


----------



## Slade01

L0rdGwyn said:


> A very good 12AU7 is the Brimar CV4034, but it is a flying lead tube so needs to be soldered to a noval base...or if you really like it, hardwired directly into your amp



I heard these were really great.  I know tubemonger.com sold them, but have been out of stock for quite a while now.


----------



## L0rdGwyn

Slade01 said:


> I heard these were really great.  I know tubemonger.com sold them, but have been out of stock for quite a while now.



If you are handy with a soldering iron they are dirt cheap from Billington.  At one point I considered buying a large stock and doing the work to apply the 9-pin base so I could spread the love, but decided that was too masochistic even for me 😂  as far as 12AU7s go, they are the best I have heard.


----------



## leftside

GDuss said:


> I think the KB/D code designates them as Mullard Mitcham.  If they are GEC's the seller probably let them go for too low of a price!!!
> 
> https://mullard.org/blogs/news/83886851-cv-numbers-and-uk-military-date-and-factory-codes


Yes you are right. Military codes. I do have one Mullard labelled 6080, which is actually a GEC. The Mullards tend to have a jagged spacer at the top, and the GECs perfectly smooth.


----------



## tintinsnowydog (Dec 14, 2020)

Rolling in some RCA black metal 6J5 at last; they sound great! I'm pairing them with some Tung Sol 7236 power tubes. I think they are somewhat overlooked (I'm guilty of leaving them at the bottom of my power tube stash too) and still super affordable. To my ears, they are one of the most linear tubes in the family, very good technically across the board, wide soundstage and add very little colour to the sound. The RCAs add some signature warmth and tame the HD800 treble without obscuring the sparkly top end from the 7236. Their sound is comparable to the grey glass RCA 6SN7, with perhaps less bass thump and a bit more refinement in the top end. I definitely prefer the 6J5 out of the two! 

Employing a desk fan to cool down the amp as it heats up here. Approaching 40 degrees (100F) indoors today!


----------



## bcowen

tintinsnowydog said:


> _Approaching 40 degrees (100F) indoors today!_



!!!!!!!!!  Holy cow!  Don't you guys have air conditioning down under?


----------



## therremans

tintinsnowydog said:


> Rolling in some RCA black metal 6J5 at last; they sound great! I'm pairing them with some Tung Sol 7236 power tubes. I think they are somewhat overlooked (I'm guilty of leaving them at the bottom of my power tube stash too) and still super affordable. To my ears, they are one of the most linear tubes in the family, very good technically across the board, wide soundstage and add very little colour to the sound. The RCAs add some signature warmth and tame the HD800 treble without obscuring the sparkly top end from the 7236. Their sound is comparable to the grey glass RCA 6SN7, with perhaps less bass thump and a bit more refinement in the top end. I definitely prefer the 6J5 out of the two!
> 
> Employing a desk fan to cool down the amp as it heats up here. Approaching 40 degrees (100F) indoors today!


Great to hear. I have a pair of these dated Feb 1945 arriving today.


----------



## GDuss

therremans said:


> Great to hear. I have a pair of these dated Feb 1945 arriving today.



Mid-40's should be good for these.  Just don't pair them with RCA power tubes.  I don't have any TS 7236's, but that sounds like a good pairing.  They also go well with TS 5998's or other power tubes that aren't midrange focused.


----------



## tintinsnowydog

bcowen said:


> !!!!!!!!!  Holy cow!  Don't you guys have air conditioning down under?


The central heating cooling is old and needs some work.. doesn't bother me most of the time, but I like to keep my capacitors cool 




GDuss said:


> Mid-40's should be good for these.  Just don't pair them with RCA power tubes.  I don't have any TS 7236's, but that sounds like a good pairing.  They also go well with TS 5998's or other power tubes that aren't midrange focused.



Do the black metal RCA extend past 40's production? I've only been seeing the GT version for later dates. I'm not very knowledgeable about the history of the black metal 6J5s in general beyond the VT military designations. 

For experimentation's sake I tried them with RCA 6AS7s. Sounded a bit flat and lacking in treble; somewhat uninspiring, most likely due to lack of top end. Good bass and mids though! I think I also prefer the black metals to the later RCA 6J5GTs, which sounded a bit more muddy across all frequencies, with some grain in the upper mids/lower treble. However, it may also be due to the pair I have being very used.


----------



## therremans (Dec 17, 2020)

The RCA VT-94s do sound great, especially when you factor the cost. I much preferred them with the TS 5998 or Bendix over the TS 7236. They were too warm with the 7236 on my amp and lacked proper dynamics. They do have that signature RCA sound. Wonderful smooth mids and lows, being quite punchy. Thankfully the highs shine through yet small details may not the most resolving. But hey, I spent about $10 for the pair and they test NOS. They sound leaps better than the only other metal tubes I own, the Tung-Sol 6C5s.


The Tung-Sol 6J5GT arrived today. They seem to be true NOS and must be rare tubes. Beautiful condition, perhaps they need some burn in time. I will leave them in for the week. They are *very *neutral but don't have a bad sound, no shimmer or shine, just neutral-land.

Edit: They have opened up after 10-20 hours of play time. Much better sound, completely unveiled and open now. They are still a bit neutral but very accurate, quite good soundstage, uncolored with clean/crisp yet not harsh highs. The bottom end extends without becoming sloppy or distorted. Listened with a NOS Mullard that I was also breaking in.


----------



## Xcalibur255

MR places them in the WWII timeframe.  Very neat tubes.


----------



## bcowen

therremans said:


> The RCA VT-94s do sound great, especially when you factor the cost. I much preferred them with the TS 5998 or Bendix over the TS 7236. They were too warm with the 7236 on my amp and lacked proper dynamics. They do have that signature RCA sound. Wonderful smooth mids and lows, being quite punchy. Thankfully the highs shine through yet small details may not the most resolving. But hey, I spent about $10 for the pair and they test NOS. They sound leaps better than the only other metal tubes I own, the Tung-Sol 6C5s.
> 
> 
> The Tung-Sol 6J5GT arrived today. They seem to be true NOS and must be rare tubes. Beautiful condition, perhaps they need some burn in time. I will leave them in for the week. They are *very *neutral but don't have a bad sound, no shimmer or shine, just neutral-land.



I haven't heard the Tung Sol 6C5's, but I rather like these KenRads.  Be interested to hear how the TS 6J5's develop. I have a pair of round plate GT's, but not any of the flat ladder plate versions.


----------



## tintinsnowydog (Dec 16, 2020)

Rolling a pair of Sylvania 6J5GT with another underrated power tube; a pair of A2293/CV4079 tubes in place of a 6AS7. I have written favourably about them in the past, and they will get you really close to the sound of the GEC 6AS7 for a fraction of the price (the adapter will cost you around the same as a pair). They have excellent technicalities, topped off with killer midrange tone.

I'm enjoying these Sylvanias, dated 33rd week 1954 but still bearing JAN-CHS military markings. I snagged these from a box of used pulls that came straight off an Aussie navy ship into a military warehouse in the 80's, along with a pair of Ken Rad 6J5GT. To me, these sound like what the best Sylvania 6SN7s could have to offer; smooth yet hyper-realistic midrange and top-end characteristic of the 40's VT-231, but with a much tighter, more texture bass response. Vocals sound wonderfully airy and real; complex orchestral passages have appropriate weight, soundstage and very accurate timbre. Sylvanias, both the 6SN7s and now 6J5s, are my top picks for classical music, excelling both tonally and technically. To top it off, everything glows very nicely as well  Now I'm only wondering how different the 40's versions of these sound...


----------



## therremans (Dec 16, 2020)

tintinsnowydog said:


> Rolling a pair of Sylvania 6J5GT with another underrated power tube; a pair of A2293/CV4079 tubes in place of a 6AS7. I have written favourably about them in the past, and they will get you really close to the sound of the GEC 6AS7 for a fraction of the price (the adapter will cost you around the same as a pair). They have excellent technicalities, topped off with killer midrange tone.
> 
> I'm enjoying these Sylvanias, dated 33rd week 1954 but still bearing JAN-CHS military markings. I snagged these from a box of used pulls that came straight off an Aussie navy ship into a military warehouse in the 80's, along with a pair of Ken Rad 6J5GT. To me, these sound like what the best Sylvania 6SN7s could have to offer; smooth yet hyper-realistic midrange and top-end characteristic of the 40's VT-231, but with a much tighter, more texture bass response. Vocals sound wonderfully airy and real; complex orchestral passages have appropriate weight, soundstage and very accurate timbre. Sylvanias, both the 6SN7s and now 6J5s, are my top picks for classical music, excelling both tonally and technically. To top it off, everything glows very nicely as well  Now I'm only wondering how different the 40's versions of these sound...


Yeah! Love these guys also. I personally prefer the smooth, mid-focused gray plates but heard some like the gloss black plates. The gray ladder plates, often labeled Made in Italy, are also good but have a brighter sound (shown here with yellow . I think my black plates were all matte.



Yes, They’re so good (and cheap).. that I can’t stop buying them. 




I am also a big fan of the 30s-40s Sylvania made 6J5Gs. (Bottom row) far bottom left is one actually branded Sylvania, these are more rare.

1930s etched base Sylvania’s.

Different sound than the 6J5GT. These will be a bit more neutral and do something wonderful with its wide open airy presentation to the sound. Try them out.


----------



## Xcalibur255

I really like your tube case.  Very smart idea.


----------



## therremans (Dec 16, 2020)

Xcalibur255 said:


> I really like your tube case.  Very smart idea.


The medium is a good choice, it has two layers of square perforated foam. The small size works too, I use it for my power tubes. It however had one thick layer of foam, but just lay down a small base from the foam you remove to protect the bottom and it’s just the same.

Link


----------



## GDuss

tintinsnowydog said:


> The central heating cooling is old and needs some work.. doesn't bother me most of the time, but I like to keep my capacitors cool
> 
> 
> 
> ...



The black metal RCA 6J5's go past the 40's.  They transition from using the meatball logo, to a different RCA font (sometimes red sometimes white color), and then into another different font and red text.  I'm not sure what logo is used for what date range, but the meatball is less common after the 40's.  These are not my photos.











I also have a pair of RCA 12J5GT (the 12V version), but these are from 1942 so I can't say if the later ones from the 50's and beyond sound different.  The ones I have sound as good or better than the metal RCA 6J5's from the 40's.


----------



## Slade01

GDuss said:


> The black metal RCA 6J5's go past the 40's.  They transition from using the meatball logo, to a different RCA font (sometimes red sometimes white color), and then into another different font and red text.  I'm not sure what logo is used for what date range, but the meatball is less common after the 40's.  These are not my photos.
> 
> 
> 
> ...



From a "in general" with all RCA branding- the meatball logo was introduced in the mid 20's and was used well into the mid to late 60s.  (The last logo in red introduced in 1968).  I wonder if that middle tube you have with the sans-serif type that usually still had a small version of the meatball logo to the side of the words "electron tube"  was maybe something in-between in the middle.  As such a sample below where the vendor indicates this is from the 50's era.


----------



## GDuss

Slade01 said:


> From a "in general" with all RCA branding- the meatball logo was introduced in the mid 20's and was used well into the mid to late 60s.  (The last logo in red introduced in 1968).  I wonder if that middle tube you have with the sans-serif type that usually still had a small version of the meatball logo to the side of the words "electron tube"  was maybe something in-between in the middle.  As such a sample below where the vendor indicates this is from the 50's era.



I think you're right about the sans-serif type being an intermediate logo style.  The small meatball logo in the photos you included is also common in combination with other lettering/text, I just don't think I have seen the large meatball-only logo style (like the one in the first photo I posted) much after the 50's.

Here is the 1942 12J5GT


----------



## therremans

Well the Tung-Sol's definitely changed after the burn-in, I updated my post above.


----------



## bcowen

therremans said:


> The medium is a good choice, it has two layers of square perforated foam. The small size works too, I use it for my power tubes. It however had one thick layer of foam, but just lay down a small base from the foam you remove to protect the bottom and it’s just the same.
> 
> Link



You guys have _*way*_ too few tubes if you can afford cases like that for all of them.


----------



## Slade01

bcowen said:


> You guys have _*way*_ too few tubes if you can afford cases like that for all of them.



Now I know what Marcellus Wallace had in his briefcase in Pulp Fiction....


----------



## bcowen

Slade01 said:


> Now I know what Marcellus Wallace had in his briefcase in Pulp Fiction....



ROFL!  Probably a factory-matched octet of true NOS 1939 Western Electric 300B's.  More valuable than a briefcase full of cocaine.    
(not that I would have any idea what a briefcase full of cocaine is worth, of course)


----------



## therremans

bcowen said:


> You guys have _*way*_ too few tubes if you can afford cases like that for all of them.


The keepers go in the case and others are posted for sale. But just think of all the lucky men who will be able to enjoy your collection one day. 168 Foton’s.


----------



## nwavesailor

My 6J5 types have been gathering dust for a few years since using them with a dual adapter in a Vali 2 and Garage 1217 amp.

I have pairs of Visseaux 6J5G, TS VT94A Fivre 6C5G and a couple of GEC L63 and 6P5G. I have just found this thread and am looking forward to using these old favorites in a new amp!


----------



## GDuss

nwavesailor said:


> My 6J5 types have been gathering dust for a few years since using them with a dual adapter in a Vali 2 and Garage 1217 amp.
> 
> I have pairs of Visseaux 6J5G, TS VT94A Fivre 6C5G and a couple of GEC L63 and 6P5G. I have just found this thread and am looking forward to using these old favorites in a new amp!



Solid collection of J5/C5/P5/L63's  . Which leads to the question, what is the new amp?


----------



## GDuss

therremans said:


> The keepers go in the case and others are posted for sale. But just think of all the lucky men who will be able to enjoy your collection one day. 168 Foton’s.



Is there going to be an estate sale on tubes at some point?  I mean, this isn't specifically referring to @bcowen , just asking for a friend


----------



## nwavesailor

GDuss said:


> Solid collection of J5/C5/P5/L63's  . Which leads to the question, what is the new amp?


It is a Ampsandsound Bigger Ben. I was going to try to use the dual J5 / P5 / C5 / L63 as well as single 6SN7 / 6F8G (mu of 20?) in the input tube location that is using a 6SL7 (mu of 70) if it works with the KT88 or Bendix 6384 as power tubes.


----------



## tintinsnowydog (Dec 17, 2020)

therremans said:


> Yeah! Love these guys also. I personally prefer the smooth, mid-focused gray plates but heard some like the gloss black plates. The gray ladder plates, often labeled Made in Italy, are also good but have a brighter sound (shown here with yellow . I think my black plates were all matte.
> 
> Yes, They’re so good (and cheap).. that I can’t stop buying them.
> 
> ...



Awesome info, thanks! Will be on the lookout for the black plate GT and the 6J5G version.




nwavesailor said:


> It is a Ampsandsound Bigger Ben. I was going to try to use the dual J5 / P5 / C5 / L63 as well as single 6SN7 / 6F8G (mu of 20?) in the input tube location that is using a 6SL7 (mu of 70) if it works with the KT88 or Bendix 6384 as power tubes.


Using 6SN7 or dual 6J5 equivalents in place of a 6SL7 definitely won't damage the amp, but it might not sound right as the bias point of the 6SL7 is very different. Of course it would depend on the specific circuit. Give them a shot though, if they sound good to you then all the better


----------



## maxpudding

bcowen said:


> You guys have _*way*_ too few tubes if you can afford cases like that for all of them.



Was planning to get a case like that...but seeing how my large cardboard boxes are getting filled with tubes coming in...I'd have to find a couple of transparent storage boxes.

Yes, a *couple*. And I think I'm done buying tubes for this year.

LOL


----------



## maxpudding

GDuss said:


> Is there going to be an estate sale on tubes at some point?  I mean, this isn't specifically referring to @bcowen , just asking for a friend



Another friend would like to know too


----------



## bcowen

maxpudding said:


> And I think I'm done buying tubes for this year.



Well since there's only 13 days left in _this_ year, we'll accept that with only a slightly raised eyebrow. If you're meaning for the next 12 month period, then we're all, of course, laughing so hard we can't see straight.


----------



## maxpudding

bcowen said:


> Well since there's only 13 days left in _this_ year, we'll accept that with only a slightly raised eyebrow. If you're meaning for the next 12 month period, then we're all, of course, laughing so hard we can't see straight.



Of course I meant the next couple of weeks of this year, who knows what kind of anxious feelings I might get _next year _


----------



## bcowen

GDuss said:


> Is there going to be an estate sale on tubes at some point?  I mean, this isn't specifically referring to @bcowen , just asking for a friend



ROFL!  My estate sale will be separate and should easily net $75, maybe $80. But I'm printing off BangyBang ads as a future (I hope) guide for my wife so she'll know how to sell $20 tubes for $500 each.  No need for a life insurance policy.


----------



## maxpudding

bcowen said:


> ROFL!  My estate sale will be separate and should easily net $75, maybe $80. But I'm printing off BangyBang ads as a future (I hope) guide for my wife so she'll know how to sell $20 tubes for $500 each.  No need for a life insurance policy.



Don't forget about that wegehighonsomething guy too


----------



## bcowen

maxpudding said:


> Don't forget about that wegehighonsomething guy too



Oh, yeah.  Good thinking!  Almost forgot about that shyster.


----------



## GDuss

bcowen said:


> ROFL!  My estate sale will be separate and should easily net $75, maybe $80. But I'm printing off BangyBang ads as a future (I hope) guide for my wife so she'll know how to sell $20 tubes for $500 each.  No need for a life insurance policy.



Well just for the record, we are hoping this is far, far in the future!!!


----------



## nwavesailor (Dec 18, 2020)

I've only read 23 of the 69 pages so far but noticed a few folks that had their C3G sockets swapped out. Are the C3G yesterday's news and displaced by some new (I should say OLD) tube(s) or shiny objects ?


----------



## leftside

nwavesailor said:


> I've only read 23 of the 69 pages so far but noticed a few folks that had their C3G sockets swapped out. Are the C3G yesterday's news and displaced by some new (I should say OLD) tube(s) or shiny objects ?


Both are good, but if you can have only one, the 6J5 socket gives you many more tube rolling opportunities.


----------



## GDuss

nwavesailor said:


> I've only read 23 of the 69 pages so far but noticed a few folks that had their C3G sockets swapped out. Are the C3G yesterday's news and displaced by some new (I should say OLD) tube(s) or shiny objects ?



I recently spent a bit of time with a pair of C3g's combined with a pair of Tung Sol 5998's.  This was mostly to see how it worked with the Verite Closed.  While it was probably too clean and detailed, the real problem was the gain.  With the C3g (mu of 40) and the 5998 (mu of 5) I basically can only get about 2 or 3 volume notches up from 0 on the GOTL (stepped attenuator) before it's too loud.  This is with the fixed 2V output of the Bifrost 2, I need to try that again with the Hugo 2 since you can set the output voltage wherever you want.  

Either way, it's nice to still have the option of running the C3g, and maybe they just need to be run with lower gain power tubes.  But then I would also have nothing to talk about related to this thread  .

So back on track,  I landed on a pair of Tung Sol 6J5 VT-94's (metal base) with the TS 5998's and that's a great combo with the VC.


----------



## JazzVinyl (Dec 18, 2020)

nwavesailor said:


> I've only read 23 of the 69 pages so far but noticed a few folks that had their C3G sockets swapped out. Are the C3G yesterday's news and displaced by some new (I should say OLD) tube(s) or shiny objects ?



C3g is an awfully good tube that you would want to own/use.  The C3g sockets can also be employed via adapters in the Glenn OTL to run some nice "driver triplets" - that is where you retain your favorite SN7 tube and run a pair of tubes after the SN7, but before the power tubes.

6J7's
EL32's
And a few more can be run in this fashion.  This configuration tends to up the details in the mids, increase stage precision, and is worth exploring...

You can also adapt 6J5 and 12J5 to the SN7 socket via an adapter, then retain C3g for the C3g or the aforementioned driver triplet configuration.


----------



## JKDJedi

I stopped following to avoid further purchases..take a peak..and the wallet emptys in mere 10 seconds flat...how does that happen!?


----------



## JazzVinyl

GDuss said:


> So back on track,  I landed on a pair of Tung Sol 6J5 VT-94's (metal base) with the TS 5998's and that's a great combo with the VC.



Thus far, GDuss...the all around fave tube combo for the Verite closed in the GOTL is....


----------



## JazzVinyl

I wish I could make animated GIF's - not display.


----------



## JKDJedi

JazzVinyl said:


> I wish I could make animated GIF's - not display.


awww.. so negative.. and I just got here too.. I don't feel pretty anymore..


----------



## GDuss

JazzVinyl said:


> Thus far, GDuss...the all around fave tube combo for the Verite closed in the GOTL is....



The TS 6J5 and TS 5998 combo.  But I think I'm still in the early phase with that headphone where I'm having fun trying to see what it can do.  It's still capable of euphonic sounding mids (maybe not on the level of the Aeolus) but I'm going after speed and top/bottom extension right now.  I'm sure I'll get over that at some point, but that's the beauty of tubes and an OTL right?  Make it sound like something different whenever you're ready.


----------



## GDuss

JKDJedi said:


> awww.. so negative.. and I just got here too.. I don't feel pretty anymore..



You've got pretty tubes, we all know it


----------



## JKDJedi

GDuss said:


> You've got pretty tubes, we all know it


Thanks for that.


----------



## nwavesailor

JazzVinyl said:


> C3g is an awfully good tube that you would want to own/use.



Thanks, I do have 3 C3g pairs so I will try them. Adapter is ordered


----------



## bcowen

JKDJedi said:


> I stopped following to avoid further purchases..take a peak..and the wallet emptys in mere 10 seconds flat...how does that happen!?



Why do you think they're called 'vacuum' tubes?


----------



## JKDJedi

bcowen said:


> Why do you think they're called 'vacuum' tubes?


HAH!! Checked the tracking.. 6L5's are stuck in Pennsylvania.


----------



## Xcalibur255

nwavesailor said:


> I've only read 23 of the 69 pages so far but noticed a few folks that had their C3G sockets swapped out. Are the C3G yesterday's news and displaced by some new (I should say OLD) tube(s) or shiny objects ?


Operated as a strapped triode the C3g performs about the same as a 6J5 in terms of linearity and distortion.  So they key difference is variety.  With the C3g you've got Siemens (balanced) and Lorenz (mellow) and that's it.  The other important detail is the C3g having twice as much gain as a 6J5.  This may or may not be undesirable depending on your amp and the sensitivity of your headphones.


----------



## bcowen

JKDJedi said:


> HAH!! Checked the tracking.. 6L5's are stuck in Pennsylvania.



LOL!  Mine haven't moved out of the origination Post Office in Washington state since they were accepted on the 14th.  Sigh.


----------



## JKDJedi

bcowen said:


> LOL!  Mine haven't moved out of the origination Post Office in Washington state since they were accepted on the 14th.  Sigh.


Snow storm.  😐


----------



## GDuss

bcowen said:


> LOL!  Mine haven't moved out of the origination Post Office in Washington state since they were accepted on the 14th.  Sigh.



I thought I was in the same boat, but the tracking went from stuck at the origin post office for 5 days to delivered, with nothing in between.  And that was Priority mail.  USPS is struggling.  At least it got here, intact.


----------



## maxpudding (Dec 19, 2020)

Looking forward to hear the outcome of the...err..6L5 challenge.


----------



## bcowen

maxpudding said:


> Looking forward to hear the outcome of the...err..6L5 challenge.



LOL!  That may not occur until late 2021, assuming of course the USPS delivers before 2022.


----------



## Ripper2860

The challenge is in receiving the tubes for the challenge.  😜


----------



## GDuss

maxpudding said:


> Looking forward to hear the outcome of the...err..6L5 challenge.



My USPS shipment was for some 12AU7's, and I doubt anyone here is anxious to hear the outcome of those.


----------



## bcowen

GDuss said:


> My USPS shipment was for some 12AU7's, and I doubt anyone here is anxious to hear the outcome of those.



I am.  What did you get?  

I don't currently have any components that use a 12AU7 natively, but I used to....and have a bit of a stash as a result.


----------



## GDuss

bcowen said:


> I am.  What did you get?
> 
> I don't currently have any components that use a 12AU7 natively, but I used to....and have a bit of a stash as a result.



A Mullard ECC82 Blackburn from 1966 and an RCA blackplate from the 50's (not sure exactly what date).  I know virtually nothing about the 12AU7 (or AT7/AX7) family, so am just starting on that rabbit hole.  Did I need another rabbit hole to go down?  Of course not.  But let's be serious, it was there, so has to be explored .


----------



## Slade01

GDuss said:


> A Mullard ECC82 Blackburn from 1966 and an RCA blackplate from the 50's (not sure exactly what date).  I know virtually nothing about the 12AU7 (or AT7/AX7) family, so am just starting on that rabbit hole.  Did I need another rabbit hole to go down?  Of course not.  But let's be serious, it was there, so has to be explored .



I'm curious as well.  Also starting down 12AU7.  I heard the Mullard Blackburn was pretty good.


----------



## bcowen

GDuss said:


> A Mullard ECC82 Blackburn from 1966 and an RCA blackplate from the 50's (not sure exactly what date).  I know virtually nothing about the 12AU7 (or AT7/AX7) family, so am just starting on that rabbit hole.  Did I need another rabbit hole to go down?  Of course not.  But let's be serious, it was there, so has to be explored .



Is the RCA a clear top (side getter)?  If so, that's quite rare. I like the clear top RCA's quite a bit -- not particularly stellar at anything, just pretty good at everything. But all the ones I have are gray plates, and clear tops with black plates are rarely seen in the wild any more.


----------



## GDuss

bcowen said:


> Is the RCA a clear top (side getter)?  If so, that's quite rare. I like the clear top RCA's quite a bit -- not particularly stellar at anything, just pretty good at everything. But all the ones I have are gray plates, and clear tops with black plates are rarely seen in the wild any more.



It's not a clear top, and I don't think it's very rare.  Both tubes came from Brent Jessee, who I have admittedly never ordered a single tube from before this.  I called him and talked to him for maybe 20 minutes.  He was super helpful.  I told him what kind of sound I was looking to start out with for 12AU7 and he recommended the Mullard and RCA.  Neither are anywhere near grail tubes, but since I don't have experience with this tube, I figured it's better to start modest.


----------



## maxpudding (Dec 19, 2020)

GDuss said:


> My USPS shipment was for some 12AU7's, and I doubt anyone here is anxious to hear the outcome of those.



I have a Tesla ECC802S coming in and I am anxious to hear what it’d sound like.

Thanks for sharing btw 😆

It is another rabbit hole for sure, did some reading on which variants sounded nice etc. but I chose to go into another rabbit hole..so I got the 6SN7 to 12AU7 adapter, and then I’ve been buying a few 6SN7’s...

The Tesla is my second 12AU7 tube, the first one is the stock tube that came with the bottlehead kit, a baldwin.


----------



## GDuss

maxpudding said:


> I have a Tesla ECC802S coming in and I am anxious to hear what it’d sound like.
> 
> Thanks for sharing btw 😆
> 
> ...



I went down the 12SN7 rabbit hole, which is a much cheaper hole to go down, because fortunately my amp can run 12V tubes.  I don't have many 6SN7's, but have a stockpile of 12V versions.

Sorry for derailing this thread  .  There has to be a thread on Head-Fi for 12A...7 tubes, but I haven't honestly looked yet.

Somewhat back on track though, I will at some point get a dual 6J5 to 12AU7 adapter to run in the Crack when I build it.  But first I want to build it without the Speedball (everyone says it's easier to diagnose problems, plus I want to hear it that way for a while), and I'm not sure if you can run the dual 6J5's on the Crack without the Speedball.  Either way, 12AU7's will be the driver tube for a while before the Speedball goes in and/or the 6J5's go in.  And the stock tube that came with my Crack kit is labeled Thomas and I think is from Japan.


----------



## Ripper2860

Let me save y'all all the aggravation - Tubemonger CV-4034 or CV-4033.  If I had found these earlier I could have saved much $$ on amassing 12A*7 family tubes.  😄


----------



## maxpudding (Dec 19, 2020)

GDuss said:


> Sorry for derailing this thread  .  There has to be a thread on Head-Fi for 12A...7 tubes, but I haven't honestly looked yet.



Did a quick look, it seems there’s no dedicated thread on 12AU7 tubes or its variants



> Somewhat back on track though, I will at some point get a dual 6J5 to 12AU7 adapter to run in the Crack when I build it.  But first I want to build it without the Speedball (everyone says it's easier to diagnose problems, plus I want to hear it that way for a while), and I'm not sure if you can run the dual 6J5's on the Crack without the Speedball.  Either way, 12AU7's will be the driver tube for a while before the Speedball goes in and/or the 6J5's go in.  And the stock tube that came with my Crack kit is labeled Thomas and I think is from Japan.



Yes you can run a stock crack with 6sn7 because there’s plenty of heater current to run the 600 mA 6SN7’s. BTW check out garage1217’s 6sn7 to 12au7 adapter, it doesn’t produce any noise, unlike the Chinese adapters, or you can get it from Deyan as usual


----------



## GDuss

Ripper2860 said:


> Let me save y'all all the aggravation - Tubemonger CV-4034 or CV-4033.  If I had found these earlier I could have saved much $$ on amassing 12A*7 family tubes.  😄



I thought the aggravation and $$ spending on tube hoarding was part of the sickness fun. You have a cure? Maybe I need to get in line for it.


----------



## maxpudding

Oh sorry I meant to say if you can run a stock crack with 6sn7, then you definitely can run dual 6J5’s with it too.

It’s almost 2.30 am here, I need to go to bed soon 😅


----------



## GDuss

maxpudding said:


> Did a quick look, it seems there’s no dedicated thread on 12AU7 tubes or its variants
> 
> 
> 
> Yes you can run a stock crack with 6sn7 because there’s plenty of heater current to run the 600 mA 6SN7’s. BTW check out garage1217’s 6sn7 to 12au7 adapter, it doesn’t produce any noise, unlike the Chinese adapters, or you can get it from Deyan as usual



Thanks, on both points.  

I've had good experience with Deyan's adapters, as well as the ones I have from xulingmrs (I have several from her, including a 12AU7 to 6SN7, but nothing from her designed to go into a 12AU7 socket).


----------



## maxpudding

Ripper2860 said:


> Let me save y'all all the aggravation - Tubemonger CV-4034 or CV-4033.  If I had found these earlier I could have saved much $$ on amassing 12A*7 family tubes.  😄



the cv4034/33 are definitely getting good reviews from some head-fiers here

might try them soon...or next year🤣


----------



## maxpudding

GDuss said:


> Thanks, on both points.
> 
> I've had good experience with Deyan's adapters, as well as the ones I have from xulingmrs (I have several from her, including a 12AU7 to 6SN7, but nothing from her designed to go into a 12AU7 socket).



I have the 6sn7 to 12au7 adapter from her, and I can definitely hear some noises, and some people over at the bottlehead forum reported they had some noise problems coming from the Chinese adapter as well. Probably because the wires aren’t shielded properly.


----------



## leftside

I've used the 12AU7 in a DAC that was designed for them. Here are some of my thoughts:
https://www.head-fi.org/threads/2359glenn-studio.600110/page-1454#post-14425291

But, if you have an amp designed for 6SN7, then maybe save yourself a few $'s and stick with the 6SN7 (or closely related tubes like 6J5). I'm not a fan of the 12AU7 in my amp using the 6SN7 sockets (with a 12AU7 adapter). Loss of detail.


----------



## L0rdGwyn (Dec 19, 2020)

L0rdGwyn said:


> A very good 12AU7 is the Brimar CV4034, but it is a flying lead tube so needs to be soldered to a noval base...or if you really like it, hardwired directly into your amp





Ripper2860 said:


> Let me save y'all all the aggravation - Tubemonger CV-4034 or CV-4033.  If I had found these earlier I could have saved much $$ on amassing 12A*7 family tubes.  😄



These are the best I have heard as well, most of the other "top" 12AU7 are not worth the time or money compared to the CV4034, IMO.  Tubemonger no longer sells the CV3034, continuously out of stock, however, if you are willing to solder them to a noval base (they are flying lead tubes), they can be gotten from Billington very cheaply, around 12 GBP per tube if memory serves.  I will be sending a pair to @Slade01 in the not-so-distant future.

Soldered pair on the left, pair from Tubemonger on the right.


----------



## Slade01

L0rdGwyn said:


> These are the best I have heard as well, most of the other "top" 12AU7 are not worth the time or money compared to the CV4034, IMO.  Tubemonger no longer sells the CV3034, continuously out of stock, however, if you are willing to solder them to a noval base (they are flying lead tubes), they can be gotten from Billington very cheaply, around 12 GBP per tube if memory serves.  I will be sending a pair to @Slade01 in the not-so-distant future.
> 
> Soldered pair on the left, pair from Tubemonger on the right.


Looking forward to it!  And FYI Billington still has them at 12 GBP , but very limited stock.


----------



## bcowen

Ripper2860 said:


> Let me save y'all all the aggravation - Tubemonger CV-4034 or CV-4033.  If I had found these earlier I could have saved much $$ on amassing 12A*7 family tubes.  😄



Those are good starter tubes.    

Just get a long plate, D-getter Holland-made Amperex 7316 and call it a day.  An obscenely stupidly priced pair below, but it shows the important details of the plates being about 2/3rds the height of the bottle, the top D getter, and the Holland manufacture. The short plate versions with O getters are still quite nice, but nothing close to the long plate D getter versions that were mostly (if not exclusively) 1950's production AKAIK.

https://www.ebay.com/itm/Amperex-73...233865?hash=item5dbc11ae49:g:GKgAAOSwoS9fx9FK


----------



## GDuss

A few questions for the amp design experts...  

1) Clearly you can run dual 6J5's in the 12AU7 socket of the Crack, and you use 6J5's because the Crack runs the 12AU7 at 6V (or maybe close at least).  If there were an amp running the 12AU7 at _12V_, is it assumed that you could run dual _12J5's_ in that socket? I guess this also applies to using a 6SN7 in the Crack, while an amp running the 12AU7 at 12V would need a 12SN7.

2) Is it generally the case that an amp running 12AU7 tubes can also run dual 6J5's or 12J5's, depending on what voltage that amp uses for the 12AU7?  Again, this also applies to the 6SN7 or 12SN7.  Or is this specific to the amp design?  In other words, is it just automatically assumed that SN7 or dual J5 tubes are a substitute for 12AU7?

3) Is all of this really only an option for 12AU7, since the 12AT7 and 12AX7 have higher gain, and the SN7 or dual J5 tube has gain similar to the 12AU7?


----------



## A2029

GDuss said:


> A few questions for the amp design experts...
> 
> 1) Clearly you can run dual 6J5's in the 12AU7 socket of the Crack, and you use 6J5's because the Crack runs the 12AU7 at 6V (or maybe close at least).  If there were an amp running the 12AU7 at _12V_, is it assumed that you could run dual _12J5's_ in that socket? I guess this also applies to using a 6SN7 in the Crack, while an amp running the 12AU7 at 12V would need a 12SN7.
> 
> ...



1) If an amp was wired for 12V on the 12AU7 socket, you could use a dual adapter for 6J5s or 12J5s. For running the 6J5s, the sockets would get wired in series in the adapter. For running the 12J5s, you would need a different adapter that wires the 12J5 sockets in parallel. You are correct, an amp running 12AU7 at 12V would use the 12SN7.

2) As long as the amp can take the extra heater current of having the dual 6J5 tubes vs the small 12AU7. The 6SN7 also takes double the heater current of the 12AU7, so just have to make sure that the amp is able to supply the extra current.

3) Not sure if I understand this question. Generally an amp built to bias one tube (e.g. 12AU7) wont give a good bias point on another tube with much higher gain such as the 12AX7.


----------



## L0rdGwyn

GDuss said:


> A few questions for the amp design experts...
> 
> 1) Clearly you can run dual 6J5's in the 12AU7 socket of the Crack, and you use 6J5's because the Crack runs the 12AU7 at 6V (or maybe close at least).  If there were an amp running the 12AU7 at _12V_, is it assumed that you could run dual _12J5's_ in that socket? I guess this also applies to using a 6SN7 in the Crack, while an amp running the 12AU7 at 12V would need a 12SN7.
> 
> 2) Is it generally the case that an amp running 12AU7 tubes can also run dual 6J5's or 12J5's, depending on what voltage that amp uses for the 12AU7?  Again, this also applies to the 6SN7 or 12SN7.  Or is this specific to the amp design?  In other words, is it just automatically assumed that SN7 or dual J5 tubes are a substitute for 12AU7?



For the above, whether or not the amp can run 6J5, 12J5 is dependent on what heater voltage is being used on the 12AU7, i.e. what is coming out of the transformer.  The 12AU7 etc. tubes have a center tapped heater such that the tubes can be heated by either a 6V or 12V transformer winding.  With each half of the heater in parallel, they run at 6V.  With both halves in series, they run at 12V.  That will be dependent on the amplifier's designer and what mains transformer is used.



GDuss said:


> 3) Is all of this really only an option for 12AU7, since the 12AT7 and 12AX7 have higher gain, and the SN7 or dual J5 tube has gain similar to the 12AU7?



The 12AU7 is electrically very similar to the 6SN7, 6J5, 12SN7, 12J5 etc., they are near equivalents, so will bias and operate similarly if used in the same circuit, the reason they are interchangeable.  Not only do the 12AX7 and 12AT7 have higher amplification factor, they have different biasing requirements / electrical characteristics.  Depending on the circuit, the 12AT7 _might _be useable, but not optimal.  It has a higher plate resistance than the 12AU7, which means higher output impedance, which means a lower cutoff frequency from the RC filter formed from the output impedance of the input stage and the input capacitance of the following stage.  With a plate resistance of 10-15K, you would probably see some high-frequency rolloff with the 12AT7 (circuit dependent of course, a buffer of some sort could mitigate this).  The 12AX7 on the other hand has wildly different bias needs from the 12AU7 and probably won't even be usable.  Not to mention it has a very high plate resistance (~60K) which would lead to substantial high-frequency rolloff in a circuit not designed for it.  These high gain, high internal resistance tubes are typically paired with a buffer or driver stage before they hit the power output tube.

I see @A2029 beat me to it


----------



## GDuss

Thanks to both @A2029 and @L0rdGwyn for your answers.  This is great information.

The GOTL, which wasn't designed to run the 12AU7 (although it can with an adapter), has a 6V/12V/25V switch to the SN7 socket.  So for example, the dual J5 to SN7 adapter is the same adapter for 6J5's and 12J5's, you just need to make sure you have the voltage set to the SN7 socket at the correct voltage for the tubes being used.  It doesn't sound like this would be the case going into a 12AU7 socket because it would be a different adapter depending on whether that socket is wired for 6V or 12V.  That's critical information I think.

And yes, for question 3, I figured since the 12AU7 has gain similar to SN7 and dual J5 tubes, it works correctly.  Given the 12AT7 and certainly the 12AX7 are quite different, this isn't optimal.

Great to have circuit expertise in this thread


----------



## Tom-s

From my years of experience with Crack(s). A simple single envelope triode will beat it's dual triode brother 9/10. And 6SN7's beat 12AU7s 9/10. Even with the best 12AU7's this holds true. I like my simple Philips Heerlen ECC82 (12AU7) described by @bcowen before, the best. My advice would be to skip 6SN7 and go 6J5's. Those 5€ metal ones, are possibly the best bang for buck available. 

 Comparing a pair 6J5's to their 6SN7 brother is a fun and worthwhile listening exercise.
Not that it's a fair comparison. It's often no match. The 6J5's just blow the 6SN7 away. 
A 6SN7, however fancy, mostly sound restricted, veiled when directly compared to their 6J5 counterparts.


----------



## L0rdGwyn

L0rdGwyn said:


> These high gain, high internal resistance tubes are typically paired with a buffer or driver stage before they hit the power output tube.



And just one other little fun fact, some of the most unobtainium and expensive triodes ever made are so highly sought after because they overcome this particular issue - they have high gain and a low plate resistance, making them excellent input tubes for hard-to-drive output tubes, like the 300B.  Tubes like the Western Electric 437A, Telefunken EC8020.  These high transconductance tubes can be emulated using specific triode-strapped pentodes, like the E55L, D3a, C3g.  Similar advantage, high gain without the high plate resistance, but prone to oscillation.


----------



## L0rdGwyn

And agree with @Tom-s 100% on the above, 12AU7 < 6SN7 < 6J5, although I found the Brimar CV4034 could hang with the top 6SN7.  I don't recall if I ever tried the Philips Heerlen ECC82  I do vividly remember being very unimpressed with the Telefunken long-plate ECC82, which is highly sought-after.


----------



## Tom-s

And agree with @L0rdGwyn "mostly" on the above, those extreme transconductance tubes don't only make for a good driver. They are also great SPUD amplifiers. 
A SPUD with these sort of tubes portrays the most clear and detailed soundstage. Placement of instruments is the best from my experience! 
And yes, oscillation is a problem. My solution on the five grid pins for the 8020; keep wire's short!  
For those into DIY, do try an E55L (triode connected) spud. It's gorgeous with headphones!


----------



## L0rdGwyn (Dec 19, 2020)

Tom-s said:


> And agree with @L0rdGwyn "mostly" on the above, those extreme transconductance tubes don't only make for a good driver. They are also great SPUD amplifiers.
> A SPUD with these sort of tubes portrays the most clear and detailed soundstage. Placement of instruments is the best from my experience!
> And yes, oscillation is a problem. My solution on the five grid pins for the 8020; keep wire's short!
> For those into DIY, do try an E55L (triode connected) spud. It's gorgeous with headphones!



Very true, they are spud specialists as well.  Can be paired with an input transformer for additional gain if needed for driving speakers in a transformer-coupled spud amplifier.


----------



## PsilocybinCube

GDuss said:


> I recently spent a bit of time with a pair of C3g's combined with a pair of Tung Sol 5998's.  This was mostly to see how it worked with the Verite Closed.  While it was probably too clean and detailed, the real problem was the gain.  With the C3g (mu of 40) and the 5998 (mu of 5) I basically can only get about 2 or 3 volume notches up from 0 on the GOTL (stepped attenuator) before it's too loud.  This is with the fixed 2V output of the Bifrost 2, I need to try that again with the Hugo 2 since you can set the output voltage wherever you want.
> 
> Either way, it's nice to still have the option of running the C3g, and maybe they just need to be run with lower gain power tubes.  But then I would also have nothing to talk about related to this thread  .
> 
> So back on track,  I landed on a pair of Tung Sol 6J5 VT-94's (metal base) with the TS 5998's and that's a great combo with the VC.


5998 is soooo loud.  So good, but it does leave the volume knob turned low.


----------



## tubebuyer2020

Why solder when you can buy an adapter: https://www.ebay.co.uk/itm/1pc-B9A-...128456?hash=item2f42707248:g:JgYAAOSwrcRdxi2w


----------



## GDuss

PsilocybinCube said:


> 5998 is soooo loud.  So good, but it does leave the volume knob turned low.



On the GOTL, you can use 6BX7's (mu of 10) or 6BL7's (mu of 15).  This is even more problematic than the 5998 with a mu of 5.  So then if you run 6BX7's and try to run a pair of C3g's (mu of 40) or 6SL7's (mu of 70), basically the first notch on the volume dial is all you have to work with and even then it's often too loud.  

This is one of those situations where too many gains are bad  .


----------



## Slade01

tubebuyer2020 said:


> Why solder when you can buy an adapter: https://www.ebay.co.uk/itm/1pc-B9A-...128456?hash=item2f42707248:g:JgYAAOSwrcRdxi2w



I believe you still have to solder the leads to the adapter properly, no?


----------



## tubebuyer2020

Slade01 said:


> I believe you still have to solder the leads to the adapter properly, no?



It does not look like it to me. Maybe with this one: https://www.ebay.co.uk/itm/1pc-B9A-...&sd=222618608407&_trksid=p2047675.c100623.m-1


----------



## tintinsnowydog

GDuss said:


> Thanks, on both points.
> 
> I've had good experience with Deyan's adapters, as well as the ones I have from xulingmrs (I have several from her, including a 12AU7 to 6SN7, but nothing from her designed to go into a 12AU7 socket).


I use the 6SN7--> 12AU7 adapter from xulingmrs and I had no problems with noise, dead silent. Perhaps previous models of the design were noisy, or others had bought them from another Chinese vendor. I also stacked her dual 6J5 --> 6SN7 adapter on top and it was fine, some 6C5G were a little noisy but this was fixed by grounding the tubes with some aluminium foil. Better shielding in her 6J5 adapter seems necessary, so perhaps grab one from Deyan or elsewhere. 




L0rdGwyn said:


> And agree with @Tom-s 100% on the above, 12AU7 < 6SN7 < 6J5, although I found the Brimar CV4034 could hang with the top 6SN7.  I don't recall if I ever tried the Philips Heerlen ECC82  I do vividly remember being very unimpressed with the Telefunken long-plate ECC82, which is highly sought-after.


I also agree with this ordering; I found the 12AU7s were ok, but the majority were prone to distortion especially at higher frequencies, often sounding a bit jarring in dense passages and overall a little tinny. No 6SN7 or 6J5 have exhibited the same problem thus far for me, and they sound a lot smoother overall with wider soundstage and better tone.

Very, very few 12AU7s I tried didn't have this problem. I have some smooth plate Telefunken ECC82 that I liked for what they did; extremely detailed and holographic sounstage, but with the classic Telefunken problem that they can get too thin and fatiguing. To me the Mullard Blackburn Gf1/2 ECC82 were the most affordable option which avoided such problems but were overall a bit boring (some might say romantic?) sounding. The Brimar 13D5 sound very similar to me for roughly the same or less cost- I imagine the CV4034 would sound similar but have not tried them myself. The CV491 welded plates I have are possibly the best 12AU I heard despite them testing deep into the reject zone, but pricing on any higher testing ones are obscene. I would say they are on par with the top quartile of 6SN7s. The Crack runs the driver tube quite lightly so I wasn't afraid to buy some of the rarer 12AUs at very low testing values, just to try out their sound signature. I can't bring myself to spend more than double digits on 12AUs so have not tried the Amperex/Philips Heerlen.

 At the end of the day, I would just buy a pair of metal 6J5 and call it a day. They'll knock out all but the best and unobtainum 12AU7s


----------



## L0rdGwyn

tubebuyer2020 said:


> Why solder when you can buy an adapter: https://www.ebay.co.uk/itm/1pc-B9A-...128456?hash=item2f42707248:g:JgYAAOSwrcRdxi2w



I would still solder the leads, a contact connection will not be reliable.  But beware, in both adapters the pins are also soldered to the same PCB pad, meaning as the pad is heated, the solder that holds the pin will be too, causing it to fall out of alignment, it is not a very well thought-out design.  If anyone tries this, let me know and I can give you some tips.


----------



## JKDJedi

GDuss said:


> I thought I was in the same boat, but the tracking went from stuck at the origin post office for 5 days to delivered, with nothing in between.  And that was Priority mail.  USPS is struggling.  At least it got here, intact.


----------



## Velozity

tintinsnowydog said:


> I use the 6SN7--> 12AU7 adapter from xulingmrs and I had no problems with noise, dead silent. Perhaps previous models of the design were noisy, or others had bought them from another Chinese vendor. I also stacked her dual 6J5 --> 6SN7 adapter on top and it was fine, some 6C5G were a little noisy but this was fixed by grounding the tubes with some aluminium foil. Better shielding in her 6J5 adapter seems necessary, so perhaps grab one from Deyan or elsewhere.
> 
> 
> 
> ...





Lot of 12AU7 hating going on so I want to mention their 6C4 single-triode brethren may fare much better in some applications.  In my testing on my GOTL the best dual-6C4 sets beat every 6SN7 I had.  Something else to consider if you want an alternative to 6J5/6C5.


----------



## maxpudding

Velozity said:


> Lot of 12AU7 hating going on so I want to mention their 6C4 single-triode brethren may fare much better in some applications.  In my testing on my GOTL the best dual-6C4 sets beat every 6SN7 I had.  Something else to consider if you want an alternative to 6J5/6C5.



I second this, the 6C4 has quite a few variants that I like. The triple mica 6C4’s types. They beat the few 6SN7’s that I have in my possession as well. The 6C4’s can still be found cheaply in the wild.


----------



## maxpudding (Dec 20, 2020)

Rolling a pair of Ken-Rad 6J5's while listening to Tool. These tubes are glorious.


----------



## Marutks

Are these 6C5V RT tubes any good? How do they sound?


----------



## JKDJedi

Marutks said:


> Are these 6C5V RT tubes any good? How do they sound?


Think it's mentioned here as the Cats Meow.


----------



## Ripper2860

I hate to be 'that guy', but I believe it was referred to as 'The Bee's Knees'.  😏


----------



## chrisdrop

Ripper2860 said:


> I hate to be 'that guy', but I believe it was referred to as 'The Bee's Knees'.  😏


Do you mean the dog's bollocks? (or perhaps even the mutt's nuts?) 

On another note. I haven't yet found a pair of 6*P*5*s that I am in love with. Not sure if it is the tube type of my lack of exploration. Here are Silvertone 6P5s (that I also shared on the Glenn thread the other day). They are absolutely adequate and fine. Does anyone else have preferences _between_ 6P5*, 6C5*, 6J5* tube types? I think a few of my favs are 6C5*s, but haven't developed a theory or ranking...





I believe 6J7*s are the same internals as 6C5s perhaps, but with a top cap, so I think they fit the thread theme... I do like these whenever I come back to them


----------



## maxpudding

chrisdrop said:


> Do you mean the dog's bollocks? (or perhaps even the mutt's nuts?)
> 
> On another note. I haven't yet found a pair of 6*P*5*s that I am in love with. Not sure if it is the tube type of my lack of exploration. Here are Silvertone 6P5s (that I also shared on the Glenn thread the other day). They are absolutely adequate and fine. Does anyone else have preferences _between_ 6P5*, 6C5*, 6J5* tube types? I think a few of my favs are 6C5*s, but haven't developed a theory or ranking...
> 
> ...



Based on my rolling experiences with the 6J5 type tubes, I like the 6J5's a little bit more in my system. Also, depending on the type of music, I roll between the 6C5's and 6J5's quite often to hear which pair suits me the best. Whenever I listen to rock/metal songs, I tend to roll the 6J5's, if listen to pop/jazz/r&b type of music, I tend to roll the 6C5's. YMMV.


----------



## Tom-s

Marutks said:


> Are these 6C5V RT tubes any good? How do they sound?



They do sound very good. They are clean / clear / detailed / airy sounding. Not the type of fat / romantic tube.

Here's a "mismatched" Miniwatt labeled long/short pair from my collection.
Luckily i've got a few more NOS like the left one. As the one on the right doesn't even fit into a socket with pins like this.


----------



## Slade01

Tom-s said:


> They do sound very good. They are clean / clear / detailed / airy sounding. Not the type of fat / romantic tube.
> 
> Here's a "mismatched" Miniwatt labeled long/short pair from my collection.
> Luckily i've got a few more NOS like the left one. As the one on the right doesn't even fit into a socket with pins like this.



What exactly distinguishes those tubes as a "V"?  are they similar at all to the "MG" type tubes?


----------



## Tom-s (Dec 21, 2020)

The V and MG are different build types.
The V is a coated glass bulb tube as far as i can tell.
*Edit*: the coating on the glass bulb is to function as a shield. It may be hard to spot on my pictures, but there's a thin metal wire between the base and the coating on these tubes that's connected to pin 1. Like the metal shield on the far right MG tube is connected on pin 1 with a small wire. See picture.

The MG is Metal Glass. So it's a metal layer over a glass tube.

Here's a picture for comparison. With RT 6C5V and RT 6J5MG (I like the logo on it!).


A picture to show what you get when you open up a few 6J5MG. *note the shield wire on the Neotron casing.


And a later date pair with clear glass in the amplifier.


Hope this helps!


----------



## L0rdGwyn

European tubes like the 6C5V of this time period coated the glass in a metallized paint and ran a ground wire around the tube base then internally to a dedicated ground pin or the cathode for shielding (you can see the wire looped around the base in @Tom-s photo), equivalent in purpose to the "metal can" of the American made 6J5, but much more affordable to manufacture.  The only other European 6J5/6C5 I have seen that does this is the RFT 6J5, although it was used in many other tube models.  The internals of the 6J5MG are identical to the Visseaux / Neotron 6J5G.  To my ears, they sound nearly the same and the 6J5MG are typically more affordable, definitely worth trying!


----------



## Slade01

Tom-s said:


> The V and MG are different build types.
> The V is a coated glass bulb tube as far as i can tell.
> *Edit*: the coating on the glass bulb is to function as a shield. It may be hard to spot on my pictures, but there's a thin metal wire between the base and the coating on these tubes that's connected to pin 1. Like the metal shield on the far right MG tube is connected on pin 1 with a small wire. See picture.
> 
> ...



Yes absolutely!  Awesome pics.  Yeah - I couldn't figure out what the envelope type on the V, but coated glass makes perfect sense.  The RT logos on the MG are indeed really cool.


----------



## Slade01

L0rdGwyn said:


> European tubes like the 6C5V of this time period coated the glass in a metallized paint and ran a ground wire around the tube base then internally to a dedicated ground pin or the cathode for shielding (you can see the wire looped around the base in @Tom-s photo), equivalent in purpose to the "metal can" of the American made 6J5, but much more affordable to manufacture.  The only other European 6J5/6C5 I have seen that does this is the RFT 6J5, although it was used in many other tube models.  The internals of the 6J5MG are identical to the Visseaux / Neotron 6J5G.  To my ears, they sound nearly the same and the 6J5MG are typically more affordable, definitely worth trying!



Now RFT is an interesting beast for sure.  I remember their 6SN7/6H8C had some striking internals.   I can only imagine the same approach is taken for their 6J5s as well.


----------



## CAJames

chrisdrop said:


> Do you mean the dog's bollocks? (or perhaps even the mutt's nuts?)
> 
> On another note. I haven't yet found a pair of 6*P*5*s that I am in love with. Not sure if it is the tube type of my lack of exploration. Here are Silvertone 6P5s (that I also shared on the Glenn thread the other day). They are absolutely adequate and fine. Does anyone else have preferences _between_ 6P5*, 6C5*, 6J5* tube types? I think a few of my favs are 6C5*s, but haven't developed a theory or ranking...
> 
> ...



I've had the same experience with 6P5s, perfectly adequate as in neither the dog's bullocks nor the dog's breakfast. For me 6J5 types work the best, followed by type 37 and some Tung Sol metal 6C5s that sound way too good for what what they cost.


----------



## JKDJedi

L0rdGwyn said:


> European tubes like the 6C5V of this time period coated the glass in a metallized paint and ran a ground wire around the tube base then internally to a dedicated ground pin or the cathode for shielding (you can see the wire looped around the base in @Tom-s photo), equivalent in purpose to the "metal can" of the American made 6J5, but much more affordable to manufacture.  The only other European 6J5/6C5 I have seen that does this is the RFT 6J5, although it was used in many other tube models.  The internals of the 6J5MG are identical to the Visseaux / Neotron 6J5G.  To my ears, they sound nearly the same and the 6J5MG are typically more affordable, definitely worth trying!


there's a pair up in France and the Philips version of this tube is sold out


----------



## bcowen

JKDJedi said:


> there's a pair up in France and the Philips version of this tube is sold out



Looky what showed up today.  Sure are pretty!  Test out quite nicely too with less than a 5% GM difference between them.  Just hoping they're not one of those "not exactly" adventures...I'll blame you


----------



## JKDJedi

bcowen said:


> Looky what showed up today.  Sure are pretty!  Test out quite nicely too with less than a 5% GM difference between them.  Just hoping they're not one of those "not exactly" adventures...I'll blame you


Love the umbrella mica supports, those are gorgeous. I hope they do pan out, at least you didn't buy a case of those this time...😂.


----------



## JKDJedi

I'm not gonna lie.. these are nice.. 

*Super* *Silvertone 6L5G
*


----------



## nwavesailor

and they are dirt cheap!


----------



## maxpudding

JKDJedi said:


> I'm not gonna lie.. these are nice..
> 
> *Super* *Silvertone 6L5G
> *



Niice

Where’s Baby Yoda?


----------



## JKDJedi (Dec 22, 2020)

maxpudding said:


> Niice
> 
> Where’s Baby Yoda?


Grounded for eating the poor (frog ladys) eggs..  (Mandalorian 2 episode 2)


----------



## bcowen

maxpudding said:


> Where’s Baby Yoda?




Very sadly, burned to death when that old, brittle paper sticker on the Silvertone caught fire.


----------



## JKDJedi

bcowen said:


> Very sadly, burned to death when that old, brittle paper sticker on the Silvertone caught fire.


L M F A O >> ROFL..


----------



## maxpudding

😂😂😂

So sorry for going off-topic


----------



## JKDJedi

Is it just me or do some of these tubes need a good 15-20 minute warm up before you get full bloom?


----------



## chrisdrop

Merry Christmas to all you enthusiastic tube fans. Thanks for sharing in this odd form of fun.


----------



## maxpudding

JKDJedi said:


> Is it just me or do some of these tubes need a good 15-20 minute warm up before you get full bloom?



Yeah, same here.



chrisdrop said:


> Merry Christmas to all you enthusiastic tube fans. Thanks for sharing in this odd form of fun.



Merry Christmas to all of you fine gentlemen


----------



## SHIMACM

Merry Christmas to all colleagues!


----------



## CAJames

And Happy Boxing Day!






(Apologies if this has been done, this is my first holiday season on Head-Fi  )


----------



## chrisdrop (Dec 29, 2020)

It's been a quiet few days here. Hopefully people have been celebrating inasmuch as we are able.

I'm enjoying a pair of Mullard 6J5Gs this morning. They are clean, spacious, clear and full-toned. They are some of the better compliments for the outputs I'm using at the moment.

Does anyone have a clue how to date these things - even vaguely? I've no idea about Mullard dating - even what decade? They look so clean, they could have been made last week for all I can tell! In fairness, I'm sure I've asked this before - so apologies for the redundant question!

Here are the innards. I guess black ladder plates, D-getters?







Just listening to whatever Tidal tells me I listened to a lot of in 2020 (a shame head-fi doesn't take Tidal links!). Here are YouTube links to the two that were on during this posting...




Cheers all,
Chris


----------



## whirlwind

chrisdrop said:


> It's been a quiet few days here. Hopefully people have been celebrating inasmuch as we are able.
> 
> I'm enjoying a pair of Mullard 6J5Gs this morning. They are clean, spacious, clear and full-toned. They are some of the better compliments for the outputs I'm using at the moment.
> 
> ...




Nice looking tubes.


----------



## tintinsnowydog

chrisdrop said:


> It's been a quiet few days here. Hopefully people have been celebrating inasmuch as we are able.
> 
> I'm enjoying a pair of Mullard 6J5Gs this morning. They are clean, spacious, clear and full-toned. They are some of the better compliments for the outputs I'm using at the moment.
> 
> ...



I happened across this tube listed for sale today which looks quite similar to yours. Luckily, the seller had a picture of the date code prominently displayed. J5G suggests it is July 1955 Tottehenham factory, which makes sense; the internals look similar to a couple GT straight glass ones that were previously identified on this thread. I haven’t found much on the different change codes for 6J5, but knowing this timeframe corresponds to UG1 is a good reference point as well.

Beautiful looking tubes!


----------



## JKDJedi (Dec 29, 2020)

chrisdrop said:


> It's been a quiet few days here. Hopefully people have been celebrating inasmuch as we are able.
> 
> I'm enjoying a pair of Mullard 6J5Gs this morning. They are clean, spacious, clear and full-toned. They are some of the better compliments for the outputs I'm using at the moment.
> 
> ...



Fink has some good stuff, like his live version of Blueberry Pancakes. And on the much lower spectrum of the collectors gamut, how about them Ken Rads(6J5)... yay we all have them, I know it..  my first..  (I'm blaming @Slade for this one.. )


----------



## therremans

JKDJedi said:


> Fink has some good stuff, like his live version of Blueberry Pancakes. And on the much lower spectrum of the collectors gamut, how about them Ken Rads(6J5)... yay we all have them, I know it..  my first..  (I'm blaming @Slade for this one.. )


How do they compare to the RCA 6J5/VT?


----------



## Slade01

JKDJedi said:


> Fink has some good stuff, like his live version of Blueberry Pancakes. And on the much lower spectrum of the collectors gamut, how about them Ken Rads(6J5)... yay we all have them, I know it..  my first..  (I'm blaming @Slade for this one.. )


Don't blame me!  I don't even have ken rads _yet...!_

*On the other hand*...I am continuing my heavy metal tour with these...(Arcturus 6J5)


----------



## leftside (Dec 30, 2020)

tintinsnowydog said:


> I happened across this tube listed for sale today which looks quite similar to yours. Luckily, the seller had a picture of the date code prominently displayed. J5G suggests it is July 1955 Tottehenham factory, which makes sense; the internals look similar to a couple GT straight glass ones that were previously identified on this thread. I haven’t found much on the different change codes for 6J5, but knowing this timeframe corresponds to UG1 is a good reference point as well.
> 
> Beautiful looking tubes!


UG is the Philips/Mullard type code for 6J5. Mullard were known to be a little late at adopting the "new" Philips date codes that came around 1955 with 3 characters for the date codes, so this could be from 1965. I don't know for sure. January and Tottenham factory yes.

Edit: I'm guessing 1965 would be too late for a 6J5? Don't suppose anyone knows the latest these tubes were produced?


----------



## JKDJedi

therremans said:


> How do they compare to the RCA 6J5/VT?



Don't have em.


----------



## tintinsnowydog

leftside said:


> UG is the Philips/Mullard type code for 6J5. Mullard were known to be a little late at adopting the "new" Philips date codes that came around 1955 with 3 characters for the date codes, so this could be from 1965. I don't know for sure. January and Tottenham factory yes.
> 
> Edit: I'm guessing 1965 would be too late for a 6J5? Don't suppose anyone knows the latest these tubes were produced?


My reasoning for 55 over 65 was that Mullard added the 4th digit to the date codes, in order to further specify the week of production, from 1961 onwards. Coupled with change code of 1 for UG (6J5) I assumed if it were 1965, it would be a larger number!
Of course, that is just my speculation and Mullard may well have just missed out on the 4th digit. I do think 65 is a bit late though, especially for the shoulder shaped tubes.


----------



## leftside

tintinsnowydog said:


> My reasoning for 55 over 65 was that Mullard added the 4th digit to the date codes, in order to further specify the week of production, from 1961 onwards. Coupled with change code of 1 for UG (6J5) I assumed if it were 1965, it would be a larger number!
> Of course, that is just my speculation and Mullard may well have just missed out on the 4th digit. I do think 65 is a bit late though, especially for the shoulder shaped tubes.


Agreed. The more of us who learn about these factory and date codes the better, so that we can share the knowledge. It was actually Philips who added the extra digit, and as Mullard were owned by Philips they also followed the same numbering scheme.

The pre 1955 Mullard date codes are a little harder to decipher. For example:
"1185 is the pre-1955 Mullard tube type code designation for the ECC32. 1955 and beyond they went to a common two-letter 
tube type code designation with Philips, and "EN" was the tube type designation for the ECC32 under that schema."

Some examples:
1185 MAA 1945
1185 MLA 1946

If anyone has any information on Mullard date codes prior to 1955 please let me know!


----------



## tintinsnowydog

leftside said:


> Agreed. The more of us who learn about these factory and date codes the better, so that we can share the knowledge. It was actually Philips who added the extra digit, and as Mullard were owned by Philips they also followed the same numbering scheme.
> 
> The pre 1955 Mullard date codes are a little harder to decipher. For example:
> "1185 is the pre-1955 Mullard tube type code designation for the ECC32. 1955 and beyond they went to a common two-letter
> ...


The pre-1955 codes are truly hard to decipher! I posted about these ECC31 tubes a little while ago; their codes still elude me. Perhaps someone here on this thread will be able to give some more insight to these as well


----------



## Marutks

Is Neotron the best 6J5G tube?   Someone claimed they are better than other 6J5G tubes.

Has anyone tried them?   Are they similar to VISSEAUX 6J5G / 6J5MG ?   This blog post says Neotrons are good but 6J5V RTs are even better.


----------



## JKDJedi

Marutks said:


> Is Neotron the best 6J5G tube?   Someone claimed they are better than other 6J5G tubes.
> 
> Has anyone tried them?   Are they similar to VISSEAUX 6J5G / 6J5MG ?   This blog post says Neotrons are good but 6J5V RTs are even better.


Different strokes for different folks..


----------



## Slade01

JKDJedi said:


> Different strokes for different folks..


...but you're searching for them right?


----------



## JKDJedi

Slade01 said:


> ...but you're searching for them right?


L M F A O.. no.. with a fancy name like that I know I can't afford them.. I'm pick pocketing the tin cans like you right now.. see what $10 can do ..


----------



## Marutks

I got a pair of reasonably priced 6C5GT Fivre from Langrex.   And some "tin cans" too.


----------



## Slade01

Question for the experts - since I am on a raytheon kick right now, and the mention of Langrex.  They have this CV1932 tube - what is the wrapping there in the middle?  It looks like an extra rubber or plastic sleeve right above the base?  Is it for extra support/protection or something?


----------



## tintinsnowydog

Slade01 said:


> Question for the experts - since I am on a raytheon kick right now, and the mention of Langrex.  They have this CV1932 tube - what is the wrapping there in the middle?  It looks like an extra rubber or plastic sleeve right above the base?  Is it for extra support/protection or something?


I've seen the likes of those grey plastic collars on a few military as well as non-military designation tubes. I also have some Sylvania VT-231 with brown plastic collars. To the best of my knowledge, they were used to reinforce the plastic base and prevent it from coming loose, perhaps necessary in military equipment where the tubes are subject to a lot of vibration.  Another possibility is that this was a way of repairing such loose bases.


----------



## Xcalibur255 (Jan 1, 2021)

Slade01 said:


> Question for the experts - since I am on a raytheon kick right now, and the mention of Langrex.  They have this CV1932 tube - what is the wrapping there in the middle?  It looks like an extra rubber or plastic sleeve right above the base?  Is it for extra support/protection or something?


Well, KenRad is listed as the brand so presumably that's the marking on the other side of the tube that we can't see.  Their own listing says it is RCA made, which I don't believe is correct either.  The photo isn't good enough to be sure, especially without a top view of the mica, but that looks like a Brimar to me.  None of the US made 6J5 tubes, at least none I have seen, had plates that wide and the mica support structures are consistent with the Brimar build too.

edit:  somehow I typed KenRad when I meant to type Raytheon.  Oops.


----------



## L0rdGwyn

Xcalibur255 said:


> Well, KenRad is listed as the brand so presumably that's the marking on the other side of the tube that we can't see.  Their own listing says it is RCA made, which I don't believe is correct either.  The photo isn't good enough to be sure, especially without a top view of the mica, but that looks like a Brimar to me.  None of the US made 6J5 tubes, at least none I have seen, had plates that wide and the mica support structures are consistent with the Brimar build too.



Like @Xcalibur255 says, that is a Brimar-made 6J5G.  The gray thingamajig is to keep a loose tube base in place.


----------



## Xcalibur255 (Jan 1, 2021)

Here's an interesting specimen:

https://www.ebay.com/itm/RCA-Victor...657796?hash=item1aaaeab384:g:UTQAAOSwylpfrAja

I get the feeling this tube was meant for specialized equipment back in the day.  It's the first time I've seen an ST version with a metal shell.


----------



## L0rdGwyn

Xcalibur255 said:


> Here's an interesting specimen:
> 
> https://www.ebay.com/itm/RCA-Victor...657796?hash=item1aaaeab384:g:UTQAAOSwylpfrAja



It's a coffin for your tube when it dies. RIP.


----------



## tintinsnowydog

Xcalibur255 said:


> Here's an interesting specimen:
> 
> https://www.ebay.com/itm/RCA-Victor...657796?hash=item1aaaeab384:g:UTQAAOSwylpfrAja
> 
> I get the feeling this tube was meant for specialized equipment back in the day.  It's the first time I've seen an ST version with a metal shell.


I had a few of these metal-clad tubes in a garage-sale box of old tubes from a retired airforce gentleman. From memory there was a 6J7G, 6A8G and 6C6G tube in them. For the metal shells on my tubes at least, It seems that the steel wire which held the halves together had been taken on and off a few times with several scratch marks, so the tubes inside may well have been replaceable.


----------



## leftside

tintinsnowydog said:


> I've seen the likes of those grey plastic collars on a few military as well as non-military designation tubes. I also have some Sylvania VT-231 with brown plastic collars. To the best of my knowledge, they were used to reinforce the plastic base and prevent it from coming loose, perhaps necessary in military equipment where the tubes are subject to a lot of vibration.  Another possibility is that this was a way of repairing such loose bases.


I have a few tubes with the same plastic collar. I believe they were added when the tube was produced - as you say for reinforcement, and not later for repair.


----------



## L0rdGwyn (Jan 1, 2021)

leftside said:


> I have a few tubes with the same plastic collar. I believe they were added when the tube was produced - as you say for reinforcement, and not later for repair.



Sorry if I was mistaken, come to think of it I haven't seen compelling evidence that they were for repair.  Have you seen them in NIB tubes before?


----------



## L0rdGwyn

I have been playing around with my new curve tracer, if anyone is interested, I would be happy to trace some of the 6J5 / 6C5 tubes in my collection and post them here.  I did the L63 the other night, as expected it is very linear!


----------



## leftside

L0rdGwyn said:


> Sorry if I was mistaken, come to think of it I haven't seen compelling evidence that they were for repair.  Have you seen them in NIB tubes before?


I have some that were advertised as NIB/NOS, but the boxes were open and not sealed. 70 years later it's hard to know 100% for sure.


----------



## L0rdGwyn

Here are the MOV L63 curves, for starters.


----------



## Xcalibur255

L0rdGwyn said:


> I have been playing around with my new curve tracer, if anyone is interested, I would be happy to trace some of the 6J5 / 6C5 tubes in my collection and post them here.  I did the L63 the other night, as expected it is very linear!


It would be interesting if there were meaningful differences in linearity between the various brands and plate styles.


----------



## tintinsnowydog

leftside said:


> I have a few tubes with the same plastic collar. I believe they were added when the tube was produced - as you say for reinforcement, and not later for repair.





L0rdGwyn said:


> Sorry if I was mistaken, come to think of it I haven't seen compelling evidence that they were for repair.  Have you seen them in NIB tubes before?


The closest to a ‘NIB’ grey collared tube I have is this 6J5G. The tube label does show sign of use and box is well worn, but the tube tests above the target of 9.0/2.6 for a new tube. I’m pretty convinced this guy wasn’t in need of repair and was built like this


----------



## maxpudding

Hi folks, so today I rolled the hytron 6C5GT's with the 5998. After a few hours of listening to some music, I can say these tubes and the pairing with the 5998 produced a good balance in the overall sound output. I really like the creamy warm sound coming from these tubes, with nice mids and highs, not too overwhelming I'd say. The lows are just enough to let the details coming through the music. Not the airiest tubes, but they are definitely fun. Song list for today's session: Naxatras - Land of Infinite Time, All Them Witches - Mellowing, The Handsome Family - Far From Any Road, Tool - Pneuma, Mastodon - Stairway to Heaven cover, Diana Krall - Cry Me a River, Jeff Goldblum & The Mildred Snitzer Orchestra - Come On-A-My House.

Have a great first weekend in 2021 everyone!


----------



## PsilocybinCube

Marutks said:


> I got a pair of reasonably priced 6C5GT Fivre from Langrex.   And some "tin cans" too.


Crazy that some pairs of Fivre tubes cost as much s a good amp.  That said, I want some Fivre tubes.  The 6sn7 is particularly expensive.

What is it about them that commands such a crazy price?


----------



## Slade01

tintinsnowydog said:


> The closest to a ‘NIB’ grey collared tube I have is this 6J5G. The tube label does show sign of use and box is well worn, but the tube tests above the target of 9.0/2.6 for a new tube. I’m pretty convinced this guy wasn’t in need of repair and was built like this



Thanks everyone for the info.  Yes i was concerned whether or not it was to help secure a loose base or something, but its probably there for added support in general.  Much appreciated!


----------



## Marutks

PsilocybinCube said:


> Crazy that some pairs of Fivre tubes cost as much s a good amp.



I paid 60 gbp + VAT for a pair.   They are much more expensive on ebay.


----------



## JKDJedi

PsilocybinCube said:


> Crazy that some pairs of Fivre tubes cost as much s a good amp.  That said, I want some Fivre tubes.  The 6sn7 is particularly expensive.
> 
> What is it about them that commands such a crazy price?


---> *Headfi.org* <------


----------



## PsilocybinCube

Marutks said:


> I paid 60 gbp + VAT for a pair.   They are much more expensive on ebay.


Where did you purchase from?


----------



## bcowen

JKDJedi said:


> ---> *Headfi.org* <------



ROFL!!!!


----------



## JKDJedi

Ever enjoy a pair so much for about a week and then notice it was an entirely different pair than what you thought they were? o.O And these aren't even matching pairs.


----------



## whirlwind

JKDJedi said:


> Ever enjoy a pair so much for about a week and then notice it was an entirely different pair than what you thought they were? o.O And these aren't even matching pairs.



Leave these in and enjoy the music


----------



## Slade01

JKDJedi said:


> Ever enjoy a pair so much for about a week and then notice it was an entirely different pair than what you thought they were? o.O And these aren't even matching pairs.


So the RCA on the right doesnt have the umbrella arms mica supports?


----------



## bcowen

JKDJedi said:


> Ever enjoy a pair so much for about a week and then notice it was an entirely different pair than what you thought they were?



No.


----------



## JKDJedi

Slade01 said:


> So the RCA on the right doesnt have the umbrella arms mica supports?


plates.. left lot smaller... lol..you knew that.. you guys are halarious.. 🤣🤣


----------



## Marutks

PsilocybinCube said:


> Where did you purchase from?



Langrex


----------



## Slade01

JKDJedi said:


> plates.. left lot smaller... lol..you knew that.. you guys are halarious.. 🤣🤣



I sorta knew but also drank a bit...so yeah maybe it was the camera angle + alcohol.  LOL.


----------



## maxpudding (Jan 3, 2021)

JKDJedi said:


> Ever enjoy a pair so much for about a week and then notice it was an entirely different pair than what you thought they were? o.O And these aren't even matching pairs.



Are those the RCA 6L5G’s?


----------



## L0rdGwyn

Xcalibur255 said:


> It would be interesting if there were meaningful differences in linearity between the various brands and plate styles.



I traced some other 6J5 and that does seem to be the case, although because it is a small sample size, it is hard to say if the differences are related to the brand or just variability between samples.  I'll try to post some more curves today or tomorrow.



PsilocybinCube said:


> Crazy that some pairs of Fivre tubes cost as much s a good amp.  That said, I want some Fivre tubes.  The 6sn7 is particularly expensive.
> 
> What is it about them that commands such a crazy price?



Fivre are one of my personal favorites, they have a very nice tonality.  However shipping internationally from Italy is expensive, so many sellers will have inflated prices as a result.  Then there are others whose prices are inflated for the sake of making more money


----------



## JKDJedi

maxpudding said:


> Are those the RCA 6L5G’s?


yes, with the Senns somewhat bloated (w RCA output) but perfectly balanced with the Beyerdynamic. Bendix 6080 & RCA 6L5G much better for Sennheiser. (vocals are ill for reals)


----------



## DeweyCH

Hi thread, quick question... can anyone explain to me why these 2 6J5 variants have different pinouts? Both are Super Silvertones, one is a 6J5G which has 7 pins, the other is a 6J5GTA with 6 pins (which matches up with what I expect to see on a 6J5).


----------



## Velozity (Jan 4, 2021)

DeweyCH said:


> Hi thread, quick question... can anyone explain to me why these 2 6J5 variants have different pinouts? Both are Super Silvertones, one is a 6J5G which has 7 pins, the other is a 6J5GTA with 6 pins (which matches up with what I expect to see on a 6J5).




Pins 4 and 6 have no connection, so even though pin 4 is present on the base of the 6J5G, it's not connected to the tube.  You could probably pull it right out if you wanted to.  Maybe the manufacturer used common bases with another similar tube to save cost/time/complexity.


----------



## L0rdGwyn

Sorry to double post if you follow my DIY thread, but I rebuilt my 6J5 - 45 parafeed amplifier, just showing it off with some MOV L63! 

  

Here are the guts.


----------



## whirlwind

L0rdGwyn said:


> Sorry to double post if you follow my DIY thread, but I rebuilt my 6J5 - 45 parafeed amplifier, just showing it off with some MOV L63!
> 
> 
> 
> Here are the guts.



Very tidy job...looks wonderful and I am sure it sounds the same. I am a believer of the CCS loads now...even in OTL amp.


----------



## PsilocybinCube

Hey everyone~

I need some help with two tubes I purchased recently in two respects:

a) finding a matching tube for each of those I purchased (or can I use these two tubes together)
b) figuring out if there is an issue with a missing pin (similar to prior post)

So...first off, we have a tube with only 5 pins:




Is this OK?  I didn't realize from the pics on ebay when i bought it that it only had 5 pins and I have no idea if that is fine or if there is an issue.  Also, I can't find an 'exact' match.  Any thoughts on if it would pair with another tube...like this one:




It's a CV1932 tube - WITH ALL 6 PINS!

Sorry for the newbish questions.  I recieved my adapter from @Deyan a few days ago.  I'm loving the sound of these (using the black metal RCA and a set of National Union glass tubes) but am working through the other horde of tubes I purchased when I was waiting for the adapter to arrive!  

I haven't had the guts to run them in the dual 6j5 to 6sn7 adapter yet.  I don't want to fry my beautiful amp from @Paladin79 

Thoughts???


----------



## maxpudding

PsilocybinCube said:


> Hey everyone~
> 
> I need some help with two tubes I purchased recently in two respects:
> 
> ...



Seems like the first tube is missing pin 1? No idea if this tube is safe to use or not, hopefully other member can help you on that. Curious to know too.


----------



## Slade01

PsilocybinCube said:


> Hey everyone~
> 
> I need some help with two tubes I purchased recently in two respects:
> 
> ...



Your CV1932 is a Tungsram 6J5G if im not mistaken.   Langrex actually has these in stock, or you can ebay it if there is a commercial retail version (non military) version with the same internal construction. 

I'm curious about the missing pin on the other one as well.


----------



## A2029

PsilocybinCube said:


> Hey everyone~
> 
> I need some help with two tubes I purchased recently in two respects:
> 
> ...



No pin1 is perfectly fine, that's just the pin that connects to the outer shield/shell in full metal or metalized 6J5 tubes.


----------



## Paladin79

PsilocybinCube said:


> Hey everyone~
> 
> I need some help with two tubes I purchased recently in two respects:
> 
> ...


I am glad you checked, I do not know those tubes and I am glad others do lol.


----------



## PsilocybinCube

A2029 said:


> No pin1 is perfectly fine, that's just the pin that connects to the outer shield/shell in full metal or metalized 6J5 tubes.





A2029 said:


> No pin1 is perfectly fine, that's just the pin that connects to the outer shield/shell in full metal or metalized 6J5 tubes.



OK...So just to confirm, the tube with just 5 pins (the Brimar) is probably OK to use?

Also, regarding the Tungsram tube - would this be a suitable mate?:  https://www.ebay.com/itm/Tungsram-CV1932-6J5G-L63-Black-Plate-Valve-Tube-V29B/173523068028   OR   https://www.langrex.co.uk/products/l63-cv1067-kb-z-gec-vintage-shouldered-nos-boxed-valve-tube/


And if I pair the two tubes pictured above together (the 5-pin Brimar and 6-pin Tungsram), do you think that's OK???  Or don't even chance it???

Side note:  When I bought my first amp (BHC) from @DenverW I had to ask him some questions and referred to the tubes as the little tube (12au7) and big tube (6as7g), so I feel like I've come a long way despite my seeming lack of knowledge


----------



## bcowen

PsilocybinCube said:


> Hey everyone~
> 
> I need some help with two tubes I purchased recently in two respects:
> 
> ...



Yup.  As @A2029 already noted, pin 1 is a "shell" (ground) connection that perhaps had some value with the first 6J5's that were encased in tin cans. Once the 6J5G's (or glass bottle) versions were introduced, that pin connection serves no purpose.  So as long as you have pins for the elements as below, you should be good to go.

6J5 (and CV1932):




Pin 1: Shell (no issue if missing)
Pin 2: Heater
Pin 3: Anode (plate)
Pin 5: Grid
Pin 7: Heater
Pin 8: Cathode


----------



## bcowen

PsilocybinCube said:


> OK...So just to confirm, the tube with just 5 pins (the Brimar) is probably OK to use?



Yes.



PsilocybinCube said:


> And if I pair the two tubes pictured above together (the 5-pin Brimar and 6-pin Tungsram), do you think that's OK???  Or don't even chance it???



Won't hurt anything at all.  May sound a bit odd with two different manufacturers....but maybe it won't. No animals will be harmed in the process regardless.


----------



## Slade01

PsilocybinCube said:


> Also, regarding the Tungsram tube - would this be a suitable mate?:  https://www.ebay.com/itm/Tungsram-CV1932-6J5G-L63-Black-Plate-Valve-Tube-V29B/173523068028   OR   https://www.langrex.co.uk/products/l63-cv1067-kb-z-gec-vintage-shouldered-nos-boxed-valve-tube/



I think the Tungsram one is a match - the internals look the same.    The 2nd link that is a KB/Z denotes that its is a GEC (MO Valve Company-Hammersmith), made in a different factory than yours (having the /T).  It would have a different internal construction between the two tubes.



> And if I pair the two tubes pictured above together (the 5-pin Brimar and 6-pin Tungsram), do you think that's OK???  Or don't even chance it???



You can plug in both, even if they are different, your sound could have slightly different properties within each channel, but it wont hurt anything otherwise.


----------



## PsilocybinCube

Great.  Thanks for all the help guys.  I'll probably go ahead and buy the matching tube and try out the tubes in parallel in tomorrow morning's listening session.


----------



## bcowen

PsilocybinCube said:


> Great.  Thanks for all the help guys.  I'll probably go ahead and buy the matching tube and try out the tubes in parallel in tomorrow morning's listening session.



Maybe you'll create an entirely new black rabbit hole in the process -- totally different single triode tubes in each channel.

My wallet hopes you fail miserably.


----------



## Slade01

PsilocybinCube said:


> Great.  Thanks for all the help guys.  I'll probably go ahead and buy the matching tube and try out the tubes in parallel in tomorrow morning's listening session.



Sure thing.  It's funny you had this issue.  Just prior to this, I had done alot of research on tungsram 6j5g, and was about to buy that same one from langrex.

I acquired what seemingly was a CV-Mark-ed Tube in a small tube lot, some of the markings rubbed off, but /T or something else remained.  But comparing the internals, mine turned out to be a Raytheon made tube.   Yours has the posts like the one on the langrex site, so i think yours is more of a real deal.  Mine is either a counterfeit or a us rebranded european military tube.    As a valuable lesson i've learned on here time and again, don't just trust the markings look at its insides! ...you can't fake the internal construction!


----------



## leftside

bcowen said:


> Maybe you'll create an entirely new black rabbit hole in the process -- totally different single triode tubes in each channel.
> 
> My wallet hopes you fail miserably.


I already run TS 5998 and Bendix or Mullard 6080 to great effect in my amp


----------



## Velozity

I posted this in the Echo thread, but I figured you guys would appreciate it also.  Dual 6C4-to-6922.  @Deyan has another hit!


----------



## maxpudding

Velozity said:


> I posted this in the Echo thread, but I figured you guys would appreciate it also.  Dual 6C4-to-6922.  @Deyan has another hit!



Round adapters? Cool 😎


----------



## DenverW

PsilocybinCube said:


> OK...So just to confirm, the tube with just 5 pins (the Brimar) is probably OK to use?
> 
> Also, regarding the Tungsram tube - would this be a suitable mate?:  https://www.ebay.com/itm/Tungsram-CV1932-6J5G-L63-Black-Plate-Valve-Tube-V29B/173523068028   OR   https://www.langrex.co.uk/products/l63-cv1067-kb-z-gec-vintage-shouldered-nos-boxed-valve-tube/
> 
> ...



When in doubt, always go with the big tube.


----------



## bcowen

DenverW said:


> When in doubt, always go with the big tube.



LOL!  Sound advice.


----------



## PsilocybinCube

bcowen said:


> Maybe you'll create an entirely new black rabbit hole in the process -- totally different single triode tubes in each channel.
> 
> My wallet hopes you fail miserably.


The rabbit hole was opened.  This morning as I listened to the two different tubes 6j5 tubes, their sonic characteristics swirled in my head, the drivers on my HD800 headphones contorting to match the cosmic sounds surrounding me.

Well, actually, it mostly sounded very good but the channels were slightly different - as you indicated they would be.  I may not have immediately noticed had I gone in blindly and not listened for it.

I managed to find a matching tube for the Brimar seemingly identical construction.  It's a Calverton:  

https://www.ebay.com/itm/1-x-6J5g-C...e=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649

There is a match for CV1932 but it's a tad expensive and coming from the UK, so I might just wait for one to pop up stateside at a (hopefully) lower price.


Thanks for all the help yesterday guys (and gals?)!


----------



## wenbinbin2010

IEC Mullard 12J5GT/VT-135 Universal General Purpose Triode Valve- BangyBang Tube | eBay 

Anyone have experience with IEC-branded Mullard tubes? Can't seem to find any helpful information online. Bought a few just now, based on the Mullard name purely, but not sure if it'll be true to the Mullard sound.


----------



## GDuss

wenbinbin2010 said:


> IEC Mullard 12J5GT/VT-135 Universal General Purpose Triode Valve- BangyBang Tube | eBay
> 
> Anyone have experience with IEC-branded Mullard tubes? Can't seem to find any helpful information online. Bought a few just now, based on the Mullard name purely, but not sure if it'll be true to the Mullard sound.



Hopefully this is just a general question and you are not considering buying from BangyBang.  They are on the list of sellers to avoid:

https://www.head-fi.org/threads/over-priced-tubes.920115/post-16063045

I'm sure others have more experience with this question than I do, but I had the same question recently when looking at 12AU7 tubes, where there are many IEC and Mullard versions that seem to be the same, if not identical.


----------



## wenbinbin2010

GDuss said:


> Hopefully this is just a general question and you are not considering buying from BangyBang.  They are on the list of sellers to avoid:
> 
> https://www.head-fi.org/threads/over-priced-tubes.920115/post-16063045
> 
> I'm sure others have more experience with this question than I do, but I had the same question recently when looking at 12AU7 tubes, where there are many IEC and Mullard versions that seem to be the same, if not identical.



Oh definitely did not buy from BangyBang. Purchased a 5-pack of these IEC Mullard 12J5GTs for just around $40, almost the same as BangyBang's asking price for one tube.


----------



## leftside

All 10 sold in less than 12 hours to one buyer! Anyone from here?
https://www.ebay.com/itm/L63-6J5G-VINTAGE-OSRAM-METAL-BASE-NOS-BOXED-VALVE-TUBE-LC93-/274647215601


----------



## Xcalibur255

Smells like a group buy that was organized somewhere other than here, or maybe somebody who thinks they can turn a profit re-selling them in pairs elsewhere.  I can't imagine an individual collector would see the straight glass version as desirable enough to horde this many, but hording isn't exactly a logic based activity either so.......


----------



## leftside

Xcalibur255 said:


> Smells like a group buy that was organized somewhere other than here, or maybe somebody who thinks they can turn a profit re-selling them in pairs elsewhere.  I can't imagine an individual collector would see the straight glass version as desirable enough to horde this many, but hording isn't exactly a logic based activity either so.......


Those straight glass (with metal base) are very desirable, and going up in price it seems. Check out the price of the equivalent B65 that Langrex has. Of course the 12 volt version B36 is cheaper.


----------



## whirlwind

leftside said:


> All 10 sold in less than 12 hours to one buyer! Anyone from here?
> https://www.ebay.com/itm/L63-6J5G-VINTAGE-OSRAM-METAL-BASE-NOS-BOXED-VALVE-TUBE-LC93-/274647215601



Maybe a group buy was organized


----------



## Xcalibur255

leftside said:


> Those straight glass (with metal base) are very desirable, and going up in price it seems. Check out the price of the equivalent B65 that Langrex has. Of course the 12 volt version B36 is cheaper.


I don't get why the straight glass is more desirable than the ST glass ones are, unless there are construction/plant origin differences.  I guess if the straight glass with the Osram sticker are literally just one of the B65 plates inside I can see why people would really want them.


----------



## tintinsnowydog

leftside said:


> All 10 sold in less than 12 hours to one buyer! Anyone from here?
> https://www.ebay.com/itm/L63-6J5G-VINTAGE-OSRAM-METAL-BASE-NOS-BOXED-VALVE-TUBE-LC93-/274647215601


Seems like another case of a mass disappearance of tubes from Langrex like the Brimar 6C5G from earlier in this thread.. Perhaps a dealer is watching this thread??




Xcalibur255 said:


> I don't get why the straight glass is more desirable than the ST glass ones are, unless there are construction/plant origin differences.  I guess if the straight glass with the Osram sticker are literally just one of the B65 plates inside I can see why people would really want them.


I have tried both the straight glass and the ST shaped 6J5G and definitely prefer the ST shape much more. The straight glass is more forward sounding and has a drier tone, with perhaps more detail. I think the high demand is indeed due to its similarities to the B65, but I have never tried one or B36 to confirm. Regardless, 100+GBP is above and beyond the market price and what I personally think they should be worth.


----------



## therremans

I’m trying to determine the manufacture of this pair. Does anyone here recognize the build? There are no codes of any kind.


----------



## leftside

tintinsnowydog said:


> Seems like another case of a mass disappearance of tubes from Langrex like the Brimar 6C5G from earlier in this thread.. Perhaps a dealer is watching this thread??
> 
> 
> 
> I have tried both the straight glass and the ST shaped 6J5G and definitely prefer the ST shape much more. The straight glass is more forward sounding and has a drier tone, with perhaps more detail. I think the high demand is indeed due to its similarities to the B65, but I have never tried one or B36 to confirm. Regardless, 100+GBP is above and beyond the market price and what I personally think they should be worth.


Have you tried the metal base L63? I do agree these sold for significantly more than others I've seen.


----------



## Xcalibur255

therremans said:


> I’m trying to determine the manufacture of this pair. Does anyone here recognize the build? There are no codes of any kind.


It's a Canadian manufactured version of the RCA design to my eyes.  Perhaps one or two others could chime in and confirm/debunk.


----------



## tintinsnowydog

leftside said:


> Have you tried the metal base L63? I do agree these sold for significantly more than others I've seen.


I have tried the metal base grey glass gold Osram labelled L63 and that is my impression of them above. I think I even prefer the brown base straight glass L63 over the metal base, it has a similar presentation but better detail and more balanced tonality in my opinion. If anyone has both the metal base L63 and the metal base B65/B36 that would be a very worthwhile comparison!  



Xcalibur255 said:


> It's a Canadian manufactured version of the RCA design to my eyes.  Perhaps one or two others could chime in and confirm/debunk.


I would agree, Marconi Canada made and branded their own tubes but seems to have gotten their parts from US companies RCA/GE/Sylvania etc. I have 'GE Canada' made 6SN7 that have identical internals to Sylvania that likely were made by Marconi. There was also the case of 'Marconi 6SN7GTB' tubes with the sought after 3-hole T-shaped Sylvania plates but different getter; I think the consensus was that the internals were bought from Sylvania then assembled (in Canada), with bases subsequently put on by Marconi. I definitely think my Canadian 6SN7 sound different to any US Sylvania 6SN7, and I wonder if these 6J5G have any similarities to RCA.


----------



## bcowen

tintinsnowydog said:


> I would agree, Marconi Canada made and branded their own tubes but seems to have gotten their parts from US companies RCA/GE/Sylvania etc. I have 'GE Canada' made 6SN7 that have identical internals to Sylvania that likely were made by Marconi. There was also the case of 'Marconi 6SN7GTB' tubes with the sought after 3-hole T-shaped Sylvania plates but different getter; I think the consensus was that the internals were bought from Sylvania then assembled (in Canada), with bases subsequently put on by Marconi. I definitely think my Canadian 6SN7 sound different to any US Sylvania 6SN7, and I wonder if these 6J5G have any similarities to RCA.



What I've read over the years is very similar, although some suggest that RCA was the primary parts supplier. Could be dependent on the tube type as well, with Sylvania the primary supplier for some types and RCA some others.  I've never found anything totally definitive one way or the other.  The only thing that does seem definitive is that the UK Marconi (a later iteration of MOV) and Canadian Marconi are entirely different animals.


----------



## wenbinbin2010

Velozity said:


> NOS Brimar 6C5G popped up today.  Get them while you can...
> 
> https://www.ebay.com/itm/313236390777





GDuss said:


> Wow, only 1 left already.  And less than I paid from Langrex.  Hopefully they went to people in this thread and not to BangyBang who will charge way more for them later.



Speaking of BangyBang...was browsing eBay and saw these Brimar 6C5Gs listed among the usual suspects and thought they looked familiar -  Vintage Brimar 6C5G/W1528 Octal Triode Antique Radio Tube Valve- BangyBang Tubes | eBay. Does anyone recall the original price compared to what they're being resold for?

I still can't find any info on the IEC Mullard 12J5 tubes, but they'll arrive early this week, so hopefully will be a pleasant surprise!


----------



## GDuss

wenbinbin2010 said:


> Speaking of BangyBang...was browsing eBay and saw these Brimar 6C5Gs listed among the usual suspects and thought they looked familiar -  Vintage Brimar 6C5G/W1528 Octal Triode Antique Radio Tube Valve- BangyBang Tubes | eBay. Does anyone recall the original price compared to what they're being resold for?
> 
> I still can't find any info on the IEC Mullard 12J5 tubes, but they'll arrive early this week, so hopefully will be a pleasant surprise!



I paid $25 per tube from Langrex for the Brimar 6C5G's when they had them.  They didn't come in original boxes though, certainly nothing like the one in the BangyBang photo.  Mine also don't have that red Brimar text on the base.


----------



## Marutks

This guy wants £846.77 for a pair of 6C5V tubes.
https://www.ebay.co.uk/itm/6c5-g-tu...r-6j7-6j5-l63-6sn7-b65-valve-pre/193639879856

Are they so much better than, for example, this metal tube?

https://www.ebay.co.uk/itm/2x-6J5MG...-VISSEAUX-MATCHED-Nos-CavKG1h123/313240146896
EUR 56.35


----------



## chrisdrop

Marutks said:


> This guy wants £846.77 for a pair of 6C5V tubes.
> https://www.ebay.co.uk/itm/6c5-g-tu...r-6j7-6j5-l63-6sn7-b65-valve-pre/193639879856
> 
> Are they so much better than, for example, this metal tube?
> ...


Those Visseaux even cheaper here.


----------



## bcowen

Marutks said:


> This guy wants £846.77 for a pair of 6C5V tubes.
> https://www.ebay.co.uk/itm/6c5-g-tu...r-6j7-6j5-l63-6sn7-b65-valve-pre/193639879856
> 
> Are they so much better than, for example, this metal tube?
> ...



Wow.  BangyBang now has an Italian division?


----------



## wenbinbin2010 (Jan 19, 2021)

wenbinbin2010 said:


> IEC Mullard 12J5GT/VT-135 Universal General Purpose Triode Valve- BangyBang Tube | eBay
> 
> Anyone have experience with IEC-branded Mullard tubes? Can't seem to find any helpful information online. Bought a few just now, based on the Mullard name purely, but not sure if it'll be true to the Mullard sound.



Reporting back on these IEC Mullard 12J5GTs that arrived today. Before plugging them in, I was trying to see if I could find a similar structure from other brands to see if this was just a re-brand. So far, it looks most similar to the Sylvania 12J5GT, specifically the military code VT-135s. Will have to upload some pictures for visual comparison.

Soundwise, immediately noted to have more accentuated treble with a hint of sibilance, in comparison to the RCA VT-135/12J5GTs that have been my favorite 12J5 tube. Switching back to the RCA, sibilance is clearly gone, but the sound was more muddy, less dynamic. Now with these IEC Mullards back in, I can tell that they are more V-shaped compared to the RCAs. Bass is very obviously harder-hitting. Layering, instrument separation, and detail retrieval do seem better too, even with the treble EQ'd down. Overall...I like them! However, for me they do require some EQ to take that treble edge off (this is paired with a HE1000se, will try out my Aeolus later). Maybe it'll smooth out with some more burn-in too. I'll have to compare them to some other Sylvania 12J5GTs I have, though they are not VT-135s, so the structure is slightly different. From memory, the Sylvania were immediately bright for me as well, so I do wonder if these are the same tubes. The RCA and Tungsol 12J5GTs I have are definitely different structures.

Also interestingly, the IEC Mullard 12J5GT listed on eBay by BangyBang has a different structure than mine.


----------



## Slade01

chrisdrop said:


> Those Visseaux even cheaper here.



Have you purchased tubes from that site before?  tubes.tw?


----------



## GDuss

Slade01 said:


> Have you purchased tubes from that site before?  tubes.tw?



I bought quite a few tubes from him last year.  I would have no concerns about buying again.  That Visseaux in the link appears to be the only one he has available.  I think the inventory is updated regularly on the website.


----------



## Slade01 (Jan 19, 2021)

GDuss said:


> I bought quite a few tubes from him last year.  I would have no concerns about buying again.  That Visseaux in the link appears to be the only one he has available.  I think the inventory is updated regularly on the website.



Sounds good thank you.  Actually, I had already gotten a pair of Visseaux from that ebay seller that @Marutks linked to from last year when that seller had alot more stock and the price was a bit lower.   But the tubes.tw site has some other interesting tubes as well ones that are not readily available on ebay.  Good to know of another reliable source.  Thank you.


----------



## GDuss

Slade01 said:


> Sounds good thank you.  Actually, I had already gotten a pair of Visseaux from that ebay seller that @Marutks linked to from last year when that seller had alot more stock and the price was a bit lower.   But the tubes.tw site has some other interesting tubes as well ones that are not readily available on ebay.  Good to know of another reliable source.  Thank you.



Actually the inventory of 6J5's at Tubes.tw is quite small compared to some of their other options (the 12AU7 list is impressive if you're into such tubes).  I didn't get any 6J5 tubes from there, but I did get some Visseaux tubes (6J7MG), among other things.  They were sealed in the original packaging.


----------



## Slade01 (Jan 19, 2021)

GDuss said:


> Actually the inventory of 6J5's at Tubes.tw is quite small compared to some of their other options (the 12AU7 list is impressive if you're into such tubes).  I didn't get any 6J5 tubes from there, but I did get some Visseaux tubes (6J7MG), among other things.  They were sealed in the original packaging.



LOL...yes i was actually/exactly looking at their 12au7 listing and inventory as I am rolling for 2 different amps.   I think the Visseaux have squared away my 6J5s.  For all the 6j5/6c5 tubes...I still go back to the metal tin cans all the time.  Its one of the best values/bang for the buck I've ever encountered.

Those 6j7 look nice.  Yes...mine came in the waterproof packaging also...it came in handy as my box the tubes were mailed in got water damaged and crumpled on one end.  Fortunately the box was bigger and the tubes and the tube boxes escaped any damage.


----------



## GDuss

Slade01 said:


> I still go back to the metal tin cans all the time. Its one of the best values/bang for the buck I've ever encountered.



Agreed.  I spent a large amount of time going through tubes after I got the Verite Closed, thinking I would end up liking different tubes on that headphone than I did with the Aeolus.  But I still ended up liking the metal RCA 6J5's.  They admittedly are not the best tubes in any one area, they just put everything together in a way that prevents me from wanting to change them out.

I did figure out that I prefer different power tubes for each headphone.  The VC are faster with more sub-bass, and the 5998 and 6BX7 tubes can better exploit that, while the Aeolus are more romantic sounding so they work better with Mullard 6080 or GEC 6AS7G (this is on the GOTL).  But the RCA 6J5's just seem to work with either, at least to my ears.  

Or maybe I'm just trying to justify having bought so many of them  .


----------



## JKDJedi

GDuss said:


> Agreed.  I spent a large amount of time going through tubes after I got the Verite Closed, thinking I would end up liking different tubes on that headphone than I did with the Aeolus.  But I still ended up liking the metal RCA 6J5's.  They admittedly are not the best tubes in any one area, they just put everything together in a way that prevents me from wanting to change them out.
> 
> I did figure out that I prefer different power tubes for each headphone.  The VC are faster with more sub-bass, and the 5998 and 6BX7 tubes can better exploit that, while the Aeolus are more romantic sounding so they work better with Mullard 6080 or GEC 6AS7G (this is on the GOTL).  But the RCA 6J5's just seem to work with either, at least to my ears.
> 
> Or maybe I'm just trying to justify having bought so many of them  .


Yup... RCA 6J5 are sweet.. thanks for the heads-up on that wonder tube guys (don't know if it was you or someone else here who just kept hyping up this guy's) ... don't have that many, just the two pair (the 2nd arriving today) for my Beyers the RCA 6as7g seems to be great mix with these guys.


----------



## chrisdrop

GDuss said:


> Agreed.  I spent a large amount of time going through tubes after I got the Verite Closed, thinking I would end up liking different tubes on that headphone than I did with the Aeolus.  But I still ended up liking the metal RCA 6J5's.  They admittedly are not the best tubes in any one area, they just put everything together in a way that prevents me from wanting to change them out.
> 
> I did figure out that I prefer different power tubes for each headphone.  The VC are faster with more sub-bass, and the 5998 and 6BX7 tubes can better exploit that, while the Aeolus are more romantic sounding so they work better with Mullard 6080 or GEC 6AS7G (this is on the GOTL).  But the RCA 6J5's just seem to work with either, at least to my ears.
> 
> Or maybe I'm just trying to justify having bought so many of them  .


@GDuss may be the king of the tin cans. Always (acoustically) living in a tin can, perhaps we should call you Oscar?

Glad you are enjoying the VCs with all of your tube/amp toys.


----------



## chrisdrop

Slade01 said:


> Have you purchased tubes from that site before?  tubes.tw?


Yes. Good vendor, no issues. I found with thanks to pointers from other keen head-fiers. So - go get em' with confidence


----------



## chrisdrop

Good looking tubes (6C5G CV581 COSSOR) here via Langrex.


----------



## GDuss

chrisdrop said:


> @GDuss may be the king of the tin cans. Always (acoustically) living in a tin can, perhaps we should call you Oscar?
> 
> Glad you are enjoying the VCs with all of your tube/amp toys.



I certainly can't take credit for generating the recent interest in the tin can tubes, I stole the idea from numerous others in the Glenn thread.  I think much of the credit also goes to you for starting this thread, and providing the platform to discuss these "workingman's tubes".  Oscar would be proud of all of us 🤢.

The VC has really taken over my listening time since its arrival.  However, as I posted last week in the Aeolus thread, I recently finished the Crack build and don't think it matches very well with the VC.  It's still in stock form and I'm not using any adapters on it for tubes other than 12AU7, so this may change when I do the Speedball and try other driver tubes.  But for now, I'm enjoying the stock Crack with the Aeolus as I think they just play well together.  I'm curious to hear what the tin can tubes can do in the Crack at some point, but I'm surprisingly (to me at least) not in a hurry to change the sound just yet.


----------



## chrisdrop

GDuss said:


> I certainly can't take credit for generating the recent interest in the tin can tubes, I stole the idea from numerous others in the Glenn thread.  I think much of the credit also goes to you for starting this thread, and providing the platform to discuss these "workingman's tubes".  Oscar would be proud of all of us 🤢.
> 
> The VC has really taken over my listening time since its arrival.  However, as I posted last week in the Aeolus thread, I recently finished the Crack build and don't think it matches very well with the VC.  It's still in stock form and I'm not using any adapters on it for tubes other than 12AU7, so this may change when I do the Speedball and try other driver tubes.  But for now, I'm enjoying the stock Crack with the Aeolus as I think they just play well together.  I'm curious to hear what the tin can tubes can do in the Crack at some point, but I'm surprisingly (to me at least) not in a hurry to change the sound just yet.


Also - guilty - _I love me some tin can tubes_!


----------



## DeweyCH

Same. I've been actively rolling tubes for a few months now, and the RCA tin cans are fantastic. Pair great with a Svetlana Winged C, even better with a TS 5998. My Beyers and AKGs dig 'em and I'm looking forward to introducing them to my Auteurs when they arrive.


----------



## Marutks

They are selling Brimar tubes:
https://mullard.org/products/6c5g-white-box-cv581


----------



## maxpudding

You can find some Taiwanese tube sellers on ruten.com.tw too, but you need to use an intermediary to purchase the tubes you want. Similar to buying tubes from yahoo Japan.


----------



## Tom-s

tintinsnowydog said:


> I have tried the metal base grey glass gold Osram labelled L63 and that is my impression of them above. I think I even prefer the brown base straight glass L63 over the metal base, it has a similar presentation but better detail and more balanced tonality in my opinion. If anyone has both the metal base L63 and the metal base B65/B36 that would be a very worthwhile comparison!



I agree with you. I prefer brown base L63 over metal base and L63 G shaped.
See post here for the comparison 6J5 vs SN7: https://www.head-fi.org/threads/the...6c5-12j5-6p5-etc.934653/page-72#post-16048372


----------



## Xcalibur255

Metal Base B65s are kind of like a cross-breed of the Brimar and Sylvania sounds with a more layered and three dimensional soundstage than either of those are capable of.  They are "golden toned" but not as overly "spotlight-ish" the way Sylvanias can be in upper frequencies and they're not as laid back sounding as the Brimar.  For certain headphones and amps it's a best of both worlds proposition, but as always synergy with other gear is important.  The tone profile isn't ideal for everything and I would say a tube like the Brimar is actually a better "all rounder" tube.


----------



## chrisdrop (Jan 27, 2021)

2x Cossor 6C5Gs today in the Blue Halo






So far, very nice all 'round... only around 2h in the amp, so we shall see how they get on with some time.


----------



## Marutks

I bought a pair of Visseaux 6J5MG tubes from ebay.  I have seen other 6J5MG tubes with different labels:  Mazda, Tungsram, Belvu and Neotron.   Are they rebranded Visseaux tubes?

https://www.radiomuseum.org/tubes/tube_6j5mg.html


----------



## maxpudding

Marutks said:


> I bought a pair of Visseaux 6J5MG tubes from ebay.  I have seen other 6J5MG tubes with different labels:  Mazda, Tungsram, Belvu and Neotron.   Are they rebranded Visseaux tubes?
> 
> https://www.radiomuseum.org/tubes/tube_6j5mg.html



Not too sure about the rebranding, but I have one pair of visseaux and another pair branded mazda, I like the mazda a bit better in terms of the soundstage


----------



## chrisdrop

chrisdrop said:


> 2x Cossor 6C5Gs today in the Blue Halo
> 
> 
> 
> So far, very nice all 'round... only around 2h in the amp, so we shall see how they get on with some time.


Anyone have a clue on dating Cossor tubes? The only markings on them seem to be the N ( I think an upright N?) in the top left of the logo visible here, and the N11 sideways on the left side in the image here. I've been really enjoying these guys...


----------



## therremans (Feb 3, 2021)

Can anyone confirm that these appear to be Mullard 6J5Gs? I already have myself but wanted someone else’s opinion. They were sold to me as “Unknown”.


----------



## PsilocybinCube (Feb 3, 2021)

therremans said:


> Can anyone confirm that these appear to be Mullard 6J5Gs? I already have myself but wanted someone else’s opinion. They were sold to me as “Unknown”.


Pretty sure they are tungsram cv1932 which is a great tube.  I just paid a lot for mine!

Btw, I think mullard bought tungsram?  A better scholar than me will know.


----------



## Slade01

PsilocybinCube said:


> Btw, I think mullard bought tungsram?  A better scholar than me will know.



Yes.. when I researched the torvac brand...which was from a tungsram factory (tottingham) managed by mullard...so mullard did buy and manage some tungsram assets within the UK if i have the facts right.


----------



## Slade01

therremans said:


> Can anyone confirm that these appear to be Mullard 6J5Gs? I already have myself but wanted someone else’s opinion. They were sold to me as “Unknown”.


Great looking tubes btw.  They look to be in very pristine condition!


----------



## chrisdrop

therremans said:


> Can anyone confirm that these appear to be Mullard 6J5Gs? I already have myself but wanted someone else’s opinion. They were sold to me as “Unknown”.


They look the same as ones I have labelled Mullard. You can see here. I like the Mullards, so I think you'll like 'em.


----------



## chrisdrop

Interesting looking Fivres


----------



## CAJames (Feb 12, 2021)

chrisdrop said:


> Interesting looking Fivres



I don't know. Those look like vacuum tubes, not Spumante bottles. Not what I want from Fivre. YMMV of course...


----------



## chrisdrop

CAJames said:


> I don't know. Those look like vacuum tubes, not Spumante bottles. Not what I want from Fivre. YMMV of course...


Oh how I need another holiday in Italy... Here are some Spumante bottles for ya. La musica è amore!


----------



## CAJames (Feb 12, 2021)

Bellissima! Ironically we wanted to holiday in the UK last summer...

Nice 1000th post BTW.


----------



## chrisdrop

CAJames said:


> Bellissima! Ironically we wanted to holiday in the UK last summer...
> Nice 1000th post BTW.


High-quality-ears always welcome for a visit. WTIAO - visit. Sadly, collaborative headphone listening isn't the most social is it... _But -_ I can eat at a helluva restaurant (you wouldn't want my cooking)! 

Relatedly, my wife had flights and a trip to CA _planned_ last spring (Chico & SF), but ... thou shalt do nothing in 2020-202?.

#holidayswap

On another note; those Fivres helping listen to Tipper @ CoSM. Here is a crazy video of the session. It is sort of insane ambient music, but it is made well for nice headphone kit...


----------



## CAJames (Feb 12, 2021)

Very interesting. WTIAO indeed. 

#headphoneholiday


----------



## Xcalibur255

I have a new favorite tube brand name:

Super Air Castle


----------



## GDuss

Xcalibur255 said:


> I have a new favorite tube brand name:
> 
> Super Air Castle


Here is an amp you can use them in:

Model 5000


----------



## SHIMACM

I am interested in a pair of zenith 6j5g.

The seller placed the following description:

"Up for sale are two (2) No 6J5G Zenith ST shape vintage vacuum tubes.
Those vacuum tubes were made in USA as indicated on the tube.
I tested tubes on my trusty Triplett tube tester, which shows it strong and in new condition.

Why buy untested tubes? We test all tubes we sell!

Save !!! - we will combine shipping!

Tubes: Two (2) No 6J5G Zenith vintage vacuum tubes, made US
booth are black smooth plates, printed base,
bottom side foil getters, tubes test: 72, 72%
Tubes did not have original boxes, I assume them a used.
Price is for all tubes pictured. "

Are they good tubes, according to the reported measurements?


----------



## DeweyCH

Picked these up last week from eBay. Had to reinstall my DV's cathode bypass caps to listen to them w/o huge unstoppable hum, but now they sound really quite nice:





Super Silvertone 6L5G


----------



## mordy

tintinsnowydog said:


> Well after a long wait, my package from Martin arrived today! Lots of goodies inside, some British L63 and plenty of affordable American 6J5/6C5. Excited to try them all, but these Fivre 76 took precedence. Not too much time to listen tonight, however first impression is that these are extremely good sounding tubes- not to mention they are possibly the most beautiful tubes I now own! Plenty of warm yet well-controlled bass, singing mids, balanced treble. Good technique and detail wrapped in a really expansive, airy presentation. These give me a strong urge to look for more Fivre, as well as more type 76 tubes!


Just wanted to add that those beautiful labels with dates on them aren't manufacturing dates. Instead, these labels are tax exemption labels from the Italian government with the batch dates of the tax exemption stamps.
Apparently certain electronic items were taxed during the war era and these tubes needed an exemption to promote their use, perhaps in consumer radios.


----------



## bcowen

SHIMACM said:


> I am interested in a pair of zenith 6j5g.
> 
> The seller placed the following description:
> 
> ...


At 72%?  No.  Most testers use ~60% of average NOS value as a minimum value, so those tubes have a_ lot_ of use on them.  "Strong" is a subjective term, but "new" isn't, and those aren't.


----------



## leftside (Mar 4, 2021)

A few 76. Reorganizing tube storage boxes, so thought I might as well take a pic.


----------



## GDuss

leftside said:


> A few 76.



LOL.  I like the way you think!!!  I really only have a few tubes too .


----------



## mordy

Xcalibur255 said:


> MR places them in the WWII timeframe.  Very neat tubes.


Just in case somebody does not know this: MR means Manufacturers Replacement and appear on US tubes made between 1942 and 1945 during WW2. Vacuum tubes were rationed since most tube production went for military use, but a certain proportion was marked MR for civilian replacement use.


----------



## SHIMACM

bcowen said:


> At 72%?  No.  Most testers use ~60% of average NOS value as a minimum value, so those tubes have a_ lot_ of use on them.  "Strong" is a subjective term, but "new" isn't, and those aren't.



I'll be happy to let you go then.

Thanks!


----------



## Xcalibur255

Nearly all of this seller's test values are at about this range so I have to wonder if perhaps they're not using/reading their tester correctly.


----------



## mordy

bcowen said:


> At 72%?  No.  Most testers use ~60% of average NOS value as a minimum value, so those tubes have a_ lot_ of use on them.  "Strong" is a subjective term, but "new" isn't, and those aren't.


I do want to point out that measuring tubes is one reality and using tubes is another reality. Recently a fellow headfier, who owns a newly refurbished and calibrated tube tester, bought a lot of 8 NOS tubes. All tested very good, except for one tube that measured below minimum good.
Based on my own personal experiences, I asked him to put in the best measuring tube and the one that measured below minimum, and do a listening test to see if there was a difference between the tubes.
To his own amazement he reported back that he could not hear any difference!  This accords with my own experiences. Unless a tube suffers a catastrophic failure such as arcing over, losing vacuum (turning white) or being dropped and broken, vacuum tubes are pretty hardy and can last a very long time, especially by people who frequently change the tubes lol. It seems that even poor measuring tubes can function well - perhaps such pairs need more volume after a long time, but they may not be ready for the dust bin so fast.
I know of people that have used the same tubes for 10 years or more, and there was still life left in them.
It appears to me that most amps do not drive the tubes that hard so as to wear them out quickly. Personally, I am not afraid to buy untested old tubes - it is rare that there is a real dud there. After all, if somebody has been saving a tube for 50 years or more, it may be safe to think that they did not save a defective tube.
There is one exception though - old tubes used in TVs. Human nature being what it is, I think most people left the TV on the entire day with the resultant excessive wear on the tubes.
I would be interested in other people's opinion regarding this topic...


----------



## mordy

nwavesailor said:


> I've only read 23 of the 69 pages so far but noticed a few folks that had their C3G sockets swapped out. Are the C3G yesterday's news and displaced by some new (I should say OLD) tube(s) or shiny objects ?


The amps that have the C3g pentode sockets can easily accept adapters for 6J5 family and 6J7 family (different adapter) tubes and thus become very versatile.
The C3g tubes are great tubes but require careful power tube matching to get the right synergy.


----------



## bcowen

mordy said:


> I do want to point out that measuring tubes is one reality and using tubes is another reality. Recently a fellow headfier, who owns a newly refurbished and calibrated tube tester, bought a lot of 8 NOS tubes. All tested very good, except for one tube that measured below minimum good.
> Based on my own personal experiences, I asked him to put in the best measuring tube and the one that measured below minimum, and do a listening test to see if there was a difference between the tubes.
> To his own amazement he reported back that he could not hear any difference!  This accords with my own experiences. Unless a tube suffers a catastrophic failure such as arcing over, losing vacuum (turning white) or being dropped and broken, vacuum tubes are pretty hardy and can last a very long time, especially by people who frequently change the tubes lol. It seems that even poor measuring tubes can function well - perhaps such pairs need more volume after a long time, but they may not be ready for the dust bin so fast.
> I know of people that have used the same tubes for 10 years or more, and there was still life left in them.
> ...


I don't disagree with you on this -- the proof is always in the listening.  But I've also had situations where the musical presentation sounds "off" (lifeless, dull, lacking dynamics, etc) and after testing the tubes in play found one or more that were testing close to or below minimum (GM-wise).  Replacing with some fresh ones returned the music to its former glory.  I think it's dependent as well on the amp or component in use -- some are more sensitive (or are more dependent) on the tubes amplification than others.   On the flip side, the KR 300BXLS's in my Jota amp are the original tubes that came with it....20 years ago.  Probably close to 10k hours on them.  They still test above minimum at this point (although the Hickok doesn't do a very thorough job at testing a 300B), and I have a replacement pair that I pop in every now and then just to see if there is any marked sonic difference.  As of now, I can't tell any difference at all.


----------



## mordy

bcowen said:


> I don't disagree with you on this -- the proof is always in the listening.  But I've also had situations where the musical presentation sounds "off" (lifeless, dull, lacking dynamics, etc) and after testing the tubes in play found one or more that were testing close to or below minimum (GM-wise).  Replacing with some fresh ones returned the music to its former glory.  I think it's dependent as well on the amp or component in use -- some are more sensitive (or are more dependent) on the tubes amplification than others.   On the flip side, the KR 300BXLS's in my Jota amp are the original tubes that came with it....20 years ago.  Probably close to 10k hours on them.  They still test above minimum at this point (although the Hickok doesn't do a very thorough job at testing a 300B), and I have a replacement pair that I pop in every now and then just to see if there is any marked sonic difference.  As of now, I can't tell any difference at all.


Wow!


----------



## CAJames

I'm not an expert, but since this is the internet it isn't going to stop me from expounding.

The thing with transconductance tube testing is you're basically asking the impossible: pick one measurement at one operating point from the entire phase space of possible cathode currents and plate voltages to determine if the tube is "good." And in the case of the audio tubes we all love so much this is especially tricky because in most (all?) cases audio was an afterthought  and the tubes were designed with some other application in mind. In general I'd say the engineers at Hickok etc. have done a remarkable job solving the impossible problem, but I think it is fair to say that the results from a tube tester are more a guideline than a rule. No one is going to die if one of the tubes in our headphone amp fails, so I agree the best test is to swap with a new tube and listen for differences. That said, I'm not buying (or at least not paying full price) for tubes that test close to or below the good level on my TV-7.


----------



## Marutks (Mar 6, 2021)

I like 6C5G Fivre (black base) tubes


----------



## CAJames

Marutks said:


> I like 6C5G Fivre (black base) tubes



Bella!


----------



## DeweyCH

Beer cans anyone?


----------



## Slade01

DeweyCH said:


> Beer cans anyone?



Yes please! Beer cans for the win. 🍻


----------



## CAJames

I've said before I think the Fivre tubes look like Spumante bottles, so it seems like we've got something for every taste.


----------



## Monsterzero

Looking for a quiet pair of metal base Sylvania 6 or 12j5s. If anyone has a pair they can part with lemme know.


----------



## Smallpie (Mar 10, 2021)

Monsterzero said:


> Looking for a quiet pair of metal base Sylvania 6 or 12j5s. If anyone has a pair they can part with lemme know.


Have you checked around Ebay yet?


----------



## Monsterzero

Akiravelvet said:


> Have you checked around Ebay yet?


4 pair...no dice


----------



## Marutks

Monsterzero said:


> Looking for a quiet pair of metal base Sylvania 6 or 12j5s. If anyone has a pair they can part with lemme know.



https://tubeworldexpress.com/collec...5gt-sylvania-lightning-logo-nos-1945-1946-p11


----------



## Monsterzero

Marutks said:


> https://tubeworldexpress.com/collec...5gt-sylvania-lightning-logo-nos-1945-1946-p11


Excellent! Much appreciated!


----------



## chrisdrop

Anyone know of a reason to prefer the black or brown base version of these (via Langrex). For example, are black bases typically older than the brown bases? Something else? 

I do tend to love Fivre valves and ... I don't have enough yet??


----------



## Marutks

This doc
https://docs.google.com/document/d/1BukZ-NuUqh4o_Z2ZOi6KrGavsw5EZNOLSvGa-l5cHLU
says the black base Fivre tubes are better.  But they compare bottle shaped tubes. Maybe the same applies to straight glass tubes.
I bought brown base Fivres from Langrex.


----------



## CAJames

Get both, then you can tell us.


----------



## Smallpie

chrisdrop said:


> Anyone know of a reason to prefer the black or brown base version of these (via Langrex). For example, are black bases typically older than the brown bases? Something else?
> 
> I do tend to love Fivre valves and ... I don't have enough yet??


I’ve been eyeing those too and plan on grabbing a few although I’ll probably pick which one based simply on esthetics. If there is a difference please let us know after trying or reading credible info


----------



## Smallpie (Mar 15, 2021)

Marutks said:


> This doc
> https://docs.google.com/document/d/1BukZ-NuUqh4o_Z2ZOi6KrGavsw5EZNOLSvGa-l5cHLU
> says the black base Fivre tubes are better.  But they compare bottle shaped tubes. Maybe the same applies to straight glass tubes.
> I bought brown base Fivres from Langrex.


Thanks for the link. A treasure trove of great info. Are there any other threads/docs like this besides this one and the GOTL tube compatibility sheet?

a power tube compatibility/description sheet would be cool. I used this thread  in the beginning for 5u4g tube compatibility:

https://www.head-fi.org/threads/dub...mparison-rectifer-tube-rolling-thread.694525/


----------



## leftside (Mar 15, 2021)

chrisdrop said:


> Anyone know of a reason to prefer the black or brown base version of these (via Langrex). For example, are black bases typically older than the brown bases? Something else?
> 
> I do tend to love Fivre valves and ... I don't have enough yet??


83 in stock of the black and 148 of the brown. Wow - that's quite a lot. These tubes are normally hard to find.

Langrex also has the Cossor and also the GEC military L63 from 1949. Doesn't get much better than that... Mind boggling he has so many of these 72 year old NOS tubes in stock.

And those Raytheon military 6J5G are top quality tubes! I haven't purchased any tubes since January, but I almost came off the wagon there. Thanks Chris.... hehe


----------



## leftside

Very well put together! I'll have to dig through my collection one weekend and take some pics of variations not listed.
https://docs.google.com/document/d/1BukZ-NuUqh4o_Z2ZOi6KrGavsw5EZNOLSvGa-l5cHLU/edit#


----------



## Xcalibur255

The Raytheons listed at Langrex are actually Brimars and not USA made but British made.  Unless the photo isn't representative of what they are selling.  The photo is definitely an STC/Brimar.  I'm surprised they wouldn't catch something like this since I'm sure they've seen plenty of British made Brimar 6J5 tubes.  Actually Brimars 6J5s being labeled as and then subsequently misidentified as other tube brands seems to be a running theme with that particular tube.

This actually makes them a pretty good deal on this particular tube price-wise.


----------



## whirlwind

Do any of the Ken Rad versions of 6J5/12J5 produce bass like the 6SN7 ?


----------



## tintinsnowydog

leftside said:


> Very well put together! I'll have to dig through my collection one weekend and take some pics of variations not listed.
> https://docs.google.com/document/d/1BukZ-NuUqh4o_Z2ZOi6KrGavsw5EZNOLSvGa-l5cHLU/edit#


Feel free to post the images here along with any impressions, and I’ll add them. You can request permission to edit the doc as well if you wish


----------



## chrisdrop

whirlwind said:


> Do any of the Ken Rad versions of 6J5/12J5 produce bass like the 6SN7 ?


I have a pair of (tin can/all metal) 6J5 VT94 Ken-Rads that do have that nice bass punch.


----------



## whirlwind

chrisdrop said:


> I have a pair of (tin can/all metal) 6J5 VT94 Ken-Rads that do have that nice bass punch.


Thanks.


----------



## Monsterzero

whirlwind said:


> Do any of the Ken Rad versions of 6J5/12J5 produce bass like the 6SN7 ?


Absolutely


----------



## Xcalibur255 (Apr 2, 2021)

It finally dawned on me that I don't have to wait for my new amp to test all these 6J5 tubes I bought so I finally picked up a 6J5 > 6SN7 adapter for my GOTL.  I'm looking forward to working through the collection to form first impressions and in particular my comparison between the 1937 Raytheon ladder plate and 1937 Raytheon round plate.

I started things off yesterday with a Sylvania 6J5GT glass metal base with round grey plates and right off the bat had my expectations upset.  To my ears this tube does not have the traditional Sylvania house sound.  It's strikingly neutral (at least in the setup I'm testing it in, I realize the DT880 is itself not an especially neutral headphone) and doesn't have the sense of cheerful upper mid and lower treble energy that I expect from a Sylvania.  Not to say it sounds bad, quite the opposite actually.  It's articulate, balanced and has an impressive sense of finesse.  The only fault I can find is the low end feels too polite but it doesn't seem to upset the midrange balance so it's easy enough to live with.  This easily tops most of the 6SN7 tubes I have heard over the years.  I just find it interesting that it doesn't seem to share characteristics with most of the Sylvania 6SN7 tubes, it's very much its own thing the way I'm hearing it.

It felt like a good start and I can't wait to try out the rest of them.


----------



## chrisdrop

Xcalibur255 said:


> my new amp


wotcha got comin'?


----------



## Xcalibur255

chrisdrop said:


> wotcha got comin'?


Custom project from 1101 Audio.


----------



## chrisdrop

Xcalibur255 said:


> Custom project from 1101 Audio.


It will be nice then won’t it!?
Pre-congratulations 
Mischa does great work


----------



## whirlwind

Xcalibur255 said:


> It finally dawned on me that I don't have to wait for my new amp to test all these 6J5 tubes I bought so I finally picked up a 6J5 > 6SN7 adapter for my GOTL.  I'm looking forward to working through the collection to form first impressions and in particular my comparison between the 1937 Raytheon ladder plate and 1937 Raytheon round plate.
> 
> I started things off yesterday with a Sylvania 6J5GT glass metal base with round grey plates and right off the bat had my expectations upset.  To my ears this tube does not have the traditional Sylvania house sound.  It's strikingly neutral (at least in the setup I'm testing it in, I realize the DT800 is itself not an especially neutral headphone) and doesn't have the sense of cheerful upper mid and lower treble energy that I expect from a Sylvania.  Not to say it sounds bad, quite the opposite actually.  It's articulate, balanced and has an impressive sense of finesse.  The only fault I can find is the low end feels too polite but it doesn't seem to upset the midrange balance so it's easy enough to live with.  This easily tops most of the 6SN7 tubes I have heard over the years.  I just find it interesting that it doesn't seem to share characteristics with most of the Sylvania 6SN7 tubes, it's very much its own thing the way I'm hearing it.
> 
> It felt like a good start and I can't wait to try out the rest of them.


Oh man...have fun most all sound good that I have tried.
You are really going to have fun when you get the new amp    

I would love to hear some impressions on the different Ken Rad 6/12 volt GT and 6J5G 
This is a tube that I never got. Love the dark glass 6SN7.


----------



## Xcalibur255

whirlwind said:


> Oh man...have fun most all sound good that I have tried.
> You are really going to have fun when you get the new amp
> 
> I would love to hear some impressions on the different Ken Rad 6/12 volt GT and 6J5G
> This is a tube that I never got. Love the dark glass 6SN7.



I'm afraid I can't help with the Ken-Rad.  I have 9 different pairs of 6J5 tubes to try out at this time, but no Ken-Rads among them.  I haven't come across the right pair that pushed my "gotta have it" button.  I actually bought a pair early on at the same time I was buying the Sylvania grey plate and had to return them because I failed to notice that they had mis-matched plate styles which is a no-go for me.  I still feel a little guilty about that..... I don't like having to return things.

I also would like to try a Ken-Rad 6J5 so I'm right there with you.  A 6J5G coke bottle version even exists and is more rare than the Tung Sols are so we even have a unicorn to hunt.


----------



## Xcalibur255

I'm going to post quick impressions of all of these tubes over the next couple of weeks, but something I think I should stress is that I'm not going to any particular length to control length of burn-in or to make sure that the tubes actually *are* fully burned-in so please don't take my notes for gospel to use for explicit comparison purposes.  I would really need to make sure all of these tubes had 50+ hours on them and that I had taken measures to control my own short-term expectation biases in order to offer impressions that I would feel comfortable offering to others for the purposes of helping them make their own tube purchases.

So, that said, today's 6J5 roll is a black ladder plate version of the metal base Sylvania, branded Triangle.  Like the Raytheons that I'll be getting to soon hopefully I was curious how different the round plate and ladder plate would sound.  The short answer is, yes, I do think it sounds different from yesterday's tube.  I really thought the grey round plate didn't even sound like a Sylvania tube, but this one does.  If I had to sum it up it kind of sounds like a cross between the "Bad Boy" 6SN7GT and a chrome dome 6SN7WGT.  It has a bit of both flavors, though overall I would say it leans more towards the bad boy sound in that its a bit on the mellow side.  The Sylvania W tubes generally are more lively and dynamic IMO.  Like the roundplate from yesterday what strikes me most is how refined the top end is, without much of the low treble spotlight effect so many Sylvanias have.  In direct comparison I find this ladder plate to have a bit more weight across the spectrum with a slightly denser sound and a more present bottom end.  The notes breath a bit less and the sense of air and space is diminished.  I also think this ladder plate loses to the round plate in sheer resolution.  The round plate had a sound I would describe as delicate but highly detailed, where as this ladder plate doesn't lay out the little details for you quite as much and is more macro detail focused.  They sound more similar than different overall and the differences I'm describing here aren't huge, but I feel confident in saying they are two different flavors.

This makes me all the more curious how the Raytheon comparison will go.  I might take more time with that one and make sure those tubes get some time to cook because I find this subject to really be worth exploring.


----------



## Xcalibur255

Here is today's tube:





And this is the roundplate from yesterday:






I realized it's probably better to show these tubes than just describe their plate styles verbally.  My phone camera sucks and the person taking the photos sucks at doing it so hopefully it's good enough.


----------



## therremans

whirlwind said:


> Do any of the Ken Rad versions of 6J5/12J5 produce bass like the 6SN7 ?


I owned the Ken-Rad 6J5GT and it's JAN version in used condition. I could not tell any difference between these two variations. However, they did not sound like the black glass 6SN7GT and lacked that V curve.. I sold them off.


Xcalibur255 said:


> Here is today's tube:
> 
> 
> And this is the roundplate from yesterday:
> ...


I love these. I also own both. Very different sound and I prefer the round plate version. Here are mine for comparison.


----------



## bcowen

therremans said:


> I owned the Ken-Rad 6J5GT and it's JAN version in used condition. I could not tell any difference between these two variations. However, they did not sound like the black glass 6SN7GT and lacked that V curve.. I sold them off.
> 
> I love these. I also own both. Very different sound and I prefer the round plate version. Here are mine for comparison.


I've never seen that before... "Made in Italy, Tested in USA."  Kind of like Sylvania didn't trust the Italians.  LOL!!


----------



## leftside

Xcalibur255 said:


> If I had to sum it up it kind of sounds like a cross between the "Bad Boy" 6SN7GT and a chrome dome 6SN7WGT.  The Sylvania W tubes generally are more lively and dynamic IMO.


I'm a huge fan of those early Sylvania 6SN7W and similar from that time period. Metal base, late 40's/very early 50's, tall bottle with chrome dome, etc. Often run them in my preamp. Seem to add a little "sparkle".


----------



## Xcalibur255

bcowen said:


> I've never seen that before... "Made in Italy, Tested in USA."  Kind of like Sylvania didn't trust the Italians.  LOL!!


I wonder if they might be Fivre tubes.


----------



## Xcalibur255

leftside said:


> I'm a huge fan of those early Sylvania 6SN7W and similar from that time period. Metal base, late 40's/very early 50's, tall bottle with chrome dome, etc. Often run them in my preamp. Seem to add a little "sparkle".


The top end is really where they sound more mellow like a bad boy, that Sylvania Sparkle isn't really there.  It's the mids and low end where I find they resemble the W tubes more.  

The Bad Boy 6SN7 has a midrange presentation that's quite unique IMO; forward in a range that's somewhat lower in frequency compared to most other Sylvania tubes but still well above the range that might contribute to a sense of bloat in the sound.


----------



## Slade01

Xcalibur255 said:


> So, that said, today's 6J5 roll is a black ladder plate version of the metal base Sylvania, branded Triangle. Like the Raytheons that I'll be getting to soon hopefully I was curious how different the round plate and ladder plate would sound. The short answer is, yes, I do think it sounds different from yesterday's tube. I really thought the grey round plate didn't even sound like a Sylvania tube, but this one does.



I completely agree with you on this.  The Sylvania Grey Round Plate/Metal Base 6J5GT did not sound like the typical Sylvania tube at all to me, which completely surprised me. I found it similarly very detailed, but really I felt it was flat overall, not lively.   I definitely favor the ladder plates in this case.  I have Sylvania (all metal cheapie cans) 6J5s which are a lot more in-line with the Sylvania house sound when I did a comparison.  

Those Made In Italy ones looks like the true diamonds among the rough though -- and especially if they ended up being Fivre tubes or at least coming close to sounding like them!


----------



## therremans

Slade01 said:


> I completely agree with you on this.  The Sylvania Grey Round Plate/Metal Base 6J5GT did not sound like the typical Sylvania tube at all to me, which completely surprised me. I found it similarly very detailed, but really I felt it was flat overall, not lively.   I definitely favor the ladder plates in this case.


Sylvania 6J5GT (metal based) - I felt more this way about the black rp but not the gray rp. Try a new pair of gray rp with a 5998.


----------



## Xcalibur255 (Mar 17, 2021)

I was going to listen to all the straight glass tubes then move on to the old coke bottle ones, but decided to break with that and carry on the Sylvania theme by putting in the late 30's vintage Zenith branded engraved base Sylvania 6J5G round black plate.





I think I'm going to give these a second day before passing any real judgement, maybe more.  I'm hoping they settle down some with some hours.  If they don't then this will be my first disappointment.  As they sound right now I'm not a fan:  very forward, quite thin and bright and somewhat raspy and edgy sounding on vocals.  Sounds like a tube in need of burn-in and I'm hoping it is, but it's so rare for tubes this old to actually be NOS so who knows.  They throw a huge open soundstage and are quite detailed, I can certainly see why some people swear by them, but if this is the way they're supposed to sound then this tonal balance is not to my taste and big airy sound doesn't make up for that.  We'll see what happens with them.


----------



## bcowen

So far I haven't found anything I like better than these.  The Tung Sol VT-94's (ST-bottle) are a close second and I like the GEC L63's (with the right power tube), but I keep going back to these Hytrons.  Dark gray (gun metal color) round plates, and yup they're 7A4's with a loctal base, so add another adapter to the pile.


----------



## Xcalibur255

bcowen said:


> So far I haven't found anything I like better than these.  The Tung Sol VT-94's (ST-bottle) are a close second and I like the GEC L63's (with the right power tube), but I keep going back to these Hytrons.  Dark gray (gun metal color) round plates, and yup they're 7A4's with a loctal base, so add another adapter to the pile.


Do you have a pair of the Sylvania grey roundplates I talked about in my first post the other day?  I'd be curious if they and these Hytrons sound the same, or at least similar.

I have to confess I'm a little bummed because I thought the coke bottle Sylvanias were going to be a favorite going in and and at the moment I actually kind of find them to be unlistenable.  But this is also why it's important to not make snap judgements either, more time could change things.


----------



## chrisdrop

Xcalibur255 said:


> Do you have a pair of the Sylvania grey roundplates I talked about in my first post the other day?  I'd be curious if they and these Hytrons sound the same, or at least similar.
> 
> I have to confess I'm a little bummed because I thought the coke bottle Sylvanias were going to be a favorite going in and and at the moment I actually kind of find them to be unlistenable.  But this is also why it's important to not make snap judgements either, more time could change things.


FYG; the tubes I keep coming back to in this tube family are; Fivre 6C5G, Mullard 6J5G, STC/Brimar 6C5G, GEC 6J5G, GEC L63 (ST style), Fivre 6J5GT, KenRad 76 (coke bottle style). I'm not in love with any Sylvanias or Hytrons, although all are fine (certainly not unlistenable). I like the RCA and KenRad tin can style enough too but I am perhaps visually biased to glow-style. In other news, I keep trying to like any 6P5* and can't come across any that I love.


----------



## CAJames

The only 6P5* tubes I found that were better than meh for me were Sylvania JAN 6P5GTs with black bases and bad boy plates. I basically got them out of some guys tube dumpster and they were pretty good. All the pretty 6P5Gs with engraved bases looked better than they sounded.  

Now, if you like the 76 you might really like the 37. I haven't been contributing much here lately because once I found 4 37s that were quiet and worked together I haven't changed them out in months. Liquid bordering on lush, but with plenty of air and detail and Goldilocks bass that isn't too heavy or too light, but is just right.


----------



## CAJames

Xcalibur255 said:


> Do you have a pair of the Sylvania grey roundplates I talked about in my first post the other day?  I'd be curious if they and these Hytrons sound the same, or at least similar...



Sylvania made virtually all the loctal tubes, so I wouldn't be surprised at all if they were the same.


----------



## bcowen

chrisdrop said:


> FYG; the tubes I keep coming back to in this tube family are; Fivre 6C5G, Mullard 6J5G, STC/Brimar 6C5G, GEC 6J5G, GEC L63 (ST style), Fivre 6J5GT, KenRad 76 (coke bottle style). I'm not in love with any Sylvanias or Hytrons, although all are fine (certainly not unlistenable). I like the RCA and KenRad tin can style enough too but I am perhaps visually biased to glow-style. In other news, I keep trying to like any 6P5* and can't come across any that I love.


These particular Hytrons surprised me.  Sat in the tub for a couple years due to a rather meh experience with some CBS/Hytrons, and on a whim I pulled them out.  The CBS versions have shiny black plates and while not a bad tube at all, they were certainly nothing special.  These Hytron (no CBS) 7A4's are a different animal altogether.  Now I don't have any of the tubes you mentioned in your first sentence (my L63's are straight bottle), so perhaps I'm just happily living in ignorance.


----------



## Xcalibur255

CAJames said:


> Sylvania made virtually all the loctal tubes, so I wouldn't be surprised at all if they were the same.


I agree.  Sylvania was a big promoter of the loctal format but others didn't want to get on board.  I personally haven't heard any of the loctal tubes so what I was getting at with my comment was whether or not the loctals sound similar to their 6SN7 counterparts, similar the 6J5 (which it turns out is quite a bit different from many of their 6SN7s), or possibly their own thing all together.


----------



## bcowen (Mar 18, 2021)

Xcalibur255 said:


> Do you have a pair of the Sylvania grey roundplates I talked about in my first post the other day?  I'd be curious if they and these Hytrons sound the same, or at least similar.
> 
> I have to confess I'm a little bummed because I thought the coke bottle Sylvanias were going to be a favorite going in and and at the moment I actually kind of find them to be unlistenable.  But this is also why it's important to not make snap judgements either, more time could change things.


I know I have a pair of round plate Sylvania 7A4's, but don't remember if they're black or gray plates.  I'll have to check and give them a head-to-head if I do.  I think @CAJames is right on the Sylvania manufacture part -- if these are like the 7N7's, then (as best I can tell) Sylvania and National Union were the only two manufacturers.


----------



## Xcalibur255

bcowen said:


> These particular Hytrons surprised me.  Sat in the tub for a couple years due to a rather meh experience with some CBS/Hytrons, and on a whim I pulled them out.  The CBS versions have shiny black plates and while not a bad tube at all, they were certainly nothing special.  These Hytron (no CBS) 7A4's are a different animal altogether.  Now I don't have any of the tubes you mentioned in your first sentence (my L63's are straight bottle), so perhaps I'm just happily living in ignorance.


My hunch would be that the older ones branded CBS/Hytron are actually that brand and the later ones were re-branded Sylvanias.  CBS/Hytron tubes often have very glossy black plates that make them look a bit unique, or at least the ones I have personally laid eyes on have.


----------



## SHIMACM

I'm looking at Langrex Fivre 6c5g straight glass.

Has anyone compared them to the retro glass GEC L63 and the Tung-Sol 6j5g bottle of coca and can supply the presses?


----------



## CAJames

Xcalibur255 said:


> I agree.  Sylvania was a big promoter of the loctal format but others didn't want to get on board.  I personally haven't heard any of the loctal tubes so what I was getting at with my comment was whether or not the loctals sound similar to their 6SN7 counterparts, similar the 6J5 (which it turns out is quite a bit different from many of their 6SN7s), or possibly their own thing all together.



7N7s (the loctal 6SN7) was my daily driver until I discovered the  single triodes (I blame @chrisdrop, as usual). And my experience is the loctals sound very much like the octal equivalents. Or at least the difference in the base isn't any bigger than the differences between different examples of the same tube.


----------



## Xcalibur255 (Mar 19, 2021)

An update and final impression on the Sylvania 6J5G engraved base.  They did settle down quite a bit with some additional run time, but there is still substantially more treble energy than what I prefer and I believe that's going to be the character of the tube.  I think it's really more fair to say they are just not a good match for the DT880s.  These tubes are adding energy in exactly the same place where the infamous Beyer treble peak lives and it's just too much.  With a more mellow headphone I could see this being a really nice sounding tube, it's just too peaky in this particular pairing.

As to the good?  They throw what might be the largest soundstage I've ever heard come from this amp and headphone.  Very impressive.  It's also a dynamic tube.  Beyond the sparkly treble it really has robust energy pretty much everywhere and just presents a big happy sound all around.  Nice bass slam, very quick transients.  I can see why some people love this tube.  I commented previous that the other Sylvanias I've tested so far didn't really sound like Sylvania tubes to me.  This was very much does.  It's absolutely the Sylvania house sound, only turned up to 11 in intensity.  V shaped in a fun happy way and very reminiscent of the Sylvania 6SN7W tubes.  I don't want to be negative on the tube because it's actually pretty impressive in its presentation, it just doesn't match my personal preferences all that well.  I think 10 years ago it might have, but that was then.

I bet with a different headphone like the LCD-3 this tube would be totally in its element.

Next up:  the comparison between the two Raytheons.  I think I'll start with the ladder plate and then run the round plate second.  Will they sound the same or different?  Tune in next week to find out.


----------



## whirlwind (Mar 20, 2021)

Seems the LCD-3 Pre-Fazor would be perfect....it is a great headphone, very engaging sound with meat on the bones    

That will be interesting...ladder and round plates....I seem to like most any round plates.


----------



## chrisdrop

SHIMACM said:


> I'm looking at Langrex Fivre 6c5g straight glass.
> 
> Has anyone compared them to the retro glass GEC L63 and the Tung-Sol 6j5g bottle of coca and can supply the presses?


I have the GEC L63 of various shapes and those Fivres on the way. In a week or so I should be able to post.

FWIW I still really like the GEC L63 brown base GT style tubes, which seem to be more readily available and not crazily priced. I sometimes like them as much or more than my 1940s GEC 6J5Gs even. That may not be a popular opinion but it is where I am.


----------



## Xcalibur255

I'm saving the GEC L63 straight glass for last, mostly because it's something of a known quantity.  I'd be VERY surprised if I didn't like it.

Next week I'll do the head to head ladder plate / round plate Raytheon comparison.  Given that both tubes are more or less identical right down to age and date codes with the plate style being the only differentiator I think this offers a fairly controlled opportunity to explore the question.


----------



## triod750

I haven't found any comments on this tube, is it an ugly duckling not worth mentioning? I don't have an adapter to try them in yet so I don't know how they sound.


----------



## bcowen

triod750 said:


> I haven't found any comments on this tube, is it an ugly duckling not worth mentioning? I don't have an adapter to try them in yet so I don't know how they sound.



Well, they are ugly on the exterior , but they may _sound_ wonderful.  Never judge a book by its cover...or something like that.


----------



## Slade01

triod750 said:


> I haven't found any comments on this tube, is it an ugly duckling not worth mentioning? I don't have an adapter to try them in yet so I don't know how they sound.


I would take the ugliest Brimar tube over many nicer looking tubes any day of the week.


----------



## triod750

Has anybody tried it? Or, rather, can you provide a listening impression?


----------



## chrisdrop

triod750 said:


> Has anybody tried it? Or, rather, can you provide a listening impression?


I have STC/Brimar 6C5 tubes that sound good. I don't have any "GT"-style Brimar 6J5s, but I imagine they'd be "good". Only 1 way to know...


----------



## bcowen

triod750 said:


> Has anybody tried it? Or, rather, can you provide a listening impression?


I only have one pair, and it's difficult to tell from the pic you posted how similar they might be internally.  Nice sounding tubes if paired with a synergistic power tube.  The Cetron 7236 pictured isn't it.    They are much more enjoyable paired with a TS 5998 or a graphite plate 6080 output tube.  Regardless of the output tube though they have a beautiful treble and lots of detail (without being hyped sounding). But they're a bit lean in the bass and need an output tube that has some whomp down low to compensate.  Just my impressions, and only of this one particular vintage/construction though.


----------



## Slade01

triod750 said:


> Has anybody tried it? Or, rather, can you provide a listening impression?


I haven't tried Brimar 6J5GT, but other variants of it (6C5G, 6SN7, 12AU7) and are all great sounding.  As @bcowen says "beautiful treble/great detail".   In some cases with my setup, they are mid-forward emphasized tubes.  They are lean on bass, but paired right with a power tube to fill out the lower end, and its right on the money.   What Brimar tubes do, they do extremely well.


----------



## triod750

bcowen said:


> I only have one pair, and it's difficult to tell from the pic you posted how similar they might be internally.  Nice sounding tubes if paired with a synergistic power tube.  The Cetron 7236 pictured isn't it.    They are much more enjoyable paired with a TS 5998 or a graphite plate 6080 output tube.  Regardless of the output tube though they have a beautiful treble and lots of detail (without being hyped sounding). But they're a bit lean in the bass and need an output tube that has some whomp down low to compensate.  Just my impressions, and only of this one particular vintage/construction though.


Mine are  6J5GT/G with 'ribbed flat plates', not like yours.  On the internal glass, where it is pressed together, one is marked W23, one A43, one A4 and maybe 0 as in A40 and the last one A41. They are unused spares from an old cinema. I'm convinced they are younger than I am. I was marked on the umbilical cord that is lost somehow.
Adapters are ordered from Deyan.


----------



## triod750

This is how they look: https://www.ebay.com/itm/KEN-RAD-6J...55-0&campid=5337590777&customid=&toolid=10001


----------



## Xcalibur255

There is a fair chance that they're actually an American made tube re-branded as Brimar, although I admit that would be unusual given that the purpose of many Brimar tubes was for export.  All the Brimars I have seen so far have had oval/round plates.  It's certainly not impossible that they made a ladder plate version at some point but I think the odds are higher that somebody else made it.


----------



## triod750

How about the codes inked to the glass internals? Could they help with identification? They are made with prominent whitish 'ink'.

My only other Brimars, a 6SN7GT pair, have the oval plates you are talking about.


----------



## Xcalibur255

My date code-fu isn't as strong as it is for some others around here.  It's not anything I recognize right away.  I have a hunch they might be Japanese made, but take that with a grain of salt because it's just a hunch.  I don't think it's very likely they are British though, they just don't share any of the usual STC construction techniques.


----------



## Xcalibur255

So it's time for part one of "A Tale of Two Raytheons" as it were.





First off these are branded Zenith just like the prior Sylvanias were but I'm pretty confident they are Raytheon made.  The extra support rod (not visible in this photo, it's on the other side) and x-shaped top mica are Raytheon hallmarks, and it shares a sonic signature with other Raytheon tubes from the 30's and 40's I have heard.  For the full description this is a 1937 Raytheon ladder plate 6J5G with engraved base and steel grid posts.  

Some interesting differences here compared to the Sylvania from the last week, which is a very similar vintage tube to this one with it also being an engraved base G tube.  The thing that strikes me right away, and really helps my understanding of the Sylvania sound too, is how the upper mids and lower treble are presented.  The Sylvania sound is very "glossy" and places a lot of emphasis on the leading edge of the note.  To my ears it is a very 'hifi' sort of sound, sort of like turning on the noise reduction on your TV.  Squeaky clean but the little details are not there anymore.  This Raytheon, on the other hand, comes off right away as a more organic and textured sound.  I find that timbre is more authentic sounding on the Raytheon and the music just sounds more natural.  Tonally the top end is not as aggressive but it is still somewhat forward in the upper mids overall.  Vocals are very present and generally front-of-mix but the overall sound is a bit more cohesive and less aggressive than the Sylvania.  Soundstaging is a bit smaller, a bit more tonally "dense" and substantially more layered.  It's nicely dynamic but not in the big splashy way the Sylvania was.  Bass doesn't kick as hard but it is better defined and more textured.  There were a few instances where I found the midrange forward in a "nasal" kind of way but I didn't get this impression very often, it mostly sounded very nice and pretty well balanced.  I still wouldn't call this a great match for the Beyers but it's a far better match than the Sylvania is.

I really like this tube.  I think it is better balanced and produces a more authentic sound with more natural instrument timbres than the Sylvania does.  I think it would come down to preference and genres.  If you're okay with the treble the Sylvania is a rock and roll tube, big drive and big energy.  This is more of a jack of all trades sound and comes off as a smaller but more layered sound overall.

Now here's the big question:  tomorrow I'm going to swap over to the round plate version of this tube.  What will I hear?  Will it sound exactly the same or will there be differences?  Tune in to find out!


----------



## leftside

The British Brimar 6SN7's that I've purchased are some of the warmest tubes I have. Let me dig out the Brimar 6J5's I have and take a look this evening.


----------



## bcowen

Xcalibur255 said:


> So it's time for part one of "A Tale of Two Raytheons" as it were.
> 
> 
> 
> ...


Really nice info...thanks for the detailed impressions.  I don't have any Raytheon 6J5's at all, but have a number of Raytheon 6SN7's of various vintages and plate construction.  One plate style I really like, and the other I don't like at all...I mean _really_ at all.  I'll keep mum on which is which at this point.     And of course these are 6SN7's so they're different animals to begin with, and I expect they are all of later manufacture ('50's and later) than what you have so any attempted comparison might be a fools errand.


----------



## Xcalibur255

bcowen said:


> Really nice info...thanks for the detailed impressions.  I don't have any Raytheon 6J5's at all, but have a number of Raytheon 6SN7's of various vintages and plate construction.  One plate style I really like, and the other I don't like at all...I mean _really_ at all.  I'll keep mum on which is which at this point.     And of course these are 6SN7's so they're different animals to begin with, and I expect they are all of later manufacture ('50's and later) than what you have so any attempted comparison might be a fools errand.


Yeah once you get into the 50's the Raytheon sound changes completely.  It really depends on which tube you have.  Some of them were made in Japan too.  My experience with the GTB versions of their 6SN7 were less than positive, but it was a long time ago and there's more than one variant.

These engraved base 6J5Gs sound nothing like any 6SN7 from the 50's or 60's, and don't especially sound like any 6SN7 I have heard at all really.  They remind me more of the sound of my Ken-Rad UX245 globes in my G45 amp actually which is high praise.  I have had this thought in the back of my head to have that amp modified in the future to take 6J5 drivers instead of C3g and the case for that change is building.


----------



## triod750

Xcalibur255 said:


> I have had this thought in the back of my head to have that amp modified in the future to take 6J5 drivers instead of C3g and the case for that change is building.


Interesting. Seems to be many more flavours of 6J5 than C3g. So far, I have only tasted C3g. That is about to change.


----------



## Xcalibur255 (Apr 2, 2021)

Here is Raytheon Part 2.  The description of the prior tubes matches this pair exactly with two differences:  these are branded GM (as in General Motors) instead of Zenith, and they have round style plates instead of ladder box plates.






So I'm going to get right to the meat of this impression post and come out with it:  yes they sound different, mostly in one key way.  The biggest question on my mind was whether or not round plate tubes have a different presentation vs. a square plate style such as the ladder plate or t-plate.  At least as far as these two tube cousins go my ears say yes.  There is a distinct difference in how the soundstage is presented and rendered to the listener.  I found the ladder plate tube to have a headstage that was distinctly foward, placed in front of your head, with a stage shape that is more wide than deep.  This round plate, on the other head, feels like it centers the sound ON your head rather than in front of it, producing less of a stage effect and more of an immersion effect.  There is a bit less soundstage width, but a great deal more front/back depth.  I think you can see where I'm going with this:  yes, IMO, the shape of the plate seems to correspond to the shape of the soundstage.  I have given a great deal of thought about whether or not this is real or if I'm just experiencing a psychosomatic perception and the difference is just expectation fulfillment.  But I think what I'm hearing here is real, again at least for these two specific tubes.  I consistently am given the impression by the round plates that musical information is being presented or projected BEHIND me, and I just didn't get that same impression while listening to the ladder plates.

I really can't say whether one would be better than the other.  It's really down to the listener's preference.  For example if you consider a stage presentation such as what you would hear in a live concert with the music coming at you from the front to be more "correct" you might prefer the ladder plate presentation.  If, on the other hand, you want the music all around you sort of like the music version of being in a planetarium then you would probably really like the round plate.

Beyond this the presentation within the soundstage is also somewhat different.  I found that, while stage width is not wider, the sense of space between notes is more prominent with these round plates.  It also feels easier to listen "into" the notes and gives a greater sense of depth to the sound.

The rest of the differences are much more subtle.  Tonally they are very close but not identical.  I find the top and bottom end here just a tiny bit rolled off compared to the ladder plate, and it's a bit more mellow throughout the top end.  These roundplates tame the Beyer treble completely which means they're a pretty mellow tube overall.  I also find them a tad bit more polite dynamically, but the really great spatialization from the soundstage presentation makes up for this in it's own way.  I would characterize it overall as similar but a touch more "vintage" than the ladder plate was.  In a blind test I don't think I could tell the two apart just from judging tone.  Overall this tube is very easy to listen to, but with faster higher energy music it can come dangerously close to being boring at times because of how laid back and even handed it is.  The difference in dynamic energy between this tube and the Sylvania engraved base for example is pretty big, those are two very different flavors.

I would rate resolution at least as good as the ladder plate and because of the 3D  soundstage probably better.  Timbre is great here because of the texture information being conveyed, but even when it's just a single note such as a single bow stroke of a violin I'm struck by the "roundness" of the note and how much depth it seems to convey.

Overall there's a strong familiar resemblence between the two Rays but the soundstage and imaging difference is key and is what lends these two tubes different characters.  I like both and am happy to have both in my collection.  If you pressed me about only keeping one I might whisper "ladder plate" just because I was really enjoying the overall presentation of them towards the end of my listen the other day.  It felt like they could do no wrong as far as my preferences for tone and balance were concerned.  I think the roundplates are almost too polite and even handed at times, but every once in a while the soundstaging and how the notes were presented would really strike me as something special and those moments were engrossing so they absolutely have their own appeal.  Better to say I'm glad to have both tubes.


----------



## Xcalibur255

Side note:  this one got pretty long.  I'll try to be more brief for my remaining impression posts, but given the experiment at play I wanted to dig a little deeper this time.


----------



## triod750

Here you have your perfect pair then; one round plate and one flat plate: https://www.ebay.co.uk/itm/No-type-...469656?hash=item4dbe235a18:g:y7YAAOSwtBNgOSak


----------



## triod750

Xcalibur255 said:


> Side note:  this one got pretty long.  I'll try to be more brief for my remaining impression posts, but given the experiment at play I wanted to dig a little deeper this time.


Long and old are both better. Brief is for boxer shorts.


----------



## Slade01

Xcalibur255 said:


> Side note:  this one got pretty long.  I'll try to be more brief for my remaining impression posts, but given the experiment at play I wanted to dig a little deeper this time.



The long impressions are cool.  It's hard to really explain auditory experiences and tube characteristics - you frame the characteristics in a very relatable way, it is much appreciated.



Xcalibur255 said:


> I think the roundplates are almost too polite and even handed at times, but every once in a while the sound staging and how the notes were presented would really strike me as something special and those moments were engrossing so they absolutely have their own appeal.



Completely agree with this sentiment.  It's weird, but up until the 6J5 series, I have been a big fan of round plates.   However, my preferences have done a 180 preferring ladder plates each and every single time to date in this universe of tubes -- they just really sound more alive to me.     But you're right -- better to have a bit of each in one's collection -- best of both worlds.


----------



## Xcalibur255

Slade01 said:


> The long impressions are cool.  It's hard to really explain auditory experiences and tube characteristics - you frame the characteristics in a very relatable way, it is much appreciated.


I really appreciate this comment.  I know what I'm trying to describe in *my* head but I often wonder if it's being interpreted that same way when other people read it.  Over the years I've realized that the visual metaphors and such I like to use to describe things aren't always conveying to others what I think they are.  It's good to know I'm making sense to somebody at least.


----------



## whirlwind

Xcalibur255 said:


> Here is Raytheon Part 2.  The description of the prior tubes matches this pair exactly with two differences:  these are branded GM (as in General Motors) instead of Zenith, and they have round style plates instead of ladder box plates.
> 
> 
> 
> ...


Those are nice looking tubes.


----------



## Xcalibur255 (Mar 25, 2021)

Here's today's tube:





Motorola 6J5GT metal base straight glass with ladder plates.  These are actually Tung-Sols, identified by a combination of construction characteristics and the presence of the Tung-Sol "322" manufacturer code on the tubes.  I had been searching for the right pair of Tung-Sol 6J5G/VT94 tubes for almost 6 months when I stumbled across these and bought them as a consolation prize figuring that at least I would have something Tung-Sol made for the new amp (I'm quite a fan of this brand so there had to be something TS in the collection).  These are no consolation prize when it comes to sound though.

To sum up, these tubes are outstanding.  They do everything well and have no bad habits whatsoever.  Tonality is spot on and resolution is excellent as well.  These kind of remind somewhat of the Tung-Sol mouse ear 6SN7GT only a better version of it.  The top end is more refined and the entire presentation is more nuanced and articulate with better note separation.  They also have good drive and energy but are never in your face about it.  I'm impressed.  For somebody needing a 6J5 but isn't into tube rolling I would have no hesitation telling them to track down a pair of these and call it a day.  This tube is an excellent all rounder that is well balanced from top to bottom.

I will be testing this tube's older brother, the VT-94 coke bottle version, next.  I have a hunch that what I'm going to hear will be very close to this with perhaps only minor differences.  If that proves true then it will make these metal base versions that much better a value for bargain hunters.

Sadly one of them is having noise issues.  I've had tubes that hum like this settle down with use and I hope that's the case here.  It would be a shame to have to consider them backup tier because of this.


----------



## leftside

Xcalibur255 said:


> I will be testing this tube's older brother, the VT-94 coke bottle version, next.  I have a hunch that what I'm going to hear will be very close to this with perhaps only minor differences.  If that proves true then it will make these metal base versions that much better a value for bargain hunters.


The metal base 6J5 in general are great value.


----------



## bcowen (Mar 25, 2021)

Xcalibur255 said:


> Here's today's tube:
> 
> 
> 
> ...


I have the round plate version of both the GT's and the ST's.  Like them both a lot.  I just need to get some flat plates to do some comparisons.


----------



## Xcalibur255

I've never seen a round plate version of the VT-94A.  Would love to have a pair.  I'm testing my VT-94A's today, but will probably hold off until next week before writing about them because I think they need some time in the oven.  The right channel was *very* weak when I powered the amp on this morning, maybe 1/3 the volume of the left.  They're leveling out now but between this and the way they sound these were probably NOS and need time to settle in.


----------



## bcowen (Mar 26, 2021)

Xcalibur255 said:


> I've never seen a round plate version of the VT-94A.  Would love to have a pair.  I'm testing my VT-94A's today, but will probably hold off until next week before writing about them because I think they need some time in the oven.  The right channel was *very* weak when I powered the amp on this morning, maybe 1/3 the volume of the left.  They're leveling out now but between this and the way they sound these were probably NOS and need time to settle in.



Well, I must apologize.  And you are right.  The ST-bottle Tung Sols I have are in fact flat ladder plates and not round (so much for the bad memory on my part).  These are the same "A" suffix, and sound great.  I think the round plate, metal base 6J5GT's are a little more open and extended in the treble, but 1) I don't have a lot of time on  these ST's yet, and 2) these have a definite "organic" sound to them that works nicely across many musical genres.


----------



## Tom-s (Mar 26, 2021)

In response to the Brimar builds discussion.

Brimars have a distinct mica shape in my experience.

A black plate clear glass version in Crack.



The 6J5GT's all have this base issue (not that it matter's i've used them without any skirt without any issue).
Left is an O getter. Right is a D getter version.
Note the distinct Brimar bottom mica's! A telltale sign it's a Brimar.
Other way to tell; the supports are riveted to the mica's.




Here's the versions in my collection. All sound great to me. But as always; get a 6J5 over 6SN7 anytime.
From left to right in the picture.
Grey plates 6SN7GT. Grey plates with black glass 6SN7GT (these have cooling fins above top mica). Black plates 6SN7GT. Black plates 6J5G STC and grey plate 6J5GT.


----------



## whirlwind

bcowen said:


> Well, I must apologize.  And you are right.  The ST-bottle Tung Sols I have are in fact flat ladder plates and not round (so much for the bad memory on my part).  These are the same "A" suffix, and sound great.  I think the round plate, metal base 6J5GT's are a little more open and extended in the treble, but 1) I don't have a lot of time on  these ST's yet, and 2) these have a definite "organic" sound to them that works nicely across many musical genres.


These are fantastic tubes IMO.


----------



## Xcalibur255

I've also found the plates themselves are wider and more "ovoid" on Brimars than they are on any other round plate tube.


----------



## Xcalibur255

bcowen said:


> Well, I must apologize.  And you are right.  The ST-bottle Tung Sols I have are in fact flat ladder plates and not round (so much for the bad memory on my part).  These are the same "A" suffix, and sound great.  I think the round plate, metal base 6J5GT's are a little more open and extended in the treble, but 1) I don't have a lot of time on  these ST's yet, and 2) these have a definite "organic" sound to them that works nicely across many musical genres.


Right you are!  These are identical to what I'm testing right now.  I think they're 90-95% the same as the metal base GTs I tested yesterday.  Just a touch more organic and a touch more layered maybe, but we're talking small differences.  If a person is hunting for a pair of these and all they can find is the metal base version they should snatch those up and not worry about it, they're getting the same flavor and very nearly the same overall listening experience.  I must confess, though, that my ears say these are just the tiniest bit better based on what I'm hearing this afternoon.  I am not ready to call a verdict on that though since I need to make sure they've settled and their sound is not still changing to any significant degree.

Of everything I've tested so far these are my favorite at the moment.  All that's left to test is an STC/Brimar round plate and the GEC L63 brown base.  Figured I would wear the tweed jacket last.


----------



## chrisdrop

I went for a pair of those Fivre 6C5GT from Langrex. ~10h so far and they are winners. Typical pleasing mids/upper bits for Fivres and even perhaps a bit more grunt than usual? We shall see in 40h or so. They are pretty and taller than most other tubes like this that I have. No "Spumante" style decorations, but lovely nonetheless.


----------



## bcowen

chrisdrop said:


> I went for a pair of those Fivre 6C5GT from Langrex. ~10h so far and they are winners. Typical pleasing mids/upper bits for Fivres and even perhaps a bit more grunt than usual? We shall see in 40h or so. They are pretty and taller than most other tubes like this that I have. No "Spumante" style decorations, but lovely nonetheless.



Gorgeous!  Be quite interested in your further thoughts once you get more play time on them.


----------



## Marutks

chrisdrop said:


> I went for a pair of those Fivre 6C5GT from Langrex.



Do they sound like bottle shaped 6C5G Fivre tubes?


----------



## chrisdrop

Marutks said:


> Do they sound like bottle shaped 6C5G Fivre tubes?


I'll let 'em burn in for a bit, and do a bit of comparison in ~1-2 weeks or so. Then - I'll report back.


----------



## SHIMACM

Those Cossor 6j5g being sold at Langrex is the same as the Brimar 6c5g?

https://www.ebay.com/itm/6C5G-CV581-COSSOR-NOS-VALVE-TUBE/274640722897


----------



## Marutks (Mar 29, 2021)

SHIMACM said:


> Those Cossor 6j5g being sold at Langrex is the same as the Brimar 6c5g?



They are not the same. Brimars are different internally and they sound different.


----------



## Xcalibur255

Here is the VT-94 I've been testing.  My photo is much crappier than bcowen's but oh well.  They all have been pretty bad.  My phone camera doesn't know what it's supposed to be focusing on in these shots I guess.

My final impression hasn't changed from the initial one.  Everything I wrote about the Motorola's last week applies here, they're very nearly identical.  I find these to be just the tiniest bit better overall but I know I would not be able to tell them apart in a blind test.  My advice to new buyers who are looking for these and coming up empty handed is to jump on the metal base GT if you see them, you're not really missing out on anything.

I could easily listen to these tubes permanently and they're my favorite of everything I've tested so far.  Next tube is the STC/Brimar which is the pair I paid the most money for.  Let's see if they were worth it.


----------



## Xcalibur255 (Mar 31, 2021)

Okay, I tried a dozen times to get a better picture but they just kept getting more and more blurry.  So I guess this is as good as it gets from me.

Anyway, here is the STC/Brimar 6J5G black roundplate.  For technicals I find this tube to be essentially the equal of the Tung Sol.  It's a very good overall sound.  The soundstage is nicely deep and three dimensional and very layered within.  I find the air and space around notes to feel a little more "dense" with this tube than any other 6J5 I've tried to date.  This lends a nice sense of ambience to some music, but I can see it working against something like rock or metal maybe (which I don't really listen to).  Not to suggest this is a slow or laid back sound, it's actually not.  Bass really kicks and dynamics are good.  I find the tonal balance to be very vocal forward with the occasional hint of bite in the treble, but the overall balance is pretty good with no major spotlighting.  It's sort of neutralish if neutral was wearing a tweed jacket.  I occasionally found the midrange to have a bit of a steely quality to it that I didn't agree with, but this was not pervasive across every piece I listened to.

This quality came out in the most interesting way with string instruments.  On the one hand the sense of body and weight from the string was great but occasionally the steely overtone would cut into the realism of the timbre for me.  It's actually rather similar sounding to the Raytheon roundplate tonally, only with better bass kick and some differences in the specific areas where the midrange is forward sounding.

A very good tube overall.  I would probably rate it behind both of the Tung Sols but probably ahead of everything else I've written about so far.  The last tube I will be writing about is the GEC L63 and if there are no surprises that will probably be a brief post since others have covered that tube here quite a bit already.

edit: Added  'not' to the last sentence in my paragraph about tone that totally changes the meaning of the statement.


----------



## Xcalibur255 (Apr 2, 2021)

Did I save the blurriest photo for last?  I sure might have!  

This tube probably needs no introduction since it's popular here, but it's the GEC L63 with black ladder plates in clear straight glass brown base clothes.

Right off the bat what struck me about the L63 is how rich the tone is.  It actually sounds quite a lot like a Marconi Osram B65 in terms of tonal balance, but it's a bit richer and bolder perhaps.  That's actually kind of the theme of this tube all round I would say:  rich and bold but without becoming too much or too heavy handed.  It pulls it off without any overt bad habits either such as glare or honk in the mids or any etch or hardness in the treble.  Pretty impressive.

I think the soundstage is what struck me most.  It's intimate, and maybe the smallest out of all the tubes I've tested the past few weeks.  Like my comment about the Brimars the sense of air and space just seems to feel more "dense" here, like it's more fog than air.  This brings a strong ambience to some kinds of music.  It's probably not actually smaller than the other tubes here but rather just comes across that way because the presentation is so musically 'dense' here.

Dynamically this tube is quite forward and expressive.  Lots of energy but it's well controlled.  I am particularly drawn to how it handles transients and leading edges.  They are quick and incisive without feeling harsh or edgy.  That's a hard balancing act to pull off.  There's something about the presentation here that says "I'm powerful, bold" but at the same time it's still refined and controlled.

Did I save the best for last?  Not quite.  If I had to pick one tube out of this whole lot of nine it would be the Tung Sol VT94, and if I dropped one of them and broke it I would swap over to the Motorolas and not feel any immediate need to hunt down a replacement.  I would put the L63s in a tie for second place with the Brimars.  I think I like the Brimar presentation a little better overall, it has some of that round plate 3D holography going on with it's soundstage presentation and I think everything breathes a little better and layers a little better.  The L63 is very good at layering and note seperation, it's just that all the musical information feels packed in so tight and I like the Brimar's presentation of that musical information a little better.  What hurts the Brimar is that sometimes steely overtone in the mids, and I'm wondering if maybe more burn-in time would make it go away.  But for now I think I'd just call it a draw between them.  Both great tubes and great sounds.

To whoever is still reading thanks for tagging along and I hope these write-ups have been worth reading.  Again this isn't meant to be used as buying advice per se.  I didn't put enough effort into controlling conditions from tube to tube, it was more just a stream of consciousness thing.  Hope somebody got something out of it though!

For a final wrap-up if I had to rank all of these tubes I think it would land like this:

1)  Tung Sol VT94
2) Motorola (Tung-Sol) 6J5GT
3) [TIE] Brimar 6J5G and GEC L63
4) Raytheon 6J5G ladder plate
5) Raytheon 6J5G round plate
6) Sylvania 6J5GT black ladder late
7) Sylvania 6J5GT grey round plate
8) Sylvania 6J5G black round plate

The only tube in this entire list that I did not like was the Sylvania in last place.  Which is super interesting because other people swear by this tube and consider it to be their absolute favorite.  I guess it just goes to show that we all listen very differently and have different priorities when it comes to what we like.  For me this tube just sounds inauthentic in a cartoonish way.  Instruments just never sounded real.  The only thing that really holds back the other Sylvanias, especially the ladder plate, was that they were simply outclassed by the tubes at the top of the list when it came to sheer resolution.  The grey roundplate has it but it's a dead fish in terms of dynamics.  The black ladder plate has the dynamics but it just doesn't have the low level detail and texture retrieval of the best tubes in the group.  The Raytheons could also basically be another tie.  I really liked the round plate soundstage presentation, but when it came to tone it wasn't as well balanced as the ladder plate whose overall presentation I thought was more even handed and pleasant.

One thing I will say is this:  nearly every tube on this list is superior to the vast majority of the 6SN7s I have heard, and the top three on this list are flat out superior to EVERY 6SN7 I have ever heard and I have owned/heard pretty much all of the desirable ones over the years.  There was consistently a sense of superior note separation and layering, but in the case of the Tung-Sols and the British duo they also had superior musical detail retrieval too.  Other than a lack of new production offerings to ensure that future scarcity doesn't become an issue I'm quite surprised more amp makers don't use this tube over the 6SN7.  Sure the circuit needs both triode sections sometimes, but in some amps it actually does not.  Some even just leave one section unused and literally operate the 6SN7 as a 6J5.  Maybe it's better, however, that this tube doesn't become as well known as the 6SN7 thought otherwise price and scarcity will quickly become an issue.


----------



## Xcalibur255

Fixed a few typos.....

Man I feel like I've been monopolizing this thread lately.  I'm all out of tubes to review at this point so the next few pages of this thread shouldn't be filled with posts from only me now.


----------



## chrisdrop (Apr 2, 2021)

Xcalibur255 said:


> Fixed a few typos.....
> 
> Man I feel like I've been monopolizing this thread lately.  I'm all out of tubes to review at this point so the next few pages of this thread shouldn't be filled with posts from only me now.


A most welcome, well expressed, and throughly enjoyable monopolisation. I have thoroughly enjoyed...


----------



## A2029

Xcalibur255 said:


> One thing I will say is this:  nearly every tube on this list is superior to the vast majority of the 6SN7s I have heard, and the top three on this list are flat out superior to EVERY 6SN7 I have ever heard and I have owned/heard pretty much all of the desirable ones over the years.  There was consistently a sense of superior note separation and layering, but in the case of the Tung-Sols and the British duo they also had superior musical detail retrieval too.  Other than a lack of new production offerings to ensure that future scarcity doesn't become an issue I'm quite surprised more amp makers don't use this tube over the 6SN7.  Sure the circuit needs both triode sections sometimes, but in some amps it actually does not.  Some even just leave one section unused and literally operate the 6SN7 as a 6J5.  Maybe it's better, however, that this tube doesn't become as well known as the 6SN7 thought otherwise price and scarcity will quickly become an issue.








*Awesome job with the write ups! Some great reads


----------



## Slade01

Xcalibur255 said:


> The only tube in this entire list that I did not like was the Sylvania in last place.  Which is super interesting because other people swear by this tube and consider it to be their absolute favorite.  I guess it just goes to show that we all listen very differently and have different priorities when it comes to what we like.  For me this tube just sounds inauthentic in a cartoonish way.  Instruments just never sounded real.  The only thing that really holds back the other Sylvanias, especially the ladder plate, was that they were simply outclassed by the tubes at the top of the list when it came to sheer resolution.  The grey roundplate has it but it's a dead fish in terms of dynamics.  The black ladder plate has the dynamics but it just doesn't have the low level detail and texture retrieval of the best tubes in the group.



Thanks for at least making me feel like i'm not crazy in this line of thinking about the Sylvanias.  I felt both round plate versions were lifeless, regardless of the power tube pairing (@therremans - I gave it a legit shot even with the 5998 - still same result for me), and the ladder plate was just lacking in detail/resolution compared to the Raytheons.

I essentially sold off all my Sylvanias.  Kept the Raytheons and GEC L63.  I haven't had the pleasure of trying the tung-sols, but i'm quite satisfied with what I have for sure.

Really appreciate your monpolisation of the thread as well - definitely eye opening and many will benefit from your impressions.


----------



## Xcalibur255

Appreciate the kind words guys.    Also, I seem to recall saying I wasn't going to post much about the L63.  That sure didn't happen.  

I returned the amp to the setup it was using before I started all this:  with the Mullard ECC32 in the driver socket.  After the last few tubes it just feels like something is missing.  That's really saying something considering I'm talking about an ECC32.


----------



## Xcalibur255

Slade01 said:


> Thanks for at least making me feel like i'm not crazy in this line of thinking about the Sylvanias.  I felt both round plate versions were lifeless, regardless of the power tube pairing (@therremans - I gave it a legit shot even with the 5998 - still same result for me), and the ladder plate was just lacking in detail/resolution compared to the Raytheons.
> 
> I essentially sold off all my Sylvanias.  Kept the Raytheons and GEC L63.  I haven't had the pleasure of trying the tung-sols, but i'm quite satisfied with what I have for sure.
> 
> Really appreciate your monpolisation of the thread as well - definitely eye opening and many will benefit from your impressions.


It's interesting you found BOTH of the round plates to be lifeless.  I definitely feel that way about the grey GT tube, but the old engraved base black G had the best dynamics out of the whole group of nine to my ears.  It was positively bombastic sounding compared to some of the others.  The problem is that tonally it just sounds ridiculous, like turning the color saturation on your TV all the way up to max.  That, and everything has this plasticky quality to it.  That tube is all macro with no micro to give the sound realism.  I ran across a thread on another forum complaining that too many people are hunting this tube to extinction.  Well, those guys can have them.    I am keeping mine because I want to see how they sound in my new amp when it arrives.  Different circuit with different biasing so maybe it will pull a 180 on me and my impression will improve.  If it doesn't I'll have no qualms about selling them to somebody who might enjoy them more.  It's a pity too because cosmetically they're probably the nicest tubes in my 6J5 stock.  I really found a nice pair of them.


----------



## Xcalibur255 (Apr 2, 2021)

So here's something interesting........ while doing some proofreading I couldn't shake the feeling that the Triangle and the Motorola look like the same tube.  So I pulled them both out and they appear identical with only one difference:  the Motorola has a bit of a chalky matte coating on it's plate and the Triangle is a bit more of a shiny black.  Other than that the construction is exactly the same.  The Motorola has Tung-Sol's 322 manufacturer code on it, the Triangle does not; only a date code.  So I have some reason to believe I've misidentified the Triangle as a Sylvania when it might be a TungSol, but to my ears the two tubes don't SOUND the same.  They share a similar character and tonal balance but the Motorola  is substantially superior in resolution and dynamics/drive.  I think I need to run the Triangle in the amp some more and see if it "turns into" the Motorola sound-wise.

I guess the other possibility is that with Triangle being both a re-brand and an "off-brand" maybe these are B-stock tubes that test worse or are inferior in some way hence their inferior technical performance.  This was rather common with these odd brand tubes like Triangle and Dumont and the like.  Sort of like "working rejects" that were cheaper for a reason.


----------



## Slade01

Xcalibur255 said:


> It's interesting you found BOTH of the round plates to be lifeless.  I definitely feel that way about the grey GT tube, but the old engraved base black G had the best dynamics out of the whole group of nine to my ears.  It was positively bombastic sounding compared to some of the others.  The problem is that tonally it just sounds ridiculous, like turning the color saturation on your TV all the way up to max.  That, and everything has this plasticky quality to it.  That tube is all macro with no micro to give the sound realism.  I ran across a thread on another forum complaining that too many people are hunting this tube to extinction.  Well, those guys can have them.    I am keeping mine because I want to see how they sound in my new amp when it arrives.  Different circuit with different biasing so maybe it will pull a 180 on me and my impression will improve.  If it doesn't I'll have no qualms about selling them to somebody who might enjoy them more.  It's a pity too because cosmetically they're probably the nicest tubes in my 6J5 stock.  I really found a nice pair of them.



Yeah - for me for some reason with 6J5 universe...i've preferred ladder plates each and every single time over the round plates of any ilk.  It is a surprising reaction to me as well...i've loved round plate presentations in other variants, but not here.    I didn't quite hear the (oversaturated) dynamics but it could have been my tube - maybe it was a low measuring tube or something (I do not have a tester), i don't know.  But in any event, they raytheon's for me are a real sweet spot.


----------



## bcowen

Xcalibur255 said:


> Fixed a few typos.....
> 
> Man I feel like I've been monopolizing this thread lately.  I'm all out of tubes to review at this point so the next few pages of this thread shouldn't be filled with posts from only me now.


Some monopolies are good things.    Lots of great information you've passed along, and I (for one) greatly appreciate the time you took to share your thoughts in such a detailed and well-written manner.  

Funny thing was that the Tung-Sol 6J5GT's were the first 6J5's I tried.  Liked them a lot. Then all I read about was Sylvania this and Sylvania that, so I grabbed a few different pairs of Sylvanias.  Well, ugh.  I mean not a global ugh (they're not _bad_ sounding tubes), just that the Tung-Sols kinda stomped all over them.  Then I grabbed a pair of the GEC L63's, and I like them a lot too.  Different sound than the Tung-Sols, but equally enjoyable in other ways.  Now I've just got to figure out what's going on with these Hytron 7A4's, because they step on even the Tung-Sols.  Not hugely, just all around a bit better (in my amp, anyway).  I keep looking for more, but all I ever see is the CBS/Hytron version which has different internal construction (from what I can make out in seller photos) than the ones labeled Hytron only.


----------



## Xcalibur255

Slade01 said:


> Yeah - for me for some reason with 6J5 universe...i've preferred ladder plates each and every single time over the round plates of any ilk.  It is a surprising reaction to me as well...i've loved round plate presentations in other variants, but not here.    I didn't quite hear the (oversaturated) dynamics but it could have been my tube - maybe it was a low measuring tube or something (I do not have a tester), i don't know.  But in any event, they raytheon's for me are a real sweet spot.



I like the Ray's too.  Maybe that didn't come across enough when I wrote about then but I could listen to them full time just like the TungSol VT94.  It's hard to pull off sounding lithe and vintage without being boring but I think these do.

I'm going to re-test the Motorola and Triangle comparing them directly.  I feel like I need to shake that tree a little more.  I'm also going to re-test the engraved base Sylvania to make sure I'm being fair to it.  My initial review wasn't super negative but that feeling really sunk in afterward and it kind of shows when I brought it up in subsequent posts.  And just for good measure I'll listen to the Sylvania grey round plate again just because it's probably the tube I spent the least amount of time with.  I feel like I got better at this as I went along so might as well circle back to the beginning again too.  Those tubes have getter that has burned off and re-deposited at the top of the tube which is an indication of a lot of hours of operation.  Naturally they were sold to me as "testing new" by the seller.    Maybe they're not representative either.

The Motorola/Triangle thing throws me off though.  I should have noticed earlier that they have the same construction, but I've got the Triangles back in the amp right now and my immediate impression is "these just sound veiled compared my memories of the Motorola" and the 3-5k region is a little more splashy the way I would associate with a Sylvania tube and not a TungSol tube.  So who knows I guess they could be basically identical looking and still be made by two different companies.  No reason that's impossible after all.


----------



## SHIMACM

Excellent reviews! Congratulations!

I was unsure if I would buy a pair of Zenith / Sylvania 6j5g to try, but after I read their reviews I ended up giving up.

I am currently with 4 pairs of the 6j5 family.

A pair of GEC L63, a pair of TS 6j5gt, a pair of TS 6j5gt and a pair of Sylvanias 6j5gt.

I have a pair of Fivre 6c5g on the way to try it out.

Of the 6j5 / 6c5 / L63 family I am still curious only on Mullard 6j5g and Brimar 6c5g.

But I have not yet acquired the courage to buy them.


----------



## triod750

I think this was a very well written review, not just for the information but also to a high degree how it was written. I really love this sentence: "the sense of air and space just seems to feel more "dense" here, like it's more fog than air". It's like music to my ears.


----------



## raindownthunda

Taking some time today to appreciate this rust-bucket of a tube I recently picked up, the Tung-Sol 6J5GT. You're probably thinking that a tube this ugly must sound awful, right??

Well, I stand with @Xcalibur255 on this tube being top-tier when it comes to price vs performance. I picked up two singles off of eBay to make a pair. Combined with a Philips (Mullard) 6080, the total cost for these three tubes came out to just under $45 total (incl. shipping + tax). Very pleased with how this combination sounds... Airy and ethereal soundstage, great bass texture and extension, luscious full bodied mids, and striking image placement and layering. I thought with the Mullard 6060 the treble would be more rolled off and muddy, but the TS 6J5GT seems to do a great job of keeping it all together. I am not missing the GEC L63 one bit. So, here is my ode to discovering and appreciating the inner beauty of the truly grotesque tubes out there. You are loved.


----------



## bcowen

raindownthunda said:


> Taking some time today to appreciate this rust-bucket of a tube I recently picked up, the Tung-Sol 6J5GT. You're probably thinking that a tube this ugly must sound awful, right??
> 
> Well, I stand with @Xcalibur255 on this tube being top-tier when it comes to price vs performance. I picked up two singles off of eBay to make a pair. Combined with a Philips (Mullard) 6080, the total cost for these three tubes came out to just under $45 total (incl. shipping + tax). Very pleased with how this combination sounds... Airy and ethereal soundstage, great bass texture and extension, luscious full bodied mids, and striking image placement and layering. I thought with the Mullard 6060 the treble would be more rolled off and muddy, but the TS 6J5GT seems to do a great job of keeping it all together. I am not missing the GEC L63 one bit. So, here is my ode to discovering and appreciating the inner beauty of the truly grotesque tubes out there. You are loved.


Sweet!  If you have a Dremel, these work wonders in making tubes like that look as good as they sound.    

https://www.amazon.com/AUSTOR-Piece...1e123&pd_rd_wg=yUYQr&pd_rd_i=B07BNCB8TW&psc=1


----------



## PsilocybinCube

bcowen said:


> Now I've just got to figure out what's going on with these Hytron 7A4's, because they step on even the Tung-Sols.


I keep looking for these and can't find them either.  I bought two pairs of 7a4 tubes, but both were terribly microphonic.  This has given me an incentive to try them again.


----------



## whirlwind

Xcalibur255 said:


> Did I save the blurriest photo for last?  I sure might have!
> 
> This tube probably needs no introduction since it's popular here, but it's the GEC L63 with black ladder plates in clear straight glass brown base clothes.
> 
> ...


Nice job and thanks for your time on all of these tubes.
Also it is interesting and shows just how *subjective *sound is....it really does not matter if someone else does not like the tubes that you like....that would mean most people hear the same, which just is not true. Besides hearing, ones preference and gear come into the equation also.
For instance, I love the Sylvania 6J5 tubes and one of my favorite tubes is the ECC32....this sure does not mean everyone or even the majority will like these in their system.
I believe the best advise for anyone is to just listen to your ears and use what tubes you like...regardless of what they are.

Thanks again for your fine work here and who knows....things could very well change with your new amp.


----------



## SHIMACM

raindownthunda said:


> Taking some time today to appreciate this rust-bucket of a tube I recently picked up, the Tung-Sol 6J5GT. You're probably thinking that a tube this ugly must sound awful, right??
> 
> Well, I stand with @Xcalibur255 on this tube being top-tier when it comes to price vs performance. I picked up two singles off of eBay to make a pair. Combined with a Philips (Mullard) 6080, the total cost for these three tubes came out to just under $45 total (incl. shipping + tax). Very pleased with how this combination sounds... Airy and ethereal soundstage, great bass texture and extension, luscious full bodied mids, and striking image placement and layering. I thought with the Mullard 6060 the treble would be more rolled off and muddy, but the TS 6J5GT seems to do a great job of keeping it all together. I am not missing the GEC L63 one bit. So, here is my ode to discovering and appreciating the inner beauty of the truly grotesque tubes out there. You are loved.



These 6j5gt Ts are wonderful. Yesterday I heard them paired with Chatham 6as7g. Wow.


----------



## Xcalibur255

whirlwind said:


> Nice job and thanks for your time on all of these tubes.
> Also it is interesting and shows just how *subjective *sound is....it really does not matter if someone else does not like the tubes that you like....that would mean most people hear the same, which just is not true. Besides hearing, ones preference and gear come into the equation also.
> For instance, I love the Sylvania 6J5 tubes and one of my favorite tubes is the ECC32....this sure does not mean everyone or even the majority will like these in their system.
> I believe the best advise for anyone is to just listen to your ears and use what tubes you like...regardless of what they are.
> ...



Something I was also reminded of this week is that the order in which I listened to these tubes can and likely did influence my impressions.  In order to really go at this in a scientific way and make it as fair as possible it would probably entail enough work to really drain the fun out of it.  That's why I plastered all those disclaimers about it being merely a stream of consciousness thing.  My choice of headphones is really big here too.  The Beyers are well known for being picky with matching and the guy listening to them is awfully picky about how much energy is present in certain tone areas too.


----------



## Xcalibur255

Also, a quick update:  I spent a fair amount of time re-listening to both the Triangle and the Motorola tubes.  Ultimately I think I can stand by what I wrote originally, but there is definitely something interesting going on here.  My concern is that I was mis-identifying one of them, given that the two tubes appear to have identical construction with only a minor difference in texture on the black coating of the anode plate being the differentiator.  This would suggest that the Triangle is also a Tung-Sol and not a Sylvania, since the Motorola tubes actually have the Tung-Sol manufacturer ID code (322) and the plates and bottom mica match the VT-94 I'm inclined to trust that ID.

However, my listening impressions hold up.  These tubes look the same but they do not sound the same.  The differences are substantial.  The Triangle is less resolving, more V-shaped in its tone profile, and less precise in its imaging.  The Motorolas are just how I remember them from a week ago, though I felt this time they had a little more upper mid energy than I wanted.  There could be any number of reasons for that, including some wild swings in barometric pressure here lately.  My ears are sensitive to those and will feel plugged up for a couple of days when they happen and everything seems a little more tinny when they do.


The Triangles don't sound bad at all, the Motorolas are just better.  They don't sound wildly different, but the Triangle matches the Sylvania sound profile better so I'm going to stick by what I wrote originally and leave the identification as is.  If they really are Tung-Sol made then the implications here are interesting.  This would mean the tube-to-tube variation on these could be very substantial, or that internal differences we cannot see such as grid wire tolerance and tension could be responsible for the difference and there is no way to know before buying.


----------



## Velozity

Since everybody else is experimenting with tubes they haven't listened to before I thought I'd share my new 6J5 addition.  These RCA (branded GE) 6J5G seem to be rather hard to find and are worth the effort to search for them.  They have black ladder plates and top mica supports similar to the 6AS7G.  They are sneaky good, especially with these Chatham 6AS7G and Cossor 53KU.  I'll listen to this for a few more days and then switch to Bendix 6080WB.  I really like the metal RCA 6J5 with Bendix so I think that will be a winner with these too.  With the RCA 6AS7G it was too warm and not my preference with the music I am listening to but with these power tubes the porridge is just right!


----------



## raindownthunda

Xcalibur255 said:


> I like the Ray's too.  Maybe that didn't come across enough when I wrote about then but I could listen to them full time just like the TungSol VT94.  It's hard to pull off sounding lithe and vintage without being boring but I think these do.
> 
> I'm going to re-test the Motorola and Triangle comparing them directly.  I feel like I need to shake that tree a little more.  I'm also going to re-test the engraved base Sylvania to make sure I'm being fair to it.  My initial review wasn't super negative but that feeling really sunk in afterward and it kind of shows when I brought it up in subsequent posts.  And just for good measure I'll listen to the Sylvania grey round plate again just because it's probably the tube I spent the least amount of time with.  I feel like I got better at this as I went along so might as well circle back to the beginning again too.  Those tubes have getter that has burned off and re-deposited at the top of the tube which is an indication of a lot of hours of operation.  Naturally they were sold to me as "testing new" by the seller.    Maybe they're not representative either.
> 
> The Motorola/Triangle thing throws me off though.  I should have noticed earlier that they have the same construction, but I've got the Triangles back in the amp right now and my immediate impression is "these just sound veiled compared my memories of the Motorola" and the 3-5k region is a little more splashy the way I would associate with a Sylvania tube and not a TungSol tube.  So who knows I guess they could be basically identical looking and still be made by two different companies.  No reason that's impossible after all.



Just wanted to say I greatly enjoyed your back-to-back comparisons between all these different tubes! I’ve gone back and re-read them several times now. I appreciate these types of long-form well articulated impression posts. I feel it helps those like myself who are relatively new to the audiophile world develop a greater sense of the different attributes to listen for.


----------



## Xcalibur255

Appreciate the kind words.  I feel like I was all over the place in terms of what I was focusing on in the first few, then started to find a bit more of a rhythm later on.  It really was meant to be a stream of consciousness more than an actual review with rigid guidelines.  I tended to focus on attributes of each tube that stood out in contrast to the other tubes I had already listened to, and that's probably why I got better as I went along.  By the end I had 8 other tubes worth of impressions to draw my comparisons against, which made the first couple of reviews seem a little spartan.

I'm wrapping the whole little project up now.  After confirming what my ears were telling me about the Motorola vs. Triangle thing I felt I had one last thing I needed to do.  That's a revisit of the Sylvania 6J5G I ranked in last place.  These are popular with other people and easier to find than some of the other tubes on the list, I wanted to be certain I was being fair to them.

I think the trick here is really what is being compared to what.  I have a hunch that the people who love these generally stick with and love the Sylvania house sound in general.  Compared to say, a chrome dome Sylvania 6SN7GT, this tube is awesome.  It's more or less an upgraded version of that same sound.  If you love the chrome dome sound you'll be over the moon for these.  Over the years I've kind of personally fallen out of love with all of the Sylvanias though because they don't reproduce timbre in a way that seems authentic to me, but if I stop comparing them to anything else and just concentrate on the things they do well in and of themselves there are certainly things to like.

I do have to add one last note.  The treble seems less piercing to me now, and hasn't been a distraction listening today the way it was in my original listening session with the tube.  Perhaps it needed more time (though I did give it an extra day because I had this thought the first time around), or maybe my ears have a different amount of wax in them today.    Either way removing that annoyance significantly improves my overall opinion of them.  Harsh bite in the treble is a massive distraction for me that I have difficulty listening past.


----------



## raindownthunda

I recently encountered a mystery that I thought I'd run by you tube sleuths...

So I've been looking for a pair of Brimar 6J5G for a while and pulled the trigger on 2x of the Raytheon 6J5G Langrex recently had for sale, based on @Xcalibur255 's comments concluding the tubes being sold are actually re-labeled Brimar's. The photos in the listing show the Brimar construction with the round/oval plates. Here is the original listing for reference: https://www.ebay.com/itm/274598256878?nordt=true&orig_cvip=true&rt=nc&_trksid=p2546137.m43663.l10137

After I purchased the tubes, I emailed Langrex inquiring if they were really Raytheon tubes. They got back to me and said "Although they look similar to Brimar, these are definitely Raytheon 6J5G". Alright, let's see what happens...

Several weeks ago I received a pair of sealed boxes... fairly uneventful so far, but cool to see that they are "true NOS" and have never been opened:


I felt a bit let down to discover the inner sleeves said "Raytheon" and "Manufactured in the USA", with US Patent #'s, etc. I didn't get a photo of the packaging unfortunately, but there definitely was no sign of Brimar tubes... yet...

To my surprise, when I took the tubes out their sleeves, this is what I found:
 
Two different plate constructions! The left is clearly a flat/ladder style plate and the tube on the right is round/oval.  You can clearly see other differences in construction to other aspects of the tubes, such as the bottom mica shape and the supports on the top. Very strange! After reading about the different constructions having different sounds, I was a bit disappointed given the price I paid for these. Are these Raytheon? Brimar? Or one of each?

I emailed Langrex to see if there was anything they could do as I was hoping for a pair of matching construction with the oval plates. James was very understanding, and although they were sold out of these NOS tubes now, he immediately offered to find another round plate to send as a replacement free of charge. Thank you James at Langrex!!

While waiting for the replacement, I realized the tube on the left above looks identical to a single Raytheon-labeled 6J5G I got from an assorted lot purchase a while back. They both have flat ladder plates and the almost-90 degree bends on the top mica and additional supports on the top:
 

Yesterday the replacement from Langrex showed up. Since I was only hoping for a single, I was pretty excited to see a matched pair! These came in plain white boxes, so I'm assuming they are used. These look a lot like the pictures I have seen of the Brimar 6J5G. Here they are in my amp now:


These replacements look to be identical construction to the 2nd NOS tube that came in Raytheon packaging. In addition to identical plates, the bottom micas are both circular and the top supports are more of an obtuse angle than one matching the Raytheon label. The printed label and "6J5G" stamps look identical as well. However one is labeled as CV1067 and the other as CV1932. Does anyone know why these codes would be different?


So what happened? My hypothesis is that Raytheon must have acquired a number of Brimar 6J5G (adding the gray rubber wrap?) to supplement their own in-house construction in order to fulfill 6J5G orders and selling them as Raytheon - "Made in the USA" 6J5G tubes. I wonder how many of the tubes Langrex sold as NOS Raythen 6J5G had round plates vs flat ladder plates? Clearly at least 2 round plates, as the photo in their ad showed round plates. Did anyone else on here buy these tubes from Langrex?

Here are all 5 tubes as a reference/comparison:
From L-R: 1) Used Raytheon 6J5G 2) NOS Raytheon from Langrex
3) NOS Raytheon, but Brimar construction(?) from Langrex 4) & 5) Brimar 6J5G replacement from Langrex


I am currently listening to the replacements (4 & 5) and initial impressions are very good. Quite resolving with a rich, smooth, airy presentation with a romantic decay. Very easy on the ears with a great dynamic punch in bass heavy tracks. I will try the flat plate versions (assuming they are Raytheon) later to compare to see if I hear a difference in sound.


----------



## Xcalibur255

That's quite an ordeal, and kind of makes me a bit weary of buying from Langrex if I'm being honest.  They must be aware people are buying these to use in amplifiers and will want them to properly match.

The crazy part is none of these tubes match the construction of any Raytheon 6J5 I have seen.  You have three Brimar tubes there, the middle and the two on the right.  I have seen the construction style for the two tubes on the left before, on tubes branded Ferranti.  Ferranti is also a British brand.  I feel somewhat confident saying none of these tubes are USA made, they're all British.

It's definitely possible they were imported and re-branded as Raytheons.  This was kind of a known thing, and in fact a good deal of STC/Brimar tube production was meant for export purposes.


----------



## Slade01

Xcalibur255 said:


> The crazy part is none of these tubes match the construction of any Raytheon 6J5 I have seen.  You have three Brimar tubes there, the middle and the two on the right.  I have seen the construction style for the two tubes on the left before, on tubes branded Ferranti.  Ferranti is also a British brand.  I feel somewhat confident saying none of these tubes are USA made, they're all British.
> 
> It's definitely possible they were imported and re-branded as Raytheons.  This was kind of a known thing, and in fact a good deal of STC/Brimar tube production was meant for export purposes.



I'll chime in and say because I have three pairs of "Raytheons" (Regular Branded, VR-67, and British Military Markings) and all of mine do look like the two on the left.   The Regular Branded Consumer Raytheons do say made in the USA.  The VR-67 and British Marked pairs, I did get from sellers in the UK (not Langrex though).  

@Xcalibur255 You are right that the right three definitely look like Brimars. 

Can I ask then what type of Raytheon 6J5 have you seen if you know them to be actual Raytheon made?  I've only ever seen the kind shown like @raindownthunda 's VR-67 marked Raytheon tube.


----------



## Xcalibur255 (Apr 14, 2021)

A couple of thoughts:  First off I absolutely could be wrong and don't want to assert my ID as fact.  It's hard to be sure sometimes given the lack of research resources and the fact that similar construction traits sometimes appear in more than one brand.  Generally speaking though I do find that there are "style" trends among the brands that help you be more sure. 

Second, it helps to know a little about Raytheon's corporate history.  They pivoted more towards military contracting and away from general consumer electronics long before many other manufacturers and often times when it comes to their tubes there is a cut-off period where they stop being "real" Raytheon tubes and start being re-brands.  In some cases such as with their old DHTs this happens quite early, even pre-WWII in some cases.  In others they maintain a manufacturing presence of their own for much longer, such as in the case of the 6SN7 which were generally made by themselves up until the 60's when they turned to having them made mostly in Japan.

You can see in my recent tube reviews photos of the tubes I identify as Raytheon made.  My ID of my own Raytheon tubes is based on a couple of things.  Some of it is knowledge from tube sellers and other people and some of it's my own observations.  In this case the key is the top mica structure IMO.  Generally an X or cross shaped mica was something of a Raytheon hallmark in their older tubes, and in the older tubes each maker did tend to each have their own spin on this.  I own other Raytheon tubes that consistently have this X shaped top mica.  Also, in the case of the tubes that rain is trying to ID, that particular mica style isn't something I would associate right away with any of the US tube makers, but I have seen quite a few Ferranti tubes now that all use is and that's been consistent.  So that's my rationale.  Even if they're not Ferranti my second guess would still not be Raytheon it would be GE/RCA.

My take is Raytheon made the 6J5 themselves through WWII then pivoted to re-branding after.  They slimmed down the number of tubes they made themselves a lot in that period of time.

Again, could be wrong, but if I was only a little sure I wouldn't have offered my take in the first place because that wouldn't be helpful.


----------



## raindownthunda (Apr 14, 2021)

Xcalibur255 said:


> That's quite an ordeal, and kind of makes me a bit weary of buying from Langrex if I'm being honest.  They must be aware people are buying these to use in amplifiers and will want them to properly match.
> 
> The crazy part is none of these tubes match the construction of any Raytheon 6J5 I have seen.  You have three Brimar tubes there, the middle and the two on the right.  I have seen the construction style for the two tubes on the left before, on tubes branded Ferranti.  Ferranti is also a British brand.  I feel somewhat confident saying none of these tubes are USA made, they're all British.
> 
> It's definitely possible they were imported and re-branded as Raytheons.  This was kind of a known thing, and in fact a good deal of STC/Brimar tube production was meant for export purposes.



Very interesting. I just looked up Ferranti 6J5G tubes and they do appear to be identical construction. 

Do you know for sure that Ferranti manufactured their own 6J5G tubes? Or could it be the reverse, that Ferranti imported Raytheon made tubes and rebranded them? I searched and found this eBay ad for a Ferranti 6J5G tube that the seller claims is made by Raytheon, which got me wondering: https://www.ebay.com/itm/224401117711

Edit: I just went back and looked at your Raytheon flat and round plates and I see now that the top mica is definitely different... Interesting that Google image search for Raytheon 6J5G has many pictures with the X supports though. Maybe they were mostly imported Ferranti made tubes which is why they style seems to be so prevalent?

Regarding Langrex selling a mismatched pair, to be honest I am not sure how they could have known about the mismatch as both of the boxes were still factory sealed and looked identical. It does seem like they should have been able to identify the construction in the tube in their ad as Brimar made though. Regardless, I am feeling like I came out on top as it appears I have accidentally ended up with a sibling for the lone Raytheon (Ferranti?) VR67 I had, while also ending up with a pair of Brimar’s and a spare to boot.


----------



## Xcalibur255

One last thought:  the ID isn't based purely on that top mica structure, that's just the part that stands out to me the most.  The plates themselves are also interesting.  They're unusually shiny in their coating and the actual shape is a bit different than other 6J5 ladder plates.  If Ferranti isn't the actual manufacturer then I feel like it's much more likely it came from somewhere else in Europe rather than from the US.  There are just too many differences that don't track.


----------



## Xcalibur255 (Apr 14, 2021)

raindownthunda said:


> Very interesting. I just looked up Ferranti 6J5G tubes and they do appear to be identical construction.
> 
> Do you know for sure that Ferranti manufactured their own 6J5G tubes? Or could it be the reverse, that Ferranti imported Raytheon made tubes and rebranded them? I searched and found this eBay ad for a Ferranti 6J5G tube that the seller claims is made by Raytheon, which got me wondering: https://www.ebay.com/itm/224401117711
> 
> ...


I don't buy anything that seller wrote about his tube as far as identification goes.  Raytheon wouldn't be making ST style tubes by the 60's.  I really think this tube is from Europe.

Again, certainly could be wrong, but my gut says no on the Raytheon thing.


----------



## Slade01

Xcalibur255 said:


> A couple of thoughts:  First off I absolutely could be wrong and don't want to assert my ID as fact.  It's hard to be sure sometimes given the lack of research resources and the fact that similar construction traits sometimes appear in more than one brand.  Generally speaking though I do find that there are "style" trends among the brands that help you be more sure.



Yeah - understood that nothing is 100% certain - but you've quite an insight into tube construction and history, so i'll take your gut feeling any day.  



Xcalibur255 said:


> I have seen quite a few Ferranti tubes now that all use is and that's been consistent.  So that's my rationale.  Even if they're not Ferranti my second guess would still not be Raytheon it would be GE/RCA.



Whatever they are - these are among my top favorite - at least in the more affordable price ranges.  @raindownthunda you are right - i had to look up Ferranti tubes and they really do look virtually identical.  I'd definitely rather they be from Ferranti (rather than GE).   Because that would mean I would be forced to like an actual GE tube (sarcasm).


----------



## Xcalibur255

I have my doubts that Ferranti actually MADE them, but I do think they're from Europe.  If they sound good to you then that's really all that matters, though it can make it hard to find another pair if you want a backup.

I've honestly had a harder time properly identifying 6J5 tubes than most for some reason.  The old DHTs and popular tubes like the 6SN7 and 12AX7 have more consistent traits that let you be certain.


----------



## Velozity

I thought all Brimar-made 6J5G have rivets in the top mica where the support rods come through?  I was under the impression that this is a Brimar hallmark.  No?


----------



## raindownthunda (Apr 15, 2021)

Xcalibur255 said:


> I have my doubts that Ferranti actually MADE them, but I do think they're from Europe.  If they sound good to you then that's really all that matters, though it can make it hard to find another pair if you want a backup.
> 
> I've honestly had a harder time properly identifying 6J5 tubes than most for some reason.  The old DHTs and popular tubes like the 6SN7 and 12AX7 have more consistent traits that let you be certain.



Found some evidence you may be right about the Raytheon labeled tubes likely being Ferranti made. This link @mordy posted on the Glenn thread mentions Ferranti became a major supplier of tubes after WWII. Seems plausible with Raytheon ramping down their tube manufacturing in the same period that they were purchasing from Ferranti for resale. Just a guess.

_1946 Began to supply valves to other makers of sets[9]._
_1948 General supplier of tubes[10]._
_WWII During the war, Ferranti became a major supplier of electronics, and was heavily involved in the early development of radar in the United Kingdom. In the post-war era this became a large segment of their company, with various branches supplying radar sets, avionics and other military electronics, both in the UK and their various international offices. Valve production was expanded to supply other companies as well as Ferranti.“_



Velozity said:


> I thought all Brimar-made 6J5G have rivets in the top mica where the support rods come through?  I was under the impression that this is a Brimar hallmark.  No?



Oooh, another curveball for the mix... perhaps they had different iterations of support structures over the years? Too bad they didn’t use date codes.


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## raindownthunda (Apr 15, 2021)

Here is an interesting report by the U.K. Competition Commission from 1956 on British tube makers engaging in monopolistic practices. Despite the hostile lens of the report there is quite a bit of rich historical information. Their website no longer works, but I was able to find a copy on the wayback machine. Each chapter is broken into a different file. If you change the last two digits of the file name in the url you can access the various chapters. Here are some that stood out after a quick skim:

chronological history of British tube companies. Last section at lists all the BVA manufacturers...
http://web.archive.org/web/20071024...rep_pub/reports/1950_1959/fulltext/020c02.pdf

stats on # valves produced and # of people employees by valve industry...
http://web.archive.org/web/20090204...rep_pub/reports/1950_1959/fulltext/020c04.pdf

On exclusivity...
http://web.archive.org/web/20090204...rep_pub/reports/1950_1959/fulltext/020c06.pdf

On imports... last paragraph talks about how British wholesalers are not allowed to deal in imported tubes from the USA or other parts of Europe...
http://web.archive.org/web/20090204...rep_pub/reports/1950_1959/fulltext/020c10.pdf

Conclusion that British valve companies engaged in anti-competitive practices with some stats on production  & import/export:
http://web.archive.org/web/20090204...rep_pub/reports/1950_1959/fulltext/020c16.pdf


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## maxpudding

raindownthunda said:


> Here is an interesting report by the U.K. Competition Commission from 1956 on British tube makers engaging in monopolistic practices. Despite the hostile lens of the report there is quite a bit of rich historical information. Their website no longer works, but I was able to find a copy on the wayback machine. Each chapter is broken into a different file. If you change the last two digits of the file name in the url you can access the various chapters. Here are some that stood out after a quick skim:
> 
> chronological history of British tube companies. Last section at lists all the BVA manufacturers...
> http://web.archive.org/web/20071024...rep_pub/reports/1950_1959/fulltext/020c02.pdf
> ...



Very interesting indeed...


----------



## Xcalibur255

It can be a bit hard to see, but the tubes in rain's photos do have rivets for their support posts.  They're visible in at least one of those photos.  All else being equal the Brimar tubes are the easiest to spot by far because nothing else shares a plate style with them.


----------



## maxpudding

raindownthunda said:


> I am currently listening to the replacements (4 & 5) and initial impressions are very good. Quite resolving with a rich, smooth, airy presentation with a romantic decay. Very easy on the ears with a great dynamic punch in bass heavy tracks. I will try the flat plate versions (assuming they are Raytheon) later to compare to see if I hear a difference in sound.



My initial impression of the CV1067 (the grey coated glass) late last year was good too. But then, other 6J5/6C5 type tubes arrived, and the CV1067's...were forgotten until a week ago. Since then, I've been keeping them on the C2A, and they have certainly opened up a bit more...more spacious than before. But not as spacious as the 6J5MG's (at least in my system). Not sure if keeping them on the C2A any longer would change that. However, the dynamic punch sound is much more pronounced than the 6J5MG. Still, the sound is great, and I'm not complaining.

I would love to hear your comparison with the flat plate versions of the "Raytheon" 6J5G later if it's not too much to ask. I have a pair of metal base 6S2S coming in, and I think @bcowen has the black base version of the Russian 6J5 tube IINM. Looking forward to trying out those soon.


----------



## mordy

Read through the last several pages with interest - especially the comments of Xcalibur255. Thanks for the comprehensive analysis!
Decided to look through my stash of 6J5GT tubes. The truth is that when I found out about the great sound of single triodes vs dual triodes I bought mainly the metal ones since the ugly ducklings were very inexpensive. 
However, I picked up some GT and G tubes as well. In looking for the acclaimed Tung-Sol tubes I did not find any 6J5GT (does anybody know who could have a made a tube labelled WIZARD?) but I did find a pair of 6C5GT Tung- Sol tubes.
Does anybody know how these compare to the TS 6J5GT tubes?

The discussion on the thread has mainly been about 6J5GT tubes, but my impression is that the all metal 6J5 tubes can hold their own very well in comparison with the GT tubes although they will never win the beauty contest lol. Especially not the rusty ones...


----------



## Xcalibur255

The only reason I don't buy the metal can versions is because I want to be able to see the internal structure of the tube.  Even if it has a major brand stamped on it there's no way to actually verify because there was so much re-branding.  On one hand if it sounds good it sounds good whoever made it, but what I'm really driving at is preventing mis-matches with tubes that have two different internal plate construction types.  On the outside they may be marked the same way but on the inside one might be substantially different than the other.

It certainly doesn't cost much to play this lottery though, so to each his own.  Those metal can tubes shouldn't be going to waste since many of them will indeed sound great.


----------



## Marutks

Xcalibur255 said:


> It can be a bit hard to see, but the tubes in rain's photos do have rivets for their support posts.  They're visible in at least one of those photos.  All else being equal the Brimar tubes are the easiest to spot by far because nothing else shares a plate style with them.



These rivets?   Where are they?


----------



## raindownthunda

Here is a better pic of the CV1067. The single CV1932 looks identical to this as well.


----------



## Marutks

maxpudding said:


> I have a pair of metal base 6S2S coming in



I like 6s5s tubes.   They are a bit warmer than 6J5G Sylvania tubes I was using before.

2 x 6s5s and 1578 Melz tube:


----------



## bcowen

maxpudding said:


> My initial impression of the CV1067 (the grey coated glass) late last year was good too. But then, other 6J5/6C5 type tubes arrived, and the CV1067's...were forgotten until a week ago. Since then, I've been keeping them on the C2A, and they have certainly opened up a bit more...more spacious than before. But not as spacious as the 6J5MG's (at least in my system). Not sure if keeping them on the C2A any longer would change that. However, the dynamic punch sound is much more pronounced than the 6J5MG. Still, the sound is great, and I'm not complaining.
> 
> I would love to hear your comparison with the flat plate versions of the "Raytheon" 6J5G later if it's not too much to ask. I have a pair of metal base 6S2S coming in, and I think @bcowen has the black base version of the Russian 6J5 tube IINM. Looking forward to trying out those soon.


Good memory!  I have some that are labeled Pinnacle, but with the UFO getters they are most definitely Russian 6S2S's (Pinnacle was a UK marketing brand I think, although not a manufacturer).  These were dirt cheap and sound quite nice.  Not like they'll ever displace the GEC L63's or Tung Sol 6J5's, but overall they have a nice balance, good bass, and impart a good amount of toe-tap especially with rock and metal. 





I've seen 3 different versions of these Pinnacle branded 6J5's. The phenolic-base ones like I have, some metal-base versions, and then another that appears to have a painted metal base.  I've only heard the plastic based ones above, so don't know how the others compare.  Even with the poor photos you can see significant internal differences between them.


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## maxpudding (Apr 15, 2021)

mordy said:


> However, I picked up some GT and G tubes as well. In looking for the acclaimed Tung-Sol tubes I did not find any 6J5GT (does anybody know who could have a made a tube labelled WIZARD?) but I did find a pair of 6C5GT Tung- Sol tubes.



I’ve been wondering about those WIZARD tubes too, especially the 6J5G’s, their internal constructions are identical to the visseaux/mazda/neotron 6J5G’s based on the photos I’ve seen.

edit: scratch that, they are not similar, huge differences.


----------



## maxpudding

bcowen said:


> Good memory!  I have some that are labeled Pinnacle, but with the UFO getters they are most definitely Russian 6S2S's (Pinnacle was a UK marketing brand I think, although not a manufacturer).  These were dirt cheap and sound quite nice.  Not like they'll ever displace the GEC L63's or Tung Sol 6J5's, but overall they have a nice balance, good bass, and impart a good amount of toe-tap especially with rock and metal.



Here’s a photo of the NEVZ 6s2s tubes from the seller. Similar internal construction and you can definitely see the UFO getters in there. Still relatively cheap but the prices are increasing.


----------



## mordy

maxpudding said:


> I’ve been wondering about those WIZARD tubes too, especially the 6J5G’s, their internal constructions are identical to the visseaux/mazda/neotron 6J5G’s based on the photos I’ve seen.


The WIZARD tube I have has a black ladder plate with two holes, side getter and is made in USA with a date code _
                                                                                                                                                                                     P0



Sylvania? P0 = March 1940?
A search of Wizard vacuum tubes (apart for tubes for sale) only leads to Thomas Edison - the wizard of Menlo Park...


----------



## maxpudding

raindownthunda said:


> Here is a better pic of the CV1067. The single CV1932 looks identical to this as well.



Thanks, I can see some differences with the grey coated CV1067.


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## maxpudding (Apr 15, 2021)

mordy said:


> The WIZARD tube I have has a black ladder plate with two holes, side getter and is made in USA with a date code _
> P0
> 
> Sylvania? P0 = March 1940?
> A search of Wizard vacuum tubes (apart for tubes for sale) only leads to Thomas Edison - the wizard of Menlo Park...



Upon further checking, although the WIZARD 6J5G has a similar concept/shape for the spacers with the visseaux/mazda 6J5G, but there are significant differences in the internal construction, i.e. different plate, supports, etc.

Edit: here’s some more related info from radiomuseum.org

“Wizard brand tubes were sold by the Western Auto Supply Co. in the late 1920's but the manufacturer is not known.

Also sold were Wizard brand panel lamps. The print style on these appears to be identical to the style used by General Electric, so this company could have made these lamps.”

Probably GE...LOL


----------



## mordy

maxpudding said:


> Very interesting indeed...


Read through most of the material - don't know if these price fixing practices would hold in the US.
One thing not mentioned is the labeling designation system instituted to further obfuscate tube designations for the purpose of stifling foreign competition. 13D1 and 6/30L2 are examples.


----------



## mordy

maxpudding said:


> Upon further checking, although the WIZARD 6J5G has a similar concept/shape for the spacers with the visseaux/mazda 6J5G, but there are significant differences in the internal construction, i.e. different plate, supports, etc.
> 
> Edit: here’s some more related info from radiomuseum.org
> 
> ...






Here is a GE 6J5GT tube. And I think that you are right - the Wizard tube I have looks very much the same.
Most of the US made 6J5GT tubes have a metal base and very few a black base. 
Here is another methodology in identifying tubes, aside from scrolling through eBay offerings - Google images or just asking Google for pictures. On a few occasions I have been able to identify rebranded tubes this way and even find hard to get tubes for sale.


----------



## maxpudding

mordy said:


> Here is a GE 6J5GT tube. And I think that you are right - the Wizard tube I have looks very much the same.
> Most of the US made 6J5GT tubes have a metal base and very few a black base.
> Here is another methodology in identifying tubes, aside from scrolling through eBay offerings - Google images or just asking Google for pictures. On a few occasions I have been able to identify rebranded tubes this way and even find hard to get tubes for sale.



Nice find! So, that confirms it then...GE manufactured the 6J5's Wizard brand tubes

BTW, thanks for the tips, Mordy!


----------



## Marutks (Apr 16, 2021)

Are these GEC L63 tubes rebranded 6J5G Brimars?

My GEC "grey glass" tubes have different internal structure.


----------



## Marutks




----------



## Xcalibur255

Looking at the plates will help you.  The GEC tubes never had round plates, they're always ladder-box style so if they have those wide oval type plates then they're STC/Brimar.


----------



## Marutks (Apr 16, 2021)

https://www.ebay.co.uk/itm/2-X-Very...Valves-Tubes-NOS-In-Original-Box/294119597100

They are Brimar tubes then.  They have the same oval plates as this Brimar.


----------



## mordy

In search of the Tung Sol sound - a pair of TS 6C5GT tubes. One tube has no legible factory markings, the other one has a date code 9. Could it be 1939?



Dynamic and punchy sound backed by a pair of Chatham 6AS7G. Involuntary toe tapping is always a good sign...
Time goes - I think I paid less for these four tubes than the adapter.

Before this combination I tried a pair of RCA 12J5GT but I like the Tung-Sols better - very lively presentation.


----------



## jonathan c

mordy said:


> In search of the Tung Sol sound - a pair of TS 6C5GT tubes. One tube has no legible factory markings, the other one has a date code 9. Could it be 1939?
> 
> Dynamic and punchy sound backed by a pair of Chatham 6AS7G. Involuntary toe tapping is always a good sign...
> Time goes - I think I paid less for these four tubes than the adapter.
> ...


Is that blue tube with the appendages a triode or a pentode?


----------



## bcowen

jonathan c said:


> Is that blue tube with the appendages a triode or a pentode?


It's a happy tube.  I think they were referred to as megatodes.


----------



## PsilocybinCube

I just ordered 5 of these and they arrived today.  Let me know if you need an extra!


----------



## bcowen

PsilocybinCube said:


> I just ordered 5 of these and they arrived today.  Let me know if you need an extra!


LOL!!!


----------



## Slade01

If I can ask the collective brain trust here about internal constructions (specifically by way of the top mica support.   Who do you think made this (6J5G) tube?  I've only got one answer so far from a tube collector whom I generally trust - but want to see if it aligns to what you all think.  Thanks!


----------



## Velozity

Slade01 said:


> If I can ask the collective brain trust here about internal constructions (specifically by way of the top mica support.   Who do you think made this (6J5G) tube?  I've only got one answer so far from a tube collector whom I generally trust - but want to see if it aligns to what you all think.  Thanks!



Resembles RCA to me.  If so, nice tubes.  I'm diggin' em.


----------



## mordy

Velozity said:


> Resembles RCA to me.  If so, nice tubes.  I'm diggin' em.


----------



## mordy (Apr 17, 2021)

Did my Google search (could not find anything similar looking on eBay now). - I does look similar to RCA, but the top mica does not look the same so not sure - it could be something else.
( Found a seller that has the RCA for $15 but the picture is not identical ):
https://lowtechelec.com/products/rca-6j5-6j5g-vacuum-tube-valve-st-shoulder-shape-nos-testing


----------



## Xcalibur255

Slade01 said:


> If I can ask the collective brain trust here about internal constructions (specifically by way of the top mica support.   Who do you think made this (6J5G) tube?  I've only got one answer so far from a tube collector whom I generally trust - but want to see if it aligns to what you all think.  Thanks!


I was wondering about this one too.  The top mica spacer design and mica shape say National Union to me actually.  You can see it in other NU tubes from the 30's such as their 45 tube.

That's my first guess FWIW.


----------



## therremans (Apr 17, 2021)

Slade01 said:


> If I can ask the collective brain trust here about internal constructions (specifically by way of the top mica support.   Who do you think made this (6J5G) tube?  I've only got one answer so far from a tube collector whom I generally trust - but want to see if it aligns to what you all think.  Thanks!


This Silvertone I own matches up. “6 C X” However it’s an oddity, as it’s a 6C5G without the cage or is actually a 6J5G? I typically think of National Union making most of the Silvertone tubes. Not sure who made these. Maybe it is RCA or Ken Rad?


----------



## Slade01 (Apr 17, 2021)

Xcalibur255 said:


> I was wondering about this one too.  The top mica spacer design and mica shape say National Union to me actually.  You can see it in other NU tubes from the 30's such as their 45 tube.
> 
> That's my first guess FWIW.



I would consider your guess to be 98-100% correct - you kind of help validate this for me.  I was told from an avid tube collector that this tube was manufactured by Arcturus.  I'm not sure how the history connects but I know that Arcturus/National Union are often mentioned in the same scope.   This tube is from 1939 - I bring it up also because @Xcalibur255 it is also a GM Branded tube.  Looking up Arcturus, up until perhaps the 2nd world war, they were making their own tubes - shifting to rebranding after the war.

@therremans - yes I agree with you and Xcalibur255 about it being probably National Union (Arcturus?).  My tube also bears the similar round logo proclaiming it to be a 6J5G (instead of the stop sign insignia).  The top mica is a dead ringer to your 6C5G Silvertone - (and without a cage - that is kind of cool too, definitely an oddity--unique.)

He was the only one who seemed to definitively know, but have never gotten any real confirmation from any one else to reaffirm the internal construction.   Thank you all for taking the time to look...I appreciate your help.

For kicks - this is the original box for the GM Branded Tube.


----------



## maxpudding

It is always nice to see pieces of history here


----------



## Xcalibur255 (Apr 20, 2021)

Silvertone was an in-house brand for Radioshack if memory serves.  I have noticed that it's quite common for the Silvertone tubes to be made by National Union, but it's not exclusively the case.

Arcturus is a wild card, and I don't know much about them.  Some of the biggest unicorns in the tube world (mesh plate blue glass stuff) are Arcturus, along with Taylor, Cunningham and other brands that all vanished after WWII or in the lead up to it.  Speaking purely in terms of name coolness I have to say I'm a fan of Arcturus.  It's not Super Air Castle cool, but it's still cool.  

edit:  Memory does NOT serve it turns out, it was Sears Roebuck and Co. not Radioshack.


----------



## Xcalibur255 (Apr 19, 2021)

Slade01 said:


> My tube also bears the similar round logo proclaiming it to be a 6J5G (instead of the stop sign insignia).


The on glass logo can help with ID sometimes, but in my experience not that much.  It seems like a circular logo was the standard in the beginning and manufacturers gradually moved to the stop sign logo over time, but they all did it at different points in time.  National Union basically kept using the circle for as long as they made tubes.  Very old Sylvania tubes from the 20's and 30's are circle logo, but once you hit WWII they switch to octagon.  Same with Tung-Sol only I think the transition happens a bit earlier with them in the late 30's.  RCA, on the other hand I think might have come out of the gate using the octagon.  There are really old tubes that have circle logos but these were actually made by Cunningham for RCA in the late 20's and early 30's.  The only brand that continued to use a circle logo into the 50's was CBS/Hytron I think.  Philco had both because the generally tended to be re-brands so they'd pick up the style of the real manufacturer.    I think Ken-Rad changed when GE took ownership of them so only their early tubes were circle logo.

That's just what I recall off the top of my head based on what I've seen over the years.


----------



## Slade01

Xcalibur255 said:


> Arcturus is a wild card, and I don't know much about them.  Some of the biggest unicorns in the tube world (mesh plate blue glass stuff) are Arcturus, along with Taylor, Cunningham and other brands that all vanished after WWII or in the lead up to it.  Speaking purely in terms of name coolness I have to say I'm a fan of Arcturus.  It's not Super Air Castle cool, but it's still cool.


Yeah - ever since I saw @gibosi 's logo of the blue type 126 as pictured on his profile pic i've been interested in the Arcturus Brand.  Yeah - not as cool sounding as Super Air Castle...but the original Arcturus logo and box branding design is really cool to me.



Xcalibur255 said:


> The on glass logo can help with ID sometimes, but in my experience not that much.  It seems like a circular logo was the standard in the beginning and manufacturers gradually moved to the stop sign logo over time, but they all did it at different points in time.  National Union basically kept using the circle for as long as they made tubes.  Very old Sylvania tubes from the 20's and 30's are circle logo, but once you hit WWII they switch to octagon.  Same with Tung-Sol only I think the transition happens a bit earlier with them in the late 30's.  RCA, on the other hand I think might have come out of the gate using the octagon.  There are really old tubes that have circle logos but these were actually made by Cunningham for RCA in the late 20's and early 30's.  The only brand that continued to use a circle logo into the 50's was CBS/Hytron I think.  Philco had both because the generally tended to be re-brands so they'd pick up the style of the real manufacturer.    I think Ken-Rad changed when GE took ownership of them so only their early tubes were circle logo.
> 
> That's just what I recall off the top of my head based on what I've seen over the years.


Yeah - I figured that the circular logo was more or less used in the beginning and over time changed over to the octagon design.  Interesting to know that NU always used it for the entire time they were around.  I also know that WW2 also really scrambled the whole tube ecosystem for demand-manufacturing/rebranding.  

Arcturus definitely had cool branding.  Then wonder if the tube pictured on the right below is a rebrand or not.  Though the left one also - the font and lettering is similar to other metal tubes i have so who knows.   Forever a mystery I suppose but i guess that is par for the course for a unicorn company.


----------



## mordy (Apr 19, 2021)

I am sure that the tubes in those light blue boxes aren't original Arcturus tubes but rebrands.
The original Arcturus boxes were very pretty:



Here is a good reference about the Arcturus history: 

 https://www.antiqueradios.com/forums/viewtopic.php?t=152508
Arcturus was established in the 20's and made tubes with blue glass as a gimmick. The company went bankrupt in the early 40's. Afterwards the brand continued under different ownership as a distributor up til 1952 when the owner died. In 1959 people bought the right to the Arcturus name and sold rebranded tubes under that name. Most likely the light blue box pictured above is from the post 1959 era.


----------



## mordy

Also want to add that many times there are letters/numbers/symbols engraved on the ring at the base of the metal tube. Sometimes this, as well as the exact shape of the metal envelope, can give you a clue to the manufacturer, but admittedly it is difficult to confirm when you cannot see the internal construction.
I have a Tung Sol 12SN7 BGRP rebranded as Arcturus as well as a couple genuine Arcturus 6N7G tubes - the internal construction is unique.


----------



## Slade01

mordy said:


> I am sure that the tubes in those light blue boxes aren't original Arcturus tubes but rebrands.
> The original Arcturus boxes were very pretty:
> 
> Here is a good reference about the Arcturus history:  https://www.antiqueradios.com/forums/viewtopic.php?t=152508
> Arcturus was established in the 20's and made tubes with blue glass as a gimmick. The company went bankrupt in the early 40's. Afterwards the brand continued under different ownership as a distributor up til 1952 when the owner died. In 1959 people bought the right to the Arcturus name and sold rebranded tubes under that name. Most likely the light blue box pictured above is from the post 1959 era.


Yeah - love the original box design (observatory).    I just actually now noticed in my picture.....on the plain Arcturus tube I have on the right pictured, the octagon symbol has breaks and a big fat dot at the top/edge.  I remember this  being an RCA trademark to signify date code?  Maybe its an RCA?


----------



## whirlwind

I have these Arcturus 6J5G tubes...originally thought they may be Sylvania's....not so sure now.


----------



## therremans

whirlwind said:


> I have these Arcturus 6J5G tubes...originally thought they may be Sylvania's....not so sure now.


I think RCA or NU. Sylvania is of a different construction.


----------



## mordy

therremans said:


> I think RCA or NU. Sylvania is of a different construction.


Are there any codes on the tubes? Not that it will help lol because I don't think that there is any information on the Arcturus coding, but there is the possibility that these tubes are made by Arcturus and not rebranded.
My guess is that if they were made before the early to mid 40's they could have been made by Arcturus.

Just checked several different listings on eBay old and current and can't find anything that looks like the Arcturus.


----------



## whirlwind

mordy said:


> Are there any codes on the tubes? Not that it will help lol because I don't think that there is any information on the Arcturus coding, but there is the possibility that these tubes are made by Arcturus and not rebranded.
> My guess is that if they were made before the early to mid 40's they could have been made by Arcturus.
> 
> Just checked several different listings on eBay old and current and can't find anything that looks like the Arcturus.


S
A 

 This is all that is on the tubes other than the Arcturus name and I am not even positive the top letter is S for sure as it is a bit worn.


----------



## mordy

whirlwind said:


> S
> A
> 
> This is all that is on the tubes other than the Arcturus name and I am not even positive the top letter is S for sure as it is a bit worn.


Nobody is going to contradict me on this lol - we just don't know, but here is an uneducated guess. Let's guess that the first letter is the month and the second the year. Going down the alphabet from Jan - Dec and skipping the letter I because it looks like 1, we end up with A through M. Starting again from N through Z  S represents May.
Make the A 1940 and SA = May 1940. 
I have a 6N7G Arcturus in the original observatory box:




The x-shaped micas are unique. The date code is N 4
                                                                                R 4
Using the same formula as above, N = January and R = 1938. The truth is that R does not fit into the system, but 4 + 4 = 8. This tube came out in 1936 och Arcturus went bankrupt around 1942 so somewhere in the middle sound about right. I am pretty sure that this is not a rebranded tube because of the mica shape which I could not find elsewhere with 6N7G tubes.

But this is a 6C5 etc thread so back to that. Here is a 6C5MG AirCastle tube which I am sure was made by Arcturus in their Coronet series:



The display stand is included in the price.
https://www.ebay.com/itm/Aircastle-...976022?hash=item217cfe8616:g:sDYAAOSwKwZfqFg-

PS: Please don't take my dating excercise seriously - only intended as a humorous attempt to decipher the unknown.


----------



## Velozity

For anyone curious what the inside of their ST-shaped gray glass L63 looks like but doesn't want to sacrifice a tube to find out, I present to you the somewhat rare clear glass version.


----------



## whirlwind

Nice....thanks for the pics.


----------



## leftside (Apr 25, 2021)

Been a while since I posted any pictures.


----------



## chrisdrop

leftside said:


> Been a while since I posted any pictures.


Love the original boxes for these. That is one area where I've not always had such good luck - getting perfect original boxes.


----------



## leftside

chrisdrop said:


> Love the original boxes for these. That is one area where I've not always had such good luck - getting perfect original boxes.


Most of my tubes don't have the original boxes - maybe 10% - 20%. And if they do have the boxes, I tend not to use the tubes and keep them preserved as historical artifacts.

I'll see what other 6J5/L63/etc I have with boxes and post up a pic. I think I have a 6J5 family of GEC/Marconi variation 1/Marconi variation 2/Osram. I think it would be very difficult to collect a "complete set" due to the amount of Marconi and Osram label differences. Then there are all the military versions as well... Even my OCD said "stop - enough is enough" . Same with the KT66 tubes. Funnily enough, there just seems to be two different GEC labels for the KT88 tubes - thankfully!! But, there are multiple construction variations...


----------



## OctavianH

Guys, anyone compared the brown glass Fivre 6C5G from Langrex with black glass Fivre 6C5G? Any difference? How do those sound?
I might make an order to Langrex and I was thinking to grab a pair, I have no idea which one. Many thanks in advance.
I have at the moment only GEC L63 grey glass black base and clear glass brown base and I want to extend a little bit the collection.


----------



## chrisdrop

OctavianH said:


> Guys, anyone compared the brown glass Fivre 6C5G from Langrex with black glass Fivre 6C5G? Any difference? How do those sound?
> I might make an order to Langrex and I was thinking to grab a pair, I have no idea which one. Many thanks in advance.
> I have at the moment only GEC L63 grey glass black base and clear glass brown base and I want to extend a little bit the collection.


Hey @OctavianH - hope all is well. Looks like you are enjoying tube/amp-land well these days!

Unfortunately, I've not compared black/brown. I have the black ones only and I like them. I think I like them > the Fivre metal base 6J5GTs FYG.

YMMV, etc.


----------



## OctavianH

chrisdrop said:


> Hey @OctavianH - hope all is well. Looks like you are enjoying tube/amp-land well these days!
> 
> Unfortunately, I've not compared black/brown. I have the black ones only and I like them. I think I like them > the Fivre metal base 6J5GTs FYG.
> 
> YMMV, etc.



Yes, I have some new land to explore and this gives me additional excitement and energy. If I remember correctly what you wrote at that time about the Fivre metal base 6J5GT you mentioned those are quite bright and I think you compared them with C3g. Are these black base ones in the same category? Just an idea, for me GEC L63 brown base clear glass is warm, full bodied.


----------



## chrisdrop

The metal base 6J5GT in the GOTL at least was lacking some "oomph" in the lower end or warmth in general perhaps. That said, perhaps I was too aggressive in saying they were C3G-like. In the Blue Halo, they are a bit more balanced/good. The GEC L63 brown-base tubes are not so much warm IMO, maybe a touch, but they are nicely bodied as you say. Does your current amp have CCS or not? My GOTL didn't have CCS in it and the Blue Halo does. It makes a difference in how I've interpreted these tubes. Many older comments come from the GOTL, more recently on the Blue Halo. I can tailor comments a bit better if I understand CCS/no-CCS and I can guess/extrapolate to your current listening environment. Perhaps you have one of those amps where you change the settings to be biased for each tube and so on?


----------



## OctavianH

As far as I know my amp does not have CCS, but I am able to bias it manually. Not per tube, but per stage (this means all outputs or all inputs). To be able to bias closely a pair, I usually find a medium value for the grid bias voltage in order for a tube to achieve a specific desired current level and adjust it. I come from the "auto-bias" world, so this mechanism is something new for me. But I learn.


----------



## raindownthunda

chrisdrop said:


> The metal base 6J5GT in the GOTL at least was lacking some "oomph" in the lower end or warmth in general perhaps. That said, perhaps I was too aggressive in saying they were C3G-like. In the Blue Halo, they are a bit more balanced/good. The GEC L63 brown-base tubes are not so much warm IMO, maybe a touch, but they are nicely bodied as you say. Does your current amp have CCS or not? My GOTL didn't have CCS in it and the Blue Halo does. It makes a difference in how I've interpreted these tubes. Many older comments come from the GOTL, more recently on the Blue Halo. I can tailor comments a bit better if I understand CCS/no-CCS and I can guess/extrapolate to your current listening environment. Perhaps you have one of those amps where you change the settings to be biased for each tube and so on?


Hey @chrisdrop have you had a chance to compare the Fivre 6C5G shouldered vs straight tubes? I'm a huge fan of the Five 6C5G shouldered tubes and was wondering if it would a redundant purchase and or if you prefer one over the other.


----------



## leftside

In general I find 6C5 and 76 to have a lighter and more airy sound than 6J5 with my amp and gear


----------



## triod750 (Apr 29, 2021)

leftside said:


> In general I find 6C5 and 76 to have a lighter and more airy sound than 6J5 with my amp and gear


I have almost zero experience with 6J5/6C5. They are new territory for me. I have only listened to a pair of 'Brimar' branded 6J5GT/G mentioned previously, and now one JAN-CRC-6C5, one JAN-CKR-6C5, these two 6C5 as a pair, and just swapped the Ken-Rad for a 6J5G 'S.T.C. 101' 10 E/348 supposed to be Brimar. My impression with this is contrary to leftsides; the 6C5 is meatier than 6J5/6J5G. Might be the Ken-Rad? As I said - zero experience. Just wanted to share that zero experience. Thats is where you all started.
I have three meatball JAN-CRC-6C5 so I will do a proper session with them later. Just mixing and unmatching right now. The 6J5G was a gift from the person that sold me the 6C5. It had a broken key. That sounds 'orrible. Have to find another.

This is how it looks but I will not buy this. I want another as cheap as the first one: https://www.ebay.co.uk/itm/265017950134?hash=item3db44cffb6:g:SdoAAOSwiAZgBJ49


----------



## OctavianH (Apr 30, 2021)

chrisdrop said:


> Does your current amp have CCS or not?



I think my answer from yesterday was not correct, so I had to ask and come back with a proper answer. I have to admit that I am no expert in tube amp design and I just scratch the surface. I use at the moment an amplifier made by UltraSonic Studios, I have asked and found that it does have a couple of CCSs inside as well as the grid drivers are CCS loaded. When I answered yesterday I was thinking at a previous discussion when he told me my amp will not have the CCS tail of the other designs.

I think I'll have to read more from The Valve Wizard!


----------



## chrisdrop

OctavianH said:


> I think my answer from yesterday was not correct, so I had to ask and come back with a proper answer. I have to admit that I am no expert in tube amp design and I just scratch the surface. I use at the moment an amplifier made by UltraSonic Studios, I have asked and found that it does have a couple of CCSs inside as well as the grid drivers are CCS loaded. When I answered yesterday I was thinking at a previous discussion when he told me my amp will not have the CCS tail of the other designs.
> 
> I think I'll have to read more from The Valve Wizard!


Cheers @OctavianH. I'm no expert either. I'm regurgitating chats elsewhere on this topic and some personal experiences. I've done some tracking along of the UltraSonic amps and it looks like you guys are having fun. 

I think that if your amp has CCS, tubes of the same type will be closer together (i.e.; BrandA 6j5g vs BrandB 6j5g) . Significant differences will be harder to discern. The difference across tube types (i.e.; 6c5 v 6j5) will be bigger. 

Given that there are other adjustments you can make on your amp it is hard for me to say, however! My default personal position has been "get moar toobz!!". But lately, I've had less urge to roll and more desire to let the same tubes sit and listen! 

I'd say to audio-quiz yourself; if you take 2 tubes (or pairs of tubesin these single triode's case) of the same type but different brands. See if you can tell a significant difference between two. If you can, then keep exploring, if you can't, do the same experiment across tube types (6c5 vs 6j5). I assume that will be more discernable, but who knows! If you can detect a material difference between 2 tubes of the same type and different brands, keep goinging until you can't! (or you run out of tube money ).

-Chris


----------



## OctavianH

Yep, you're right. Thinking more I think I'll go for a pair of Cossor 6C5G and just let others discover the mysteries of the Fivre.


----------



## leftside

OctavianH said:


> Yep, you're right. Thinking more I think I'll go for a pair of Cossor 6C5G and just let others discover the mysteries of the Fivre.


I grabbed a pair of Cossor 6C5G from Langrex. Very fine tubes. I already had the Fivre brown and black base, otherwise I would have grabbed those as well. I can't tell any difference between the two Fivre's in my 1101 Audio (CCS based) amp.


----------



## OctavianH

leftside said:


> I grabbed a pair of Cossor 6C5G from Langrex. Very fine tubes. I already had the Fivre brown and black base, otherwise I would have grabbed those as well. I can't tell any difference between the two Fivre's in my 1101 Audio (CCS based) amp.



I have bought a quad of Cossor 6C5G because the stock was low and I do not want to regret this in the future. I bought also backup for GEC L63 grey glass, those are maybe the best drivers I have heard in my life. I renounced on Fivre since I expect them to be brighter and not as good. But I might try them at a later date, can you compare them to something I know? Maybe GEC L63 brown base straight clear glass?


----------



## leftside

OctavianH said:


> I have bought a quad of Cossor 6C5G because the stock was low and I do not want to regret this in the future. I bought also backup for GEC L63 grey glass, those are maybe the best drivers I have heard in my life. I renounced on Fivre since I expect them to be brighter and not as good. But I might try them at a later date, can you compare them to something I know? Maybe GEC L63 brown base straight clear glass?


With Cossor, Fivre and GEC I think you have a lot of bases covered. Fivre are some of my favorite tubes, but I guess it all depends on the rest of your system and music tastes. I'd say grab the Fivres while you can, because before Langrex stumbled upon this large stash, they were very hard to find.


----------



## OctavianH

leftside said:


> With Cossor, Fivre and GEC I think you have a lot of bases covered. Fivre are some of my favorite tubes, but I guess it all depends on the rest of your system and music tastes. I'd say grab the Fivres while you can, because before Langrex stumbled upon this large stash, they were very hard to find.



Then ok, I bought 2 pairs (one brown and one black). Let's see. I'll compare them! 

The only Fivre I have are a pair of 6N7G and those are exceptional.


----------



## SHIMACM

leftside said:


> With Cossor, Fivre and GEC I think you have a lot of bases covered. Fivre are some of my favorite tubes, but I guess it all depends on the rest of your system and music tastes. I'd say grab the Fivres while you can, because before Langrex stumbled upon this large stash, they were very hard to find.



I have Fivre 6c5g. I'm interested in Cossor. How do they compare?


----------



## whirlwind

OctavianH said:


> I have bought a quad of Cossor 6C5G because the stock was low and I do not want to regret this in the future. I bought also backup for GEC L63 grey glass, those are maybe the best drivers I have heard in my life. I renounced on Fivre since I expect them to be brighter and not as good. But I might try them at a later date, can you compare them to something I know? Maybe GEC L63 brown base straight clear glass?


Congrats and congrats on the extra pair GEC L63...they indeed are very good sounding drivers.

Your CCS load will sound great with 6J5GT drivers also....I like most metal based 6J5GT and can be found cheap if patient.


----------



## SHIMACM

Guys help me there. Are these GEC?


----------



## chrisdrop

SHIMACM said:


> Guys help me there. Are these GEC?


The bottom pic sure looks like they are MOV L63s. I assume all pics are the same tubes. I can’t say if they are GEC or Osram etc but I have tubes that look like these, the lettering is just clearer.


----------



## OctavianH

These look the same as my GEC L63 grey glass bought from here.


----------



## SHIMACM

Thank you guys! The construction is identical. As it was reasonably priced, I decided to buy it.


----------



## CAJames

So, I was feeling like I haven't spent enough money on tubes lately and came across the 7193 aka 2C22 aka CV6 which looks like a 6J5 with external connections for the grid and plate:

7193

Anyone ever tried one? Any thoughts?


----------



## therremans

CAJames said:


> So, I was feeling like I haven't spent enough money on tubes lately and came across the 7193 aka 2C22 aka CV6 which looks like a 6J5 with external connections for the grid and plate:
> 
> 7193
> 
> Anyone ever tried one? Any thoughts?


I tried the National Union and Ken-Rad version. These were the main producers I think. I haven’t tried any from EU. But, I preferred the sound from the National Unions and sold off the Ken-Rads.


----------



## CAJames

Decided to pass on the 7193s cuz I didn't want YAA (Yet Another Adapter) and didn't want to mess with 8 external connections. So I got a lovely matched quad of black base National Union 6J5GTs:





And even with just a couple hours on them they sound fantastic! Probably better than even the GEC L63s, my previous fav. They are detailed, fast and extended and have just a touch of seductive sweetness that sets them apart from the GECs. Also less than half the price says my Scottish Heritage.


----------



## Monsterzero

CAJames said:


> Decided to pass on the 7193s cuz I didn't want YAA (Yet Another Adapter) and didn't want to mess with 8 external connections. So I got a lovely matched quad of black base National Union 6J5GTs:
> 
> 
> 
> And even with just a couple hours on them they sound fantastic! Probably better than even the GEC L63s, my previous fav. They are detailed, fast and extended and have just a touch of seductive sweetness that sets them apart from the GECs. Also less than half the price says my Scottish Heritage.


Did National Union make 6J5s or are these a rebrand?


----------



## CAJames

Good question. I sorta assumed these were like one half of the highly regarded NU 6SN7, but I can't say for sure.


----------



## therremans (May 8, 2021)

Monsterzero said:


> Did National Union make 6J5s or are these a rebrand?


From my understanding, they made them. You can find them fairly easily. National Union liked using round plates for many of their designs.


----------



## Marutks (May 8, 2021)

Awesome,   I didnt know NU 6SN7 is highly regarded.
I have a NU 6SN7 and a pair of 6J5.    Here are all three of them.










They are still burning in  ( just plugged into my Blue Halo OTL amp ).


----------



## leftside

I've yet to see a 6J5 that isn't highly regarded  I think because most of them were made before 6SN7, and if we agree (not always true of course) that "earlier is better" when it comes to tubes, then this is probably the reason.


----------



## whirlwind

leftside said:


> I've yet to see a 6J5 that isn't highly regarded  I think because most of them were made before 6SN7, and if we agree (not always true of course) that "earlier is better" when it comes to tubes, then this is probably the reason.


Yep.


----------



## tintinsnowydog

The NU 6J5s sound awesome, and I'm pretty certain they made them too. Construction wise it's difficult to see inside the grey/black glass 6SN7s, but my ears tell me they are doing very similar things- in my experience, the 6J5s sound closer to the black glass.


----------



## whirlwind

Monsterzero said:


> Did National Union make 6J5s or are these a rebrand?


@Monsterzero  here are some NU 12J5GT for pretty cheap...military grade too
https://www.ebay.com/itm/133188931766?hash=item1f02add0b6:g:PxMAAOSwYxxdk4LV


----------



## tintinsnowydog (May 9, 2021)

Some new 6J5 tubes have landed with me recently after quite a while in transit! The highlight for me is this pair of RFT 6J5- really incredible soundstage, tone and detailed presentation. For some reason I had built up the expectation in my head that these would be bright (perhaps thinking Telefunken sound), but they are effortlessly detailed and airy up top without any unnecessary emphasis or harshness.  They are a little more forward even than the grey glass L63s with exceptional bass response and smoothness across the board. One of my new favourite 6J5s!





Also these very sleek looking Mazda/Neotron 6J5MG. I'm still deciding if they sound the same.. They are very midrange focused tubes with tastefully rolled off bass and treble, which would be great for enhancing any vocal-centric music


----------



## CAJames

Marutks said:


> Awesome,   I didnt know NU 6SN7 is highly regarded.
> I have a NU 6SN7 and a pair of 6J5.    Here are all three of them.
> 
> 
> ...



Nice. I've been using a NU gray glass 12SN7 in my phono stage for a while. It is what started my romance with NU.


----------



## Monsterzero

whirlwind said:


> @Monsterzero  here are some NU 12J5GT for pretty cheap...military grade too
> https://www.ebay.com/itm/133188931766?hash=item1f02add0b6:g:PxMAAOSwYxxdk4LV


Thank you. Grabbed a pair.


----------



## leftside

Family of L63/6J5. All the same construction. There are quite a few more sticker variations out there...


----------



## Monsterzero

Thats some serious tube porn right there.


----------



## jonathan c

leftside said:


> Family of L63/6J5. All the same construction. There are quite a few more sticker variations out there...


The guards at Tubeingham Palace?....


----------



## CAJames

Monsterzero said:


> Thats some serious tube porn right there.


It should come with a warning label.


----------



## Tom-s

leftside said:


> Family of L63/6J5. All the same construction. There are quite a few more sticker variations out there...


The center pair are STC / Brimar bases on build. Not GEC. But I think you knew that


----------



## leftside (May 10, 2021)

Tom-s said:


> The center pair are STC / Brimar bases on build. Not GEC. But I think you knew that


Good eye @Tom-s! You've made me go and check all my MOV tubes, and indeed they are the only ones with that type of construction. But, they don't look like any of my Brimars. I'll share a few photos here.


----------



## leftside (May 10, 2021)

Here is a better photo of the construction of the "GEC"/Brimar tube. I've never seen a tube with GEC sticker, box and date codes not be a GEC.... but just goes to show only the construction tells the truth.


----------



## leftside (May 10, 2021)

Here are Brimars that I have. O getter and D getter in first photo. Brown and black base in second (although difficult to see in photo)

The center micas are the same as the tube from above with the round holes in the micas diagonally opposite each other.


----------



## leftside

And here are some Mullard tubes I think... labelled Marconi.


----------



## Xcalibur255

We have a growing body of evidence that shows re-branding to be prolific for the 6J5 tube, especially the British ones.

I see two Brimars and three Mullards across all five sets of photos.  The first tube labeled GEC is the more common construction variant of the Brimar with both micas being round.  The second tube with the rectangular top mica is a less common variant of the Brimar in my experience.


----------



## leftside

Xcalibur255 said:


> We have a growing body of evidence that shows re-branding to be prolific for the 6J5 tube, especially the British ones.
> 
> I see two Brimars and three Mullards across all five sets of photos.  The first tube labeled GEC is the more common construction variant of the Brimar with both micas being round.  The second tube with the rectangular top mica is a less common variant of the Brimar in my experience.


I tend to agree. I never stop learning coming on this forum.


----------



## leftside

Think these all also Mullards then?


----------



## Tom-s

@leftside Yes they very much are. Note the factory code KB/T With T indicating Mullard Tottenham.

Here's an overview photo of some Brimar build types. See the similarities across the 6J5 / 6SN7 family?



GEC and Mullard tend to follow the same similarities from one tube type to another.

First, a tube is recognized upon build type, second factory code, further print and other details.

For the tube codes on the Mullard codes, consult: https://frank.pocnet.net/other/Philips/PhilipsCodeListAB.pdf


----------



## leftside

Tom-s said:


> @leftside Yes they very much are. Note the factory code KB/T With T indicating Mullard Tottenham.
> 
> Here's an overview photo of some Brimar build types. See the similarities across the 6J5 / 6SN7 family?
> 
> ...


I'm usually pretty good with GEC and Mullard tubes. The "GEC" tube from above has a factory code of "22". This should have made me question the tube, as I'm unaware of any GEC/MOV factory that had that code. 

I did see the KB/T Tottenham on the Mullard tube, but after being thrown by the "GEC" tube I guess I'm not in a trusting mood today of the print on the tubes! 

I have a bunch of Brimar 6C5, metal base 6J5GT and and also 6SN7's that I'll check later today. Some of the 6SN7's have black glass so are difficult to see through, but the others should be fine.

Man you've got my OCD on overdrive today.


----------



## Xcalibur255 (May 10, 2021)

leftside said:


> Think these all also Mullards then?


I believe so yes.  Not only does the construction look the same but the KB marking is a Mullard factory code marking.

edit:  I see Tom answered definitively already.  Always good to have a consensus.


----------



## tintinsnowydog

Any additional history on which factories the non-rebranded Brimar tubes were made at? I tend to distinguish Brimar tubes by their use of round plates which is quite rare among other brands/factories. Those round plate, round mica Brimars look similar to the STC labelled CV1067 I have which I believe to be Brimar-made tubes.

The above 6J5G/CV1932 tubes labelled KB/T from the Tottenham factory have internal constructions identical to a pair of metal base, Philips branded Mullard 6J5GT I have with similar date codes. H.E suggests May 1952 production. I think the Tottenham factory 6J5s can reliably be distinguished by the 'spiked' top mica.

The Marconi branded pair of Mullard 6J5G with date codes UG1 J5G also indicates they are from the Tottenham factory, with UG1 being the 'change code', J indicating Tottenham, 5= 1955, G = July. A little hard to tell from the pictures, but @leftside is the internal construction on the Marconi pair and the CV1932 KB/T labelled pair similar?


----------



## leftside

tintinsnowydog said:


> Any additional history on which factories the non-rebranded Brimar tubes were made at? I tend to distinguish Brimar tubes by their use of round plates which is quite rare among other brands/factories. Those round plate, round mica Brimars look similar to the STC labelled CV1067 I have which I believe to be Brimar-made tubes.
> 
> The above 6J5G/CV1932 tubes labelled KB/T from the Tottenham factory have internal constructions identical to a pair of metal base, Philips branded Mullard 6J5GT I have with similar date codes. H.E suggests May 1952 production. I think the Tottenham factory 6J5s can reliably be distinguished by the 'spiked' top mica.
> 
> The Marconi branded pair of Mullard 6J5G with date codes UG1 J5G also indicates they are from the Tottenham factory, with UG1 being the 'change code', J indicating Tottenham, 5= 1955, G = July. A little hard to tell from the pictures, but @leftside is the internal construction on the Marconi pair and the CV1932 KB/T labelled pair similar?


I'm not really a good source of info for Brimar tubes I'm afraid. Over the last few years I've focused on GEC and Mullard/Philips. I do believe that STC and Brimar might be the same company or had very close ties? I have a pair of Brimar 6SN7 black glass with 'STC' and 'Brimar" printed on the glass.

Yes HE = May 1952. 

'UG' is actually the Philips identifier for 6J5G tubes. '1' is the change code. Yes 'J' = Mullard Tottenham (used to be the Tungsram factory).


----------



## leftside

Here's a few more. I believe these are Mullard. D getter.


----------



## leftside

I believe these are also Mullard? Foil getter.


----------



## leftside

More Mullard:


----------



## leftside (May 10, 2021)

How about these?  All printed 'Mullard 6J5GT British Made'


----------



## leftside

And to finish the pictures this evening with some more tube porn. A few US tubes tomorrow.


----------



## Xcalibur255 (May 10, 2021)

leftside said:


> I believe these are also Mullard? Foil getter.


This one's quite interesting.  I think the Mullard tubes have those extra support rods quite consistently and they're absent here.  We have a notably different bottom mica which looks like it was design for those extra support straps you often see on the RCA/GE models, but the supports themselves are not here.  The grid posts are copper too, Mullard tubes typically use steel here.

It actually looks a lot like a Ken-Rad to my eyes, but I would not go so far as to suggest it is one because there is no evidence that Ken-Rad tubes were ever exported and re-branded during the time Ken-Rad was actually making these.


----------



## Xcalibur255

Also, man there is some tube porn being posted here today!  

I'm increasingly of the opinion that when it comes to 6J5 the motto should be "don't worry be happy" as long as you like the sound and they match.  The amount of cross-branding on these tubes is crazy.  It is fun to try and figure it out though.


----------



## leftside

Xcalibur255 said:


> This one's quite interesting.  I think the Mullard tubes have those extra support rods quite consistently and they're absent here.  We have a notably different bottom mica which looks like it was design for those extra support straps you often see on the RCA/GE models, but the supports themselves are not here.  The grid posts are copper too, Mullard tubes typically use steel here.
> 
> It actually looks a lot like a Ken-Rad to my eyes, but I would not go so far as to suggest it is one because there is no evidence that Ken-Rad tubes were ever exported and re-branded during the time Ken-Rad was actually making these.


Boom! You nailed it. I also took photos of my US metal base tubes and indeed this is the same construction as KenRad. Will post up the photos tomorrow.


----------



## whirlwind

Awesome tube pron @leftside 

At some point I need to add a pair of Mullard 6J5G


----------



## Tom-s

leftside said:


> How about these?  All printed 'Mullard 6J5GT British Made'


For me. This would be. 
Mullard. Brimar. Sylvania.


----------



## whirlwind

Tom-s said:


> For me. This would be.
> Mullard. Brimar. Sylvania.



I can see that....love the extra support rods on all of those Mullards....sexy!


----------



## triod750

leftside said:


> I believe these are also Mullard? Foil getter.


My 'Brimar' 6J5GT/G that I have posted about previously look to my uneducated eye the same as these. They seem to have some kind of bottom getter on the same side as the foil. This can also be seen in one of the links to that bay that I posted previously. They are marked  with white lettering and numbers inside on the pinched glass structure. The one I am looking at now says A43. (I'm sorry, I haven't found my Kodak Instamatic yet)

The orange lettering on the glass rubs easily off. It says Brimar BVA. To the left of this you find 10 and below 10 you find 1. To the left of 1 is a 4. It's not 41. Some letters above Brimar has almost totally rubbed of. The metal base is corroded. The remnants of the text on it is also orange.

A photo says more than a thousand words...


----------



## leftside

Xcalibur255 said:


> This one's quite interesting.  I think the Mullard tubes have those extra support rods quite consistently and they're absent here.  We have a notably different bottom mica which looks like it was design for those extra support straps you often see on the RCA/GE models, but the supports themselves are not here.  The grid posts are copper too, Mullard tubes typically use steel here.
> 
> It actually looks a lot like a Ken-Rad to my eyes, but I would not go so far as to suggest it is one because there is no evidence that Ken-Rad tubes were ever exported and re-branded during the time Ken-Rad was actually making these.


Same as KenRad. KenRad making tubes for Brimar....


----------



## leftside

Tom-s said:


> For me. This would be.
> Mullard. Brimar. Sylvania.


I wasn't sure about the tube on the far right. So here we have another US manufacturer, in this case Sylvania making a tube for Mullard... And here's a Sylvania tube marked Sylvania (same construction as the Sylvania/"Mullard" from above).


----------



## leftside

triod750 said:


> My 'Brimar' 6J5GT/G that I have posted about previously look to my uneducated eye the same as these. They seem to have some kind of bottom getter on the same side as the foil. This can also be seen in one of the links to that bay that I posted previously. They are marked  with white lettering and numbers inside on the pinched glass structure. The one I am looking at now says A43. (I'm sorry, I haven't found my Kodak Instamatic yet)
> 
> The orange lettering on the glass rubs easily off. It says Brimar BVA. To the left of this you find 10 and below 10 you find 1. To the left of 1 is a 4. It's not 41. Some letters above Brimar has almost totally rubbed of. The metal base is corroded. The remnants of the text on it is also orange.
> 
> A photo says more than a thousand words...


If your "Brimars" are identical to these, then they are also actually KenRad manufactured. Good tubes btw.


----------



## triod750

leftside said:


> If your "Brimars" are identical to these, then they are also actually KenRad manufactured. Good tubes btw.


They look the same or very similar. Do these have a sheet metal bottom getter with a wart on it? Any lettering on the pinched glass innards?

Now the question is; who made these for Ken-Rad? (I seem to remember that one of the auctions I linked to previously was a Ken-Rad and the other a Brimar).


----------



## leftside

triod750 said:


> They look the same or very similar. Do these have a sheet metal bottom getter with a wart on it?


Yes - foil getter. You can just about make it out in the pics. I'll check for any lettering, but can't remember seeing any.


----------



## Xcalibur255

There's a decent chance that Ken-Rad would be the actual manufacturer, but it's difficult to call this one.  This would be around the time when GE took ownership of them, but the manufacturing didn't change overnight it happened over time.  It would be either Ken-Rad or GE most likely, and looking at some GE tubes to compare for similarities might help shed light on it further.

I don't have a Ken-Rad in my collection yet so I can't give it the ear test.  Would be curious to know if they have the same warm bassy sound as the Ken-Rad black glass 6SN7s do.

One thing I've noticed is that the metal bases on the Ken-Rads always look terrible.  For some reason they seem more susceptible to corrosion than other 6J5 tubes.  Maybe a different grade of material or missing a coating that other manufacturers used?


----------



## leftside

TungSol? Nope - looks like a Sylvania.


----------



## leftside

TungSol? Maybe...


----------



## leftside

Raytheon? Maybe...


----------



## leftside (May 11, 2021)

Perhaps these are all Raytheon? And not TungSol? I think that's all I have with the US 6J5's.

I have quite a few European 6J5: Sicte, Neotron, Fivre, Visseaux, Mazda and multiple construction variations, but that discussion of "who made who" can wait for another time.


----------



## triod750

leftside said:


> Raytheon? Maybe...


That getter looks like the one in my 'Brimar'.

The 'Made in USA' or 'Made in England' on the metal bases maybe only tells you where the bases have been made . No fraud then.


----------



## leftside (May 11, 2021)

triod750 said:


> That getter looks like the one in my 'Brimar'.
> 
> The 'Made in USA' or 'Made in England' on the metal bases maybe only tells you where the bases have been made . No fraud then.


A lot of the early tubes manufactured used that type of getter. At least if it has that getter type you can tell the tube is "very old" no matter who manufactured it 

I'm inclined to think those really are Raytheon in the pictures I posted, as the mica construction at the top is the same as on the larger 6J5G Raytheon tubes. And which is why I think those 6J5G TungSol are really Raytheon, but of course I could be wrong.


----------



## triod750

You mean Raytungsoltheon, don't you?


----------



## whirlwind

This thread just flat out rocks 


Xcalibur255 said:


> There's a decent chance that Ken-Rad would be the actual manufacturer, but it's difficult to call this one.  This would be around the time when GE took ownership of them, but the manufacturing didn't change overnight it happened over time.
> 
> I don't have a Ken-Rad in my collection yet so I can't give it the ear test.  Would be curious to know if they have the same warm bassy sound as the Ken-Rad black glass 6SN7s do.


You are reading my mind....the Ken -Rads are a hole in my collection and if the bass is anything close to similar with the black glass  or any Ken Rad staggered plate 6/12 SN7
Then I want a pair or two


----------



## Xcalibur255

leftside said:


> TungSol? Maybe...


Definitely Tung-Sols, and they sound super good.


----------



## Xcalibur255

leftside said:


> Perhaps these are all Raytheon? And not TungSol? I think that's all I have with the US 6J5's.
> 
> I have quite a few European 6J5: Sicte, Neotron, Fivre, Visseaux, Mazda and multiple construction variations, but that discussion of "who made who" can wait for another time.


I can't believe you have so many different brandings of the same tube here.  I honestly don't know how to call this one anymore.  I asserted a few weeks ago that I personally didn't think this Raytheon, but honestly I don't know anymore.  I've seen this exact construction style on more than a *dozen* different branding variations now, it may not be possible to actually nail it down.

I will say I was pretty confident that my own Raytheon tubes are Raytheon made.  Not 100% but fairly close.  They are just more closely aligned with similar construction techniques you can see in many other types of Raytheons from the same period (late 30's).


----------



## Xcalibur255

leftside said:


> Raytheon? Maybe...


I actually think this is a real Raytheon GT tube here.  They use this mica style in their 6SN7s and others in the late 50's and early 60's, and you can see an extra hole for the optional extra support rod they put in the military spec versions which is a classic Raytheon design element.


----------



## whirlwind

Xcalibur255 said:


> There's a decent chance that Ken-Rad would be the actual manufacturer, but it's difficult to call this one.  This would be around the time when GE took ownership of them, but the manufacturing didn't change overnight it happened over time.  It would be either Ken-Rad or GE most likely, and looking at some GE tubes to compare for similarities might help shed light on it further.
> 
> I don't have a Ken-Rad in my collection yet so I can't give it the ear test.  Would be curious to know if they have the same warm bassy sound as the Ken-Rad black glass 6SN7s do.
> 
> One thing I've noticed is that the metal bases on the Ken-Rads always look terrible.  For some reason they seem more susceptible to corrosion than other 6J5 tubes.  Maybe a different grade of material or missing a coating that other manufacturers used?


 It is one of the reasons that I don't own any yet, all the metal bases look like they came from the scrap pile    
I have seen some with nice test results, just too unpleasing to the eye!
I think you are probably right, bad materials used or something.

I have seen a few 12J5GT Ken Rad , but don't own any.


----------



## Marutks

This is military spec version of Raytheon I guess.  It has two extra support rods and top getter.


----------



## Monsterzero

I have the rusty KenRad 6J5s and they have the same bass as their younger brothers.

On an entirely different topic, does anyone have a source for the Zenith 6 or 12j5 that are shown in the Google spreadsheet?


----------



## tintinsnowydog

The first image is from this post, but I have not seen any for sale that look similar. Very nice looking tubes! Would expect them to sound very similar to the Sylvania 6J5GT which are more readily available. https://www.head-fi.org/threads/the-reference-6j5-thread-l63-6c5-12j5-6p5-etc.934653/post-15726050

Lots of pics to add to the doc thanks to leftside's awesome contributions!


----------



## Monsterzero

Oh, I have a plethora of Sylvania tubes, which I adore with the VC, hence my interest in the Zenith counterpart, but none look like those tubes....and yes, theyre very nice looking.


----------



## chrisdrop

leftside said:


> Yes - foil getter. You can just about make it out in the pics. I'll check for any lettering, but can't remember seeing any.


I think I can say on our collective behalf; @leftside - you have a pretty beautiful and fantastic 6J5+Friends tube collection. I'm quite certain the total scope of your tube collection is museum-worthy. Pristine, boxed, gorgeous!


----------



## leftside

chrisdrop said:


> I think I can say on our collective behalf; @leftside - you have a pretty beautiful and fantastic 6J5+Friends tube collection. I'm quite certain the total scope of your tube collection is museum-worthy. Pristine, boxed, gorgeous!


Thanks @chrisdrop. Only a few original boxes though, and some of those tubes have seen better days I think. Hopefully folks found the pics interesting and informative. I certainly learnt a few things the last couple of days - especially all the rebranding by the manufacturers. Taking the photos and posting on here has helped me identify all the posted tubes - so thanks to all for the informative identification comments.

I can post up pics of the Euros if people are interested? And then there's the 6C5s....


----------



## maxpudding (May 12, 2021)

leftside said:


> Thanks @chrisdrop. Only a few original boxes though, and some of those tubes have seen better days I think. Hopefully folks found the pics interesting and informative. I certainly learnt a few things the last couple of days - especially all the rebranding by the manufacturers. Taking the photos and posting on here has helped me identify all the posted tubes - so thanks to all for the informative identification comments.
> 
> I can post up pics of the Euros if people are interested? And then there's the 6C5s....



Thank you for all the hard work @leftside!

Please post pics of the European tubes AND the 6C5s too  It has certainly been a joy to read through all the information offered by the members here


----------



## Xcalibur255

@Monsterzero 

The Zeniths will always be a re-brand, so I wouldn't recommend specifically looking for one if you're looking for a flavor for rolling.  They seem to most commonly be Sylvanias, but not always.


----------



## Monsterzero

Yeah I kind of figured that, but I have yet to see that glass type on any Sylvania, so I figured it might be a "Zenith-only" design.


----------



## Xcalibur255

I have a Zenith that's definitely not a Sylvania.  I identified it as a Raytheon, but as we're all learning here it's actually pretty tough to be 100% sure.


----------



## PsilocybinCube

@Deyan adapters for the win.


----------



## leftside

PsilocybinCube said:


> @Deyan adapters for the win.


Brimars?


----------



## PsilocybinCube

leftside said:


> Brimars?


Good eye!  Yes (and no) to Brimar.  One is a Brimar.  The other is a Calverton that is identical to the Brimar in construction but was purchased for cheap on ebay.  I was on the hunt for similar construction without the Brimar name and found it.  They pair really well with the Verite Open and Chatham 6as7g.  

As has been mentioned, the Brits played fast and loose with their branding back in the day.


----------



## tintinsnowydog (May 17, 2021)

leftside said:


> And to finish the pictures this evening with some more tube porn. A few US tubes tomorrow.


In an attempt to complement this superb photo, here are all the designs of the brown base L63/CV1067 I have. They sure knew how to make pretty labels!



Something interesting I noticed is the two main types of construction on MOV L63 tubes. All the brown base clear glass L63 I have have the 'half' plate construction, best seen on the rightmost tube above. However, in all L63 tubes which have grey glass, and those with metal skirts, or both grey and metal, they seem to have the full, symmetrical plates.




A picture of clear glass L63 that were for sale a while ago, the only MOV L63 like this I have seen so far, that show the plates of metal skirt L63 which are otherwise grey glass.


Two versions of the B65/36 also exist; brown base clear glass, and metal base grey or clear glass. From what I have found, the plate structures of the brown base tubes correspond directly, but I lack a metal base B65/36 to inspect closely myself and confirm. The top mica construction however is clearly different between my metal and brown base L63.

The brown base B36 has the exact same internals as the brown base L63, with the top mica adapted to fit two triodes. Moreover, it seems from date codes that the metal base grey glass, symmetrical plates L63 are an older iteration; hard to see in the picture below, but it is HE/4= May 1952. The B36 with code LM/4 = December 1955  has new construction. I haven't seen any metal base with newer date codes, or brown base with older date codes as of yet. So I believe the change in construction occurred somewhere between 1952-55. If anyone has any L63 with date codes J or K to fill in the missing years, that would narrow it down even further!




B36 from 1955, L63 from 1956 and L63 from 1952.



Top mica positioning and heater spaces 'diagonal' opposing for the brown base B36 (left). Asymmetrical and larger holes in top mica on brown base L63 (centre) vs. completely symmetrical mica and smaller holes on metal base L63 (right).



A pair of brown base B65 for sale on ebay right now with identical micas, getter and plates to the brown base B36.

Further searching for past sales, it seems only the clear glass(!) B65/B36 (2nd from left) has a symmetrical top mica and plate orientation as per the metal base L63; the grey glass metal base B65/36s have the same top mica construction as the brown base B65/36 and L63.





So now I'm wondering; perhaps the grey glass B65s actually have asymmetrical plates hidden inside them?


----------



## leftside

tintinsnowydog said:


> In an attempt to complement this superb photo, here are all the designs of the brown base L63/CV1067 I have. They sure knew how to make pretty labels!
> 
> Something interesting I noticed is the two main types of construction on MOV L63 tubes. All the brown base clear glass L63 I have have the 'half' plate construction, best seen on the rightmost tube above. However, in all L63 tubes which have grey glass, and those with metal skirts, or both grey and metal, they seem to have the full, symmetrical plates.
> 
> ...


Very nice! I will read again properly later today. There was also a year/month when they switched from inverted cup getter to D getter (around 1958 I think), and from D getter to O getter (late 60's - when only making brown base/tall glass with O getter).


----------



## Xcalibur255

@tintinsnowydog

My B65 looks like this:









Unfortunately the top mica and plates are almost impossible to photograph because so much getter has burned off and re-deposited at the top of the glass.  This tube has probably seen several thousand hours of operation before it passed into my hands.  From what I can see my mica looks different than any of the ones you can see clearly in your photos.  The slots are angled differently and the heat radiator fins are mounted differently.  The glass coating is thick enough on this tube that it's hard to see the plates, but from the outline I can see the plates appear symmetrical on this one.


----------



## leftside (May 19, 2021)

tintinsnowydog said:


> Something interesting I noticed is the two main types of construction on MOV L63 tubes. All the brown base clear glass L63 I have have the 'half' plate construction, best seen on the rightmost tube above. However, in all L63 tubes which have grey glass, and those with metal skirts, or both grey and metal, they seem to have the full, symmetrical plates.
> 
> 
> 
> ...


1. "Something interesting I noticed is the two main types of construction on MOV L63 tubes. All the brown base clear glass L63 I have have the 'half' plate construction, best seen on the rightmost tube above. However, in all L63 tubes which have grey glass, and those with metal skirts, or both grey and metal, they seem to have the full, symmetrical plates.". 
- Good point!

2. "A picture of clear glass L63 that were for sale a while ago, the only MOV L63 like this I have seen so far, that show the plates of metal skirt L63 which are otherwise grey glass.". 
- I think it was me who grabbed those. But now I'm thinking they might be Mullards! Check out the support rods.

3. "Two versions of the B65/36 also exist; brown base clear glass, and metal base grey or clear glass". 
- Also black base grey glass. I have a few B65 UK and Holland black base grey glass with Marconi lettering.

4. "I lack a metal base B65/36 to inspect closely myself and confirm".
- I have metal base B65 and B36. Construction tends to be the same if the year of manufacture is the same. Ie beginning of 1952 (H) = cup getter, later in the year = D getter. (I have two grey glass black base B36 H date coded tubes - each with different getter type) I also have metal base Osram stickered B36 with cup getter and D getter. I need to check mica construction again.

5. "So I believe the change in construction occurred somewhere between 1952-55. If anyone has any L63 with date codes J or K to fill in the missing years, that would narrow it down even further!" I think it was June 1952 (see above) but I would need to double check. Disclaimer: GEC/MOV have been known to mix and match tubes with whatever parts they could find! For example, I have a GEC 6AS7G with a D getter. Most have a cup getter.


----------



## whirlwind (May 19, 2021)

Here is my B36 metal base...not very good pics however



This is a d getter.


----------



## Tom-s

Not a 6J5 but a tube worth mentioning. I posted about this one in the Bottlehead Crack thread.

The 6J5 was developed somewhere in 1936. Somewhere in 1937 a pair of 6J5G's was placed in a single envelope and the 6F8G was first registered Sept 24 1937.

This was the first double triode (with separate cathodes) and popular in these places. It's successor, introduced in 1939 as the 6SN7, is even more popular.

The Sylvania shown here is from Oktober (J) 1937 (7) and has an engraved (hot stamped) base (Sylvania went to their yellow silk screen mid 1938).

It must be one of the first 6F8G's ever to be mass produced and has a unique build. It uses the round anode construction seen in some military Sylvania 6J5GT (VT-94D).

My later Sylvania 6F8G and VT-99 (WWII era tubes)  all have T plates with grid cooling above the top mica.

This is the only 6F8G in my collection that predates any 6SN7.

Here's a recent post with the single Sylvania 6J5GT's with a similar round anode build.

Here's a topic with explanation for Sylvania date codes.
Oh, and here's how to figure out RCA date codes.

Enough for the history lesson. It sounds great. Haven't compared it yet to other 6F8G's yet. Here's some pictures (while in use).


----------



## Slade01

Tom-s said:


> Not a 6J5 but a tube worth mentioning. I posted about this one in the Bottlehead Crack thread.
> 
> The 6J5 was developed somewhere in 1936. Somewhere in 1937 a pair of 6J5G's was placed in a single envelope and the 6F8G was first registered Sept 24 1937.
> 
> ...



The engraved based and font lettering is insane/cool, i've never seen it until now.  Thank you very much for sharing!


----------



## Marutks

tintinsnowydog said:


> Two versions of the B65/36 also exist; brown base clear glass, and metal base grey or clear glass. From what I have found, the plate structures of the brown base tubes correspond directly, but I lack a metal base B65/36 to inspect closely myself and confirm.



I have got metal base GEC B36.   The internal structure seems to be identical to brown base Osram B36.


----------



## mordy

Tom-s said:


> Not a 6J5 but a tube worth mentioning. I posted about this one in the Bottlehead Crack thread.
> 
> The 6J5 was developed somewhere in 1936. Somewhere in 1937 a pair of 6J5G's was placed in a single envelope and the 6F8G was first registered Sept 24 1937.
> 
> ...


There is another similar tube with the same pinout that predates the 6F8G with a couple of months - the 6C8G (Jan 21, 1937). It is a double triode but the heater current is 0.3A compared to 0.6A for the 6F8G.
IMHO the sound is similar as I recall, and the prices are much lower - it is not as well known as the 6F8G.


----------



## tubebuyer2020

mordy said:


> There is another similar tube with the same pinout that predates the 6F8G with a couple of months - the 6C8G (Jan 21, 1937). It is a double triode but the heater current is 0.3A compared to 0.6A for the 6F8G.
> IMHO the sound is similar as I recall, and the prices are much lower - it is not as well known as the 6F8G.



Also, the 6C8G tends to be confused with some sort of a 6SL7 predecessor for some weird reason 🤷‍♂️ - despite having a twice smaller amplification factor.


----------



## Tom-s

mordy said:


> There is another similar tube with the same pinout that predates the 6F8G with a couple of months - the 6C8G (Jan 21, 1937). It is a double triode but the heater current is 0.3A compared to 0.6A for the 6F8G.
> IMHO the sound is similar as I recall, and the prices are much lower - it is not as well known as the 6F8G.



Thanks @mordy; for this.

They don't only sound similar. They were also build very similar. Could have been the same production line on a different day. Most of my 6F8G and 6C8G look alike when from the same manufacturer.

Here's an example from a National Union tube type 6F8G and 6C8G. Both carry the same base (with date code 1U) and very much similar internal construction.
And here's a link to a 6J5 with a similar internal structure: http://www.r-type.org/exhib/aaa0074.htm



tubebuyer2020 said:


> Also, the 6C8G tends to be confused with some sort of a 6SL7 predecessor for some weird reason 🤷‍♂️ - despite having a twice smaller amplification factor.



It's somewhat in between SN7 and SL7 but could have well been the predecessor of the 6SL7. The 26 (->27 -> 37 -> 76 ->) was the predecessor of the 6J5 despite being a very much different tube (with half the gain).


----------



## mordy

Tom-s said:


> Thanks @mordy; for this.
> 
> They don't only sound similar. They were also build very similar. Could have been the same production line on a different day. Most of my 6F8G and 6C8G look alike when from the same manufacturer.
> 
> ...


Based on some National Union tubes that I have, I think that the date code IU is June 1945.


----------



## triod750 (May 23, 2021)

mordy said:


> Based on some National Union tubes that I have, I think that the date code IU is June 1945.


Well, @mordy, what does then 'EN' mean? Please? 6F8G.


----------



## mordy

triod750 said:


> Well, @mordy, what does then 'EN' mean? Please? 6F8G.


This is an educated guess regarding the month(s). The first letter is the year, and the second letter probably a sequence of months, perhaps a quarter of the year. It is possible that the second letter, designating the months, changed for different years.
E = 1941
N = possibly March /April/ May
Here is a list of the the first letters designating the year for National Union tubes from the 40's:
D =1940
E = 1941
F = 1942
G = 1943
H = 1944
I  = 1945
J  = 1946
Here is a source: https://audiokarma.org/forums/index.php?threads/1940s-national-union-date-codes.763037/


----------



## triod750

mordy said:


> This is an educated guess regarding the month(s). The first letter is the year, and the second letter probably a sequence of months, perhaps a quarter of the year. It is possible that the second letter, designating the months, changed for different years.
> E = 1941
> N = possibly March /April/ May
> Here is a list of the the first letters designating the year for National Union tubes from the 40's:
> ...


Let's say May, so I will celebrate 60 years this month. I wish I was that young!


----------



## tubebuyer2020

Tom-s said:


> It's somewhat in between SN7 and SL7 but could have well been the predecessor of the 6SL7. The 26 (->27 -> 37 -> 76 ->) was the predecessor of the 6J5 despite being a very much different tube (with half the gain).



Maybe, but I doubt it. I mean take 12AU7, 12AV7, 12AY7, 12AX7, 12AT7 - all are just different tubes with different amplification factors serving their purposes.

If I had to nominate a tube to be a predecessor of 6SL7 it would be 6F5G, it's a single triode but it has an amplification factor of 100 like 12AX7.


----------



## Velozity (May 25, 2021)

The GEC L63 sounds killer in any scenario.  Here's a fun setup I just put together to use on my work desk.  The L63 are almost worth more than everything else pictured, LOL (except the Fivre 6V6G power tubes of course).  This setup sounds waaaaaay better than I thought it would.  I'm going to have fun rolling 6J5 + 6V6 combos with this.  Shout out to @Deyan for the quick adapter work!


----------



## Slade01

Velozity said:


> The GEC L63 sounds killer in any scenario.  Here's a fun setup I just put together to use on my work desk.  The L63 are almost worth more than everything else pictured, LOL (except the Fivre 6V6G power tubes of course).  This setup sounds waaaaaay better than I thought it would.  I'm going to have fun rolling 6J5 + 6V6 combos with this.  Shout out to @Deyan for the quick adapter work!


I must say, that is the first time I've seen a car stereo repurposed like that - really creative - pretty freaking cool.   That looks like a fun setup for sure.


----------



## Velozity

Slade01 said:


> I must say, that is the first time I've seen a car stereo repurposed like that - really creative - pretty freaking cool.   That looks like a fun setup for sure.



Thanks!  I'm actually planning to make some wooden side and top panels to screw into the chassis of the Alpine.  That should take the coolness factor up a notch  .  It's been collecting dust in my garage for 5 years.  I think I only paid like $25 for it but it works great and gives me CD/AUX/iPod/FM.  It's being powered by an AC/DC adapter from an old cable box that happens to output 12V.  Perfect!


----------



## leftside

Visseaux family:


----------



## leftside

And their bigger brothers:


----------



## jonathan c

leftside said:


> And their bigger brothers:


They look like rival gangs: the Tubes and the Rubes from Left Side Story 😆....


----------



## leftside

jonathan c said:


> They look like rival gangs: the Tubes and the Rubes from Left Side Story 😆....


I wouldn't mess with the metal tubes


----------



## leftside

A few 6C5 tubes will the silver paint. As a Few others have mentioned, these are great tubes. Come up for sale cheaply but some patience is required.


----------



## mordy

At the present time I am exploring different 6V and 12V tubes of the 6C/J5 families backed up by a sextet of Melz 6N12S. The Melz tubes have exceptional clarity and instument separation.

A couple of observations: The internal construction of the 6J5GT tubes varies considerably, even from the same make.
There seems to be much more variation in the internal construction than other tube families I have tried.

I am using a Glenn OTL amp that can accomodate 12V tubes. One of the arguments for an amp that can use 12V tubes is that the 12V versions often are much less expensive than the 6V versions of the same tube. I was under the impression that a 12V version of a 6V tube from the same maker would sound the same, but I am finding that this is not the case at all. Many of the 12V version tubes have their individual sound compared to the 6V versions.
Perhaps this can be attributed to different internal construction - have to see if I can find something that has the same internal construction in 6 and 12V and from the same time period (not sure if I can accomplish this).


----------



## raindownthunda

I've been giving these "Italian RCA" ATES 6J5GT a go for the past few days.. From what I can tell, these are very similar sounding to the RCA 6J5 in all the best ways. Really enjoying them so far with the Chatham 6as7g (yesterday) and Chatham 6080WB currently in the tower-o-crack.





Here is a bit of information I found while researching ATES/RCA collaboration:
_"The company ATES was established in 1959 in Italy. The production started with the cooperation of RCA which was one of the major shareholders of ATES. Tubes made in the L’Aquila plant came out with the double marking RCA – ATES and were sold through RCA commercial channels. When, in the late sixties, RCA abandoned this market segment in Italy, Marconi bought the plant."_

Italian born tubes in RCA clothing:


----------



## mordy

Anybody tried these "Made In Holland" tubes?






Well, I was intrigued by these tubes - could they possibly have been made by Mullard-Philips? After some research,
however, my conclusion is that they are Russian 6S2S NEVS tubes - look at this picture:




I don't have any of the 6S2S these tubes - does anybody have experience with them?


----------



## Slade01

mordy said:


> Anybody tried these "Made In Holland" tubes?
> 
> 
> Well, I was intrigued by these tubes - could they possibly have been made by Mullard-Philips? After some research,
> ...



I agree with you.  I did the same research - I came across a pair of CEI "Made In Japan" 6J5s on ebay and they also look identical to the Nevs 6S2S.  As such the pair was selling for 40 dollars.  The NEVS pair (same as your picture) was 15.   

If they are like the Pinnacle 6J5s, @bcowen has them and likes them for certain genres I believe.


----------



## mordy

Slade01 said:


> I agree with you.  I did the same research - I came across a pair of CEI "Made In Japan" 6J5s on ebay and they also look identical to the Nevs 6S2S.  As such the pair was selling for 40 dollars.  The NEVS pair (same as your picture) was 15.
> 
> If they are like the Pinnacle 6J5s, @bcowen has them and likes them for certain genres I believe.


Pinnacle was a rebrander that often used Russian tubes so this is a good possibility.
It seems a little strange to me that there are fakes of these tubes which usually are not so much in demand and not super expensive.


----------



## maxpudding

I have the metal base 6S2S, sounds great when paired with warm power tubes


----------



## Slade01

mordy said:


> Pinnacle was a rebrander that often used Russian tubes so this is a good possibility.
> It seems a little strange to me that there are fakes of these tubes which usually are not so much in demand and not super expensive.


Very true.  I was surprised, as well.  I was hoping they were not fakes also, was curious to see what types of 6J5s came out of Japan if any as well, as I have had surprising tubes made from there with other tube types.  But Russians - even here they still use a bottom saucer getter...so its still the key give away.   I chalk it up to some company having too much stock and trying to sell it off anyway they can.


----------



## mordy

maxpudding said:


> I have the metal base 6S2S, sounds great when paired with warm power tubes


So far I have found two Russian factories that made the 6S2S - NEVS /Novosibirsk and Fonon (Foton?)


----------



## maxpudding (Jun 10, 2021)

mordy said:


> So far I have found two Russian factories that made the 6S2S - NEVS /Novosibirsk and Fonon (Foton?)



The metal base 6S2Ss that I have were manufactured by NEVS, and if the seller is correct, they were made in 1952/53


----------



## Marutks

mordy said:


> It seems a little strange to me that there are fakes of these tubes which usually are not so much in demand and not super expensive.



I think they were made for export purposes and "made in Holland" was stamped on them to avoid import restrictions (from USSR).


----------



## tintinsnowydog

I have a similar looking Russian tube with the British CV1934 label on it. This was previously sitting in a guy's warehouse for about 30 years in country Australia, so more evidence these are unlikely to be 'fakes'. It looks like 6J5 tubes were not only prominently rebranded but also imported.


----------



## triod750

Good - average - bad? Where does it belong?


----------



## bcowen (Jun 10, 2021)

Slade01 said:


> I agree with you.  I did the same research - I came across a pair of CEI "Made In Japan" 6J5s on ebay and they also look identical to the Nevs 6S2S.  As such the pair was selling for 40 dollars.  The NEVS pair (same as your picture) was 15.
> 
> If they are like the Pinnacle 6J5s, @bcowen has them and likes them for certain genres I believe.


Yup, I bought a dozen Pinnacles (for about $70 total) on a whim, and they are most definitely Russian with UFO getters.  Not sure of factory or vintage as I haven't really researched them.  I like them though!  Not an uber tube by any means, but overall a dynamic and punchy sound with full bass and an extended top end that never gets too hot.  Great for rock and metal, but missing some bloom and tubeliness in the mids when playing less raucous stuff. They are similar in stature (to me) as the Foton 6N8S -- not going to knock any top tier tube off its perch, but play very nicely for a cheap tube.


----------



## jonathan c

bcowen said:


> Yup, I bought a dozen Pinnacles (for about $70 total) on a whim, and they are most definitely Russian with UFO getters.  Not sure of factory or vintage as I haven't really researched them.  I like them though!  Not an uber tube by any means, but overall a dynamic and punchy sound with full bass and an extended top end that never gets too hot.  Great for rock and metal, but missing some bloom and tubeliness in the mids when playing less raucous stuff. They are similar in stature (to me) as the Foton 6N8S -- not going to knock any top tier tube off its perch, but play very nicely for a cheap tube.


Should we infer that you are a cheap tube dude?


----------



## maxpudding

jonathan c said:


> Should we infer that you are a cheap tube dude?



Finding good and cheap tubes is what this thread is about lol


----------



## jonathan c (Jun 10, 2021)

bcowen said:


> Yup, I bought a dozen Pinnacles (for about $70 total) on a whim, and they are most definitely Russian with UFO getters.  Not sure of factory or vintage as I haven't really researched them.  I like them though!  Not an uber tube by any means, but overall a dynamic and punchy sound with full bass and an extended top end that never gets too hot.  Great for rock and metal, but missing some bloom and tubeliness in the mids when playing less raucous stuff. They are similar in stature (to me) as the Foton 6N8S -- not going to knock any top tier tube off its perch, but play very nicely for a cheap tube.


Oddly enough, in golf the Pinnacles were a “distance” ball that were hard as stones - for many, they replaced the Top-Flites aka Rock-Flites. The Pinnacles went far, were no good for the short game, and felt like crap when putting....Did the tubes come three in a sleeve?


----------



## triod750

maxpudding said:


> Finding good and cheap tubes is what this thread is about lol


And when they are found, and written about, they will become expensive and good. And expensive. Make @bcowen an offer before this happens.


----------



## triod750

Did Philips make any 6J5GT? These were sold as such.


----------



## L0rdGwyn

triod750 said:


> Did Philips make any 6J5GT? These were sold as such.



Plate structure looks like Raytheon to me.


----------



## triod750

L0rdGwyn said:


> Plate structure looks like Raytheon to me.


This was the only photo unfortunately. I was outbid since I wasn't eager enough.
I lack knowledge and experience regarding 6J5.

What does the shape of the mica tell us, in combination with the plates?


----------



## bcowen

jonathan c said:


> Should we infer that you are a cheap tube dude?


Yes.


----------



## bcowen

jonathan c said:


> Oddly enough, in golf the Pinnacles were a “distance” ball that were hard as stones - for many, they replaced the Top-Flites aka Rock-Flites. The Pinnacles went far, were no good for the short game, and felt like crap when putting....Did the tubes come three in a sleeve?


No, but there were 12 in the shipping box when I opened it.  Does that count?


----------



## Slade01

mordy said:


> So far I have found two Russian factories that made the 6S2S - NEVS /Novosibirsk and Fonon (Foton?)



I just thought of your post as I am going through eBay right now.  There are sellers who make the distinction between foton and fonon.   There is a seller whom I bought from who is selling both types (6sn7 variant) that the tubes have different internal constructions...leads me to believe they are different. (I Could be wrong) but I had never heard of fonon until now either.


----------



## mordy (Jun 15, 2021)

I have one WIZARD 6J5GT where I cannot identify the manufacturer - maybe somebody can help with who made this tube?
Western Auto was a chain that sold Truetone radios among many other things. Their tubes were labeled WIZARD but apparently sourced from several different manufacturers.
The tube says Made In USA and has a code   -  perhaps March 1940/50?
_
P0



(Pardon the dust - Scotch tape has been around for a long time)



Copper rods




Very distinct type top mica with cutouts; the left side has a black metal band extending down and connecting to the plate. The black blotch on top is anode boil-off but only indicating a used tube and nothing to worry about.


----------



## Slade01

mordy said:


> I have one WIZARD 6J5GT where I cannot identify the manufacturer - maybe somebody can help with who made this tube?
> Western Auto was a chain that sold Truetone radios among many other things. Their tubes were labeled WIZARD but apparently sourced from several different manufacturers.
> The tube says Made In USA and has a code   -  perhaps March 1940/50?
> _
> ...



I am no expert but the only thing I'll throw out there for the experts to consider is that the only time i've seen that cut out mica is in the Ken Rad 6J5GT like the one pictured in the consolidated list.  However, it appears as the bottom mica, not the top:



I only realized this - I myself am trying to identify some unknown tubes as well that I just acquired which closely match these ken-rads.  But - I have never, however, seen them at the top like the wizards.  However, per usual - I could be completely off base.  But just an observation.


----------



## Slade01

I'll throw crazy into the mix.  take a look at these tubes below.  I'm guessing these are ken rads for sure.  I got that cut out mica but its on the bottom.  The craziness here is the black metal base.   The guy I got it from says he got them like that in a lot.   Either that is some bizzare manufacturing thing where they maybe used metal from what they use to produce the metal tin can 6j5s?   My more plausible take is that someone painted them to cover up the notorious ken-rad 6j5gt rust.   There is a faint code on the glass (F44?)- but no idea about it.  Since I don't have a pair of ken rads, no buyers remorse here, and they were very decently priced for matched and close to NOS testing tubes.  Hope they sound good....


----------



## mordy (Jun 16, 2021)

Slade01 said:


> I am no expert but the only thing I'll throw out there for the experts to consider is that the only time i've seen that cut out mica is in the Ken Rad 6J5GT like the one pictured in the consolidated list.  However, it appears as the bottom mica, not the top:
> 
> 
> 
> I only realized this - I myself am trying to identify some unknown tubes as well that I just acquired which closely match these ken-rads.  But - I have never, however, seen them at the top like the wizards.  However, per usual - I could be completely off base.  But just an observation.


I am looking and looking - only found one another tube in this family with the cut-out mica but it is a RCA 12J5GT 12V tube:



But it aint it....
I have seen these cutouts with other tubes (Visseaux) but they were European and the Wizard tube is US made. Here is a picture for reference but obviously a very different tube (6N7GT):


----------



## mordy

Slade01 said:


> I'll throw crazy into the mix.  take a look at these tubes below.  I'm guessing these are ken rads for sure.  I got that cut out mica but its on the bottom.  The craziness here is the black metal base.   The guy I got it from says he got them like that in a lot.   Either that is some bizzare manufacturing thing where they maybe used metal from what they use to produce the metal tin can 6j5s?   My more plausible take is that someone painted them to cover up the notorious ken-rad 6j5gt rust.   There is a faint code on the glass (F44?)- but no idea about it.  Since I don't have a pair of ken rads, no buyers remorse here, and they were very decently priced for matched and close to NOS testing tubes.  Hope they sound good....


I think that you are right - these bases may have been painted. Re the F44, perhaps it is VT-94D?
Maybe your tube looked like this before being painted?


----------



## Slade01

mordy said:


> I think that you are right - these bases may have been painted. Re the F44, perhaps it is VT-94D?
> Maybe your tube looked like this before being painted?



Yup.  This is exactly my thoughts as well!  Lol.  Well at least my mystery is more solvable.  Yours is definitely a stumper.


----------



## mordy

Slade01 said:


> Yup.  This is exactly my thoughts as well!  Lol.  Well at least my mystery is more solvable.  Yours is definitely a stumper.


I have full faith that the knowledgable Head-Fi members will come up with an answer. Maybe a 1940 Arcturus 6J5GT?
Just kidding, but they made a 6C5GT tube:


----------



## triod750

Slade01 said:


> I'll throw crazy into the mix.  take a look at these tubes below.  I'm guessing these are ken rads for sure.  I got that cut out mica but its on the bottom.  The craziness here is the black metal base.   The guy I got it from says he got them like that in a lot.   Either that is some bizzare manufacturing thing where they maybe used metal from what they use to produce the metal tin can 6j5s?   My more plausible take is that someone painted them to cover up the notorious ken-rad 6j5gt rust.   There is a faint code on the glass (F44?)- but no idea about it.  Since I don't have a pair of ken rads, no buyers remorse here, and they were very decently priced for matched and close to NOS testing tubes.  Hope they sound good....


They do look like my Brimar branded versions that we agreed upon being made by Ken-Rad. The code on the pinched glass part on mine is A43 (on the pair I am looking at right now).


----------



## mordy (Jun 16, 2021)

triod750 said:


> They do look like my Brimar branded versions that we agreed upon being made by Ken-Rad. The code on the pinched glass part on mine is A43 (on the pair I am looking at right now).


Well, if that is the case, F44 would be June 1944, and A43 January 1943. (This fits well with the late 40's GE date code system)
Ken-Rad was sold to GE in 1945, and GE continued to use the name Ken-Rad for a few years after that - it seems that the Ken-Rad name stopped being used in the very early 50's.
I think that the common GE factory code 188-5 refers to the Owensboro, Kentucky, old Ken-Rad factory. But don't look for the building today - it was torn down in 2007 and is now a park.


----------



## triod750

mordy said:


> Well, if that is the case, F44 would be June 1944, and A43 January 1943.


I've always been told that older is better .


----------



## mordy

chrisdrop said:


> Cheers @OctavianH. I'm no expert either. I'm regurgitating chats elsewhere on this topic and some personal experiences. I've done some tracking along of the UltraSonic amps and it looks like you guys are having fun.
> 
> I think that if your amp has CCS, tubes of the same type will be closer together (i.e.; BrandA 6j5g vs BrandB 6j5g) . Significant differences will be harder to discern. The difference across tube types (i.e.; 6c5 v 6j5) will be bigger.
> 
> ...


Or until you find that ideal elusive combinationt that you have been looking for for so long!
- And then that becomes the new normal and gets boring and the search goes on.....

It never ends....


----------



## mordy

Monsterzero said:


> Did National Union make 6J5s or are these a rebrand?


I am sure they were made by National Union. EU is a date code (not Europe lol) :
E = 1941
U = a quarter or sequence of months, maybe March, April, June or March-May


----------



## tintinsnowydog

Been a bit quiet here lately! Received a big lot of metal cans recently and found some pretty rebranded tubes- I believe they're all RCA made, the Cossor is branded Ken Rad on the other side. 





And this little guy made it all the way to the Düsseldorf cinema


----------



## mordy

tintinsnowydog said:


> Been a bit quiet here lately! Received a big lot of metal cans recently and found some pretty rebranded tubes- I believe they're all RCA made, the Cossor is branded Ken Rad on the other side.
> 
> 
> 
> And this little guy made it all the way to the Düsseldorf cinema


It is my impression that a lot of these tubes were made by RCA and rebranded by many brands. It is also my impression that these tubes, that can be found with dates from 1937 up to the 70's, were mostly made a long time ago and more recent dates were printed on them, perhaps indicating a shipping date. It would be remarkable if the same tube was manufactured for several decades!
Now, some of these tubes have an embossed code on the ring at the base:



This 6J5 RCA tube has a date code printed 1-13 which maybe means March 1951. On the base ring it says 6J5 and then a code - C 5. Sometimes the hyphen is in a different position (C 3- as an example). The letter could mean a two month period and the position of the hyphen could indicate one or the other month; The number 5 possibly means 1945. In other words, there is a manufacturing date and a shipping date on the tube.
Some tubes have straight date codes, others encoded ones, even from the same year and month - perhaps military and civilian dates. In addition, only some tubes have the embossed codes. It is a real mystery maze....


----------



## mordy (Jul 2, 2021)

Just got a small lot of old 6J5GT tubes. Among them is this pair of Sylvania tubes with the same construction:



I have trouble dating them. The left tube is a 6J5GT that says LOM on the glass under the designation. Then there are two codes vertically:
2     5
0     0
9     5
The right tube says 6J5GT/G on the glass and has a vertical code T
                                                                                                        2

The tubes seem to be quite old. And they sound very good....

While I am at it - one more question: Also in this lot was a 6J5G Zenith tube with a vertical date code
N
2
1
What could it be?


----------



## Slade01

mordy said:


> Just got a small lot of old 6J5GT tubes. Among them is this pair of Sylvania tubes with the same construction:
> 
> I have trouble dating them. The left tube is a 6J5GT that says LOM on the glass under the designation. Then there are two codes vertically:
> 2     5
> ...


Im not sure about the codes...but i know about the logos -- the sylvania green leaf should be indicative of make in the 30s.  The Triangle flashing S logo used more in the 40s.  Allegedly green print (especially the flashing/triangle S logo) was designated for military.


----------



## whirlwind

Slade01 said:


> I'll throw crazy into the mix.  take a look at these tubes below.  I'm guessing these are ken rads for sure.  I got that cut out mica but its on the bottom.  The craziness here is the black metal base.   The guy I got it from says he got them like that in a lot.   Either that is some bizzare manufacturing thing where they maybe used metal from what they use to produce the metal tin can 6j5s?   My more plausible take is that someone painted them to cover up the notorious ken-rad 6j5gt rust.   There is a faint code on the glass (F44?)- but no idea about it.  Since I don't have a pair of ken rads, no buyers remorse here, and they were very decently priced for matched and close to NOS testing tubes.  Hope they sound good....



I just bought a NOS pair of Ken Rad 12J5GT with the exact same construction.
Nice sounding tubes.


----------



## mordy (Jul 27, 2021)

Just got a GM labeled tube 6J5G. I asume it was made for car radios. The date code is G 8 - perhaps July 1938 and made in the USA. The top mica is very distinct - cannot figure out who made it:







Any suggestions?
PS: Actually now found out that GM did make regular household radios, but it looks like they stopped around 1931:



Five years after the Dayton Fan and Motor Company began manufacturing radio parts and two years after building their first receivers, Charles Kettering, vice president of General Motors’ research organization, took over as company president, changing its name to the Day-Fan Electric Company. GM purchased Day-Fan in 1929 and created the General Motors Radio Corporation—51 percent of which was owned by GM and the other 49 percent by RCA, GE, and Westinghouse. Radio prices ranged from $130–$270, or $1933–$4014 when adjusted for inflation. But RCA, already battling the Department of Justice over monopolistic practices, raised the DOJ’s suspicions. By May 1930, an antitrust lawsuit was filed against General Motors Radio Corporation. The company was liquidated late the following year


----------



## Tom-s

The tube you have there could Raytheon. It’s from the 1930’s four pillar series. More often are these found in type 76.
This is based on the mica seen. The bottom mica should be round with a metal lip over it on the side of the support pin. 
The plate however is not typical four pillar style as these are usually large and round. This is similar to a 6J5 made by Sylvania. As is the round logo on the glass. Search for the metal base round plate 6J5GT Sylvania and it will show up on google.
I don’t have a close up picture of these at hand from my own collection. Here’s a 6 pictured with this mica.  As the four pillar Raytheon are harder to find. 
Search for date code information on both brands. Maybe this solves the riddle.


----------



## mordy

Scrolled though a bunch of pictures of 6J5G tubes: Raytheon, Sylvania, Zenith on Google Images.
I did find a single tube with the unusual top mica (the bottom mica is a very small rectangle) and this tube had the Zenith name on it.
http://zenithtuberadio.cricket/no_6..._shape_vacuum_tubes_4_valves_tested_6j5gt.php
Bottom picture third from the left:



I do not know if Sylvania and Zenith were separate companies or the same company in 1938.
The main thing is that it sounds good...


----------



## bcowen (Jul 27, 2021)

mordy said:


> Five years after the Dayton Fan and Motor Company began manufacturing radio parts and two years after building their first receivers, Charles Kettering, vice president of General Motors’ research organization, took over as company president, changing its name to the Day-Fan Electric Company. GM purchased Day-Fan in 1929 and created the General Motors Radio Corporation—51 percent of which was owned by GM and the other 49 percent by RCA, GE, and Westinghouse. Radio prices ranged from $130–$270, or $1933–$4014 when adjusted for inflation. But RCA, already battling the Department of Justice over monopolistic practices, raised the DOJ’s suspicions. By May 1930, an antitrust lawsuit was filed against General Motors Radio Corporation. The company was liquidated late the following year


Too bad GE wasn't liquidated instead.


----------



## mordy

mordy said:


> Scrolled though a bunch of pictures of 6J5G tubes: Raytheon, Sylvania, Zenith on Google Images.
> I did find a single tube with the unusual top mica (the bottom mica is a very small rectangle) and this tube had the Zenith name on it.
> http://zenithtuberadio.cricket/no_6..._shape_vacuum_tubes_4_valves_tested_6j5gt.php
> Bottom picture third from the left:
> ...


Did some more reading. Zenith was a hitech manufacturer of radios and ham equipment and invented a bunch of stuff, notable the ultimate coach potato gadget - the remote control.
Seems that Zenith did use Sylvania tubes among others. In any case, they did not manufacture their own tubes. Looked through pictures of Raytheon 6J5G but they all seem to have umbrella spoke top micas. Which leads us to another tube with a similar top mica that I have - the Arcturus 6N7G :



Close, but no cigar:



I enjoy the 6J5G and GT tubes - there is more variety in construction than any other tubes I know of.


----------



## CAJames

mordy said:


> Scrolled though a bunch of pictures of 6J5G tubes: Raytheon, Sylvania, Zenith on Google Images.
> I did find a single tube with the unusual top mica (the bottom mica is a very small rectangle) and this tube had the Zenith name on it.
> http://zenithtuberadio.cricket/no_6..._shape_vacuum_tubes_4_valves_tested_6j5gt.php
> Bottom picture third from the left:
> ...



Pretty sure Zenith and Sylvania were separate companies. Zenith made radios but I think they rebranded tubes. I have Zenith tubes that look like Sylvania and RCA, I wouldn't be surprised if they rebranded Raytheon as well.


----------



## Velozity

mordy said:


> Did some more reading. Zenith was a hitech manufacturer of radios and ham equipment and invented a bunch of stuff, notable the ultimate coach potato gadget - the remote control.
> Seems that Zenith did use Sylvania tubes among others. In any case, they did not manufacture their own tubes. Looked through pictures of Raytheon 6J5G but they all seem to have umbrella spoke top micas. Which leads us to another tube with a similar top mica that I have - the Arcturus 6N7G :
> 
> Close, but no cigar:
> ...




As Tim-S said I believe these are made by Raytheon.  And I'll just go ahead and let the cat out of the bag too, they are my favorite 6J5G/6C5G tube right now.  Yes even besting the GEC L63 and Brimar 6C5G.  I've been secretly hoarding _collecting_ them for a little while now, trying to match pairs.  Particularly I go for the oldest ones, with engraved bases.  These are from the mid-1930s.  Far as I can tell there are 3 or 4 styles.  All have the "X" shaped top mica, but some have either a round bottom mica or another "X" shaped bottom mica.  The plates are either flat ribbed-ladder round ribbed-ladder.  All of mine have round bottom micas, but I have both plate styles.  The bases are engraved Raytheon, Zenith, Philco, or GM.  I've also seen them labeled as Super Silvertone.  All are made by Raytheon to my knowledge.  Excellent tube and a sleeper for sure.  They have the bass of a Ken-Rad, the midrange of a GEC, and the treble of a Brimar.  Really well-balanced tube that I highly recommend.


----------



## leftside

Not a bad price for 6. Anyone from here grab them?
https://www.ebay.ca/itm/6x-6C5G-Philips-NOS-tube-Valve-/384328421799


----------



## mordy

leftside said:


> Not a bad price for 6. Anyone from here grab them?
> https://www.ebay.ca/itm/6x-6C5G-Philips-NOS-tube-Valve-/384328421799


You must have been referring to the beginning auction price - they sold for $41 each.


----------



## leftside

mordy said:


> You must have been referring to the beginning auction price - they sold for $41 each.


Beginning auction price was $1. I thought $41 each isn’t a bad price for these tubes? I’m not sure if they are available cheaper elsewhere? My apologies if someone out there is selling for cheaper.


----------



## mordy (Aug 23, 2021)

leftside said:


> Beginning auction price was $1. I thought $41 each isn’t a bad price for these tubes? I’m not sure if they are available cheaper elsewhere? My apologies if someone out there is selling for cheaper.


You may very well be right - just shows my own personal bias of not wanting to spend too much on tubes.
Just checked current prices - it is indeed a good deal compared to the jawdropping prices being asked!


----------



## leftside

mordy said:


> You may very well be right - just shows my own personal bias of not wanting to spend too much on tubes.
> Just checked current prices - it is indeed a good deal compared to the jawdropping prices being asked!


All good. I was hoping you'd found a secret stash somewhere that we could have taken advantage of


----------



## Monsterzero

leftside said:


> Not a bad price for 6. Anyone from here grab them?
> https://www.ebay.ca/itm/6x-6C5G-Philips-NOS-tube-Valve-/384328421799


Have you tried these in the TRP yet?


----------



## therremans (Aug 23, 2021)

yeah Raytheon, here’s a pair that I own.


----------



## leftside

Monsterzero said:


> Have you tried these in the TRP yet?


They won't work there. Just never ending different power tube variations...


----------



## Monsterzero

leftside said:


> They won't work there. Just never ending different power tube variations...


DOH! I thought those were the Philips EL51s you posted in the other forum...so anyways have you tried the EL51s in the TRP?

*sorry for derailing the thread


----------



## leftside

Monsterzero said:


> DOH! I thought those were the Philips EL51s you posted in the other forum...so anyways have you tried the EL51s in the TRP?
> 
> *sorry for derailing the thread


Yeah they are very good. Slightly warmer than the Tesla's. I see the same seller was selling those EL51's, and they went for about the same price as the 6C5 - which is also a good deal.


----------



## SHIMACM

therremans said:


> yeah Raytheon, here’s a pair that I own.



What did you think of these Raytheons compared to the TS 6j5g?


----------



## therremans

SHIMACM said:


> What did you think of these Raytheons compared to the TS 6j5g?


Tung sol VT-94A > Sylvania 6J5G > Raytheon 6J5G
(In my use)


----------



## mordy

therremans said:


> Tung sol VT-94A > Sylvania 6J5G > Raytheon 6J5G
> (In my use)


Every setup and preference is different. Personally, I prefer the Sylvania 6J5GT from the very early 50's. These are metal base tall tubes and I imagine that they sound better than the metal base Sylvania 6SN7W (only have black base Sylvania 6SN7W) - at a fraction of the price.


----------



## therremans (Aug 24, 2021)

mordy said:


> Every setup and preference is different. Personally, I prefer the Sylvania 6J5GT from the very early 50's. These are metal base tall tubes and I imagine that they sound better than the metal base Sylvania 6SN7W (only have black base Sylvania 6SN7W) - at a fraction of the price.


Ah yes, love those too. I have quite a few and one of those great bargains to be had in 6J5GTs (Gray plate version).

The tubes I listed were the coke bottle G variations and I wasn’t including the GTs. But yeah every amp and headphones alone make a dramatic difference in a tubes performance.

Also on the note of Tung Sols.. I can hear a difference between my civilian Tung Sol 6J5G and the VT-94a coke bottle. They do also have difference in build.


----------



## mordy

therremans said:


> Ah yes, love those too. I have quite a few and one of those great bargains to be had in 6J5GTs (Gray plate version).
> 
> The tubes I listed were the coke bottle G variations and I wasn’t including the GTs. But yeah every amp and headphones alone make a dramatic difference in a tubes performance.
> 
> Also on the note of Tung Sols.. I can hear a difference between my civilian Tung Sol 6J5G and the VT-94a coke bottle. They do also have difference in build.


I see that I got a little bit mixed up with the nomenclature. You listed VT-94A which is the same as 6J5G - didn't know that.
I was thinking it was a version of VT-94D which is the same as 6J5GT -tubular glass.
Then you have VT-94 which is the same as 6J5.
To add to the alphabeth soup there are also VT-94B and VT-94C but I don't know what  they are.


----------



## mordy

BTW, it took a huge amount of research to decode the VT designation. Finally, after hours and hours of research and inquiries and consulting obscure websites,  I discovered the elusive meaning:

*VT* is military speak for *V*acuum *T*ube.

There is even a Swedish variant of the 94D:


----------



## maxpudding

mordy said:


> *VT* is military speak for *V*acuum *T*ube.



Thanks Mordy for this info, I always wondered what VT was 😆


----------



## mordy

maxpudding said:


> Thanks Mordy for this info, I always wondered what VT was 😆


Too simple, eh?


----------



## maxpudding

mordy said:


> Too simple, eh?



Quite obvious when you think about it


----------



## SHIMACM

I have the Tung-Sol 6j5g (vt-94 a - (coca bottle and black base) and the Tung-Sol 6j5gt (vt-94-D - metal base).
To my ears, the Tung-Sol vt94-d sounds considerably better.

I believe they are older.


----------



## SHIMACM (Aug 25, 2021)

therremans said:


> Tung sol VT-94A > Sylvania 6J5G > Raytheon 6J5G
> (In my use)



Nice. These I will pass up.

I think my curiosity about valves is over for now. At least while I'm with Darkvoice.

I sold many of my valve drivers. Currently, I'm only with Foton 52/55/58. Melz 1578 59/69. Fivre 6c5g. GEC L63 (coca bottle). Tung-Sol 6j5g and 6j5gt.


----------



## SHIMACM

mordy said:


> Every setup and preference is different. Personally, I prefer the Sylvania 6J5GT from the very early 50's. These are metal base tall tubes and I imagine that they sound better than the metal base Sylvania 6SN7W (only have black base Sylvania 6SN7W) - at a fraction of the price.



I've had these Sylvania 6j5gt too.

But I ended up selling them too.

They really are pretty good, but they didn't make me fall in love like the other valves I listed above did.


----------



## mordy

SHIMACM said:


> Nice. These I will pass up.
> 
> I think my curiosity about valves is over for now. At least while I'm with Darkvoice.
> 
> I sold many of my valve drivers. Currently, I'm only with Foton 52/55/58. Melz 1578 59/69. Fivre 6c5g. GEC L63 (coca bottle). Tung-Sol 6j5g and 6j5gt.


Good company! As somebody who brought attention to the ladder plate Fotons (6H8C) , I was under the impression that they were made between 1952 and 1955. Is the1958 the same construction?


----------



## mordy

SHIMACM said:


> I have the Tung-Sol 6j5g (vt-94 a - (coca bottle and black base) and the Tung-Sol 6j5gt (vt-94-D - metal base).
> To my ears, the Tung-Sol vt94-d sounds considerably better.
> 
> I believe they are older.


The 6J5G (ST Coke bottle shape) tubes appeared first in 1936.
The 6J5GT (straight glass) appeared first in 1938.


----------



## SHIMACM

mordy said:


> Good company! As somebody who brought attention to the ladder plate Fotons (6H8C) , I was under the impression that they were made between 1952 and 1955. Is the1958 the same construction?



The 1958 Foton does not have ribbed plates. Ribbed plates, if I'm not mistaken, is until the year 1955. However, they also sound pretty good.


----------



## SHIMACM

mordy said:


> The 6J5G (ST Coke bottle shape) tubes appeared first in 1936.
> The 6J5GT (straight glass) appeared first in 1938.



Interesting. I thought that just because the 6j5gt had a metal base, they could be older. Anyway, thanks for the info.


----------



## mordy

SHIMACM said:


> Interesting. I thought that just because the 6j5gt had a metal base, they could be older. Anyway, thanks for the info.


All this information is in the Radiomuseum and it is very easy to access.
Just go to Google, type in Radiomuseum 6J5G and all the information is there.
https://www.radiomuseum.org/tubes/tube_6j5g.html
On the left, a couple of lines down, it says First Source and gives the year the tube was introduced.


----------



## bcowen

mordy said:


> Good company! As somebody who brought attention to the ladder plate Fotons (6H8C) , I was under the impression that they were made between 1952 and 1955. Is the1958 the same construction?


I have 1951 - 1956 ladder (ribbed) plates.  And I also have some 1956 smooth plates.  All my 1957 and later have smooth plates, so it appears that the plate configuration was changed sometime during 1956.  1951 is the earliest year I have (and have seen), but it's possible they were made before then too and I just haven't run across any.


----------



## leftside

Been a little quiet on here lately, so thought I’d post a pic. Not 6J5, but 6N7. I can use in my 6J5 sockets so does this count as a valid post?!  Both are French Philips, but obviously different boxes.

My new amp from Mishca/1101 Audio will also use these tubes as drivers. Hopefully next month…


----------



## Monsterzero

leftside said:


> Been a little quiet on here lately, so thought I’d post a pic. Not 6J5, but 6N7. I can use in my 6J5 sockets so does this count as a valid post?!  Both are French Philips, but obviously different boxes.
> 
> My new amp from Mishca/1101 Audio will also use these tubes as drivers. Hopefully next month…


I asked this question in the Glenn thread and never received a response, but what are the sonic differences or economic advantages, if any, between those and a J5?


----------



## leftside

Monsterzero said:


> I asked this question in the Glenn thread and never received a response, but what are the sonic differences or economic advantages, if any, between those and a J5?


More power with 6N7. The Fivre 6N7G see a lot of time in my amp. Combined with TungSol 5998 and things are rocking. In general I’d say 6J5 are cheaper, but it all depends on brand.


----------



## mordy

leftside said:


> More power with 6N7. The Fivre 6N7G see a lot of time in my amp. Combined with TungSol 5998 and things are rocking. In general I’d say 6J5 are cheaper, but it all depends on brand.


The 6N7 is a 0.8A dual triode - one tube is enough with an adapter for a 6SN7 socket.
The 6J5 is a 0.3A triode and you will need two of them so 0.6A vs 0.8A. 
The metal versions of these tube are still very inexpensive; glass GT straight glass versions can also be found at reasonable prices . The Shoulder type G versions cost more and especially the European made G/GT ones can be pricey.

In my personal experience I get better results with two triodes than one dual triode. I don't know why it is so; perhaps it is amplifier dependent (or maybe not).


----------



## leftside

mordy said:


> The 6N7 is a 0.8A dual triode - one tube is enough with an adapter for a 6SN7 socket.
> The 6J5 is a 0.3A triode and you will need two of them so 0.6A vs 0.8A.
> The metal versions of these tube are still very inexpensive; glass GT straight glass versions can also be found at reasonable prices . The Shoulder type G versions cost more and especially the European made G/GT ones can be pricey.
> 
> In my personal experience I get better results with two triodes than one dual triode. I don't know why it is so; perhaps it is amplifier dependent (or maybe not).


I use 2 6N7.





Yes agreed. All amp dependent and what tubes the amp was designed for.


----------



## tintinsnowydog

Anyone know of a place to get 90 degree octal socket savers/adapters? Have a friend wanting to use 6J5s in place of 6SN7 but their amp doesn't fit the adapter in the current configuration!


----------



## maxpudding

tintinsnowydog said:


> Anyone know of a place to get 90 degree octal socket savers/adapters? Have a friend wanting to use 6J5s in place of 6SN7 but their amp doesn't fit the adapter in the current configuration!


Maybe you could send a PM to @Deyan?


----------



## Deyan

maxpudding said:


> Maybe you could send a PM to @Deyan?


I also make rotating dual adapters.


----------



## triod750

One thing to remember regarding 6N7 is that it has a common cathode in spite of being a dual triode. I was going to try them as output tubes, substituting 6SN7 used as stacked triodes and ordered adapters for them. Then I read a reply from Glenn to someone else that this wasn't going to work, or so I interpreted what he wrote. I had to change my plan accordingly and used my 6N7 as input instead.


----------



## leftside

triod750 said:


> One thing to remember regarding 6N7 is that it has a common cathode in spite of being a dual triode. I was going to try them as output tubes, substituting 6SN7 used as stacked triodes and ordered adapters for them. Then I read a reply from Glenn to someone else that this wasn't going to work, or so I interpreted what he wrote. I had to change my plan accordingly and used my 6N7 as input instead.


The custom amp builders can make you an amp where you can use 6J5 or 6N7 in the same socket. This is what Mischa/1101 Audio did for me. He's also doing the same for me in my second amp from him. Coming soon.... (but with KT66/EL34/4654/etc instead of 5998/6080).


----------



## triod750

leftside said:


> The custom amp builders can make you an amp where you can use 6J5 or 6N7 in the same socket. This is what Mischa/1101 Audio did for me. He's also doing the same for me in my second amp from him. Coming soon.... (but with KT66/EL34/4654/etc instead of 5998/6080).


Custom amp builders can make wonderful things - I don't doubt that. Knowing your tubes is good anyway. I have a Tung-Sol black glass 6N7GT/G where I can barely see the plates with a strong light shining through the glass. The plates are probably 'flattish'. I cannot see a common cathode. It is difficult to see the '6N7GT/G' within some kind of octagon on the glass. The only lettering on the socket is Tung- Sol Made in USA. No date code or factory code. The glass is all black except for about 3mm just above the socket.


----------



## mordy

leftside said:


> The custom amp builders can make you an amp where you can use 6J5 or 6N7 in the same socket. This is what Mischa/1101 Audio did for me. He's also doing the same for me in my second amp from him. Coming soon.... (but with KT66/EL34/4654/etc instead of 5998/6080).


Are the 6N7 tubes wired as triodes in your amp?


----------



## A2029

mordy said:


> Are the 6N7 tubes wired as triodes in your amp?



They are wired as triode with both plates tied together and both grids tied together.


----------



## triod750

I just bought this. I wonder what is within it and how it performs?


----------



## bcowen

triod750 said:


> I just bought this. I wonder what is within it and how it performs?


A tube maybe?  Or possibly a Genie?  Did you rub it?      

(sorry)


----------



## triod750

bcowen said:


> A tube maybe?  Or possibly a Genie?  Did you rub it?
> 
> (sorry)


I haven't even received it. Neither have I paid for it yet. But that seller usually sends the tubes before payment.

No need to be sorry. I hope I won't be sad. I will try that metal robe on a Brimar 6J5G I have that has some hum. I had that for free from the same seller since the key pin was broken.


----------



## bcowen

triod750 said:


> I haven't even received it. Neither have I paid for it yet. But that seller usually sends the tubes before payment.
> 
> No need to be sorry. I hope I won't be sad. I will try that metal robe on a Brimar 6J5G I have that has some hum. I had that for free from the same seller since the key pin was broken.


I meant sorry for the lame joke.  Hope you get something cool!


----------



## jonathan c

triod750 said:


> I just bought this. I wonder what is within it and how it performs?


King Tubetankahmen?…


----------



## mordy

triod750 said:


> I just bought this. I wonder what is within it and how it performs?


From looking at pictures it should be possible to separate the shield in two halves after first taking off the top cap.
I have no idea why some sellers call it a goat shield.
It seems that some early 6C/J5G and 6J7G tubes employed these tube shields.


----------



## jonathan c

mordy said:


> From looking at pictures it should be possible to separate the shield in two halves after first taking off the top cap.
> I have no idea why some sellers call it a goat shield.
> It seems that some early 6C/J5G and 6J7G tubes employed these tube shields.


Goat was a brand name, a manufacturer of tube shields:


----------



## mordy

jonathan c said:


> Goat was a brand name, a manufacturer of tube shields:


Thanks for clarifying the name Goat Shield!


----------



## triod750

bcowen said:


> A tube maybe?  Or possibly a Genie?  Did you rub it?
> 
> (sorry)


I haven't even received it. Neither have I paid for it yet. But that seller usually sends the tubes before payment.

No need to be sorry. I hope I won't be sad. I will try that metal robe on a Brimar 6J5G I have that has some hum. I had that for free from the same seller since the key pin was broken.


bcowen said:


> I meant sorry for the lame joke.  Hope you get something cool!


Oh, you really should be sorry. But I'm cool and so are you. We're in it together, happy not to be lame ourselves...


----------



## PsilocybinCube

bcowen said:


> A tube maybe?  Or possibly a Genie?  Did you rub it?
> 
> (sorry)


Don't you know that touching vacuum tubes with your hands imparts oil on the tubes which greatly impacts the sound quality and makes amplifiers explode!!!!  Or at least that's what I was told on YouTube.


----------



## maxpudding

PsilocybinCube said:


> Don't you know that touching vacuum tubes with your hands imparts oil on the tubes which greatly impacts the sound quality and makes amplifiers explode!!!!  Or at least that's what I was told on YouTube.


Wear gloves whenever possible


----------



## triod750

PsilocybinCube said:


> Don't you know that touching vacuum tubes with your hands imparts oil on the tubes which greatly impacts the sound quality and makes amplifiers explode!!!!  Or at least that's what I was told on YouTube.


I will be selling metal robes for tubes to prevent this. I will start to take orders next week.


----------



## PsilocybinCube

maxpudding said:


> Wear gloves whenever possible


In all seriousness, I was joking...I don't think touching the tubes makes a difference, even with oily hands, right?  Everything I've ever read on the subject says that the issue is akin to 'snakeoil.'  Sorry for the pun.

Here's one example from Upscale Audio addressing the topic in their FAQ:  https://upscaleaudio.com/pages/tube-basics-and-frequently-asked-questions


----------



## maxpudding

PsilocybinCube said:


> In all seriousness, I was joking...I don't think touching the tubes makes a difference, even with oily hands, right?  Everything I've ever read on the subject says that the issue is akin to 'snakeoil.'  Sorry for the pun.
> 
> Here's one example from Upscale Audio addressing the topic in their FAQ:  https://upscaleaudio.com/pages/tube-basics-and-frequently-asked-questions



I was being sarcastic, but yeah, it's ridiculous and doesn't make sense at all.


----------



## jonathan c

maxpudding said:


> Wear gloves whenever possible


…plus: freshly disinfected white hazmat gear in a room irradiated with UV rays…


----------



## triod750

PsilocybinCube said:


> In all seriousness, I was joking..


You must be kidding?


----------



## PsilocybinCube

triod750 said:


> You must be kidding?


I was kidding about joking about being serious and trying to joke about the serious topic of oil on tubes.

That certainly clears it up!  Now...where are those gloves I changed my car's oil with...I have some hot tubes to swap on my amp...


----------



## therremans (Oct 4, 2021)

maxpudding said:


> Wear gloves whenever possible


Yes, just make sure they are lint free white gloves. 😅


----------



## mordy

PsilocybinCube said:


> Don't you know that touching vacuum tubes with your hands imparts oil on the tubes which greatly impacts the sound quality and makes amplifiers explode!!!!  Or at least that's what I was told on YouTube.


I think that there is such a concept as not to touch high temperature halogen bulbs for automotive use because the natural oils on the fingers can cause damage and breakage of such bulbs.
_What happens if you touch a halogen bulb with your fingers?







You should never touch a halogen light bulb with your bare hands. Sounds strange, doesn't it? Well, there is actually good reason to avoid contact with the surface of the bulb. *The oils on your fingers and skin can damage the quartz glass* which creates a hot spot on the surface of the bulb when illuminated._


----------



## triod750

I have read another explanation: The oils turns to gasses and damages the reflector with deposits.


----------



## therremans

triod750 said:


> I have read another explanation: The oils turns to gasses and damages the reflector with deposits.


Man, I have got to stop eating so much pepperoni.


----------



## PsilocybinCube

mordy said:


> I think that there is such a concept as not to touch high temperature halogen bulbs for automotive use because the natural oils on the fingers can cause damage and breakage of such bulbs.
> _What happens if you touch a halogen bulb with your fingers?
> 
> 
> ...


Very true on halogen!  Not so true on big thick vacuum tubes that can ride aboard an ICBM.


----------



## bcowen

therremans said:


> Yes, just make sure they are lint free white gloves. 😅


Preferably cryo treated ones, and if you're OCD, quantum-tunneled too.  And I shouldn't even have to say to be sure they are demagnetized first.  As we all know, the benefits of demagnetizing are _not_ limited to the aluminum layer in your CD's.


----------



## jonathan c

bcowen said:


> Preferably cryo treated ones, and if you're OCD, quantum-tunneled too.  And I shouldn't even have to say to be sure they are demagnetized first.  As we all know, the benefits of demagnetizing are _not_ limited to the aluminum layer in your CD's.


You _will _need the white gloves for handling your demagnetised Ortofon _Anna_ moving-coil cartridge 😄…


----------



## bcowen

jonathan c said:


> You _will _need the white gloves for handling your demagnetised Ortofon _Anna_ moving-coil cartridge 😄…


I'm a Koetsu man.  I have this on my Christmas list, and I've been (mostly) good all year.


----------



## triod750

If you sell your GE tubes you can buy that Koetsu and have plenty left.


----------



## bcowen

triod750 said:


> If you sell your GE tubes you can buy that Koetsu and have plenty left.


Perhaps, but I'd suddenly have a lot of enemies.


----------



## triod750

bcowen said:


> Perhaps, but I'd suddenly have a lot of enemies.


As you said - sorry for a lame joke. Deeply sorry.


----------



## jonathan c

triod750 said:


> If you sell your GE tubes you can buy that Koetsu and have plenty left.


The ultimate buyer’s remorse: a(ny) GE tube…


----------



## triod750

triod750 said:


> I just bought this. I wonder what is within it and how it performs?


I have received this tube now. I put the delivery on hold to combine shipping. It would be time now to reveal what is inside that metal costume. But this costume is soldered to one of the pins so the tube will stay where it is. I have decided that it is a state-of-the-art Turkish manufacture and the only one of its kind. It is warming up with another 6C5G of unknown origin that sounded very good with a Brimar branded Sylvania manufactured 6J5GT/G from June, 1944. This, bought as a single from the same seller, now has a pal manufactured in August that same year. 

I also received an AMERTY/Mullard branded 6J5GT/G with innards looking exactly like the Ken-Rad manufactured Brimar 6J5GT/G I previously have posted about. Hmmm - who might have made that?

And then another Brimar branded 6J5GT/G with plates similar to the Ken-Rad manufacture and round micas. Haven't got a clue so far. Will look for pictures.

And then some I already have forgotten . And a couple of Ken-Brimar-Rad 6J5GT/G.


----------



## triod750

triod750 said:


> a Brimar branded Sylvania manufactured 6J5GT/G from June, 1944.


@gibosi helped me with this so I feel confident...


----------



## mordy

triod750 said:


> I have received this tube now. I put the delivery on hold to combine shipping. It would be time now to reveal what is inside that metal costume. But this costume is soldered to one of the pins so the tube will stay where it is. I have decided that it is a state-of-the-art Turkish manufacture and the only one of its kind. It is warming up with another 6C5G of unknown origin that sounded very good with a Brimar branded Sylvania manufactured 6J5GT/G from June, 1944. This, bought as a single from the same seller, now has a pal manufactured in August that same year.
> 
> I also received an AMERTY/Mullard branded 6J5GT/G with innards looking exactly like the Ken-Rad manufactured Brimar 6J5GT/G I previously have posted about. Hmmm - who might have made that?
> 
> ...


Which pin is the cover soldered to?


----------



## triod750

mordy said:


> Which pin is the cover soldered to?


I will check that later. It is the pin sitting in the right input socket in my amp, playing a nice melody, together with a few other pins. I expected you to ask but it was too late when it dawned on me.


----------



## mordy

triod750 said:


> I will check that later. It is the pin sitting in the right input socket in my amp, playing a nice melody, together with a few other pins. I expected you to ask but it was too late when it dawned on me.


The reason I am asking because I have some 6J7G variants that sound good but hum - cannot get rid of the hum so far. In pictures of old radios these tubes often have those full size shields. Perhaps grounding an enclosure to a specific tube pin will help for the hum.


----------



## Xcalibur255

If it's external interference then a shield would help, but I find it's more common for the hum to have an internal source within the tube itself.


----------



## therremans

mordy said:


> Which pin is the cover soldered to?


Should be Pin 1.


----------



## mordy

Does that mean if I am looking at the pins holding the tube upside down, that it is the pin to the left of the guide pin?


----------



## triod750

mordy said:


> Does that mean if I am looking at the pins holding the tube upside down, that it is the pin to the left of the guide pin?


When I hold the tube upside down, with the key at 6 o'clock, the cover is soldered to the pin to the left of the key. That must be pin number x.


----------



## therremans

triod750 said:


> When I hold the tube upside down, with the key at 6 o'clock, the cover is soldered to the pin to the left of the key. That must be pin number x.


Yes, that’s pin one.


----------



## RobertSM (Oct 19, 2021)

Question for those in the know.

How does a MWT L63 compare to a GEC L63 or other British made L63?

I'm wondering of the difference are minimal or something greater.

My question is specifically regarding the straight bottle tube. Not the older shouldered envelope type.

Okay, after some quick reading I see that Marconi-Osram was a direct subsidiary of GEC. So it would stand to reason that a MWT L63 should be very similar to a GEC L63.

I actually knew this from my experience with other GEC,MWT and Osram tube types. I think I was just second guessing myself due to my lack of experience with the L63 tube type.


----------



## triod750

http://www.r-type.org/pdfs/6c5g.pdf See S on page one.


----------



## whirlwind

RobertSM said:


> Question for those in the know.
> 
> How does a MWT L63 compare to a GEC L63 or other British made L63?
> 
> ...


Yup....they are the same.


----------



## bcowen

mordy said:


> Does that mean if I am looking at the pins holding the tube upside down, that it is the pin to the left of the guide pin?


Pin 1, which the shell is tied to is probably connected to ground in a component designed for that tube (or close relatives like a 6J5).  If using an adapter, then all bets are off.


----------



## mordy

bcowen said:


> Pin 1, which the shell is tied to is probably connected to ground in a component designed for that tube (or close relatives like a 6J5).  If using an adapter, then all bets are off.


Hmmm, I am using 6J7 tubes with C3g adapters; pentode to pentode. This is the pinout for C3g:




Is there any way of figuring it out?


----------



## mordy (Oct 19, 2021)

RobertSM said:


> Question for those in the know.
> 
> How does a MWT L63 compare to a GEC L63 or other British made L63?
> 
> ...


The same tube can have the names Marconi, GEC, MWT, Osram or MOV and probably some more labels. This is helpful since sometimes you can get a better buy on a less well known name.
At times the L63 is labeled 6J5G even when made by GEC. Strangely enough, the L63 can be both shoulder type and straight glass, even though they are differentiated as 6J5G (G=glass) and 6J5GT (glass tubular) tubes.
And sometimes there is no name at all on the tube and then you have to familirize yourself with the inside structure of the tube to identify it.

PS: I get a chuckle when some sellers label a GE tube as GEC.


----------



## triod750

bcowen said:


> Pin 1, which the shell is tied to is probably connected to ground in a component designed for that tube (or close relatives like a 6J5).  If using an adapter, then all bets are off.


So, should you connect pin 1 to ground in the amp then, to try to fight hum?


----------



## triod750

triod750 said:


> I have received this tube now. I put the delivery on hold to combine shipping. It would be time now to reveal what is inside that metal costume. But this costume is soldered to one of the pins so the tube will stay where it is. I have decided that it is a state-of-the-art Turkish manufacture and the only one of its kind. It is warming up with another 6C5G of unknown origin that sounded very good with a Brimar branded Sylvania manufactured 6J5GT/G from June, 1944. This, bought as a single from the same seller, now has a pal manufactured in August that same year.
> 
> I also received an AMERTY/Mullard branded 6J5GT/G with innards looking exactly like the Ken-Rad manufactured Brimar 6J5GT/G I previously have posted about. Hmmm - who might have made that?
> 
> ...


The Sylvania 6J5GT/G from -44 sound very good. They ought to cost at least $83. And with time they will sound better...

The AMERTY/Mullard  has R43 in white on the pinched glass, just as in the Ken-Rad made Brimars. And the it has 'F1G' in white on the metal, just under  the AMERTY Mullard Made in U.S.A. in white on the glass.

The tube with round micas has a taller bottle and I haven't found tim to look at photos yet.


----------



## mordy

triod750 said:


> The Sylvania 6J5GT/G from -44 sound very good. They ought to cost at least $83. And with time they will sound better...
> 
> The AMERTY/Mullard  has R43 in white on the pinched glass, just as in the Ken-Rad made Brimars. And the it has 'F1G' in white on the metal, just under  the AMERTY Mullard Made in U.S.A. in white on the glass.
> 
> The tube with round micas has a taller bottle and I haven't found tim to look at photos yet.


The Sylvania 1944 6J5GT is the same as the VT-94. Personally, I found the Sylvania 6J5GT tall bottles from 1950-51 to sound even better, and that is my go-to pair as drivers. I do not have the Sylvania metal base 6SN7A/W tubes, but these tubes have the same look and in my imagination may sound better.
The collective experience seems to be that two 6J5GT triode tubes (each half of a 6SN7) sound better than one dual triode 6SN7 tube.
Please keep this under wraps so that the prices should not jump.
Now, let’s see what happens on eBay with how many new offerings there will be of 6J5GT tubes....


----------



## triod750

triod750 said:


> The Sylvania 6J5GT/G from -44 sound very good. They ought to cost at least $83. And with time they will sound better...
> 
> The AMERTY/Mullard  has R43 in white on the pinched glass, just as in the Ken-Rad made Brimars. And the it has 'F1G' in white on the metal, just under  the AMERTY Mullard Made in U.S.A. in white on the glass.
> 
> The tube with round micas has a taller bottle and I haven't found tim to look at photos yet.


https://collections.museumsvictoria.com.au/items/415087 Lousy photo but some history behind AMERTY. My tube was DOA but I had them to try before I buy. I wish all sellers had that policy...


----------



## Slade01

triod750 said:


> https://collections.museumsvictoria.com.au/items/415087 Lousy photo but some history behind AMERTY. My tube was DOA but I had them to try before I buy. I wish all sellers had that policy...



Despite that history for AMERTY tubes, it was also not uncommon for Mullard to also brand their own UK made tubes with the AMERTY brand whether just to satisfy import demands, tax reasons, or whatever else unknown to us.  I was shown this as evidenced by internal construction that there are AMERTY 6J5G tubes that were clearly Great Britain made.


----------



## mordy

triod750 said:


> https://collections.museumsvictoria.com.au/items/415087 Lousy photo but some history behind AMERTY. My tube was DOA but I had them to try before I buy. I wish all sellers had that policy...


Are you saying that the tube worked when sold, and arrived dead?


----------



## triod750

mordy said:


> Are you saying that the tube worked when sold, and arrived dead?


No. I bought the 6C5G. In delivery he included six 6J5GT/G for me to try. If I was interested in any of them we could discuss a price. One of these tubes doesn't light up, the Amerty Mullard, most likely made by Ken-Rad. I have several of these, branded Brimar. One of these six was a Brimar branded Sylvania from August 1944 that I have been looking for, since I already had one from June. So I am perfectly happy.


----------



## triod750

Slade01 said:


> Despite that history for AMERTY tubes, it was also not uncommon for Mullard to also brand their own UK made tubes with the AMERTY brand whether just to satisfy import demands, tax reasons, or whatever else unknown to us.  I was shown this as evidenced by internal construction that there are AMERTY 6J5G tubes that were clearly Great Britain made.


I have no doubt since Amerty means American Type.


----------



## leftside

Slade01 said:


> Despite that history for AMERTY tubes, it was also not uncommon for Mullard to also brand their own UK made tubes with the AMERTY brand whether just to satisfy import demands, tax reasons, or whatever else unknown to us.  I was shown this as evidenced by internal construction that there are AMERTY 6J5G tubes that were clearly Great Britain made.


I've found the same.


----------



## mordy

Interesting - you really have to know the tubes well to figure out who made what.


----------



## triod750

And howhat do the micas and anodes look in these GB made AMERTY 6J5G? Can you show an example? Please, please me...


----------



## Slade01 (Oct 21, 2021)

triod750 said:


> And howhat do the micas and anodes look in these GB made AMERTY 6J5G? Can you show an example? Please, please me...



Start reading at post 887 and onward and you can see an earlier conversation on AMERTY tubes.  But in short, some look like STC/Brimar construction.


----------



## leftside

triod750 said:


> And howhat do the micas and anodes look in these GB made AMERTY 6J5G? Can you show an example? Please, please me...


I think I remember where mine are.... if I can find them I'll post up a pic.


----------



## Marutks

triod750 said:


> And howhat do the micas and anodes look in these GB made AMERTY 6J5G? Can you show an example? Please, please me...


I have a pair of Amerty 6J5G tubes.






Internals look identical to Brimar 6J5G tube.





This is the Brimar.





Both tubes.


----------



## triod750

And I have one STC 101 6J5G. N  10 E/348 that looks almost the same but unfortunately hums somewhat. I suppose the mica is closer to the anode in mine, maybe, and I can't see the grid? wire just below top mica. Mica is the same.


----------



## bcowen

triod750 said:


> So, should you connect pin 1 to ground in the amp then, to try to fight hum?


I'm not an electronics expert by any means, but if the amp is set up for that tube type natively, I'd guess pin 1 is already connected to ground.  If not and there is nothing else attached to it then connecting it to ground _may _help with hum. Whether it helps would depend on the RFI in the environment and the EMI fields of nearby transformers, etc.  And that's only if using the external metal shell....without the shell I can't see where grounding that pin would make any difference.


----------



## triod750

So is this a genuine Brimar? Notice different shape of top and bottom mica.












Photos borrowed from commercial auction site somewhere...


----------



## triod750

What about the micas in these? What do they look like?


----------



## Xcalibur255

I don't see any photos in your posts.  Not sure if it's just me.


----------



## triod750

https://i.ebayimg.com/images/g/hskAAOSwjqJdrvGJ/s-l1600.jpg
https://i.ebayimg.com/images/g/v5sAAOSwT9ZdrvGW/s-l1600.jpg
https://i.ebayimg.com/images/g/SD8AAOSww9ddrvGh/s-l1600.jpg

Can you see them with these links?

And in the second post, the micas were more difficult to see:

https://i.ebayimg.com/images/g/umgAAOSwLBVhE-zx/s-l1600.jpg


----------



## bcowen

Xcalibur255 said:


> I don't see any photos in your posts.  Not sure if it's just me.


It's just you.      Although the posted photos aren't of sufficient bit depth to show what the micas look like in the Visseaux's.


----------



## triod750

bcowen said:


> Although the posted photos aren't of sufficient bit depth to show what the micas look like in the Visseaux's.


I admit to being a complete failure. That's what my wife thinks anyway.


----------



## triod750

triod750 said:


> I admit to being a complete failure. That's what my wife thinks anyway.


This needs an explanation - we were walking our dog alongside a ditch filled with water and mud earlier today. She slipped and took a dive and only one half of her was to be seen above the surface and I wasn't there to catch her!


----------



## Xcalibur255

Yeah that's one of the possible Brimar constructions.

Dunno why your images don't load for me, I'm not using any add-ons that would block them on this site.


----------



## Marutks (Oct 23, 2021)

I have a pair of Brimar tubes that look like bottle shaped version of those in @triod750 post.





This pair is one of the best 6J5G tubes I own.  They are dead quiet.


----------



## triod750

Marutks said:


> I have a pair of Brimar tubes that look like bottle shaped version of those in @triod750 post.
> 
> 
> 
> This pair is one of the best 6J5G tubes I own.  They are dead quiet.


I have a dead quiet Amerty Mullard you could have for a song....  

Yes, this tube looks close. Nice photo!


----------



## leftside

I thought some might find this interesting. My preamp builder (Supratek) can build a “signature” preamp. He’s a huge fan of 6SN7, but guess what tubes he uses in this “signature” preamp? That’s right 6J5. In this case the KenRad 6J5 metal base.


----------



## tintinsnowydog (Nov 10, 2021)

Been a bit quite here recently! Here is a really interesting find today on this pair of Mullard 6J5G. The construction looks identical to the MOV L63/6J5G we know and love, with the grey glass and the distinctive top mica construction as viewed from the top. But I've never seen them with brown bases nor Mullard print.

The white print on the rear glass should have been revealing- CV193(2) = 6J5G, KB/D(A) = factory code of Mullard Blackburn. However the date code is confusing me- BK(?) would suggest 1946 production, but the factory code for Blackburn pre 1951 should be A instead of DA. The only other possibility is that it is a printed 8, but as far as I know the Mullard date codes were only ever 2 letters, no numbers used. Rear print on the right tube has rubbed off completely unfortunately so no second reference. Would be interested to hear others' thoughts on these. Also interesting is the letter B printed on the spigot base, perhaps denoting Blackburn?

First impressions paired with GEC 6AS7G are fantastic, I am not sure if it is mental bias (I am leaning towards it is) but they seem to be sounding a little warmer to me than the MOV L63. This should be the case if they were in fact made at Blackburn instead of MOV Hammersmith. I need more time to compare between them to make a definitive judgement. I have L63 from the same/very similar vintage to compare to minimise variation. At the end of the day, there is no going wrong with these British L63/CV1932/6J5G whatever they decide to conceal themselves as, some of the best in this family of tubes


----------



## leftside

tintinsnowydog said:


> Been a bit quite here recently! Here is a really interesting find today on this pair of Mullard 6J5G. The construction looks identical to the MOV L63/6J5G we know and love, with the grey glass and the distinctive top mica construction as viewed from the top. But I've never seen them with brown bases nor Mullard print.
> 
> The white print on the rear glass should have been revealing- CV193(2) = 6J5G, KB/D(A) = factory code of Mullard Blackburn. However the date code is confusing me- BK(?) would suggest 1946 production, but the factory code for Blackburn pre 1951 should be A instead of DA. The only other possibility is that it is a printed 8, but as far as I know the Mullard date codes were only ever 2 letters, no numbers used. Rear print on the right tube has rubbed off completely unfortunately so no second reference. Would be interested to hear others' thoughts on these. Also interesting is the letter B printed on the spigot base, perhaps denoting Blackburn?
> 
> First impressions paired with GEC 6AS7G are fantastic, I am not sure if it is mental bias (I am leaning towards it is) but they seem to be sounding a little warmer to me than the MOV L63. This should be the case if they were in fact made at Blackburn instead of MOV Hammersmith. I need more time to compare between them to make a definitive judgement. I have L63 from the same/very similar vintage to compare to minimise variation. At the end of the day, there is no going wrong with these British L63/CV1932/6J5G whatever they decide to conceal themselves as, some of the best in this family of tubes


I think that when Mullard used the military designation "CV", then "DA" does indeed = Blackburn. Nice find! They could still be GEC tubes and rebranded/reprinted by Mullard. Who knows...


----------



## triod750

Does anybody recognize this tube, branded Philips. Who might have made it?






I have just bought it, out of curiosity, but it isn't delivered yet. Also bought another, supposed to have been manufactured by National Union.






Photos from the auction.


----------



## therremans (Nov 17, 2021)

triod750 said:


> Does anybody recognize this tube, branded Philips. Who might have made it?
> 
> 
> 
> ...


What is the tube model/type of the Phillips?


----------



## Xcalibur255

The mica says 1950's Raytheon to me, but don't take that as gospel because I'm not completely certain.


----------



## mordy (Nov 17, 2021)

triod750 said:


> Does anybody recognize this tube, branded Philips. Who might have made it?
> 
> 
> 
> ...


I've got a mate for you Triod750:



This is a Super Silvertone 6J5GT from November 1943. And thanks to X255 I now know that it is a Raytheon. Codes are M-R and L3. 
M-R means manufacturers replacement - a certain proportion was allocated for civilian use of WW2 tube production and the M-R designation was in effect between 1942-45. If I count the months on my fingers and skip the letter I (looks like 1) the letter "L" is 11 = November. 
Silvertone indicates that it was sold by Sears department store.


----------



## triod750

mordy said:


> I've got a mate for you Triod750:
> 
> This is a Super Silvertone 6J5GT from November 1943. And thanks to X255 I now know that it is a Raytheon. Codes are M-R and L3.
> M-R means manufacturers replacement - a certain proportion was allocated for civilian use of WW2 tube production and the M-R designation was in effect between 1942-45. If I count the months on my fingers and skip the letter I (looks like 1) the letter "L" is 11 = November.
> Silvertone indicates that it was sold by Sears department store.


If you have only one, this means that I am supposed to ship mine to you since you had your's first  .


----------



## mordy

triod750 said:


> If you have only one, this means that I am supposed to ship mine to you since you had your's first  .


Or maybe the opposite?


----------



## mordy

mordy said:


> Or maybe the opposite?





mordy said:


> I've got a mate for you Triod750:
> 
> This is a Super Silvertone 6J5GT from November 1943. And thanks to X255 I now know that it is a Raytheon. Codes are M-R and L3.
> M-R means manufacturers replacement - a certain proportion was allocated for civilian use of WW2 tube production and the M-R designation was in effect between 1942-45. If I count the months on my fingers and skip the letter I (looks like 1) the letter "L" is 11 = November.
> Silvertone indicates that it was sold by Sears department store.


However, I looked through a bunch of pictures of Raytheon 6J5GT tubes. Most of them look very different. The closest thing to the Philips/Silvertone tube that I found is this:




But the micas on the Raytheon only have four little pegs - the Philips/Silvertone tubes have seven pegs on the micas. 
So the mystery remains....


----------



## triod750

We love mysteries. That is what prevents us from falling asleep at night, wasting our time...


----------



## therremans (Nov 17, 2021)

My Raytheon’s have the same design but my micas have less teeth. If you have a 6J5, I asked as you also posted a 6C5 with the same post.


----------



## triod750

If you are asking me - the Philips posted is a 6J5GT - I mistakenly left out that information. I don't know when it will be delivered. He stores them for me and I buy more eventually and save on shipping cost.


----------



## Xcalibur255

It's entirely possible for both mica variants to be Raytheon.  You can see both of those design variants in their 6SN7s too.  But again I'm not certain it's just my best guess.  I believe the one with fewer teeth would generally be older in age.


----------



## jonathan c

Xcalibur255 said:


> I believe the one with fewer teeth would generally be older in age.


Except for infants…


----------



## Xcalibur255 (Nov 22, 2021)

I finally broke down and picked up a pair of Marconi L63 grey glass.  It has been a while since I have listened to my well used B65 but my gut feeling is that tonally the two are close to identical.  The usual 6J5 advantages, such as improved separation and imaging, apply of course.  I fully expect the prices on these to keep quickly climbing skyward as more and more people realize they can get the B65 sound through adapter usage.

To my ears they sound substantially different from the GEC L63 straight glass too.  The presentation is quite a bit different IMO.  The GEC presents with a much denser stage and dare I say is superior at pulling out low level texture detail.  The Marconi grey glass is quite a bit more open and airy.  Hard to really call one better than the other..... I think a better way to think of it would be in terms of what headphones you are matching them to.  Paired with something that is already very open sounding like an HD800 I could see the Marconi leaning to the thin side, so the GEC would probably provide a nice counterbalance there for example. 

The coke bottle Raytheons, especially the round plate version, are actually fairly close to the Marconi tonal presentation too.  Not super close, but there is definitely a resemblance compared to some of the others that are clearly different flavors.  Mostly the Marconi is just one step higher in overall refinement and finesse, but you certainly pay a premium for what is ultimately a fairly subtle improvement.

I'm glad I stopped hunting for a pristine pair that I would then not want to actually use in an amp.  The ones I have test well but kind of look like mutts so I will have no qualms actually running them when I feel like it.


----------



## leftside

Xcalibur255 said:


> I finally broke down and picked up a pair of Marconi L63 grey glass.  It has been a while since I have listened to my well used B65 but my gut feeling is that tonally the two are close to identical.  The usual 6J5 advantages, such as improved separation and imaging, apply of course.  I fully expect the prices on these to keep quickly climbing skyward as more and more people realize they can get the B65 sound through adapter usage.


That's right! And having a pair of B65, I was looking for something that would sound similar without me having a minor heart attack every time I pulled the tubes out of a box and put them into a tube socket. Then I discovered the GEC/Marconi 6J5/L63 and various reports on the Internet that said how good 6J5/L63 were in general. Then came the adapters for the WA22 I had at the time, and then came an amp (or two...) that didn't need adapters for 6J5.


----------



## triod750

triod750 said:


> Does anybody recognize this tube, branded Philips. Who might have made it?
> 
> 
> 
> ...


The 'Philips 6J5GT/G arrived prematurely and has an assymetric 'sheet metal' bottom getter. Don't know how to describe the shape. Six-sided, with a little bulb in the middle.
The NU 6C5GT/G has a two letter code on the metal socket beside National Union. First letter could be M, N or H and second is C.


----------



## jgwtriode

Happy thanksgiving gentleman will be getting an Airmid from Keenan, made some arrangements with him sometime in January or February!  So I am preplanning an appropriate tube roll.  Trying to get some recommendations.  Will be running it with My ZMF leopardwood VC's using a Wywires platinum harness.  I have heard Monster's take on the GEC 6J5's and the Tung Sol 5998's.  Any other suggestions?

Thanks and Happy Listening,

jgwtriode


----------



## Monsterzero

jgwtriode said:


> Happy thanksgiving gentleman will be getting an Airmid from Keenan, made some arrangements with him sometime in January or February!  So I am preplanning an appropriate tube roll.  Trying to get some recommendations.  Will be running it with My ZMF leopardwood VC's using a Wywires platinum harness.  I have heard Monster's take on the GEC 6J5's and the Tung Sol 5998's.  Any other suggestions?
> 
> Thanks and Happy Listening,
> 
> jgwtriode


You're in for a treat. Congrats!


----------



## bcowen

jgwtriode said:


> Happy thanksgiving gentleman will be getting an Airmid from Keenan, made some arrangements with him sometime in January or February!  So I am preplanning an appropriate tube roll.  Trying to get some recommendations.  Will be running it with My ZMF leopardwood VC's using a Wywires platinum harness.  I have heard Monster's take on the GEC 6J5's and the Tung Sol 5998's.  Any other suggestions?
> 
> Thanks and Happy Listening,
> 
> jgwtriode


Congrats!!!!

I haven't heard the GEC 6J5's so can't comment on those.  The Tung Sol 5998 is one of my favorites...ballsy and very dynamic with a natural sounding top end. To my ears it lacks a bit of color in the mids compared to some others, but that's more a function of preference and synergy than anything else.  A Chatham 6AS7G is always a good bet.  Not the rocker that the 5998 is, but has that finesse and harmonic texture in the mids in spades, and can still be found for reasonably sane prices on occasion. The Bendix slotted graphite plate 6080 is another fave.  Only issue is that it takes a good 20 minutes to warm up each time to fully strut its stuff, and the patience that requires is beyond my capability at times.


----------



## whirlwind

Xcalibur255 said:


> I finally broke down and picked up a pair of Marconi L63 grey glass.  It has been a while since I have listened to my well used B65 but my gut feeling is that tonally the two are close to identical.  The usual 6J5 advantages, such as improved separation and imaging, apply of course.  I fully expect the prices on these to keep quickly climbing skyward as more and more people realize they can get the B65 sound through adapter usage.
> 
> To my ears they sound substantially different from the GEC L63 straight glass too.  The presentation is quite a bit different IMO.  The GEC presents with a much denser stage and dare I say is superior at pulling out low level texture detail.  The Marconi grey glass is quite a bit more open and airy.  Hard to really call one better than the other..... I think a better way to think of it would be in terms of what headphones you are matching them to.  Paired with something that is already very open sounding like an HD800 I could see the Marconi leaning to the thin side, so the GEC would probably provide a nice counterbalance there for example.
> 
> ...



You are going to love these tubes...these are at the top of their class IMO.  I splurged for three pair since I liked them so well and I am  using them in my OTL.
Wish I could use them in my SET as well.


----------



## mordy

Just got a pair of Brimar branded 6J5GT tubes (no visible codes). Based on how they look and internal construction they are Ken-Rad VT-94 tubes from the mid 40s.
After playing for a couple of hours one tube started to develop a greyish shadow on top - I assume that it will turn into a black spot later.








I have been told this is called anode boiloff and is not detrimental to the lifespan of the tube. (If the tube has a cleartop it indicates that it is not new = NOS; with a getter flash on top I don't think that you can see it).
Why does this happen?


----------



## whirlwind

mordy said:


> Just got a pair of Brimar branded 6J5GT tubes (no visible codes). Based on how they look and internal construction they are Ken-Rad VT-94 tubes from the mid 40s.
> After playing for a couple of hours one tube started to develop a greyish shadow on top - I assume that it will turn into a black spot later.
> 
> 
> ...



Nice tubes.

Yeah, if these clear top tubes have no mark it is NOS.  Someone else will have to chime in about what process exactly cause's this...I have heard before, but can't remember


----------



## Xcalibur255 (Nov 30, 2021)

It can be an indicator of whether or not a tube is truly NOS, but it is definitely not a reliable one.  Some tubes have some of their getter flash boil off and redeposit at the top of the tube, but it doesn't happen with all tubes.  This process can also happen either slowly or quickly.  FWIW this seems to be a thing with British made tubes more than American ones in my experience. 

Coincidentally I recently grabbed an ST glass version of those same Ken-Rad VT94s and one tube darkened its glass top almost immediately where as the other didn't.  About 50 hours in now the one tube has actually silvered the top of its glass quite a bit while its partner is still completely clear on top so this process isn't even consistent within the same type and make of tube.

I wonder if the quality/hardness of the vacuum has something to do with it.  It might be somewhat of an indicator of whether the tube will have an above or below average lifespan if it is.

As an aside I am actually a little disappointed in how these sound, assuming they really are Ken-Rads.  This doesn't have the Ken-Rad house sound to my ears.  Mine have those copper straps connecting the micas to the plates which is a pretty distinctive construction trait.


----------



## therremans

Xcalibur255 said:


> As an aside I am actually a little disappointed in how these sound, assuming they really are Ken-Rads.  This doesn't have the Ken-Rad house sound to my ears.  Mine have those copper straps connecting the micas to the plates which is a pretty distinctive construction trait.


I second the sound.. I quickly sold the couple pairs of Ken-Rad 6J5GTs after listening. They were some of the first 6J5s that I purchased. I believe I had shiny black and gray plate versions. However, some may vary in construction/sound. I just didn’t like mine much.


----------



## mordy

therremans said:


> I second the sound.. I quickly sold the couple pairs of Ken-Rad 6J5GTs after listening. They were some of the first 6J5s that I purchased. I believe I had shiny black and gray plate versions. However, some may vary in construction/sound. I just didn’t like mine much.


The 6J5GT tubes I have are from the early or mid 40s. The bases were shiny but corrode easily; the plates are black and ladder style. With a sixpack of Melz 6N12S they sound excellent in my GOTL. (As always synergy is paramount as well as the amp you are using.)
Here is a representative picture of the tube (mine aren't as corroded):


----------



## Xcalibur255

They don't sound bad per se, but they are forward in the upper mids in a way that doesn't mesh well at all with either my preferences or the headphones I was using.  I generally use the DT880-600 with this amp pretty exclusively, but funny enough today I had the Ethers in here to do some troubleshooting (they're exhibiting a channel imbalance).  The Ken-Rads suit this headphone quite a bit better.  I still wouldn't call this a flavor I would seek out deliberately but it works a lot better on this headphone than it did on the Beyer.  Too bad the channel imbalance wasn't present............ which means the problem is in the amp at home.  Fun.


----------



## jgwtriode

Monsterzero said:


> You're in for a treat. Congrats!


----------



## jgwtriode

Thanks Monster I appreciate it.  What tubes would you recommend as best option for the VC's.   Looking forward to listening to it as soon as possible, 
Appreciate your review that started the process of communicating with Keenan.  He is awesome.

Thanks again,

jgwtriode


----------



## Monsterzero

jgwtriode said:


> Thanks Monster I appreciate it.  What tubes would you recommend as best option for the VC's.   Looking forward to listening to it as soon as possible,
> Appreciate your review that started the process of communicating with Keenan.  He is awesome.
> 
> Thanks again,
> ...


My fav tube combo on the Airmid was a pair of GEC L63 and a pair of  5998s. There seems to be a few variations of the GEC l63, but these are the ones I have.




The other tubes I tried, including Bendix 6080s, Ken Rad 6J5, Tung Sol black can 6J5, and Sylvania 6J5s, did not impress me much on this amp.
FWIW, my impressions were based on the Verite open. My VC wasn't doing well when I had the Airmid, and has since been returned to ZMF for some driver replacements.


----------



## Curtisvill

Monsterzero said:


> My fav tube combo on the Airmid was a pair of GEC L63 and a pair of 5998s. There seems to be a few variations of the GEC l63, but these are the ones I have.


I have a pair of those GEC l63s and they are very nice.


----------



## jgwtriode

Monsterzero said:


> My fav tube combo on the Airmid was a pair of GEC L63 and a pair of  5998s. There seems to be a few variations of the GEC l63, but these are the ones I have.
> 
> 
> The other tubes I tried, including Bendix 6080s, Ken Rad 6J5, Tung Sol black can 6J5, and Sylvania 6J5s, did not impress me much on this amp.
> FWIW, my impressions were based on the Verite open. My VC wasn't doing well when I had the Airmid, and has since been returned to ZMF for some driver replacements.


Ouch, so you may not have been hearing your VC properly on the Airmid???  I had to have drivers replaced on my Auteur Blackwoods after about 2.5 years.  Weird buzzing
at high frequencies of a certain intensity.  Was only aware of it on certain music.  But Zach figured it out and replaced them.  Been fine since, albeit i rarely listen to them,
much prefer Leopardwood VC's.     Welll hopefully they are returned soon.

Happy Listening,

jgwtriode


----------



## L0rdGwyn

I decided the red Airmid prototype needed a home, so it will be going to @jgwtriode early next year.  Personally, I like the GEC L63 and Tung-Sol 5998 combination myself.  Expensive these days, but they pair very well in the amp.


----------



## jgwtriode

L0rdGwyn said:


> I decided the red Airmid prototype needed a home, so it will be going to @jgwtriode early next year.  Personally, I like the GEC L63 and Tung-Sol 5998 combination myself.  Expensive these days, but they pair very well in th





L0rdGwyn said:


> I decided the red Airmid prototype needed a home, so it will be going to @jgwtriode early next year.  Personally, I like the GEC L63 and Tung-Sol 5998 combination myself.  Expensive these days, but they pair very well in the amp.


So how close do the stick Soviet tubes get.  Will probably upgrade in stages.  6j5's first, then 5998's.  Do it over a few months time.  I trust that albeit pricey this combo really is the way to go.  Really looking forward to the Airmid In my system.  My late Xmas/New years present to myself!

Happy listening to all,

jgwtriode


----------



## Monsterzero

jgwtriode said:


> Ouch, so you may not have been hearing your VC properly on the Airmid???


That's correct.


----------



## leftside

L0rdGwyn said:


> I decided the red Airmid prototype needed a home, so it will be going to @jgwtriode early next year.  Personally, I like the GEC L63 and Tung-Sol 5998 combination myself.  Expensive these days, but they pair very well in the amp.



Great combo in my 1101 Audio V6 amp as well.


----------



## mordy

mordy said:


> Just got a pair of Brimar branded 6J5GT tubes (no visible codes). Based on how they look and internal construction they are Ken-Rad VT-94 tubes from the mid 40s.
> After playing for a couple of hours one tube started to develop a greyish shadow on top - I assume that it will turn into a black spot later.
> 
> 
> ...


Remember these two 40's Ken-Rad tubes labeled Brimar? I stated that  there were no codes visible on the base or on the glass envelope. Now, thanks to the efforts of the Antiquities and Preservation Department of Trivia University, date codes were discovered in an unlikely place:






On the glass piece which holds the wires and rods in place under the bottom mica date codes are etched. 
The above two tubes look like it says W17 and W32?. On two other tubes it seems to say W44 (but the two 4s are upside down) and Y43. 
Since Ken-Rad was sold in 1945 to GE it is reasonable to assume that these tubes are from the 40's. Don't know what W and Y stands for, but it seems logical that the first digit is the year and the second digit is the month.
Thus we have July 1941, February(?) 1943 ,  April 1944 and March 1944.
I find this interesting since I have not seen codes etched on the glass support inside the tube before. The codes are hard to see unless you angle the tube carefully, but they are there.
Is somebody can supply more accureate information, please do.


----------



## triod750

mordy said:


> Antiquities and Preservation Department of Trivia University


Professor Mordy, I presume 
These markings have been visible on all of the Ken-Rad 'Brimar' 6J5GT/G I have handled. I think I mentioned this when I first posted about them. My Sylvania 'Brimar' don't have these markings but 'H4' and 'F4' on the glass, below the '6J5GT/G' marking.


----------



## mordy

triod750 said:


> Professor Mordy, I presume
> These markings have been visible on all of the Ken-Rad 'Brimar' 6J5GT/G I have handled. I think I mentioned this when I first posted about them. My Sylvania 'Brimar' don't have these markings but 'H4' and 'F4' on the glass, below the '6J5GT/G' marking.


What are the markings on the Ken-Rads?


----------



## Xcalibur255

My pair of KenRad 6J5G also have these etched codes on the side of their glass stems.  One is labeled D42 and the other C53.


----------



## triod750

mordy said:


> What are the markings on the Ken-Rads?


The four Ken-Rad 'Brimar's I now could find had the following markings on the glass pinch; A44, A41, A41 and W17. Of these I have passed on, several had either the letter A or W. I have commented on this in a previous post somewhere. (One of these markings was upside down). All of them came from a box of spares from an old cinema - also my Sylvania made 6J5GT/G (with better metal band around the socket).


----------



## mordy (Dec 2, 2021)

triod750 said:


> The four Ken-Rad 'Brimar's I now could find had the following markings on the glass pinch; A44, A41, A41 and W17. Of these I have passed on, several had either the letter A or W. I have commented on this in a previous post somewhere. (One of these markings was upside down). All of them came from a box of spares from an old cinema - also my Sylvania made 6J5GT/G (with better metal band around the socket).


The reason I asked was that I was trying to understand the meaning of the first letter in the code. So far we have the letters A, C, D, W and Y but I am none the wiser from knowing this lol....
To play it safe, we'll call it a production code which basically is saying nuttin'.


----------



## triod750

I am no wiser about the code but I now know that it is called a 'glass pinch'; the piece of glass holding the metal innards. I learnt it when reading some history about tubes here: https://www.dos4ever.com/EF50/EF50.html
A lot of interesting reading.


----------



## triod750

This is the kind of information that can be found in the article I linked to: "During the Korean War, in 1951, endeavors were made to standardize the radio tube techniques used by the NATO members. The result was the NOVAL technique (nine pins in a circle providing room for ten). This tube was equiped with three-electrode lead-ins like the ”miniature“ tubes. Philips, however improved the shape of the envelope by sealing the tube base upwards. It is typical of technical progress in mass production that this technique, owing to its simplicity and logic design, has been universally accepted in spite of advertizing arguments such as ”it shows more“, ”it looks stronger“, which could be put forward in favour of other designs. Once this version had been chosen for nearly all types, the only difference being the length of the envelope, mechanization could be furthered. Machines were designed to weld the three-piece electrodes together at a rate of about 10,000 per hour, to press these electrodes into the glass base (Fig. 6.8) and to make envelopes of tube glass and to seal on stems at a reate of 2500 per hour. Thus it became possible to turn out a relatively compact unit for production of about 2,000,000 radio tubes per year. These machines were installed in Philips’ and Philips-supported factories in twelve different countries spread over the world". 

Or this:"Klaas Rodenhuis recollects an amusing anecdote from around this period [47]. During the war, a group of engineers at Philips had worked on a competing metal tube concept. In an attempt to eliminate the expensive projection welding, somebody had had the cleaver idea to give both the base and the metal envelope a conical shape in such a way that they would fit snugly over each other. After evacuation the two parts would form a tight fit. Apparently the idea worked, so that a decision had to be made which concept to pursue. This decision was made by Frans Otten, the president of Philips who had just returned from exile. Today it seems unimaginable that the president of Philips should be involved in a decision on such a technical detail! The meeting was held, and Otten entered. After a short technical explanation by both camps, Otten asked ‘And gentlemen, which concept is cheapest?’ Everybody had to admit that the glass concept was cheapest. ‘Fine,’ Otten answered, ‘in that case we will drop the metal tube concept, good afternoon gentlemen!’ That is how decisions were made those days"!


----------



## triod750

"At the peak of production in the fifties, Philips produced about 200 million radio tubes a year. It was an enormous industry, in which thousands of people were employed. Over a period of forty years the science and craftsmanship of radio tube manufacturing had been mastered to the level of perfection. It is almost inconceivable, that apart from half a shelf of books in the library and a few hundred forgotten reports, all this knowledge and craftsmanship has almost vanished today".

Some of them are still out there. Not all of them end up on that bay. Go looking...


----------



## triod750

Try this at home:








Figure 48. Wolters, an exceptionally gifted technician in the model workshop, was able to straighten out a bent cathode by a controlled tapping of the tube against the edge of the table.


----------



## L0rdGwyn

triod750 said:


> Try this at home:
> 
> 
> 
> ...



I've broken shorts in valuable tubes this way, saved a globe 45 and a 5998


----------



## triod750

By 'controlled tapping' or 'random tapping'?


----------



## L0rdGwyn

Controlled tapping, obviously


----------



## triod750

L0rdGwyn said:


> Controlled tapping, obviously


Hmmmm....


----------



## leftside

triod750 said:


> Try this at home:
> 
> 
> 
> ...


That’s Mordy!


----------



## Xcalibur255 (Dec 2, 2021)

Controlled tapping a.k.a. smacking a tube against the palm of your hand a couple of times is always worth a try as a last resort before throwing a tube out.  Unless it's a short, then it's just not worth the risk of putting it back in your amp IMO, at least not for the average user.  Sometimes it's not just the fuse that blows.


----------



## triod750

In 1962, the Mullard Blackburn factory provided employment for 6200 people. They were still investing in valve manufacturing. Where are all those tubes now? And why so expensive?


----------



## bcowen

triod750 said:


> In 1962, the Mullard Blackburn factory provided employment for 6200 people. They were still investing in valve manufacturing. *Where are all those tubes now? *And why so expensive?


I'm pretty sure @L0rdGwyn has most of them.


----------



## Monsterzero

bcowen said:


> I'm pretty sure @L0rdGwyn has most of them.


----------



## leftside

triod750 said:


> In 1962, the Mullard Blackburn factory provided employment for 6200 people. They were still investing in valve manufacturing. Where are all those tubes now? And why so expensive?


It's almost 60 years ago. A lot were destroyed when transistors started to appear. A lot were used and then burnt out.  I'm amazed we can still find decent tubes from that era. For now....


----------



## triod750

leftside said:


> It's almost 60 years ago. A lot were destroyed when transistors started to appear. A lot were used and then burnt out.  I'm amazed we can still find decent tubes from that era. For now....


It's not very long ago at all. I remember that period very well, probably better than what happened last week. No, there must be some other explanation. And I suppose you are part of that explanation and trying to sneak away from your responsibility. We aren't that easily fooled. Just sayin'...


----------



## triod750




----------



## therremans

triod750 said:


> In 1962, the Mullard Blackburn factory provided employment for 6200 people. They were still investing in valve manufacturing. Where are all those tubes now? And why so expensive?


Closets, basements, garages and stuff. The limited supply ran out a long time ago. It seems tubes last a long time but they do have a lifespan. The repair shops went out of business people bought up their stock probably back in the 70s, 80s and 90s? Then in the 90s-2000s, i’d take a guess that lot of people were buying a lot of tubes up when the price seemed fair enough to collect multiples as spares for a lifetime supply as they knew the demand should only increase. If you were the betting man, you’d be right. Although digital back then was exciting enough to make you consider selling off your vinyl collection (and then regret it). And well today some of these tube owners are selling them off at a much higher market price. I get pretty damn excited if I find a desirable true nos tube nowadays.


----------



## jonathan c (Dec 5, 2021)

triod750 said:


> Where are all those tubes now?


🤪 nature abhors a vacuum…(Aristotle) 🤪


----------



## bcowen

therremans said:


> Closets, basements, garages and stuff. The limited supply ran out a long time ago. It seems tubes last a long time but they do have a lifespan. The repair shops went out of business people bought up their stock probably back in the 70s, 80s and 90s? Then in the 90s-2000s, i’d take a guess that lot of people were buying a lot of tubes up when the price seemed fair enough to collect multiples as spares for a lifetime supply as they knew the demand should only increase. If you were the betting man, you’d be right. Although digital back then was exciting enough to make you consider selling off your vinyl collection (and then regret it). And well today some of these tube owners are selling them off at a much higher market price. I get pretty damn excited if I find a desirable true nos tube nowadays.


The '80's and early '90's were great times to buy tubes (and vinyl).  Big lots of some very desirable tubes being sold off for cheap.  I remember buying 50 Cifte (Mazda) 12AU7's for $100.  These days they go for $100 _each_.  30 Mullard CV4033's for $50.  The first reissue of the WE 300B's were $400 a pair.  Even GEC KT-77's for $40 each.  Just wish I'd waited until now to sell all those.  

Nobody wanted Russian tubes because that sound was identified with the Sovtek-branded crap being manufactured at the time.  Wish I'd bought a few thousand Melz 1578's back then...


----------



## jonathan c (Dec 5, 2021)

Xcalibur255 said:


> Unless it’s a short If it’s a GE, then it's just not worth the risk of putting it back in your amp IMO, at least not for the average any user.  Sometimes it's not just the fuse that blows sucks.


FTFY…[Reg. TM; © bcowen: 2021]


----------



## mordy

I always wanted to have all red tubes - don't know why; maybe because they are pretty and look different than anything else.. In any case, here is a pair of red Mullard EF39 tubes. These are from the 6J7 family from which the 6C5 was derived. 




At first I thought that these tubes are metal such as the US made 6J7 but they are made out of glass and probably covered with some kind of RFI coating.
Maybe somebody can help me with the coding and dates? - I am stumped:



Each tube has the markings 1002 and underneath 2 F O (or 0?).
Here is a useful post about British markings: https://mullard.org/blogs/news/83886851-cv-numbers-and-uk-military-date-and-factory-codes
but in this case I don't know if it helps.  F could be a factory code or a month; 2 could be a year? 
Here is another post - unfortunately none of the links quoted work:
https://www.radiomuseum.org/forum/ef39_ef39.html
It seems that 1002 is another designation for EF39.
Taking a uneducated guess if would venture to say that these tubes were made in 1950-52?
In any case, this pair of 0.2A tubes sound very nice with 6 x 6N12S i my amp. Mullard nice.


----------



## whirlwind

mordy said:


> I always wanted to have all red tubes - don't know why; maybe because they are pretty and look different than anything else.. In any case, here is a pair of red Mullard EF39 tubes. These are from the 6J7 family from which the 6C5 was derived.
> 
> At first I thought that these tubes are metal such as the US made 6J7 but they are made out of glass and probably covered with some kind of RFI coating.
> Maybe somebody can help me with the coding and dates? - I am stumped:
> ...



Those are sexy!


----------



## triod750

Some more history: https://www.dos4ever.com/EF50/PTT_okt_1946_large_eng.pdf 
Not a 6J5 in sight - beware!


----------



## triod750

Bombing of Philips facilities in Eindhoven during the war:


----------



## bcowen

triod750 said:


> Bombing of Philips facilities in Eindhoven during the war:



Um, Eindhoven is in the Netherlands.  While there was a lot of damage done in eastern Holland from Allied bombers being off target, I kinda doubt they would have made a video about it with the pilot(s) smiling.


----------



## triod750

bcowen said:


> Um, Eindhoven is in the Netherlands.  While there was a lot of damage done in eastern Holland from Allied bombers being off target, I kinda doubt they would have made a video about it with the pilot(s) smiling.


He might have been a daredevil!


----------



## mordy (Dec 8, 2021)

triod750 said:


> Bombing of Philips facilities in Eindhoven during the war:



https://en.wikipedia.org/wiki/Operation_Oyster
Above is a link to a detailed account of the bombing raids of the Dutch Philips radio and tube factories in Eindhoven and nearby. According to this account, production was halted for around 6 months in the middle of the war.
The allied bombing was considered a huge success and involved a massive coordinated operation.


----------



## triod750

Thanks, Mordy.


----------



## jonathan c

mordy said:


> https://en.wikipedia.org/wiki/Operation_Oyster
> Above is a link to a detailed account of the bombing raids of the Dutch Philips radio and tube factories in Eindhoven and nearby. According to this account, production was halted for around 6 months in the middle of the war.
> The allied bombing was considered a huge success and involved a massive coordinated operation.


Also, this:


----------



## triod750

Now we know what happened to some of the tubes from yesteryear. Hoarding isn't the full explanation.

And keeping museum pieces is a noble thing to do....


----------



## leftside

I have some Philips wartime 4654 tubes with the nazi symbols. I need to check and see if they were made in the Eindhoven factory.

I love a bit of history - one of the reasons for my fascination with old tubes and why I read the old books by Philips, Marconi, etc. I treat many of these old tubes as historical museum artifacts.


----------



## jonathan c (Dec 9, 2021)

triod750 said:


> Now we know what happened to some of the tubes from yesteryear. Hoarding isn't the full explanation.
> 
> And keeping museum pieces is a noble thing to do....


…@bcowen will enjoy nobility…👑…the Earl of Eindhoven…


----------



## leftside (Dec 9, 2021)

Here you go. Can't tell which factory these were made though.
https://www.head-fi.org/threads/the...39-4654-4699-kt63-kt61-6v6-etc.959519/page-12


----------



## jonathan c

jonathan c said:


> Also, this:


Did the squadron miss (not know of) the ECG warehouses?…🤔…


----------



## Slade01 (Dec 10, 2021)

jonathan c said:


> Did the squadron miss (not know of) the ECG warehouses?…🤔…



@bcowen you should send out some of those blue phillips ecg tubes as loaners gifts to give some others here what they are missing. lol.   you know, Christmas Spirit!  Spreading.....Cheer.....


----------



## jonathan c

Slade01 said:


> @bcowen you should send out some of those blue phillips ecg tubes as loaners to give some others here what they are missing.  lol.    you know, Christmas gifts!


Not loaners…that implies that you would want them back…😳


----------



## Slade01

jonathan c said:


> Not loaners…that implies that you would want them back…😳


You have a point.  I did edit accordingly.   You know how generous @bcowen is.


----------



## jonathan c

Slade01 said:


> You have a point.  I did edit accordingly.   You know how generous @bcowen is.


Only with GE / ECG….with GEC, Foton, he’s Cowenezer Scrooge…


----------



## CaptainFantastic

My L63/6J5 options got a booster today. The curved bottle GEC L63s arrived. Group photo with its cousins. Apologies for the poor lighting.


----------



## Xcalibur255

Slade01 said:


> You have a point.  I did edit accordingly.   You know how generous @bcowen is.


Very GEnerous.


----------



## leftside (Dec 10, 2021)

CaptainFantastic said:


> My L63/6J5 options got a booster today. The curved bottle GEC L63s arrived. Group photo with its cousins. Apologies for the poor lighting.


Nice set! Do the metal base have ""D" or "cup" getters? I presume the brown base ones have "D" getters, as those Osram stickers are quite early (most of the straight glass/brown base I've seen have the "O" getters). 

I tried to find more of those wooden tube holders, but couldn't find them. Do you know of a place?

Edit: I see they are both "D" getters. I bet the years are very close. The date order for the straight glass went:
metal base/cup getter
metal base/D getter
brown base/D getter
brown base/O getter

There are also straight glass/black base with cup and D getter which seem to have similar dates of manufacture to the metal base, but most seem to be branded "MWT". They are all great tubes! Only crazy collectors go after all of them


----------



## raindownthunda (Dec 10, 2021)

Recently picked up a pair of RSD branded 6J5G from a seller in Spain. The seller claimed these are re-branded Ates 6J5G. Does anyone have any information on these?

I did some research previously on Ates, and found they partnered with RCA for tooling but were manufactured in Italy. However, these appear to be quite different than any RCA 6J5G I've seen. The distinct round black plates made me think they might be Brimars, but upon closer look there are a number of differences in construction.

They sound phenomenal. Detail and imaging is excellent. To my ears at least as good as GEC L63 ST, but with a bit more warmth and deeper bass extension. Definitely a step up from the RCA's I've heard. I would roughly describe them as a blend between GEC L63 ST and Brimar 6J5G.


----------



## bcowen

Slade01 said:


> @bcowen you should send out some of those blue phillips ecg tubes as loaners gifts to give some others here what they are missing. lol.   you know, Christmas Spirit!  Spreading.....Cheer.....


While I don't go out of my way to be liked, I _do_ try not to be disliked.  Sending ECG's out as gifts would be a sure path to the latter.    

Sending GE's would be a joke.  ECG's?  Cruel.


----------



## bcowen

jonathan c said:


> Only with GE / ECG….with GEC, Foton, he’s Cowenezer Scrooge…


The last person that tried to grab one of my Fotons is down to one hand now.  But I'm always happy to share.


----------



## jonathan c

bcowen said:


> The last person that tried to grab one of my Fotons is down to one hand now.  But I'm always happy to share.


Are Fotons now part of your anatomy..? 😳


----------



## bcowen

jonathan c said:


> Are Fotons now part of your anatomy..? 😳


Nope.  The other guy's either.  LOL!


----------



## leftside

raindownthunda said:


> Recently picked up a pair of RSD branded 6J5G from a seller in Spain. The seller claimed these are re-branded Ates 6J5G. Does anyone have any information on these?
> 
> I did some research previously on Ates, and found they partnered with RCA for tooling but were manufactured in Italy. However, these appear to be quite different than any RCA 6J5G I've seen. The distinct round black plates made me think they might be Brimars, but upon closer look there are a number of differences in construction.
> 
> They sound phenomenal. Detail and imaging is excellent. To my ears at least as good as GEC L63 ST, but with a bit more warmth and deeper bass extension. Definitely a step up from the RCA's I've heard. I would roughly describe them as a blend between GEC L63 ST and Brimar 6J5G.


Very nice! I don't think I have any ATES or RSD 6J5, but they do look a little like my Visseaux. Let me check...


----------



## leftside

Similar but different


----------



## Monsterzero

leftside said:


> Similar but different


Or, as they say in Thailand & Viet Nam....


----------



## triod750

You have probably already seen this, borrowed from here: https://vacuumtubesinc.com/index.php/hallofshame

*
Fake 6C5G*




"The tube at left is clearly branded 6L5G, but has a paper tag labeling it as a 6C5. 6L5G tubes have a shiny nickel plate with no internal shielding. Most 6C5G tubes have a perforated or mesh shield as the center tube. To be fair, there is a rare form of the 6C5G made for Silvertone (pictured at right) that does not have the shield.


The 6L5G is essentially a 150mA filament version of the 6C5G, which has a 300mA filament. However, the internal shield of the 6C5G makes the output capacitances much different".


----------



## leftside

triod750 said:


> You have probably already seen this, borrowed from here: https://vacuumtubesinc.com/index.php/hallofshame
> 
> 
> *Fake 6C5G*
> ...


That’s probably a mistake rather than a deliberate fake. Hardly seems worth it for that tube.

I have some 6L5 somewhere that work perfectly fine in the 6J5 sockets. I’ll have to dig them out.


----------



## triod750

If it was a fake, it was a really bad one. You would at least cover the 6L5G branding with the paper label so I agree, no fake intended.


----------



## bcowen

leftside said:


> That’s probably a mistake rather than a deliberate fake. Hardly seems worth it for that tube.
> 
> I have some 6L5 somewhere that work perfectly fine in the 6J5 sockets. I’ll have to dig them out.


Mine work just fine in place of 6J5's.  These RCA's aren't top contenders for me, but they sound OK....and look cool.


----------



## maxpudding

I think the purpose of the sticker is just to tell people that the tube is interchangeable with 6C5 tubes


----------



## triod750

maxpudding said:


> I think the purpose of the sticker is just to tell people that the tube is interchangeable with 6C5 tubes


But it should tell that it 'might be'.


----------



## maxpudding

triod750 said:


> But it should tell that it 'might be'.


“satisfaction guaranteed”

😂


----------



## JKDJedi

What happens if you drop dual triode tubes in an adapter designed for dual single triode tubes ? I sold the adapter and the buyer dropped dual triode tubes in there, now their amp has distortion.


----------



## therremans

JKDJedi said:


> What happens if you drop dual triode tubes in an adapter designed for dual single triode tubes ? I sold the adapter and the buyer dropped dual triode tubes in there, now their amp has distortion.


Like using two 6sn7s in a dual 6j5 (single triode octal) adapter? Never tried it.  Two totally different pin layouts. Can’t imagine it would be good for the tubes or amp. So it sounds like it damaged the amp?


----------



## L0rdGwyn

Depends, but the major issue would be causing a short that damages a component.


----------



## JKDJedi

therremans said:


> Like using two 6sn7s in a dual 6j5 (single triode octal) adapter? Never tried it.  Two totally different pin layouts. Can’t imagine it would be good for the tubes or amp. So it sounds like it damaged the amp?


yeah ..the amp I just sold... Jesus Christ...the luck..


----------



## CAJames

Based on the pinouts it seems like it would be bad for the tubes. Hard to tell how the amp would react though.


----------



## therremans

JKDJedi said:


> yeah ..the amp I just sold... Jesus Christ...the luck..


Well hopefully you got paid and it’s their amp and their (bad, “unlucky”) choices they have to live with. Which amp? DM me if you need.


----------



## JKDJedi

therremans said:


> Well hopefully you got paid and it’s their amp and their (bad, “unlucky”) choices they have to live with. Which amp? DM me if you need.


thanks I'll do that soon as I get out of this supermarket..


----------



## leftside

JKDJedi said:


> yeah ..the amp I just sold... Jesus Christ...the luck..


Hopefully they live in an area with a good local tech. Good luck.


----------



## JKDJedi

leftside said:


> Hopefully they live in an area with a good local tech. Good luck.


thanks, if we're lucky it's just cables. I'm tempted to ship them a set.


----------



## Monsterzero

I picked these up a couple weeks ago. Westinghouse branded NU(I think?)
Man these might be ugly, but they really sound good!

I have a pair of Fivre inbound as well.


----------



## maxpudding

JKDJedi said:


> What happens if you drop dual triode tubes in an adapter designed for dual single triode tubes ? I sold the adapter and the buyer dropped dual triode tubes in there, now their amp has distortion.



Lots of frustration can happen


----------



## mordy

Monsterzero said:


> I picked these up a couple weeks ago. Westinghouse branded NU(I think?)
> Man these might be ugly, but they really sound good!
> 
> I have a pair of Fivre inbound as well.


Are they 6J5GT tubes? Some of the NU tubes have triple micas.


----------



## Monsterzero (Jan 3, 2022)

mordy said:


> Are they 6J5GT tubes? Some of the NU tubes have triple micas.


Yes, theyre 6j5s. The seller advertised them as NU tubes, and based upon comments earlier in this thread, I decided to take the plunge.

TBH, they kinda sound like my dearly departed 'magic' Sylvania 6j5s, that I've been unable to replicate despite buying several pairs of Sylvania 6 and 12j5s since the magic pair died....either way, im very pleased with the sound. Very deep, prominent sub bass, and smooth, but sparkly highs.

Here's a better photo. You tell me....


----------



## Xcalibur255

The heat radiator fins and micas with only two "teeth" per side are both pretty uncommon construction details.  You may have gotten your hands on one of the more rare ones here.


----------



## whirlwind

Monsterzero said:


> Yes, theyre 6j5s. The seller advertised them as NU tubes, and based upon comments earlier in this thread, I decided to take the plunge.
> 
> TBH, they kinda sound like my dearly departed 'magic' Sylvania 6j5s, that I've been unable to replicate despite buying several pairs of Sylvania 6 and 12j5s since the magic pair died....either way, im very pleased with the sound. Very deep, prominent sub bass, and smooth, but sparkly highs.
> 
> Here's a better photo. You tell me....



If they are NU they are different than mine also.


----------



## mordy

Xcalibur255 said:


> The heat radiator fins and micas with only two "teeth" per side are both pretty uncommon construction details.  You may have gotten your hands on one of the more rare ones here.


I have one National Union 6J5GT but it looks completely different:



Triple round mica, top getter, ladder plate, (is it called) riveted plates? The date code HC could be May-June 1944.
I also have a Super Silvertone (Sears) 6J5GT with triple mica. The top mica is round but the other two look similar to Monsterzero's except for with three teeth. This one has round plate. The date code is 24X which I will make into July-August 1942 until somebody has better information.
Since I have only seen triple micas on National Union 6J5GT tubes I am guessing that this one is also made by National Union, but I may be wrong.



As I have said before, I don't know of any tube family like the 6J5 family that has such a large variety of construction and looks - it is very hard to find real pairs when buying lots and odds and ends.
But most of them sound very good no matter what construction.


----------



## triod750 (Jan 3, 2022)

My NU 6C5GT has two teeth on the mica that look like Monster's. Everything else is different, naturally. But that mica is a lookalike.

You can hardly see it on this photo: https://www.head-fi.org/threads/the-reference-6j5-thread-l63-6c5-12j5-6p5-etc.934653/post-16665414


----------



## triod750

Maybe it is made in the same factory as this Westinghouse 6B4G that Langrex is selling: https://www.ebay.co.uk/itm/312730683342?hash=item48d03387ce:g:stQAAOSw1XZdelYx


----------



## mordy

triod750 said:


> My NU 6C5GT has two teeth on the mica that look like Monster's. Everything else is different, naturally. But that mica is a lookalike.
> 
> You can hardly see it on this photo: https://www.head-fi.org/threads/the-reference-6j5-thread-l63-6c5-12j5-6p5-etc.934653/post-16665414


Don't think that you can compare the 6C5GT and 6J5GT tubes. Although electrically similar the construction is very different.


----------



## triod750

mordy said:


> Don't think that you can compare the 6C5GT and 6J5GT tubes. Although electrically similar the construction is very different.


I am aware of this. Maybe you can compare design of micas used?


----------



## Monsterzero

So, after looking at my Sylvania tubes and auctions on both NU and Sylvania 6j5s, I dont see another with the same construction, though to my untrained eyes, it looks closer to a Sylvania than an NU.


----------



## mordy

triod750 said:


> Maybe it is made in the same factory as this Westinghouse 6B4G that Langrex is selling: https://www.ebay.co.uk/itm/312730683342?hash=item48d03387ce:g:stQAAOSw1XZdelYx


The Westinghoue 6J5GT tube has a US passport.
The Westinghouse branded tube that Langrex is selling (and listing as US made) has a Russian passport with double inverted getter cups embedded.


----------



## triod750

mordy said:


> The Westinghoue 6J5GT tube has a US passport.
> The Westinghouse branded tube that Langrex is selling (and listing as US made) has a Russian passport with double inverted getter cups embedded.


Absolutely, in spite of presented as 'Made in USA', and I have told Langrex so on December 16. Seriously...


----------



## leftside

What do we have here? I presume someone recognizes the plate style? Must be an early tube with the foil/nipple getter.


----------



## therremans

leftside said:


> What do we have here? I presume someone recognizes the plate style? Must be an early tube with the foil/nipple getter.


Might be a Marconi L63 - https://www.ebay.com/itm/RARE-STRON...2349624.m46890.l49286&mkrid=710-127635-2958-0


----------



## Xcalibur255

This is definitely the first time I have seen that specific plate style.  Those rounded and extruded "ribs" on the anodes is distinctive.  It gives off the impression of very premium build quality.  Those little eyelet inserts that the support rods go through suggests it's European, I have never seen a US made 6J5 that uses that construction technique.

Very cool find!


----------



## Xcalibur255

therremans said:


> Might be a Marconi L63 - https://www.ebay.com/itm/RARE-STRON...2349624.m46890.l49286&mkrid=710-127635-2958-0



The detail on the micas isn't the same as the Marconi/GEC tubes I have seen.  Those L shaped cutout patterns are unique.  It certainly could be a Marconi still, just a rare variant of it that doesn't pop up often.  Perhaps the ones labeled VR67 were produced on a different line or location and had this different design?


----------



## leftside

therremans said:


> Might be a Marconi L63 - https://www.ebay.com/itm/RARE-STRON...2349624.m46890.l49286&mkrid=710-127635-2958-0


Same tubes 🙂 Those are my purchase. But the construction isn’t like any of the other MOV tubes I have. I’m sure I’ve seen that plate style elsewhere tho, but can’t remember.


----------



## mordy

Xcalibur255 said:


> This is definitely the first time I have seen that specific plate style.  Those rounded and extruded "ribs" on the anodes is distinctive.  It gives off the impression of very premium build quality.  Those little eyelet inserts that the support rods go through suggests it's European, I have never seen a US made 6J5 that uses that construction technique.
> 
> Very cool find!


Here is a 6J5GT tube with what seems like those riveted holes:



The brand is BesTest - who could the manufacturer be?


----------



## Xcalibur255

The bottom mica on that tube seems like it's meant for another design and is being subbed in.  Very unusual getter and heat fin radiators too.  6J5 have so many weird unicorn tubes.


----------



## mordy

Would you say that it might be a British unicorn?


----------



## Slade01

mordy said:


> Here is a 6J5GT tube with what seems like those riveted holes:
> 
> The brand is BesTest - who could the manufacturer be?



It looks closest to a Raytheon JAN-CRP to me.  I wish I still had my pair, but I swear they had those riveted holes on the bottom like this one.


----------



## Xcalibur255

Slade01 said:


> It looks closest to a Raytheon JAN-CRP to me.  I wish I still had my pair, but I swear they had those riveted holes on the bottom like this one.


I think this would be my guess too.  I had to eat my words pretty fast after making that comment about USA tubes not having those rivets.  Or perhaps not.  A lot of Raytheon tubes from this production era were actually made in Japan.  That's not necessarily the case here, but in general Raytheon produced quite a few tubes in Japan.


----------



## Slade01

Xcalibur255 said:


> I think this would be my guess too.  I had to eat my words pretty fast after making that comment about USA tubes not having those rivets.  Or perhaps not.  A lot of Raytheon tubes from this production era were actually made in Japan.  That's not necessarily the case here, but in general Raytheon produced quite a few tubes in Japan.



So interestingly enough, I found a picture of a pair on sale on ebay that look similar to what I had owned.  And it seems to have the same rivets.  Though oddly enough, I have never seen this internal construction in a rebranded tube until now.   

The other "clues" that really muddle things up -- i saw that BesTest 6J5GT tube on ebay as well.  It also utilizes in part the GE "Electronic Tube" script besides its own logo.   And the top has three smaller etched dots by the stop sign.   I know there is a significance to the dots around the stop sign logo, but I can't find the information right now unfortunately (to confirm if it was an early GE code scheme or not).  

It's a real mystery.


----------



## maxpudding

I always wondered about those 6J5WGT tubes. Seems there are quite some of them in the Japanese market.


----------



## maxpudding

Here's a pair of Philips ECG 6J5WGT






And:


----------



## mordy (Jan 6, 2022)

maxpudding said:


> Here's a pair of Philips ECG 6J5WGT
> 
> 
> 
> ...


Radiomuseum has a USA made Raytheon 6J5WGT pictured:
https://www.radiomuseum.org/tubes/tube_6j5wgt.html
It says that this tube first appeared in 1938, but I wonder if the WGT versions came later.


----------



## maxpudding

mordy said:


> Radiomuseum has a USA made Raytheon 6J5WGT pictured:
> https://www.radiomuseum.org/tubes/tube_6j5wgt.html
> It says that this tube first appeared in 1938, but I wonder if the WGT versions came later.


The PhilipsECG tubes in my post above were manufactured in 1986 😆


----------



## leftside

maxpudding said:


> The PhilipsECG tubes in my post above were manufactured in 1986 😆


I didn't realize they made 6J5 that late. This means they've been manufactured for around 50 years.


----------



## leftside

More Raytheon
https://www.ebay.com/itm/265479930506


----------



## leftside

Looking at the plates in the first photo from above, I thought they were the same as the plates in the photos I posted, but then in the second photo I see they are different.

I'm still not sure what mine are. I'll contact the seller again and see if he has more information. He's a good guy who I've purchased from before and we've communicated a fair bit.


----------



## mordy

leftside said:


> I didn't realize they made 6J5 that late. This means they've been manufactured for around 50 years.


The all metal 6J5 tubes were made in the 40s and 50s but abandoned because glass tubes were cheaper to make. You can find 6J5 metal tubes with dates from the 70's. My guess is that there was old stock lying around and they just put later dates on them - seems strange that they would start again to use the old manufacturing equipment.
This is just a guess on my side, but the possibility exists that old tubes got later dates put on them.


----------



## leftside

mordy said:


> The all metal 6J5 tubes were made in the 40s and 50s but abandoned because glass tubes were cheaper to make. You can find 6J5 metal tubes with dates from the 70's. My guess is that there was old stock lying around and they just put later dates on them - seems strange that they would start again to use the old manufacturing equipment.
> This is just a guess on my side, but the possibility exists that old tubes got later dates put on them.


The all glass tubes were also made in the 40s and 50s. I have some from the early 40's. According to this the earliest was 1937 https://www.radiomuseum.org/tubes/tube_6j5.html

A guy locally had some red metal Mullard Canadian 6J5 so I purchased a couple. I'll have to post up a picture.

Are there any metal 6SN7?


----------



## mordy

Slade01 said:


> So interestingly enough, I found a picture of a pair on sale on ebay that look similar to what I had owned.  And it seems to have the same rivets.  Though oddly enough, I have never seen this internal construction in a rebranded tube until now.
> 
> The other "clues" that really muddle things up -- i saw that BesTest 6J5GT tube on ebay as well.  It also utilizes in part the GE "Electronic Tube" script besides its own logo.   And the top has three smaller etched dots by the stop sign.   I know there is a significance to the dots around the stop sign logo, but I can't find the information right now unfortunately (to confirm if it was an early GE code scheme or not).
> 
> It's a real mystery.


Went through my stash of Raytheon 6J5GT/WGT tubes. I have around 6 such tubes + a couple of rebranded ones that might be Raytheon. The only Raytheon pair that looked similar in this batch was like the picture above with the red print och rivet holes (1959/1962); all the others each had different construction. There is really an incredible variety of construction in these tubes - makes me wonder if there is a similar variety in internal construction of the 6J5 metal tubes, but I am afraid that I will not find out...




Don't worry - this was a GE tube.
And here is a pretty picture of a late model Sylvania 6J5WGT:


----------



## mordy

leftside said:


> The all glass tubes were also made in the 40s and 50s. I have some from the early 40's. According to this the earliest was 1937 https://www.radiomuseum.org/tubes/tube_6j5.html
> 
> A guy locally had some red metal Mullard Canadian 6J5 so I purchased a couple. I'll have to post up a picture.
> 
> Are there any metal 6SN7?


To the best of my knowledge no metal 6SN7 but there are 6N7 all metal tubes.


----------



## whirlwind

I bought a decent size lot of Raytheon 12J5WGT tubes  I have about 5 sets too many, but the deal was to good to pass up.

Here is the construction of those


----------



## mordy

whirlwind said:


> I bought a decent size lot of Raytheon 12J5WGT tubes  I have about 5 sets too many, but the deal was to good to pass up.
> 
> Here is the construction of those


They look to have the same construction as the 6V tubes. The question I have is if they sound the same - I am not convinced that the same tube in 6 and 12V versions sound the same.


----------



## whirlwind

mordy said:


> They look to have the same construction as the 6V tubes. The question I have is if they sound the same - I am not convinced that the same tube in 6 and 12V versions sound the same.


Yeah, I have no idea as I don't have any 6V metal base Raytheon.

They sound good though, nice and quiet.


----------



## Isaacc7

mordy said:


> They look to have the same construction as the 6V tubes. The question I have is if they sound the same - I am not convinced that the same tube in 6 and 12V versions sound the same.


Why would they sound different? With an indirectly heated tubes the filament is only there for heat. Once proper temperature is achieved everything else works the same way. If everything else in the tube is the same the 12v and 6v will sound exactly the same.


----------



## mordy (Jan 7, 2022)

Isaacc7 said:


> Why would they sound different? With an indirectly heated tubes the filament is only there for heat. Once proper temperature is achieved everything else works the same way. If everything else in the tube is the same the 12v and 6v will sound exactly the same.



In theory you are right, but practically there may be differences depending on production run, materials etc.
My personal experience has been that identical looking pairs of tubes don't always sound the same.
(I am not speaking about certain tubes that can be run on both 6 and 12 V depending on how they are connected.)


----------



## Isaacc7

mordy said:


> In theory you are right, but practically there may be differences depending on production run, materials etc.
> My personal experience has been that identical looking pairs of tubes don't always sound the same.
> (I am not speaking about certain tubes that can be run on both 6 and 12 V depending on how they are connected.)


Well, following that thought process then there's no guarantee that 6v tubes that look the same will sound the same either. That's the path to madness. I'm already neurotic about tube choices, I don't need more things to worry about! lol


----------



## maxpudding

Isaacc7 said:


> Well, following that thought process then there's no guarantee that 6v tubes that look the same will sound the same either. That's the path to madness. I'm already neurotic about tube choices, I don't need more things to worry about! lol



We are indeed mad people here 😂


----------



## bcowen

maxpudding said:


> We are indeed mad people here 😂


Who's mad?  I'm happy as a clam.  Slightly insane, but blissfully so.  

But then the real question arises:  how exactly do we determine if a clam is happy?  🤣🤣


----------



## Slade01

bcowen said:


> Who's mad?  I'm happy as a clam.  Slightly insane, but blissfully so.
> 
> But then the real question arises:  how exactly do we determine if a clam is happy?  🤣🤣



LOL.  Random Fact:   Interestingly enough, the old (and original) adage of the "happy as a clam" is "happy as a clam in high water (or/at high tide)".   cux you know, it was safe (and happy) not to be eaten from predators.   but over time, that phrase got truncated to what it is now.


----------



## Monsterzero

bcowen said:


> But then the real question arises: how exactly do we determine if a clam is happy?


This is a family friendly forum...language, young man!!


----------



## pravous

Having a problem with a pair of tubes.  Fivre 6c5gt black base from Langrex.  Hissing at all volumes in both my OTLs from both channels so seems to be both tubes. Never had this happen before.  Did I get bum tubes?  Need to burn in and they will settle down?   Any advice would be appreciated.


----------



## Monsterzero

pravous said:


> Having a problem with a pair of tubes.  Fivre 6c5gt black base from Langrex.  Hissing at all volumes in both my OTLs from both channels so seems to be both tubes. Never had this happen before.  Did I get bum tubes?  Need to burn in and they will settle down?   Any advice would be appreciated.


Have you tried cleaning the pins?


----------



## pravous

These came so new and shiny I did not even consider it.  Gave them a once over with alcohol and a tip, no change.  




Here are some pics.


----------



## mordy

Monsterzero said:


> Have you tried cleaning the pins?


Gently scrape the pins and give it a try. if no change, let them burn in for say 20 hours to see if the hiss goes away. 
If not, ask Langrex to replace them.
Sometimes I have luck heating the tube pins with a soldering iron for 30 seconds each pin, but this method of re-flowing the solder seems to help more for pops and ticks but worth a try for the hissing sound. (Usually does not help for hum).


----------



## pravous

Will try both tomorrow.  Thanks for all the helpful tips.  On a happier note first listen on some Brimar 6c5g.  Very happy with initial impressions.


----------



## Monsterzero

mordy said:


> heating the tube pins with a soldering iron for 30 seconds


FWIW, thats what killed my magic pair of Sylvania. Proceed with caution.


----------



## mordy

Monsterzero said:


> FWIW, thats what killed my magic pair of Sylvania. Proceed with caution.


Sorry to hear that.
I use an old 50W soldering iron and touch the tip of the soldering iron to each pin, making sure to time it with a watch for 30 seconds. I am holding the tube slanted so that if the solder starts to flow it will flow away from the tube (happens rarely that the solder starts flowing. And if that happens, I stop.).
So far I did not ruin any tube. Some tubes I was able to resuscitate and take away the loud pops and crackling and hiss; some others did not respond to this treatment.
All part of the tube mystique. I have also found that it is not unusual for very old 60-80 year old tubes to be grumpy when you wake them up after their decades of sleep. It could take several hours of burn-in for noises such as crackling, ticking and other sounds to go away.


----------



## Marutks

pravous said:


> Having a problem with a pair of tubes.  Fivre 6c5gt black base from Langrex.  Hissing at all volumes in both my OTLs from both channels so seems to be both tubes. Never had this happen before.  Did I get bum tubes?  Need to burn in and they will settle down?   Any advice would be appreciated.



Bum tubes.  I bought a pair of Fivre 6c5gt black base from Langrex and they had the same problem.  I had never heard any tubes hissing so much !
They asked me to return the tubes.  I sent them the tubes but they later said they never received tubes.  
Maybe they sold the same pair to you.


----------



## mordy

Marutks said:


> Bum tubes.  I bought a pair of Fivre 6c5gt black base from Langrex and they had the same problem.  I had never heard any tubes hissing so much !
> They asked me to return the tubes.  I sent them the tubes but they later said they never received tubes.
> Maybe they sold the same pair to you.


Tracking?


----------



## CaptainFantastic

Marutks said:


> Bum tubes.  I bought a pair of Fivre 6c5gt black base from Langrex and they had the same problem.  I had never heard any tubes hissing so much !
> They asked me to return the tubes.  I sent them the tubes but they later said they never received tubes.
> Maybe they sold the same pair to you.


I had a problem with the same type of tubes (bought indirectly from Langrex). One of the tubes had very, very, very low volume. It hasn't happened to me with other 6J5 or any other tubes.


----------



## Marutks

mordy said:


> Tracking?



I sent them without tracking.    I have never heard of RM losing parcels.


----------



## whirlwind

pravous said:


> Will try both tomorrow.  Thanks for all the helpful tips.  On a happier note first listen on some Brimar 6c5g.  Very happy with initial impressions.



Nice tubes/amp....I would give the noisy ones some time to settle down.
They were probably laying away on a shelf somewhere sleeping, and need some time to wake up.
Sometimes they wake up and sometimes they don't.


----------



## Monsterzero

I picked up two more pairs of the NU.
First pair has a very similar construction to my Westinghouse pair. 
Second pair looks to be different construction as Westinghouse. Im curious to see if they sound similar.

will report back when they arrive.


----------



## whirlwind

Monsterzero said:


> I picked up two more pairs of the NU.
> First pair has a very similar construction to my Westinghouse pair.
> Second pair looks to be different construction as Westinghouse. Im curious to see if they sound similar.
> 
> will report back when they arrive.


Nice!


----------



## mordy

More mysterious codes:



On the left is a GE tube, on the right a RCA tube. The date codes are 4-26 and 4-17. Easy?
Logically it should be the 26 and 17th weeks of 1954? (June and April 1954)

But the numbers 26 and 17 are not a week or a quarter code. It is a month code that looks like a week code. There are only 12 different ones (except on tubes made for the military, which have actual weeks)
The 12 month codes are 04, 09, 13, 17, 22, 26, 30, 35, 39, 43, 48, and 52. 

OK - but the results are the same using both methods: 26 is June and 17 is April. So instead of knowing the precise week we know which month....

Maybe a saving in using 12 instead of 52 numbers lol?


----------



## Isaacc7

whirlwind said:


> I bought a decent size lot of Raytheon 12J5WGT tubes  I have about 5 sets too many, but the deal was to good to pass up.
> 
> Here is the construction of those


How do they sound? I found one of these in my stash. Love the look but I’d need to get three more to use them in my preamp. Wonder if it’s worth doing.


----------



## Isaacc7

maxpudding said:


> Here's a pair of Philips ECG 6J5WGT
> 
> 
> 
> ...


Those Philips look like the classic, “Crap, we have to fill this contract For 6j5gt tubes but we haven’t made them in decades! I know, just take our 6sntgtb and only have one triode connected at the pins. Done!” Things got weird in the last days of tube manufacturing in the US. You can find tubes labeled 6b4g (which should be a triode, an Indirectly heated 2a3 with a 6v filament) but have the guts of a 6av5, a TV pentode. Turns out that if you triode wire a 6av5 it was close enough to a 6b4 in a particular task, probably as pass elements in a voltage regulator. Instead of retooling a factory for an old tube for a last run, just repurpose what you have. Close enough for government work! 

You’ll also see a bunch of other weird things like the guts of a 6l6gc in a 6bg6gt, or a 6dq6 stuffed into a tube labeled 6av5. I own a pair of tubes labeled Sylvania 6ez5 that are actually GE 6v6gt. They sound pretty good too despite GE’s reputation.


----------



## Isaacc7

As bad as my current tube buying habits are, I bought a much larger quantity a couple of decades ago when I had DIY aspirations. Stocked up on useful tubes in different voltages and bases. Oh how I wish I stuck to the regular tubes and bought up things that would appreciate in value!

Anyway, amongst my stash I have a bunch of 12j5gt tubes. And of those I have two types that I might get around to trying some day. I have a bunch of the Sylvania tubes that have what appear to be round plates. I’m a fan of their 6sn7 tubes but I don’t recall ever seeing a 6sn7 with the same construction. Maybe I’ll try them some day…

I also have a bunch of JAN Tungsol 12j5gt tubes in the original packaging. Thought folks here might get a kick out of seeing it. 




All of my tubes have the same packaging. Safe to say the tubes were made before 1945 I guess. Inside they are in a trapezoidal corrugated cardboard sleeve.




And here is the actual tube:









To use any of these I would need to buy two adapters and use 4 at a time in my preamp. Seeing as I have… many 12sn7 tubes I’m not sure I’ll ever get around to trying these but we’ll see if my tube rolling mania gets the better of me lol.


----------



## jonathan c

Isaacc7 said:


> As bad as my current tube buying habits are, I bought a much larger quantity a couple of decades ago when I had DIY aspirations. Stocked up on useful tubes in different voltages and bases. Oh how I wish I stuck to the regular tubes and bought up things that would appreciate in value!
> 
> Anyway, amongst my stash I have a bunch of 12j5gt tubes. And of those I have two types that I might get around to trying some day. I have a bunch of the Sylvania tubes that have what appear to be round plates. I’m a fan of their 6sn7 tubes but I don’t recall ever seeing a 6sn7 with the same construction. Maybe I’ll try them some day…
> 
> ...


This may be of interest to you. The Linear Tube Audio MZ3 headphone amplifier does take two 12SN7 + two 12AT7 tubes without adapters. On the pcb is a ‘12SN7 / 6SN7’ switch which is easily accessed when the cover is taken off (six screws).


----------



## Isaacc7

jonathan c said:


> This may be of interest to you. The Linear Tube Audio MZ3 headphone amplifier does take two 12SN7 + two 12AT7 tubes without adapters. On the pcb is a ‘12SN7 / 6SN7’ switch which is easily accessed when the cover is taken off (six screws).


Thanks for the info! My current preamp (Supratek Cabernet) allows me to use either 6sn7 or 12sn7 tubes So I am putting my 12v tubes to good use. I was explaining that in order to use 12j5 tubes I would need to buy a couple adapters and use 4 tubes at a time. That sounds fun but I can’t really justify that right now since I have so many 12sn7 and 6sn7 tubes to go through. Oh, I also have equivalents like 7n7/14n7 and 6f8g. So many tubes!


----------



## leftside

Isaacc7 said:


> Thanks for the info! My current preamp (Supratek Cabernet) allows me to use either 6sn7 or 12sn7 tubes So I am putting my 12v tubes to good use. I was explaining that in order to use 12j5 tubes I would need to buy a couple adapters and use 4 tubes at a time. That sounds fun but I can’t really justify that right now since I have so many 12sn7 and 6sn7 tubes to go through. Oh, I also have equivalents like 7n7/14n7 and 6f8g. So many tubes!


I have a similar preamp. You must have got Mick to put in a 12v switch for you? I've used 4 6J5 with two adapters with that preamp.

I can use 12SN7 in one of my headphone amps, so with an adapter I can use 2 12J5 tubes. Those TS you have look great.


----------



## Xcalibur255

I actually tried the whole 6AV5 thing a long time ago in an amp that was modified to operate 6B4Gs.  Had this "bright" idea to buy one of those cheapo Chinese tube amps and see if a few tweaks could make it good.  The 6AV5 oscillated like crazy because the adapters needed snubbers and didn't have them, and that was the end of it.  That amp is still sitting somewhere in Glenn's garage with a blown left channel after I had the nerve to try to adjust the volume with socks on one day......  The whole thing was just a pet project but still a waste of money.


----------



## Isaacc7

leftside said:


> I have a similar preamp. You must have got Mick to put in a 12v switch for you? I've used 4 6J5 with two adapters with that preamp.
> 
> I can use 12SN7 in one of my headphone amps, so with an adapter I can use 2 12J5 tubes. Those TS you have look great.


Yeah, had him put in a switch so I can use either 6sn7 or 12sn7. It cost an extra $500 which gave me pause but it was a good decision. It has allowed me to use some tubes I might not otherwise be able to find/afford like the tungsol RP and Sylvania “bad boys.” It also lets me use things like the 12sx7 and 14n7 (which are actually a little different than the 7n7). Of course I’m currently using some 6f8g tubes that wouldn’t have needed the extra switch lol. 

I would love to try some non 6sn7 tubes in there like the 2c50 or 7af7 but Mick said the Cabernet is not designed for that. He said that it “would not like it” if I put in a different tube. I don’t actually know what that means but I spent enough on it that I’m not going to tempt fate!


----------



## Isaacc7

Xcalibur255 said:


> I actually tried the whole 6AV5 thing a long time ago in an amp that was modified to operate 6B4Gs.  Had this "bright" idea to buy one of those cheapo Chinese tube amps and see if a few tweaks could make it good.  The 6AV5 oscillated like crazy because the adapters needed snubbers and didn't have them, and that was the end of it.  That amp is still sitting somewhere in Glenn's garage with a blown left channel after I had the nerve to try to adjust the volume with socks on one day......  The whole thing was just a pet project but still a waste of money.


Years ago I stumbled across the epic “Edcor meets the 6av5” thread on DIYaudio. I blame it for giving me DIY pretentions. Sounds like it can be an amazing tube but yeah, as George found out they oscillate unless you take precautions. I still would love to have an amp that uses them. Just love the idea of getting great sound out of a useless TV tube.


----------



## mordy

Isaacc7 said:


> Years ago I stumbled across the epic “Edcor meets the 6av5” thread on DIYaudio. I blame it for giving me DIY pretentions. Sounds like it can be an amazing tube but yeah, as George found out they oscillate unless you take precautions. I still would love to have an amp that uses them. Just love the idea of getting great sound out of a useless TV tube.


Well, I am getting great sound out of "useless TV tubes" like 6EJ7/EF184 and variants in the SW51+.


----------



## CaptainFantastic

Quick question:

With respect to the GEC/Osram/Marconi metal base tubes, what is the difference between the ones marked L63 and the ones marked CV1067? Is it essentially the same tube? Can they be paired?


----------



## mordy (Jan 21, 2022)

CaptainFantastic said:


> Quick question:
> 
> With respect to the GEC/Osram/Marconi metal base tubes, what is the difference between the ones marked L63 and the ones marked CV1067? Is it essentially the same tube? Can they be paired?


I always thought that they were the same but the Radiomuseum says slightly different:
https://www.radiomuseum.org/tubes/tube_cv1067.html
Personally, I think that there is no problem mix and match, but maybe somebody else can weigh in on this.
The Valve Museum considers it a "sensibly equivalent":
http://www.r-type.org/exhib/abi0057.htm


----------



## mordy

Here is an interesting explanation of "Sensibly equivalent":

http://www.r-type.org/static/eqi-ex.htm


----------



## RobertSM

mordy said:


> Here is an interesting explanation of "Sensibly equivalent":
> 
> http://www.r-type.org/static/eqi-ex.htm



I've spent a good amount of time on this site but somehow haven't come across this page and article. Thank you for sharing!


----------



## jonathan c

Thank you, @mordy! A good primer. I just hope that my ‘hearing’ in the day is _sensibly equivalent _to my ‘hearing’ in the next day…🙂…


----------



## raindownthunda

It's been a while since there's been any love for the metal children in this family. It feels wrong to admit how good these GE 6C5 sound...


----------



## therremans

raindownthunda said:


> It's been a while since there's been any love for the metal children in this family. It feels wrong to admit how good these GE 6C5 sound...


I recently ordered some Ken Rad 6C5s. Wonderful tubes with the right pairing. For me it’s a Mullard or GEC 6080 and Senn HD6XX. Jazz all day with that setup.


----------



## maxpudding

Can’t go wrong with those all metal tubes, nice bass


----------



## mordy

raindownthunda said:


> It's been a while since there's been any love for the metal children in this family. It feels wrong to admit how good these GE 6C5 sound...


I have been saying for a long time that certain GE tubes sound very good, and these and the 6J5 metal ones are among them. (I know that GE tubes don't get much love, but there are exceptions to every rule.)


----------



## therremans

mordy said:


> I have been saying for a long time that certain GE tubes sound very good, and these and the 6J5 metal ones are among them. (I know that GE tubes don't get much love, but there are exceptions to every rule.)


Yeah, most notably the 5692 red base. Also some 9 pin tubes like the 6C4.


----------



## mordy

therremans said:


> Yeah, most notably the 5692 red base. Also some 9 pin tubes like the 6C4.


Add 5687 as well.


----------



## pravous

Has anyone played around with type 76 or 37 tubes?   Looking for some recommendations to try in 6j5 slots with an adaptor.


----------



## jonathan c

When the ‘6J5+6J5’ adapter arrives soon, these will be atop the Schiit Lyr 3….


----------



## CAJames

pravous said:


> Has anyone played around with type 76 or 37 tubes?   Looking for some recommendations to try in 6j5 slots with an adaptor.



Yes, I'm a big fan of those types. I've been listening to RCA "silver meatball" 76s in my system from the last couple of months and am in no hurry to change them out. If you are just getting started an easy recommendation is the Sylvania VT37s at Langrex. Note that both a 37 and 76 have less gain than pretty much any other driver tube I've used, so if that is an issue the UX5 lifestyle might not be for you.


----------



## pravous

CAJames said:


> Yes, I'm a big fan of those types. I've been listening to RCA "silver meatball" 76s in my system from the last couple of months and am in no hurry to change them out. If you are just getting started an easy recommendation is the Sylvania VT37s at Langrex. Note that both a 37 and 76 have less gain than pretty much any other driver tube I've used, so if that is an issue the UX5 lifestyle might not be for you.


Thanks for the tips.  My amp builder gave me the green light and said the gain was 6j5>76>37.  Found a couple of pairs of 76 and a pair of 37 globes.  Now the waiting game for the Deyan adaptors.  Really curious how these Philco globes sound.


----------



## mordy

Has anybody used EF37A tubes?


----------



## leftside

pravous said:


> Has anyone played around with type 76 or 37 tubes?   Looking for some recommendations to try in 6j5 slots with an adaptor.


What adapters are you using for the 37 tubes?

I use 76 tubes (76 to 6J5 adapters) and like them for sure. I have some Fivre 76 tubes.


----------



## pravous

Deyan said the 37s use the same adapter as the 76.


----------



## CAJames

leftside said:


> What adapters are you using for the 37 tubes?
> 
> I use 76 tubes (76 to 6J5 adapters) and like them for sure. I have some Fivre 76 tubes.



You use the same adapter for 37 and 76.


----------



## maxpudding

CAJames said:


> You use the same adapter for 37 and 76.


Time to hunt for some 37 tubes


----------



## bcowen

maxpudding said:


> Time to hunt for some 37 tubes


Just like the universe, the rabbit hole is continuously expanding.  🤣🤣


----------



## maxpudding

bcowen said:


> Just like the universe, the rabbit hole is continuously expanding.  🤣🤣



😆 “Just when I thought I was out, they pull me back in!”


----------



## Slade01

bcowen said:


> Just like the universe, the rabbit hole is continuously expanding.  🤣🤣


Speaking of which I think the type 27 and type 56 are the next levels of the rabbit hole after the 37/76?  I always admired the blue glassed arcturus type 27.


----------



## mordy

Slade01 said:


> Speaking of which I think the type 27 and type 56 are the next levels of the rabbit hole after the 37/76?  I always admired the blue glassed arcturus type 27.


I may be wrong, but I think I remember reading that the 27 tubes can be very noisy and you may have to sort through a lot of them to find a quiet pair.


----------



## leftside

CAJames said:


> You use the same adapter for 37 and 76.


Oh no. Lol. I've been doing really well this year not buying more tubes...


----------



## bcowen

leftside said:


> Oh no. Lol. I've been doing really well this year not buying more tubes...


All bad things must come to an end.  😆


----------



## Slade01

mordy said:


> I may be wrong, but I think I remember reading that the 27 tubes can be very noisy and you may have to sort through a lot of them to find a quiet pair.


Not wrong - these are the early predecessors so I'm sure noise and microphonics increase with age and earlier designs.  But they are pretty.  Lol.


----------



## pravous

Type 27 would require heater voltage change.  From what I have read "The heater operates at 2.5V and consumes 1.75A."  Same with the 56, 2.5V and 1A.


----------



## jonathan c (Feb 8, 2022)

Well, based on post #1,894 by @raindownthunda, these are on the way for use in an adapter for a Schiit Lyr 3…😳 I know, it’s GE…but not even $30…🤪


----------



## bcowen

jonathan c said:


> Well, based on post #1,894 by @raindownthunda, these are on the way for use in an adapter for a Schiit Lyr 3…😳 I know, it’s GE…but not even $30…🤪


You mean you were paid $30 to take them?  Not _too _terrible a deal...


----------



## mordy

Came across a fascinating story how the US army used sound deception during WW2 to give the enemy the impression that they were being attacked by thousands of soldiers and tanks by using mobile units with loud speakers and inflatable tanks and artillery pieces.
Looks like they used 16" records that were transferred to wire recordings.
Wonder if any of those huge horn speakers survived - should have great low bass!

https://historyofyesterday.com/the-ghost-army-of-world-war-ii-5ca05269e9c1
Great name for a line of tube amps: Sonic Deception


----------



## bcowen

mordy said:


> Came across a fascinating story how the US army used sound deception during WW2 to give the enemy the impression that they were being attacked by thousands of soldiers and tanks by using mobile units with loud speakers and inflatable tanks and artillery pieces.
> Looks like they used 16" records that were transferred to wire recordings.
> Wonder if any of those huge horn speakers survived - should have great low bass!
> 
> ...



That's pretty cool.  I'd seen the inflatable tanks/artillery before, but not the speakers.  Project sound for 15 _miles?_ I'd hate to be in the nearfield for one of those.


----------



## mordy

bcowen said:


> That's pretty cool.  I'd seen the inflatable tanks/artillery before, but not the speakers.  Project sound for 15 _miles?_ I'd hate to be in the nearfield for one of those.


The 15 miles range was over water - you will need a big pool lol.


----------



## jonathan c

bcowen said:


> That's pretty cool.  I'd seen the inflatable tanks/artillery before, but not the speakers.  Project sound for 15 _miles?_ I'd hate to be in the nearfield for one of those.


Can you imagine if GE tubes were used in those speakers’ amps? The Normandy invasion wouldn’t have been needed…


----------



## CaptainFantastic

Added this to my basket for $40 on good advice that Ken Rad metal 6J5s are worth it  . Please tell me Brimar in this case does not mean GE.


----------



## bcowen

CaptainFantastic said:


> Added this to my basket for $40 on good advice that Ken Rad metal 6J5s are worth it  . Please tell me Brimar in this case does not mean GE.


I think it's pretty safe to say that those are not GE's.   I've never heard any Brimar tin cans.  Be interested to hear what you think of them.


----------



## mordy

CaptainFantastic said:


> Added this to my basket for $40 on good advice that Ken Rad metal 6J5s are worth it  . Please tell me Brimar in this case does not mean GE.


There is a good possibility that these tubes are Ken-Rads. I have Brimar labelled Ken-Rad 6J5GT tubes from the 40s.

LOL,  you should be able to tell from the good bass which is the house sound of the Ken-Rads.


----------



## jonathan c

CaptainFantastic said:


> Added this to my basket for $40 on good advice that Ken Rad metal 6J5s are worth it  . Please tell me Brimar in this case does not mean GE.


made in USA…rebrand from ???…K-R…GE…Sylvania?…


----------



## bcowen

mordy said:


> There is a good possibility that these tubes are Ken-Rads. I have Brimar labelled Ken-Rad 6J5GT tubes from the 40s.
> 
> LOL,  you should be able to tell from the good bass which is the house sound of the Ken-Rads.


LOL! 

And if it sounds like you just stuffed your HP's earcups full of wet cotton balls, they would be GE's.  😂


----------



## jonathan c

bcowen said:


> LOL!
> 
> And if it sounds like you just stuffed your HP's earcups full of wet cotton balls, they would be GE's.  😂


Oh…is that the tip-off?…I was thinking along the lines of 07-Dec-1941…sirens & explosions…


----------



## leftside

I have some great GE power tubes. When I get time I’ll post up in the EL34/KT66/etc thread.


----------



## jonathan c

leftside said:


> I have some great GE power tubes. When I get time I’ll post up in the EL34/KT66/etc thread.


I do like the GE 5998A…own four…


----------



## mordy

jonathan c said:


> I do like the GE 5998A…own four…


I have some metal GE 6C5 that sound very good; also the GE 5687.
Every rule has exceptions...


----------



## Isaacc7

mordy said:


> I have some metal GE 6C5 that sound very good; also the GE 5687.
> Every rule has exceptions...


Yup, I have some Sylvania branded GE 6ez5 tubes that sound quite nice in my amp.


----------



## whirlwind

I need to get some Ken Rad metal tubes.  I like the general house sound of the old 1940 Ken Rads
All seem to have great bass


----------



## Xcalibur255

The Ken-Rad name seems to be a crapshoot on these tubes.  I bought a pair of 6J5G that are labeled Ken-Rad and I'm 99% sure they are not Ken-Rads.  They're pretty much the exact opposite of the Ken-Rad house sound.  Ended up being horribly noisy too unfortunately.  I keep smacking the one in my palm and that will settle it down for a day or two but it always comes back.

I have basically decided the thing to do is associate a particular sound with the physical construction details of the tube and pay no mind to the brand name printed on it.  This is why I haven't bought any metal cans, I really want to be able to see the guts of the tube to know what I'm getting.


----------



## therremans

Xcalibur255 said:


> The Ken-Rad name seems to be a crapshoot on these tubes.  I bought a pair of 6J5G that are labeled Ken-Rad and I'm 99% sure they are not Ken-Rads.  They're pretty much the exact opposite of the Ken-Rad house sound.  Ended up being horribly noisy too unfortunately.  I keep smacking the one in my palm and that will settle it down for a day or two but it always comes back.
> 
> I have basically decided the thing to do is associate a particular sound with the physical construction details of the tube and pay no mind to the brand name printed on it.  This is why I haven't bought any metal cans, I really want to be able to see the guts of the tube to know what I'm getting.


Bummer, try sticking to VT-65 and VT-94, that’s what I’ve been doing for my metal tubes. Try the KR VT-65. I purchased mine from this seller below and they sound great for jazz on my HD6XX. I didn’t care for them with my DT-1990s.

https://www.ebay.com/itm/6C5-VT65-J...2349624.m46890.l49286&mkrid=711-127632-2357-0


----------



## mordy

Xcalibur255 said:


> The Ken-Rad name seems to be a crapshoot on these tubes.  I bought a pair of 6J5G that are labeled Ken-Rad and I'm 99% sure they are not Ken-Rads.  They're pretty much the exact opposite of the Ken-Rad house sound.  Ended up being horribly noisy too unfortunately.  I keep smacking the one in my palm and that will settle it down for a day or two but it always comes back.
> 
> I have basically decided the thing to do is associate a particular sound with the physical construction details of the tube and pay no mind to the brand name printed on it.  This is why I haven't bought any metal cans, I really want to be able to see the guts of the tube to know what I'm getting.


Ken-Rad was sold to GE in 1945 and GE continued to use the name for a couple of years.

The upside of the metal tubes is that they are not in demand and you can buy them at low prices.
There is something strange going on with these tubes that were introduced in the 30’s - you can find tubes dated in the 70’s.


----------



## CAJames

mordy said:


> Ken-Rad was sold to GE in 1945 and GE continued to use the name for a couple of years.
> 
> The upside of the metal tubes is that they are not in demand and you can buy them at low prices.
> There is something strange going on with these tubes that were introduced in the 30’s - you can find tubes dated in the 70’s.



They were still needed as replacements. A lot of vacuum tube equipment stuck around for many years after semiconductors became popular.


----------



## mordy

CAJames said:


> They were still needed as replacements. A lot of vacuum tube equipment stuck around for many years after semiconductors became popular.


Do you think these were old tubes from storage that were given new dates? Or new production?


----------



## CAJames

mordy said:


> Do you think these were old tubes from storage that were given new dates? Or new production?



My guess would be new production.


----------



## Velozity

Since we're on the topic, here's a treasure trove of Ken-Rad dual-branded Cossor 6C5 VT-65 that I stumbled upon last year.  I have three more not pictured.  I love the boxes with the price labels.


----------



## Monsterzero

Velozity said:


> Since we're on the topic, here's a treasure trove of Ken-Rad dual-branded Cossor 6C5 VT-65 that I stumbled upon last year.  I have three more not pictured.  I love the boxes with the price labels.


sooo....im  confused. Are those KRs or Cossor? How do they sound vs. regular KenRads?


----------



## Velozity

Monsterzero said:


> sooo....im  confused. Are those KRs or Cossor? How do they sound vs. regular KenRads?



I've assumed they're KR because I haven't seen a British metal can tube yet to compare.  By the same token I don't have and haven't heard any other KR drivers so I don't have a point of reference for the sound.  The bass is amazing though.  Aside from what's painted on the cans the only other characters stamped in the metal is "4-" at the base as seen on the tube on the right in the second picture.  This is a mystery for the sleuths I guess.  @gibosi?


----------



## therremans

Answer is 100% Ken-Rad. Cossor commonly rebranded tubes from what I’ve seen, including Soviet made.


----------



## mordy

Velozity said:


> I've assumed they're KR because I haven't seen a British metal can tube yet to compare.  By the same token I don't have and haven't heard any other KR drivers so I don't have a point of reference for the sound.  The bass is amazing though.  Aside from what's painted on the cans the only other characters stamped in the metal is "4-" at the base as seen on the tube on the right in the second picture.  This is a mystery for the sleuths I guess.  @gibosi?


Since the tubes clearly state USA (and not Gt Britain) we have to assume that they were made in USA and by Ken-Rad. 
The date code shown is S 4. Starting the alphabet from M (one system for coding months is A-L; another system is starting from M and omitting O and Q which may look like 0 [zero]. Thus S = May. The 4 would be 1944.


----------



## triod750

So my 'R4' is April -44 then. Thanks Mordy. Good tubes.


----------



## whirlwind

I see VT65, so I am going to say these are made from Ken Rad. Made in USA in 1944.


----------



## triod750

This JAN-CKR-6C5 performs so well with 6BX7GT that I just bought a pair from -43. Production month to be seen when their boxes will be opened for the first time. The combination makes for really relaxed listening. Mordy told me this long ago but I am a bit slow.


----------



## maxpudding (Feb 12, 2022)

Hi @gibosi any idea on how to read the label codes on these 6J5 tubes. Appreciate your expertise





I'm guessing it’s Feb 1978? 😅


----------



## Monsterzero (Feb 12, 2022)

Has anyone tried these Fivre 6c5? Brown or black base? Thoughts?


----------



## triod750

maxpudding said:


> Hi @gibosi any idea on how to read the label codes on these 6J5 tubes. Appreciate your expertise
> 
> 
> 
> I'm guessing it’s Feb 1978? 😅


Mordy has told me that this isn't a date code but a military 'stamp of control', comparable to the Soviet 'OTK'. I don't remember the details. I think the number is the number of the controller. Maybe.

I am looking at an RCA 6C5 here, with the code H3E. I suppose this is the date code. On my JAN-CKR-6C5, the date code is R4.

But let's wait for the guys with knowledge...


----------



## pravous

Monsterzero said:


> Has anyone tried these Fivre 6c5? Brown or black base? Thoughts?


I bought the black base ones from Langrex.  They had a terrible hiss.  Tried burning them in  for 30+ hours and it did not improve.  Ultimately ended up returning them for a refund.


----------



## Marutks

pravous said:


> I bought the black base ones from Langrex.  They had a terrible hiss.  Tried burning them in  for 30+ hours and it did not improve.  Ultimately ended up returning them for a refund.



I also had bought black base ones from Langrex.   The same problem.   terrible hiss !
Returned them but I got no refund.


----------



## therremans (Feb 12, 2022)

Langrex has been a stand up individual in my experience. One of my GEC L63’s had a minor low register hum that didn’t go away after months. It wasn’t going to. I wrote to explain the issue and try to find a resolution, not even requesting a new tube but he sent me a nice replacement at no charge and he made sure my getters matched. (Re-soldering the pins didn’t fix it either.)

My most recent purchase was this Fivre 6SN7.


----------



## gibosi

maxpudding said:


> Hi @gibosi any idea on how to read the label codes on these 6J5 tubes. Appreciate your expertise
> 
> 
> 
> I'm guessing it’s Feb 1978? 😅



As above, this isn't a date code. It has something to do with the Army Signal Corp. The date code on RCA metal tubes was usually stamped into the base ring of the tube. Typically, there is a letter for the year and a number (1 - 6) indicating a two-month interval. 

Letters are in no particular order. For example, H = 1944, A = 1945 and so on. And for the months, 1 = Jan -Feb. and so on. Further, to indicate either Jan or Feb, the year/month indicator is reversed. For example, C6 = Nov 1950 and 6C = Dec 1950.

So do you see anything stamped into the base ring?


----------



## jonathan c

gibosi said:


> As above, this isn't a date code. It has something to do with the Army Signal Corp. The date code on RCA metal tubes was usually stamped into the base ring of the tube. Typically, there is a letter for the year and a number (1 - 6) indicating a two-month interval.
> 
> Letters are in no particular order. For example, H = 1944, A = 1945 and so on. And for the months, 1 = Jan -Feb. and so on. Further, to indicate either Jan or Feb, the year/month indicator is reversed. For example, C6 = Nov 1950 and 6C = Dec 1950.
> 
> So do you see anything stamped into the base ring?


Could the letters be for ‘Signal Corps: Army’?….


----------



## triod750

I received one 6J5 in a tube lot and when consulting @bcowen I understood that it is 'the best a man can get'. The plant code is 188-4 and I don't know where this is. Date code is 57-17 and acceptance date for Swedish military is November -60. So where was this 188-4 plant?
I can't bring myself to use this tube since it is so valuable. I paid almost one dollar for it and received nine white dots on the black tube for my money.


----------



## gibosi

"188" is General Electric based in the old Ken Rad factory in Owensboro, KY, USA. But they stamped this number on all their tubes, even those purchased from other companies. And I see that you are joking.


----------



## bcowen

gibosi said:


> "188" is General Electric based in the old Ken Rad factory in Owensboro, KY, USA. But they stamped this number on all their tubes, even those purchased from other companies. And I see that you are joking.


ROFL!  bcowen, like, and GE all used in the same sentence would likely blow up the internet.


----------



## triod750

Said (sad?) bcowen told me that these tubes need to be broken in for at least two hours before showing their true capacity but this is just hearsay since he hasn't tried any of them for such a long period.

Anyway, I have previously only seen the EIA code 188-5 on GE tubes, which is supposed to be another plant (or factory, as we in developed countries say).


----------



## triod750

https://antiqueradios.com/forums/viewtopic.php?t=230932 GE Tube plant/date codes. Can't find 188-4 there.


----------



## bcowen

triod750 said:


> https://antiqueradios.com/forums/viewtopic.php?t=230932 GE Tube plant/date codes. Can't find 188-4 there.


According to this, 188-4 was also Owensboro, KY.  I'm not familiar with the Owensboro facility layout, but if they had multiple buildings on that site it could have been a way of identifying them. 

http://pax-comm.com/pa01017.htm


----------



## mordy

maxpudding said:


> Hi @gibosi any idea on how to read the label codes on these 6J5 tubes. Appreciate your expertise
> 
> 
> 
> I'm guessing it’s Feb 1978? 😅


The code means Signal Corps, inspector 278A. This is similar to the Russian military OTK code which was just a quality control inspection stamp. 
And speaking of stamps, those beautiful colored large labels with stamps on the Italian old tubes are just tax exempt stamps - the government wanted to promote vacuum tube production. The dates on them I don't think are linked to manufacturing dates.



Seems like these stamps are worth their weight in gold - this 2A3 pair is listed for well over 4K...


----------



## mordy

triod750 said:


> Mordy has told me that this isn't a date code but a military 'stamp of control', comparable to the Soviet 'OTK'. I don't remember the details. I think the number is the number of the controller. Maybe.
> 
> I am looking at an RCA 6C5 here, with the code H3E. I suppose this is the date code. On my JAN-CKR-6C5, the date code is R4.
> 
> But let's wait for the guys with knowledge...


H3E
H = 1944
3  = March
E  = OEM 
Here is a good reference for RCA codes:
http://pax-comm.com/rcadates.pdf


----------



## jonathan c

bcowen said:


> ROFL!  bcowen, like, and GE all used in the same sentence would likely blow up the internet.


bcowen…..trust…..bangybang….all used in the same sentence would likely blow up the internet…💥 ⌨️ 🧨 💻 …


----------



## bcowen

jonathan c said:


> bcowen…..trust…..bangybang….all used in the same sentence would likely blow up the internet…💥 ⌨️ 🧨 💻 …


Ugh.  _That_ might create a black hole.


----------



## maxpudding (Feb 12, 2022)

gibosi said:


> As above, this isn't a date code. It has something to do with the Army Signal Corp. The date code on RCA metal tubes was usually stamped into the base ring of the tube. Typically, there is a letter for the year and a number (1 - 6) indicating a two-month interval.
> 
> Letters are in no particular order. For example, H = 1944, A = 1945 and so on. And for the months, 1 = Jan -Feb. and so on. Further, to indicate either Jan or Feb, the year/month indicator is reversed. For example, C6 = Nov 1950 and 6C = Dec 1950.
> 
> So do you see anything stamped into the base ring?



Ah I see, thank you for that bit of info about the placement of date codes for RCA metal tubes. Unfortunately I cannot see anything on the base ring that could indicate date codes…


----------



## gibosi

maxpudding said:


> Ah I see, thank you for that bit of info about the placement of date codes for RCA metal tubes. Unfortunately I cannot see anything on the base ring that could indicate date codes…



That's unfortunate. I thought you might see date codes and also "Q" which indicates 6J5. If the paint wore off, this enabled someone to know what kind of tube it is. It's disappointing that nothing is visible.


----------



## maxpudding

mordy said:


> The code means Signal Corps, inspector 278A. This is similar to the Russian military OTK code which was just a quality control inspection stamp.
> And speaking of stamps, those beautiful colored large labels with stamps on the Italian old tubes are just tax exempt stamps - the government wanted to promote vacuum tube production. The dates on them I don't think are linked to manufacturing dates.
> 
> Seems like these stamps are worth their weight in gold - this 2A3 pair is listed for well over 4K...



I have at least one Fivre 6C5Gs with that stamp. Bought them when the prices were still relatively low.


----------



## mordy

mordy said:


> H3E
> H = 1944
> 3  = March
> E  = OEM
> ...


Have to correct the above post. The second character (in this case the number 3) is a two month period. 1 = Jan-Feb, 2= March-April and three would be May-June.
H3E would then mean Original Equipment Manufacture May-June 1944.


----------



## maxpudding

gibosi said:


> That's unfortunate. I thought you might see date codes and also "Q" which indicates 6J5. If the paint wore off, this enabled someone to know what kind of tube it is. It's disappointing that nothing is visible.



I can only clearly see 6J5









Another way to make sure is probably I need to buy the tubes 🤣


----------



## mordy

maxpudding said:


> Ah I see, thank you for that bit of info about the placement of date codes for RCA metal tubes. Unfortunately I cannot see anything on the base ring that could indicate date codes…


I looked in my box of RCA 6J5 tubes and found a 6J5 with the SC 278A markings. This tube also has the following markings: Round RCA logo, JAN CRC-6J5 VT-94. Then it says MADE IN USA and underneath in small letters H1E meaning Jan-Feb 1944.
Now I also looked at the bottom ring under a magnifying glass: It says 1  5 in very tiny letters which are hard to see, and then the letter Q twice.
Do you mean to say that your tubes don't have any of these markings?


----------



## mordy

maxpudding said:


> I can only clearly see 6J5
> 
> 
> 
> ...


In your top picture I can see markings on the left tube ring under the RCA logo: a line - followed by what looks like numbers. Try again in good light and use a magnifying glass if you have.


----------



## maxpudding

mordy said:


> In your top picture I can see markings on the left tube ring under the RCA logo: a line - followed by what looks like numbers. Try again in good light and use a magnifying glass if you have.


I would need to buy the tubes first 😂 thanks for the tips mordy


----------



## gibosi

maxpudding said:


> I can only clearly see 6J5
> 
> 
> 
> ...



The fact that CJ5 is imprinted indicates that the tubes were manufactured after 1944. But still, if you buy these, you should see some additional letters and numbers and perhaps one or more non-ASCII characters such as +, =  and  /.  So yes, by all means BUY THEM! lol


----------



## maxpudding

gibosi said:


> The fact that CJ5 is imprinted indicates that the tubes were manufactured after 1944. But still, if you buy these, you should see some additional letters and numbers and perhaps one or more non-ASCII characters such as +, =  and  /.  So yes, by all means BUY THEM! lol



😂 

I am grateful for all the knowledgeable people in here, but not my wife apparently 😏 time to make a deal 🤝


----------



## gibosi

maxpudding said:


> 😂
> 
> I am grateful for all the knowledgeable people in here, but not my wife apparently 😏 time to make a deal 🤝



Good luck on that! 

If she is like my late wife, she might like to buy a new pair of shoes or a new purse. So yes, I think a deal can be made!


----------



## bcowen

gibosi said:


> Good luck on that!
> 
> If she is like my late wife, she might like to buy a new pair of shoes or a new purse. So yes, I think a deal can be made!


But that might prove costly.  Small octals are so easy to smuggle in and hide.  😂


----------



## mordy

bcowen said:


> But that might prove costly.  Small octals are so easy to smuggle in and hide.  😂


Wife: Honey - why do you need so many of those little thingamajigs?
Me: I am looking for sonic perfection.


----------



## bcowen

mordy said:


> Wife: Honey - why do you need so many of those little thingamajigs?
> Me: I am looking for sonic perfection.


LOL!!  Mine:

Wife: Don't they make stereo stuff that doesn't need thingies that have to be replaced every week?
Me: The tubes in my (ahem) "stereo" don't have to be replaced every week, they last a very long time.
Wife: Then why do you have so many?
Me: Why do you have so many shoes?
Wife: You answered a question with a question.
Me: The question _is_ the answer.
Wife: I'm going shopping.


----------



## jonathan c

bcowen said:


> But that might prove costly.  Small octals are so easy to smuggle in and hide.  😂


Especially in the wife’s new purse 🥲🤣🤣


----------



## maxpudding

bcowen said:


> LOL!!  Mine:
> 
> Wife: Don't they make stereo stuff that doesn't need thingies that have to be replaced every week?
> Me: The tubes in my (ahem) "stereo" don't have to be replaced every week, they last a very long time.
> ...


Wife: You answered a question with a question.
Me: I thought we were in an improv scene.


----------



## jonathan c

mordy said:


> Wife: Honey - why do you need so many of those little thingamajigs?
> Me: I am looking for sonic perfection.


Wife:  More tubes? Why?
Me:    These aren’t tubes, they’re pre-solid state. AND I’m saving $$$ in buying them now versus later ! 😏


----------



## mordy

jonathan c said:


> Wife:  More tubes? Why?
> Me:    These aren’t tubes, they’re pre-solid state. AND I’m saving $$$ in buying them now versus later ! 😏


Yes, there is always that little inner voice that whispers: Buy them now! They always go up in price! It's a good investment!

Problem with me is that I don't mind buying, but I hate selling. Perhaps because of a couple of difficult buyers in the past that gave me trouble...


----------



## jonathan c

bcowen said:


> LOL!!  Mine:
> 
> Wife: Don't they make stereo stuff that doesn't need thingies that have to be replaced every week?
> Me: The tubes in my (ahem) "stereo" don't have to be replaced every week, they last a very long time.
> ...


----------



## pravous

My wife “A package arrived from Europe today?”
Me “Awesome must be the adaptors I ordered from Deyan”
My wife “You are such a geek.”
On that note adaptors are here which mean it’s time to test out some type 37 philco globes? balloons?   




Only have about an hour on them.  Definately some background hum independent of volume level.  Gain doesn’t seem to be much of an issue.  Normal listening levels about 12/46 with 6j5s.  These seems to need about 16-18 to get to the same level.  Both tubes are pretty microphonic but it seems to settle down the longer they are in.   Hoping the hum will go away with some burn in time.   The first thing that jumps out about these at first is a holographic staging.  Second thing that stands out is some really nice decay not just on snare hits but also on bass guitar.   I will try and get some pictures of internals later on tonight.


----------



## jonathan c

mordy said:


> Yes, there is always that little inner voice that whispers: Buy them now! They always go up in price! It's a good investment!
> 
> Problem with me is that I don't mind buying, but I hate selling. Perhaps because of a couple of difficult buyers in *NC* in the past that gave me trouble...


FTFY…[Reg. TM; © bcowen: 2021]


----------



## gibosi

pravous said:


> My wife “A package arrived from Europe today?”
> Me “Awesome must be the adaptors I ordered from Deyan”
> My wife “You are such a geek.”
> On that note adaptors are here which mean it’s time to test out some type 37 philco globes? balloons?
> ...



Most Philco tubes of that era were manufactured by Sylvania. And I hope they will settle down for you. However, in my Glenn, 37's were always too noisy. I had better luck with 27's, but not much. lol


----------



## bcowen

pravous said:


> My wife “A package arrived from Europe today?”
> Me “Awesome must be the adaptors I ordered from Deyan”
> *My wife “You are such a geek.”*
> On that note adaptors are here which mean it’s time to test out some type 37 philco globes? balloons?


You can't let her get away with that.  Remind her of the last chick flick she watched.  _That's_ geeky.  🤣


----------



## pravous

My type 37 experiment went much better with a pair of RCA radiotron.  






These have black round plates while the Philco have mesh plates that make me think of 6c5. 



A side by side.  Similar internals but different plates. 



Happy to report that the RCAs have no hum.


----------



## pravous

bcowen said:


> You can't let her get away with that.  Remind her of the last chick flick she watched.  _That's_ geeky.  🤣


Could be worse.  I could be this guy


----------



## jonathan c

bcowen said:


> You can't let her get away with that.  Remind her of the last chick flick she watched made you watch with her. _That's geeky cruelty_. 🤣


FTFY…[Reg. TM; © bcowen: 2021]


----------



## whirlwind

pravous said:


> My type 37 experiment went much better with a pair of RCA radiotron.
> 
> 
> These have black round plates while the Philco have mesh plates that make me think of 6c5.
> ...



Nice looking tubes


----------



## L0rdGwyn

pravous said:


> My type 37 experiment went much better with a pair of RCA radiotron.
> 
> 
> These have black round plates while the Philco have mesh plates that make me think of 6c5.
> ...



Glad to see you went for it!  Great looking tubes, love those mesh plates.


----------



## triod750

Most 'mesh', or perforated sheet metal, in tubes is some kind of screen, isn't it? Real mesh plates are quite rare if I'm not mistaken. The Philco up above has a genuine mesh plate while I think the Fivre 6C5GT, for example, has a perforated screen of some sort. It is usually called  mesh plate anyway since we like mesh as it is cool.


----------



## L0rdGwyn

triod750 said:


> Most 'mesh', or perforated sheet metal, in tubes is some kind of screen, isn't it? Real mesh plates are quite rare if I'm not mistaken. The Philco up above has a genuine mesh plate while I think the Fivre 6C5GT, for example, has a perforated screen of some sort. It is usually called  mesh plate anyway since we like mesh as it is cool.



Correct, many times it is a screen, as in the 6C5 tubes, mesh plate is less common, seen in very old tubes, typically from the 1930-40s.

But that won't stop eBay sellers from advertising them as "mesh plate".  They know there is audiophile voodoo beliefs around mesh plate triodes.


----------



## L0rdGwyn

I should probably add that the sellers probably don't understand themselves that the mesh parts are screens and not plates.


----------



## triod750

L0rdGwyn said:


> I should probably add that the sellers probably don't understand themselves that the mesh parts are screens and not plates.


'Educated' buyers often know much more than average sellers do, absolutely.


----------



## pravous

One more unique thing I noticed about the type 37 is that both pairs have a getter that looks like a button battery held in place by a wire. 




Anyone know what this particular type of getter is called?   Any other tube types that use this type?


----------



## gibosi

pravous said:


> Anyone know what this particular type of getter is called? Any other tube types that use this type?



It's called "old".


----------



## gibosi

pravous said:


> Anyone know what this particular type of getter is called? Any other tube types that use this type?



More seriously, I don't know anything about the names of the different styles of getter holders in these early 1930's tubes. I can say that what I would call the "inverted cup" style is very common in 27's and early 37's. However, by the mid 1930's globe-style bottles had been replaced by shoulderd bottles and the getters were small pieces of sheet metal with a small dimple.


----------



## Xcalibur255

I believe the dimple sheets are usually called foil getters.


----------



## mordy

Xcalibur255 said:


> I believe the dimple sheets are usually called foil getters.


Here is a picture of a foil getter:



In this article it says that foil getters are better, but I am not convinced that this is the case. After all, isn't the purpose of a getter to hold the reactive substance (usually Barium) that is fired up to remove impurities in the tube to achieve a better vacuum? What difference does it make if the getter is a band, a cup, a ring or D-shaped, as long as it does it's job?
https://tubemaze.info/what-is-foil-getter/


----------



## bcowen

mordy said:


> Here is a picture of a foil getter:
> 
> In this article it says that foil getters are better, but I am not convinced that this is the case. After all, isn't the purpose of a getter to hold the reactive substance (usually Barium) that is fired up to remove impurities in the tube to achieve a better vacuum? What difference does it make if the getter is a band, a cup, a ring or D-shaped, as long as it does it's job?
> https://tubemaze.info/what-is-foil-getter/


From what I've seen, the shape/configuration itself is not important -- it's an indication of when the tubes were made.  Foil getters preceded horseshoe, D, O, and UFO getters, so the foil indicates an earlier manufacture.  And IME, earlier is better when it comes to sonics.  Perhaps overgeneralizing to some degree, but it follows along the progression pretty well.


----------



## whirlwind

gibosi said:


> It's called "old".



Ha


----------



## Slade01

bcowen said:


> From what I've seen, the shape/configuration itself is not important -- it's an indication of when the tubes were made.  Foil getters preceded horseshoe, D, O, and UFO getters, so the foil indicates an earlier manufacture.  And IME, earlier is better when it comes to sonics.  Perhaps overgeneralizing to some degree, but it follows along the progression pretty well.


So, is the exception to the rule insofar to what you've said in the past that "Double Ds" are VERY important?


----------



## mordy

Slade01 said:


> So, is the exception to the rule insofar to what you've said in the past that "Double Ds" are VERY important?


As mentioned above, the shape of the getters can serve in identifying certain production runs of the same tube and can help in finding the most desirable version.
It was not uncommon for the manufacturers to use different shaped/sized getters in the same tube. As an example, I have three different pairs of the Cetron 6336B tube, and each pair has a different getter.


----------



## bcowen

Slade01 said:


> So, is the exception to the rule insofar to what you've said in the past that "Double Ds" are VERY important?


LOL!  IMO, any tube with double D's is worth having even if it sucks.  🤣🤣🤣


----------



## jonathan c

Ken-Rad VT-65s start the parade…


----------



## Xcalibur255

bcowen said:


> From what I've seen, the shape/configuration itself is not important -- it's an indication of when the tubes were made.  Foil getters preceded horseshoe, D, O, and UFO getters, so the foil indicates an earlier manufacture.  And IME, earlier is better when it comes to sonics.  Perhaps overgeneralizing to some degree, but it follows along the progression pretty well.



I agree with you.  If two tubes with different getters sound different, it isn't going to be because of the getter, it's because one is older than the other and may have been made on different equipment and have other construction differences that explain the sonic changes.  Getters are just one part of the puzzle in figuring out when tubes were made.

One exception I would note is that in the case of tubes whose *quantity* of getters varies I would suspect that more = better.  Such as a 5998 tube where you will see ones that have only a top getter and some that have both a top and a side getter, I would be willing to bet the tube with the triple getter setup may have a longer usable lifespan.  Possibly the reason for this variation was that some of these tubes were meant to be "long life" variants, but that's just me theory crafting..... I haven't read anything to confirm that.


----------



## gibosi (Feb 16, 2022)

gibosi said:


> More seriously, I don't know anything about the names of the different styles of getter holders in these early 1930's tubes. I can say that what I would call the "inverted cup" style is very common in 27's and early 37's. However, by the mid 1930's globe-style bottles had been replaced by shoulderd bottles and the getters were small pieces of sheet metal with a small dimple.



Here's an example. This is an RCA Type 37 manufactured in 1934. The 37 was first introduced in 1931 and early 37's had a globe bottle and an inverted cup getter. By 1934, the globe bottles had been discontinued and replaced with shouldered bottles. And the "inverted cup" getter had been replaced with a small piece of sheet metal with a small dimple. But again, I don't know the precise name for these early getters so I just describe them.


----------



## mordy

Xcalibur255 said:


> I agree with you.  If two tubes with different getters sound different, it isn't going to be because of the getter, it's because one is older than the other and may have been made on different equipment and have other construction differences that explain the sonic changes.  Getters are just one part of the puzzle in figuring out when tubes were made.
> 
> One exception I would note is that in the case of tubes whose *quantity* of getters varies I would suspect that more = better.  Such as a 5998 tube where you will see ones that have only a top getter and some that have both a top and a side getter, I would be willing to bet the tube with the triple getter setup may have a longer usable lifespan.  Possibly the reason for this variation was that some of these tubes were meant to be "long life" variants, but that's just me theory crafting..... I haven't read anything to confirm that.


There is a Russian tube GU50 (basically a copy of the Telefunken LS50) that has four getters and uses both Barium and Zirconium getters. Zirconium is supposed to work better than Barium - another tube that uses Zirconium getters is the C3g tube. My guess is that it helps to get better vacuum.
https://www.jacmusic.com/techcorner/ARTICLES/English/Portraits/GM50/index-GM50-Portraits.html
Telefunken LS50:




GU50:


----------



## leftside

Been a little quiet on here, so time for more tube photos. Here is a pair of Brimar early foil getters 6J5 with matching date codes. I tend to find Brimar on the slightly warmer side. Enjoying these a lot.


----------



## Isaacc7

OK, finally got my adapters in and am joining the party. Currently listening to a quad of Sylvania 12j5gt round plates in my Supratek Cabernet preamp. Wow! There is a big, clear window into the sound now. It's hard to know if it's the specific tubes I'm using or moving to separate triodes that has made the biggest difference. Suffice it to say I will be trying some other varieties now. This never ends does it? Lol. Well, at least these are a lot cheaper than the 6sn7!


----------



## jonathan c

I am right behind you, Isaacc7. The 2x6J5 -> 6SN7 adapter by @Deyan just arrived. The first conscripts for Schiit Lyr 3 duty are the Ken-Rad 6J5 pair. Definite improvement in soundstage clarity and dimension versus the single K-R VT-231:


----------



## Isaacc7

Whoops, posted this question on another (incorrect) thread. Did any of the European manufacturers make 12j5 tubes?


----------



## Monsterzero

I have a Deyan built 6sn7 to 6j5 adapter im not using anymore. Had my GOTL modded to take 6j5s w/o an adapter If anyone wants one drop me a message.

And yes, the 6j5s smoke the 6sn7 counterparts on all levels, including price and performance.


----------



## Isaacc7

Monsterzero said:


> I have a Deyan built 6sn7 to 6j5 adapter im not using anymore. Had my GOTL modded to take 6j5s w/o an adapter If anyone wants one drop me a message.
> 
> And yes, the 6j5s smoke the 6sn7 counterparts on all levels, including price and performance.


I have a bunch of the sylvania round plate 12j5gt tubes. I don't think they ever made a 6sn7 version of that tube. Are there other flavors of 6/12j5 that are not in the twin triode world?


----------



## therremans

Monsterzero said:


> And yes, the 6j5s smoke the 6sn7 counterparts on all levels, including price and performance.


Hm, I agree partially as it’s really subjective and tube/gear dependent. I see them as differently constructed tubes that do something different. I still use many of my 6sn7s. As far as counterparts, RCA VT-231 for example does something different than metal RCA 6J5s. I enjoy both.


----------



## mordy

therremans said:


> Hm, I agree partially as it’s really subjective and tube/gear dependent. I see them as differently constructed tubes that do something different. I still use many of my 6sn7s. As far as counterparts, RCA VT-231 for example does something different than metal RCA 6J5s. I enjoy both.


People usually say that a 12V version of a 6V version of a tube sounds the same (I am not speaking of small signal tubes that are designed to be used with both voltages depending on wireing, (f. ex. a 12AT7). My contention is that a 6J5GT tube from the same manufacturer may sound different than the same tube in a 12J5GT version.
My personal experience has been that two 6J5 tubes usually sounds better than one double triode 6SN7.


----------



## CaptainFantastic

Been quiet here. Here are some recent arrivals. I find 6J5s really pleasing on the eye.


----------



## whirlwind

leftside said:


> Been a little quiet on here, so time for more tube photos. Here is a pair of Brimar early foil getters 6J5 with matching date codes. I tend to find Brimar on the slightly warmer side. Enjoying these a lot.



That is a lot of 5998 tube glow!


----------



## L0rdGwyn

Looks like I am back to being invested in this tube family!  Listening to my other top tube aside from the MOV L63, early construction Fivre 6C5G.  Paired with Cetron 6336B, sounding very good with the Atrium.  Going to have to go through the collection and see what else I've got to try out.

Nice to kick back for an hour or two after a long work day.


----------



## therremans

L0rdGwyn said:


> Looks like I am back to being invested in this tube family!  Listening to my other top tube aside from the MOV L63, early construction Fivre 6C5G.  Paired with Cetron 6336B, sounding very good with the Atrium.  Going to have to go through the collection and see what else I've got to try out.
> 
> Nice to kick back for an hour or two after a long work day.


Hi, have you ever had the chance to compare the older ST shape vs still available straight bottle Fivre 6C5G?


----------



## L0rdGwyn

therremans said:


> Hi, have you ever had the chance to compare the older ST shape vs still available straight bottle Fivre 6C5G?



Sorry I have not, in fact I do not own any straight-bottle Fivre 6C5GT, only the 6C5G.  I am sure they are quite good though.  Other than the bottle, the construction appears to be identical.


----------



## L0rdGwyn

I am slowly making my way through my 6J5 collection.  I hadn't spent much time with these in the past, they are quite nice, the STC 6J5G.


----------



## triod750

L0rdGwyn said:


> they are quite nice, the STC 6J5G.


Where does that put them, compared to other tubes you have used?
Many of my tubes are quite nice, more being different than better. When I find a good, or very good, pairing I only have to change to another recording to change my mind. Well, kind of....


----------



## L0rdGwyn

triod750 said:


> Where does that put them, compared to other tubes you have used?
> Many of my tubes are quite nice, more being different than better. When I find a good, or very good, pairing I only have to change to another recording to change my mind. Well, kind of....



I think they are very good, if my S tier is L63 and Fivre 6C5G, I would put them perhaps in A tier at the moment.  More listening is required!


----------



## triod750

Thanks. Listening is always required. I try hard to love L63. They are good but 'L' doesn't mean 'Love' so far. More listening is required.


----------



## L0rdGwyn (Mar 28, 2022)

It will depend on the circuit too, in my amp the differences are not enormous, most all 6J5 sound good, but some are slightly better than others.  Bigger difference is heard changing power tubes.  I have to wait a long time if I want to swap them though, unless I want second degree burns.

Now Fivre 6J5GT.


----------



## triod750

Yes, I suppose a lot is circuit dependant. (Not written from own experience but from reading).

Restaurant chefs use to say that 'fingers are there to be burnt'.


----------



## L0rdGwyn

I need to get an oven mitt 👨‍🍳


----------



## whirlwind

L0rdGwyn said:


> I need to get an oven mitt 👨‍🍳



Ha, grab two, chances are you will burn in hole in one of them


----------



## L0rdGwyn

Here is sort of a weird one, Mullard-made GEC labeled 6C5G.  As I recall, I didn't think much of these tubes when I listened to them in the past, but going from Fivre 6J5GT to to Mullard 6C5G shows BIG step up in bass heft and instrument separation.  A great pairing with the 6528!  Which I have found are a little more picky to match with compared to the 6336 in this circuit.


----------



## mordy

L0rdGwyn said:


> Here is sort of a weird one, Mullard-made GEC labeled 6C5G.  As I recall, I didn't think much of these tubes when I listened to them in the past, but going from Fivre 6J5GT to to Mullard 6C5G shows BIG step up in bass heft and instrument separation.  A great pairing with the 6528!  Which I have found are a little more picky to match with compared to the 6336 in this circuit.


Perhaps the reason why the 6528 is harder to match is because the 6528 has much more gain than the 6336.


----------



## L0rdGwyn

mordy said:


> Perhaps the reason why the 6528 is harder to match is because the 6528 has much more gain than the 6336.



Well it is operating as a cathode follower in this circuit, so the gain for both the 6336 and the 6528 is roughly 1.  The higher  transconductance of 6528 as a cathode follower results in lower distortion and output impedance.  The contribution the 6528 makes to the harmonic distortion is very low, whereas the contribution by the 6336 is slightly higher.  My suspicion is that there is some distortion masking effect occurring between the 6336 and the input stage, which is less pronounced by the 6528, so the harmonic profile of the 6J5 input with a 6528 output is more audible than it is with the 6336.  Just my theory at the moment.


----------



## mordy

L0rdGwyn said:


> Well it is operating as a cathode follower in this circuit, so the gain for both the 6336 and the 6528 is roughly 1.  The higher  transconductance of 6528 as a cathode follower results in lower distortion and output impedance.  The contribution the 6528 makes to the harmonic distortion is very low, whereas the contribution by the 6336 is slightly higher.  My suspicion is that there is some distortion masking effect occurring between the 6336 and the input stage, which is less pronounced by the 6528, so the harmonic profile of the 6J5 input with a 6528 output is more audible than it is with the 6336.  Just my theory at the moment.


Thanks - which 5A tube results in a more pleasing sound?


----------



## L0rdGwyn (Mar 28, 2022)

mordy said:


> Thanks - which 5A tube results in a more pleasing sound?



My impression so far is that the 6528 is the more detailed and resolving of the two, not surprising as it has lower distortion and output impedance.  BUT like I said, I think it is a little bit harder to pair with an input tube.  When the pairing is good though, it is incredible, the resolution and airiness is astounding.  With a good 6J5, I have measured 0.007% THD 1mW into 300ohm with the 6528 and a 15ohm output impedance.

The 6336 is the more smooth and rounded of the two, I wouldn't call it gooey or anything like that, it is also very detailed, perhaps a bit more easy-going than the 6528, and not so picky about tube pairing.

So the complement each other well, the 6528 has a high "wow factor" ceiling but is more picky whereas the 6336 is easier to put on and enjoy out of the box.  As an analogy, it's similar to what using a quality 6AS7G versus a 5998 does in a 6AS7G-type amplifier.

There are some earlier versions of the 6336 I intend to try that have metal plates as opposed to graphite, we'll see if that is a good or bad thing!


----------



## L0rdGwyn (Mar 28, 2022)

I did some rapid fire tube rolling to get some first impressions of how each 6J5 fits with the 6528 in this amplifier.  None of these tubes sound bad, differences are quite subtle, but they can be heard.  Going with my gut first impressions on this one, I don't have time to do extensive comparisons, critical listening is a chore!!!

RFT 6J5 - these are quite good, well-balanced top to bottom, maybe a little more lean than the Mullard 6C5G, but very detailed, satisfying treble without stridency, great bass resolution.  A top 6J5 for me.



STC 6C5G - the only one I really did not like.  I found vocals to sound slightly harsh and unnatural on the tracks I was listening to, which pretty much made it a no go.  This was probably the 6C5G I remembered not liking, not the Mullard.



Visseaux 6J5G - I've always liked these tubes, this pair is slightly noisy, but once they settle down they are very resolving, airy, and smooth.  Up there for me with the best.



Sicte 6J5GT - pretty uncommon tube, they are pretty good, similar character to Fivre tubes, slightly warm leaning and smooth.  I like them, very easy listening, but not the last word in resolution.  Above average, I think I prefer them over the gray plate Fivre 6J5GT.



Ken-Rad 6J5GT - these are quite good, excellent body, warm leaning, good bass heft, and smooth upper midrange.  Very easy to listen to and quite detailed.



Tung-Sol 6J5G - these used to be one of my favorites, but not quite as impressive as I remember them being.  Maybe they are getting old?  I felt the midrange was a little uneven, but a nice full low end.  I would put the middle of the pack in this circuit.



Sylvania 6J5GT - I have thought highly of these in the past, still do now, they are nicely balanced, nice full low end, sparkly highs, but not harsh, and good resolution.  They don't seem to do anything "wrong", but perhaps don't separate themselves from the rest to be called top tier, but above average.



Nippon Electric 6J5GT - one thing I have found about Japanese tubes, they all seem to be exceptionally quiet.  These are no different.  Another middle of the pack tube I would say, midrange could be a tad smoother, but a nice low end, detailed highs.



Right now my personal tier list goes something like this.

S - MOV L63, Fivre 6C5G, Mullard 6C5G, Visseaux 6J5G, RFT 6J5
A - Ken-Rad 6J5GT, Sylvania 6J5GT, Sicte 6J5GT, STC 6J5G
B - Tung-Sol 6J5G, Nippon Electric 6J5GT, Fivre 6J5GT
C - STC 6C5G

That's right, my scale only goes to C, every tube gets a passing grade.  Cs get degrees!

I know I have more 6J5 somewhere, but that's what's in the drawer next to me lol maybe I'll update the list as time goes on.


----------



## leftside

Those silver RFT 6J5 are top notch tubes. Also the Philips. I think I might have another brand as well. I'll have to double check.


----------



## raindownthunda

L0rdGwyn said:


> I did some rapid fire tube rolling to get some first impressions of how each 6J5 fits with the 6528 in this amplifier.  None of these tubes sound bad, differences are quite subtle, but they can be heard.  Going with my gut first impressions on this one, I don't have time to do extensive comparisons, critical listening is a chore!!!
> 
> RFT 6J5 - these are quite good, well-balanced top to bottom, maybe a little more lean than the Mullard 6C5G, but very detailed, satisfying treble without stridency, great bass resolution.  A top 6J5 for me.
> 
> ...


Great list and nice comparisons! It just goes to show how much of a difference amps, tube synergy, and ears can make in tube rankings. Personally STC 6J5G are quite possibly my all time favorite in the Bottlehead Crack w/ SB with the Chatham 6AS7G, with Visseaux 6J5G being one of my least favorite. Completely agree it’s all relative and all of the tubes in this family are enjoyable to listen to, some just more magical and better power tube synergies than others.


----------



## L0rdGwyn

raindownthunda said:


> Great list and nice comparisons! It just goes to show how much of a difference amps, tube synergy, and ears can make in tube rankings. Personally STC 6J5G are quite possibly my all time favorite in the Bottlehead Crack w/ SB with the Chatham 6AS7G, with Visseaux 6J5G being one of my least favorite. Completely agree it’s all relative and all of the tubes in this family are enjoyable to listen to, some just more magical and better power tube synergies than others.



Oh yeah for sure!  The STC 6J5G was one of the first I listened to during the day and wasn't part of my tube rolling blitz, I'll give it another listen today and see if it gets bumped up a notch.


----------



## whirlwind

L0rdGwyn said:


> I did some rapid fire tube rolling to get some first impressions of how each 6J5 fits with the 6528 in this amplifier.  None of these tubes sound bad, differences are quite subtle, but they can be heard.  Going with my gut first impressions on this one, I don't have time to do extensive comparisons, critical listening is a chore!!!
> 
> RFT 6J5 - these are quite good, well-balanced top to bottom, maybe a little more lean than the Mullard 6C5G, but very detailed, satisfying treble without stridency, great bass resolution.  A top 6J5 for me.
> 
> ...



I have some Fivre 6C5G and I like them a lot.

I don't have the Fivre 6J5GT.  What is the biggest difference between those ?  I understand different amps and circuits, but just between what you are hearing between the tubes ?


----------



## L0rdGwyn

whirlwind said:


> I have some Fivre 6C5G and I like them a lot.
> 
> I don't have the Fivre 6J5GT.  What is the biggest difference between those ?  I understand different amps and circuits, but just between what you are hearing between the tubes ?



To me, I am getting a little bit more resolution and air with the Fivre 6C5G over the 6J5GT, it's pretty subtle however.  I would say you are good shape if you already have the 6C5G, plus it seems the 6J5GT are pretty hard to come by nowadays.


----------



## whirlwind

L0rdGwyn said:


> To me, I am getting a little bit more resolution and air with the Fivre 6C5G over the 6J5GT, it's pretty subtle however.  I would say you are good shape if you already have the 6C5G, plus it seems the 6J5GT are pretty hard to come by nowadays.



Thanks, I was kind of hoping you would say that...they seem to be quite pricey, if that was not the case I would grab a pair.


----------



## L0rdGwyn

Yeah the more rare 6J5 seem to be harder to come by than they used to be, I've been out of the loop for a while lol but still a good supply of more common types.  I am hitching my cart to this OTL for the long haul, so we'll see if I end up picking up some more pairs.  Will need some backup 6528 as well.

I am back on the STC 6J5G.


----------



## Velozity

I've been enjoying this roll with the Tung Sols for some time.  Wish they weren't so hard to find.


----------



## therremans (Mar 31, 2022)

Velozity said:


> I've been enjoying this roll with the Tung Sols for some time.  Wish they weren't so hard to find.


I have a decent number of tested Tung-Sol VT-94a matched pairs, NOS/NIB that I will consider selling or for trade. In my experience, they sound superior to the non-military version. The build is slightly different. Send PM if interested


----------



## therremans

Okay, so only 4 pairs left and I would prefer to keep 1-2 pairs for myself. I’ll reply to the PMs shortly as I am not completely sure what they’re worth.. as I never see them come up for sale anymore.


----------



## Velozity

therremans said:


> Okay, so only 4 pairs left and I would prefer to keep 1-2 pairs for myself. I’ll reply to the PMs shortly as I am not completely sure what they’re worth.. as I never see them come up for sale anymore.


 

The "PMs" _plural_??  Somebody better not snipe me, lol.  These look great.  If the price is right I'll take a pair.  Thanks.


----------



## bcowen

therremans said:


> Okay, so only 4 pairs left and I would prefer to keep 1-2 pairs for myself. I’ll reply to the PMs shortly as I am not completely sure what they’re worth.. as I never see them come up for sale anymore.


I think they’re going for $9.99/pair on EBay right now.


----------



## pravous

I have been running the Tung Sol VT-76 in the Airmid for the last week and I really like them.  Pair very well with the 5998. 






They share a lot of the same construction characteristics with the Tung Sol VT 37 as well.


----------



## mordy

Received an unknown tube today - except what you see in the picture (6C5G Made in England) there are no other markings.



The screen grid is unique in that the holes are larger than in other tubes and the flanges are protruding like a grating iron.
Tried to identify the tube on the internet. One source (LordGwyn) thinks they are made by Mullard (although that pair had GEC labels) and another site said that BRIMAR made them (Haltron rebrand). They are supposedly very early production which would place them in the second half of the 30's.
I think that GEC made them because I have only seen such "Swiss Cheese" holes on GEC tubes.



What do you think?


----------



## pravous

mordy said:


> Received an unknown tube today - except what you see in the picture (6C5G Made in England) there are no other markings.
> 
> The screen grid is unique in that the holes are larger than in other tubes and the flanges are protruding like a grating iron.
> Tried to identify the tube on the internet. One source (LordGwyn) thinks they are made by Mullard (although that pair had GEC labels) and another site said that BRIMAR made them (Haltron rebrand). They are supposedly very early production which would place them in the second half of the 30's.
> ...


Not sure who made those.  I have two pairs of the Brimar that have the finer mesh shield. 



One of my favorite input tubes.  A little on the warm side but amazing with live music.  I like these a little better with the GEC 6as7g than the 5998.


----------



## mordy

pravous said:


> Not sure who made those.  I have two pairs of the Brimar that have the finer mesh shield.
> 
> One of my favorite input tubes.  A little on the warm side but amazing with live music.  I like these a little better with the GEC 6as7g than the 5998.


I do want to point out that even though a lot of people call the perforated/stamped shields mesh shields, they really aren’t mesh but perforated metal shields with different size and shaped holes.
Real mesh is a weave of metal threads. Some people claim that such mesh results in better sound, but you usually only find it in very old tubes, and I personally don’t have any experience with mesh tubes to be able to compare.


----------



## pravous

Philco mesh plate 37. While they sound great they are microphonic and seem to pick up just about any interference you can imagine.  Furnace kicks on, buzzing, dishwasher cycles humming.  They only work when I have the house to myself and nothing else is using power.


----------



## L0rdGwyn

The shield on the 6C5 is an actual shield connected to ground to reduce noise, the plate (anode) sits interior to it and is solid, at least on all 6C5 I have on hand.  The mesh in the type 37 above is the actual plate (anode).

The reason the shield exists on the 6C5 is because it is actually a converted pentode, a 6J7 without a suppressor grid and the screen is tied to the plate, so the 6C5 is essentially a triode-strapped 6J7.  It was later replaced by a dedicated triode, the 6J5.


----------



## mordy

L0rdGwyn said:


> The shield on the 6C5 is an actual shield connected to ground to reduce noise, the plate (anode) sits interior to it and is solid, at least on all 6C5 I have on hand.  The mesh in the type 37 above is the actual plate (anode).
> 
> The reason the shield exists on the 6C5 is because it is actually a converted pentode, a 6J7 without a suppressor grid and the screen is tied to the plate, so the 6C5 is essentially a triode-strapped 6J7.  It was later replaced by a dedicated triode, the 6J5.


Hi LG,
Apparently you own this pair labeled GEC, but in your post you state that they are relabeled Mullard. Are there any markings indicating that they were made by Mullard? What I see here seems to say May 63.


----------



## L0rdGwyn (Apr 3, 2022)

mordy said:


> Hi LG,
> Apparently you own this pair labeled GEC, but in your post you state that they are relabeled Mullard. Are there any markings indicating that they were made by Mullard? What I see here seems to say May 63.



There isn't strong evidence they were made by Mullard.  I don't believe the date on the tube is the date of manufacture, I've come across a number of tubes that were inspected at a later time and rebranded.  Unlikely they are GEC as they were using smoked glass on their tubes at the time these would have been made.  Also as I said, the 6C5 is an altered 6J7, and GEC had their own model equivalent to the 6J7, the KTZ63, which had smoked glass.  Based on the construction, they were most likely made by STC / Brimar, but I can't be 100% certain.


----------



## L0rdGwyn

Here is a picture of a KTZ63 labeled with the same perforated shield, but of course its unclear who manufactured the pictured tube.  If you could discover the manufacture of one of these KTZ63, then probably the 6C5G would be the same.


----------



## mordy

L0rdGwyn said:


> Here is a picture of a KTZ63 labeled with the same perforated shield, but of course its unclear who manufactured the pictured tube.  If you could discover the manufacture of one of these KTZ63, then probably the 6C5G would be the same.


The print on this tube is exactly the same type as on my 6C5G tube.


----------



## pravous

More 76 on my 6j5 rolling journey.  Hytron (CBS?) and Westinghouse (not sure who made these) 76. 

Hytron 76 oval micas top and bottom. Made in USA underneath the 76 print on the glass of the tube. 







Westinghouse 76 have a cross shaped mica supports up top with a rectangle on the bottom.  Made in Canada under the the logo on the glass. 






Westinghouse are kind of meh.  Unremarkable across the board.  Hytron are pretty neutral.  Very nice mids, sort of the middle ground between the Tung Sol 76 (nice bass) and Sylvania (bright).


----------



## JazzVinyl

KaZow!  Those are beautiful!  Hope they sound as good (or better) than they look.


----------



## mordy

pravous said:


> More 76 on my 6j5 rolling journey.  Hytron (CBS?) and Westinghouse (not sure who made these) 76.
> 
> Hytron 76 oval micas top and bottom. Made in USA underneath the 76 print on the glass of the tube.
> 
> ...


Do you find any advantages in sound using type 76 tubes compared to 6C5G/6J5G tubes?
Hytron was a small Massachusetts manufacturer (later bought by CBS).
Your descriptions of the sound of TS and Syl are good descriptions of their house sound. I also found that Sylvania tubes often have a wide sound stage.


----------



## JazzVinyl

mordy said:


> Do you find any advantages in sound using type 76 tubes compared to 6C5G/6J5G tubes?
> Hytron was a small Massachusetts manufacturer (later bought by CBS).
> Your descriptions of the sound of TS and Syl are good descriptions of their house sound. I also found that Sylvania tubes often have a wide sound stage.



Aren't most CBS tubes rebadgers?


----------



## jonathan c

mordy said:


> Do you find any advantages in sound using type 76 tubes compared to 6C5G/6J5G tubes?
> Hytron was a small Massachusetts manufacturer (later bought by CBS).☑️
> Your descriptions of the sound of TS and Syl are good descriptions of their house sound. I also found that Sylvania tubes often have a wide sound stage.


☑️  www.pax-comm.com/pa01007.htm


----------



## mordy (Apr 4, 2022)

JazzVinyl said:


> Aren't most CBS tubes rebadgers?


Could be, but may not apply to Hytron. Hytron must have been well regarded in it's day, because the British government asked them to produce tubes for them.


----------



## pravous

mordy said:


> Do you find any advantages in sound using type 76 tubes compared to 6C5G/6J5G tubes?
> Hytron was a small Massachusetts manufacturer (later bought by CBS).
> Your descriptions of the sound of TS and Syl are good descriptions of their house sound. I also found that Sylvania tubes often have a wide sound stage.


So far I have found that the 76 seem to match the 6j5g which make sense because most of them have almost identical internals.  The one downside to the 76 is that they can be noisy, but not as bad as the 37. Funny you mention the Sylvania.  Just so happen to be rolling Sylvania 76 this morning.  I agree with your soundstage observation.  These really bring Eva Cassidy Live at Blues Alley to life.  




76 internals similar to 6J5G with a few differences. Both have the wire top supports, rounded rectangle micas and round plates.  76 plates have 2 holes while the 6J5G have 3 holes.  
  76 internals



   6J5G (Zenith rebrand) internals



The 6J5G also have a U shield around the top of the filaments that is not found on the 76.


----------



## pravous

Visseaux 76 and 6J5G seem to have the same exact internals. 
76 on the left 6J5G on the right. 







Unfortunately I only have one 76 so I can’t really speak to how similar they might sound. The 6J5G are tied with the Fivre 76 as my favorite input tubes for the WE 421a.  
  Fivre 76. 






Internals are a mix of features from the Sylvania (wire spreaders) and the Visseaux (copper bands on the top mica).


----------



## jonathan c (Apr 5, 2022)

I intend to keep the Schiit Lyr 3 healthy and strong with vitamin K-R in 6C5 doses… 

…Lyr warming up…


----------



## triod750

Those tubes are very healthy and plays well for me!


----------



## Isaacc7

Just got in another batch of JAN Sylvania 12j5gt. I have been very impressed with the round plate Sylvanias, and they're so cheap! The boxes are dated 4-21-43. They just turned 78! The only thing I don't like about using *j5 tubes is I need twice as many, I could conceivably end up using 8 at a time when my new amp comes. Still, they are much less than half the price of the *sn7 tubes and might sound better anyway lol. 

Did Tungsol make round plate 6/12j5gt tubes? I have a bunch of the Tungsol ladder plate (which I actually need to try at some point) but would love to get my hands on some of the round plate variants if they exist. Love the 12sn7 black glass round plate tubes and would love to get the same in my amp. It only uses 6v tubes though and the prices of the TSRPBG 6sn7 are well out of my comfort zone.


----------



## Marutks (Apr 8, 2022)

I am running 12j5 sylvania (and Osram B36) tubes in my amp at the moment.  They are ladder plate tubes but they sound good to me.  Maybe round plate tubes sound even better?


----------



## Isaacc7

Marutks said:


> I am running 12j5 sylvania (and Osram B36) tubes in my amp at the moment.  They are ladder plate tubes but they sound good to me.  Maybe round plate tubes sound even better?


I do need to try some more versions. I do know that that I like the Sylvania round plates and that they are cheap so I don't feel guilty stocking up. I have enough of the Tungsol ladder plates that I will try them, maybe tonight. I only have 3 Raytheon 12j5gt though, frustrating.


----------



## leftside

Visseaux 6C5MG and 6J5MG. Will try and do a comparison this evening. Interestingly 3 of the boxes state “License Sylvania”, but one doesn’t.


----------



## bcowen

leftside said:


> Visseaux 6C5MG and 6J5MG. Will try and do a comparison this evening. Interestingly 3 of the boxes state “License Sylvania”, but one doesn’t.


Cool!  Schiit should make their new LISST tubes devices look like those.


----------



## leftside

Philips 6J5MG. Matching codes. Different box styles.


----------



## L0rdGwyn

leftside said:


> Visseaux 6C5MG and 6J5MG. Will try and do a comparison this evening. Interestingly 3 of the boxes state “License Sylvania”, but one doesn’t.



I have a pair of these, the internals are actually the same as the Visseaux 6J5G.  They did a lot of licensing through Sylvania, the only other company to manufacture the 6A5G used in my power amplifier.


----------



## pravous

leftside said:


> Philips 6J5MG. Matching codes. Different box styles.


You need to open your own personal tube museum.  Tube porn at its best!


----------



## pravous

On a more serious note.  Metal can tubes seem to have had a brief time frame.  Anyone have any clue why?


----------



## Monsterzero

pravous said:


> On a more serious note.  Metal can tubes seem to have had a brief time frame.  Anyone have any clue why?


The rumor around the interwebs is that dry dog food was invented out of necessity to save metal for the war effort. Might apply here too?


----------



## jonathan c

bcowen said:


> Cool!  Schiit should make their new LISST tubes devices look like those.


…use eight in V-8 formation: switch to a checkered flag 🏁 logo…🤪


----------



## jonathan c (Apr 10, 2022)

pravous said:


> On a more serious note.  Metal can tubes seem to have had a brief time frame.  Anyone have any clue why?


Beer?🤔🤷🏻‍♂️


----------



## gibosi

pravous said:


> On a more serious note.  Metal can tubes seem to have had a brief time frame.  Anyone have any clue why?



Despite all the hype when they were first introduced, any advantages over glass never materialized. And given that they were more expensive to manufacture, there was little or no reason to keep making them.


----------



## leftside

gibosi said:


> Despite all the hype when they were first introduced, any advantages over glass never materialized. And given that they were more expensive to manufacture, there was little or no reason to keep making them.


Yep. @gibosi beat me to it.


----------



## Isaacc7

Finally got a chance to try the JAN Tungsol 12j5gt in my preamp. Compared to the Sylvania 12j5 round plate tubes the Tungsol give a bigger, warmer sound with less detail. This is what I think the stereotypical "tube" sound is. It can be nice but having heard what my system sounds like with other tubes like the aforementioned Sylvania 12j5gt, 12sx7, and a variety of 12sn7 I don't think I'll be using these in my preamp. Once my new amp comes in I'll give them another try as inout tubes.


----------



## triod750

Matching tubes is imperative in order to enjoy the music. I am now listening to Litania, music of Krzyzstof Komeda, performed by Tomasz Stanko Septet. Output tubes are Melz 6N12S and input tubes are perfectly matched Philips 6J5GT, made in USA and National Union 6C5GT, also made in USA. Can't get any better. Both made in USA, hence a perfect match. And the music is very enjoyable.


----------



## Isaacc7

A while back I had asked if Sylvania ever made a round plate 6/12sn7 to match the round plate 6/12j5gt they made. I still haven't found any of those but I have found the 12ah7gt! It is a round plate tube that seems to be similar to the 6sn7 but with a different pin out. Apparently there was a 6ah7 but they are relatively rare. The 12ah7gt is super cheap, I might pick some of them up from various manufacturers and see what they have to offer. Will also post this in the 6sn7 thread too to see if anyone there has any insights.


----------



## gibosi (Apr 17, 2022)

Isaacc7 said:


> A while back I had asked if Sylvania ever made a round plate 6/12sn7 to match the round plate 6/12j5gt they made. I still haven't found any of those but I have found the 12ah7gt! It is a round plate tube that seems to be similar to the 6sn7 but with a different pin out. Apparently there was a 6ah7 but they are relatively rare. The 12ah7gt is super cheap, I might pick some of them up from various manufacturers and see what they have to offer. Will also post this in the 6sn7 thread too to see if anyone there has any insights.



The 12ah7 and 6ah7 are fairly similar to a 12au7. And there are loctal versions, 7AF7 and 14AF7. I've had good luck with these and IMHO they are good sounding tubes. 
Oh, I have never seen a round plate Sylvania 6/12SN7. I am pretty sure it was never made.


----------



## bcowen

gibosi said:


> The 12ah7 and 6ah7 are fairly similar to a 12au7. And there are loctal versions, 7AF7 and 14AF7. I've had good luck with these and IMHO they are good sounding tubes.
> Oh, I have never seen a round plate Sylvania 6/12SN7. I am pretty sure it was never made.


I have a few 7AF7's.  The lower gain (versus a 6SN7 / 7N7) is barely noticeable, if at all.  I still prefer the Sylvania tall bottle 7N7, but the 7AF7's are quite nice themselves.

(note that the GE was made by Sylvania...I haven't totally lost it )


----------



## Isaacc7

gibosi said:


> The 12ah7 and 6ah7 are fairly similar to a 12au7. And there are loctal versions, 7AF7 and 14AF7. I've had good luck with these and IMHO they are good sounding tubes.
> Oh, I have never seen a round plate Sylvania 6/12SN7. I am pretty sure it was never made.


I also don't think Sylvania made a round plate sn7 tube. Too bad, the 12j5gt tubes I have are really nice. All of the 14af7 tubes were made by Sylvania, were the 12ah7 all made by sylvania too? Are the 7af7 and 6ah7 really the same tube? I went over the data sheets quickly and I thought there were some differences. Maybe the published specs by different companies were written differently?


----------



## gibosi

Yes, there are some small differences. In fact, the 7AF7 is considered to be a successor to the 6AH7GT. However, I couldn't hear any difference between a 12AH7GT and the 14AF7 in my Glenn. So to my mind they are close enough to be considered the same. But of course, YMMV.


----------



## OldSkool

Finally found a nice pair of NOS GEC L63 for my ToolShed preamp.

Up to now I have been using Brimar or Visseaux 6J5g's in this preamp, but these GEC's are giving me more detail...nice! However, the upper treble is more pronounced. Is that something that a few hours burn-in will tame or is that just the GEC house sound?

Cheers, JC


----------



## gibosi

OldSkool said:


> Finally found a nice pair of NOS GEC L63 for my ToolShed preamp.
> 
> Up to now I have been using Brimar or Visseaux 6J5g's in this preamp, but these GEC's are giving me more detail...nice! However, the upper treble is more pronounced. Is that something that a few hours burn-in will tame or is that just the GEC house sound?
> 
> Cheers, JC



In my experience, the GEC house sound is indeed characterized by more treble emphasis and air. And I hear this with GEC rectifiers, out-put tubes and drivers.


----------



## leftside

OldSkool said:


> Finally found a nice pair of NOS GEC L63 for my ToolShed preamp.
> 
> Up to now I have been using Brimar or Visseaux 6J5g's in this preamp, but these GEC's are giving me more detail...nice! However, the upper treble is more pronounced. Is that something that a few hours burn-in will tame or is that just the GEC house sound?
> 
> Cheers, JC


Ah someone else mentioning what I hear with the GEC tubes - the detail. They seem to extract that last drop of detail for me. But, I don't find the upper treble _too_ pronounced. Give them a bit more time.


----------



## gibosi

Everyone has different ears and gear. And for me, too much GEC, and especially too much Telefunken, is just too much upper treble. My go-to test is Norah Jones. To my ears, there is a slightly raspy quality in her voice. And in some recordings that raspyness can be "uncomfortable" to listen to. Just this evening, I pulled out a GEC rectifier and installed a Holland-made Philips rectifier instead. Easier on my ears. But again, my ears and my gear. YMMV.


----------



## pravous

More adaptor shenanigans.  Tonight Ken Rad 7193.  Top connections are for the plate and grid.   Only have an hour or so on them but so far very impressed.  Expansive soundstage of a Sylvania combined with the bottom end Ken Rads are known for.


----------



## CAJames (Apr 19, 2022)

pravous said:


> More adaptor shenanigans.  Tonight Ken Rad 7193.  Top connections are for the plate and grid.   Only have an hour or so on them but so far very impressed.  Expansive soundstage of a Sylvania combined with the bottom end Ken Rads are known for...



Cool. I've always been a little #7193curious, but I'd need 4 of them and am a little afraid of interference with that many top connections. But I haven't spent nearly enough money on tubes lately so it might be time to try it out.


----------



## pravous

CAJames said:


> Cool. I've always been a little #7193curious, but I'd need 4 of them and am a little afraid of interference with that many top connections. But I haven't spent nearly enough money on tubes lately so it might be time to try it out.


I am only using 2 of them in place of 6j5 but they are dead quiet.  None of the noise issues that occur with type 37 and some type 76.  Might be new toy syndrome but absolutely loving the Ken Rad 7193.  There is a great post about this family in the Bottlehead crack tube rolling thread.  (Post 9737 by Tom-s).  One of the more interesting variations is the Hytron E1148 which has horizontal instead of vertical construction.  Some pretty interesting Gec/Marconi under the CV6 designation as well.


----------



## Marutks

Do you like this tube?


----------



## maxpudding

Marutks said:


> Do you like this tube?


All of my 6J5MGs are the tall silver versions, made by Mazda or Visseaux. I like them very much. I think a couple of members here have some experience with this short version of the 6J5MG.


----------



## triod750

Why not? It seems to have a black foreground....


----------



## OldSkool

Good thing for burn-in. The NOS GEC L63 upper treble is starting to mellow at 20 hours. Treble is now down to 6J5G Visseaux territory but with more detail. Nice!


----------



## jonathan c

OldSkool said:


> Good thing for burn-in. The NOS GEC L63 upper treble is starting to mellow at 20 hours. Treble is now down to 6J5G Visseaux territory but with more detail. Nice!


I really enjoy the double GEC L63 via @Deyan adapter on the Schiit Lyr 3. I will not be returning to 6SN7s for Lyr.


----------



## Slade01

jonathan c said:


> I really enjoy the double GEC L63 via @Deyan adapter on the Schiit Lyr 3. I will not be returning to 6SN7s for Lyr.


This!   Dual Single Triodes trump nearly 99% of 6SN7s any day of the week.   I'll stand by that pepsi challenge.


----------



## bcowen

jonathan c said:


> I really enjoy the double GEC L63 via @Deyan adapter on the Schiit Lyr 3. I will not be returning to 6SN7s for Lyr.


They sound pretty good n the Incubus too.


----------



## pravous

I think these would be perfect if one had a sideways amp.  Hytron e-1148. 



Horizontal internals.


----------



## jonathan c

pravous said:


> I think these would be perfect if one had a sideways amp.  Hytron e-1148.
> 
> Horizontal internals.


Don’t give @bcowen ideas! He has a sideways Incubus (in)Elegans which was built by @Paladin79 …😳


----------



## bcowen

jonathan c said:


> Don’t give @bcowen ideas! He has a sideways Incubus (in)Elegans which was built by @Paladin79 …😳


LOL!  We may have to reclassify my Incubus as a 90-degree amp.


----------



## maxpudding

Or a perpendicular amp


----------



## jonathan c

bcowen said:


> LOL!  We may have to reclassify my Incubus as a 90-degree amp.


Make it seem sophisticated…call the Incubus ‘orthogonal’…🤔…☑️…


----------



## jonathan c

bcowen said:


> LOL!  We may have to reclassify my Incubus as a 90-degree amp.


Second response:  classify it as the world’s only ‘electrically in-phase, structurally half out-phase amp’.


----------



## bcowen

jonathan c said:


> Make it seem sophisticated…call the Incubus ‘orthogonal’…🤔…☑️…


Problem is that *my* Incubus is _correctly_ oriented.  @Paladin79 just built all the other ones sideways 90-degrees.


----------



## jonathan c

bcowen said:


> Problem is that *my* Incubus is _correctly_ oriented.  @Paladin79 just built all the other ones sideways 90-degrees.


…the _Copernicus Incubus…? around which all others orbit?…🤣🤣🤪…_


----------



## jgwtriode

Well I really must say I thoroughly enjoy my GEC l63's in my Airmid, but I don't have any other experience with 6J5's so figured I would try to inform myself a 
bit more.

Happy listening,

jgwtriode


----------



## les24preludes

I've been doing a shootout of my 28 6SN7s and the plate/anode construction is basically these:
1. T plates, early 6SN7GT
2. ladder plates, many types
3. angled plates
4. round plates e.g. Brimar

The best sounding ones are the T plates, which are mellow, the angled plates which are a tad brighter but still smooth, and the Brimars. I found the ladder plates a tad edgy and hollow, especially on orchestral strings which were smooth with the T plates in particular. 

I'm about to make a rig to try out 6J5 types - I have a couple of 6J5G round plates and several 7193/2C22, all of which are ladder plates. I remember from many years ago that the 7193s sounded pretty good, so I was surprised to see they are ladder plates. Maybe the top caps help. 

Anyway, looking to buy a few more 6J5 types so looking for recommendations for smooth and mellow sounding ones, maybe some of the very early ones. Loctal 7A4 possible too. Must have a gain of 20.


----------



## Isaacc7

les24preludes said:


> I've been doing a shootout of my 28 6SN7s and the plate/anode construction is basically these:
> 1. T plates, early 6SN7GT
> 2. ladder plates, many types
> 3. angled plates
> ...


The 7a4 I have all look like the round plate Sylvania so I haven’t gotten adapters for them. I really like my round plate Sylvania 12j5gt so I’m sure the 7a4 would sound good too.


----------



## les24preludes (May 3, 2022)

Isaacc7 said:


> The 7a4 I have all look like the round plate Sylvania so I haven’t gotten adapters for them. I really like my round plate Sylvania 12j5gt so I’m sure the 7a4 would sound good too.


Yes - I used to have some 7A4 and 7N7 and I thought they were plentiful. I'm in the UK and there are no 7N7s or 7A4s advertised that I can see. Folks have cleaned them out it seems. Prices for earlier 6J5 types have rocketed up now as well. Frustrating - I want to try some of the earlier ones. I have plenty of 6SN7s so nil desperandum, but all the same.........

Update - I got a pair of early L63/6J5G working, round grey anode. I expected a lot and was disappointed. Bass was quite woolly, violins rather papery. My 6SN7 angled anodes were a lot better and pretty nice in fact. This might save me some money........


----------



## Isaacc7

les24preludes said:


> Yes - I used to have some 7A4 and 7N7 and I thought they were plentiful. I'm in the UK and there are no 7N7s or 7A4s advertised that I can see. Folks have cleaned them out it seems. Prices for earlier 6J5 types have rocketed up now as well. Frustrating - I want to try some of the earlier ones. I have plenty of 6SN7s so nil desperandum, but all the same.........
> 
> Update - I got a pair of early L63/6J5G working, round grey anode. I expected a lot and was disappointed. Bass was quite woolly, violins rather papery. My 6SN7 angled anodes were a lot better and pretty nice in fact. This might save me some money........


With a sample of one it's easy to write off an entire line of tubes if you get a bad set. I remember being really disappointed with the 14n7 and figured I should stop looking for them. Tried another pair on a whim and found gold. Even if tubes test well they may not sound great. 

7n7 seems to be pretty easy to find in the states. I'll admit to actually having a bunch of 14a4 so I'm not exactly sure what the availability of the 7a4 is like these days.


----------



## bcowen

les24preludes said:


> I've been doing a shootout of my 28 6SN7s and the plate/anode construction is basically these:
> 1. T plates, early 6SN7GT
> 2. ladder plates, many types
> 3. angled plates
> ...


These Hytron 7A4's are some of my favorites. Not just favorite 7A4's, but favorite period.  Note they do not have the additional 'CBS' labeling which indicates they were made prior to the CBS acquisition of Hytron.


----------



## Slade01

bcowen said:


> These Hytron 7A4's are some of my favorites. Not just favorite 7A4's, but favorite period.  Note they do not have the additional 'CBS' labeling which indicates they were made prior to the CBS acquisition of Hytron.


Genuine Hytrons are hard to come by these days.


----------



## bcowen

Slade01 said:


> Genuine Hytrons are hard to come by these days.


Yeah, I know.  I got these about a year ago roughly -- $20 for five of them.  Been looking for some backups for the backups, but I haven't seen any pop up in quite a while.


----------



## jonathan c

bcowen said:


> Yeah, I know.  I got these about a year ago roughly -- $20 for five of them.  Been looking for some backups for the backups, but I haven't seen any pop up in quite a while.


…you have them all…🤦🏻…🤣


----------



## Isaacc7

bcowen said:


> These Hytron 7A4's are some of my favorites. Not just favorite 7A4's, but favorite period.  Note they do not have the additional 'CBS' labeling which indicates they were made prior to the CBS acquisition of Hytron.


I'm pretty sure Sylvania built all of the US made Loctals regardless of the branding. I have heard that NU made some early 7n7, round plate no less, but I've never actually seen any.


----------



## pravous

I recently got a pair of sylvania and a pair of hytron 7a4 but have not really had a chance to do much listening.  I can see why this variety of tube did not take off.  Practically had to break out the angle grinder to get the pins clean and finding a decent socket for them is a pita!


----------



## gibosi

Isaacc7 said:


> I'm pretty sure Sylvania built all of the US made Loctals regardless of the branding. I have heard that NU made some early 7n7, round plate no less, but I've never actually seen any.



Sylvania 7N7 on the left and NU 7N7 on  the right. And yes, the NU has round plates.


----------



## Isaacc7

gibosi said:


> Sylvania 7N7 on the left and NU 7N7 on  the right. And yes, the NU has round plates.


I would love to hear of those NU round plates at some point. I have some 14n7 tubes with the grey coating but none of my 7n7 tubes have it.


----------



## gibosi

Isaacc7 said:


> I would love to hear of those NU round plates at some point. I have some 14n7 tubes with the grey coating but none of my 7n7 tubes have it.



As I recall the NU 7N7 has the same round plates as the NU 6F8G and sounds about the same.


----------



## bcowen

Isaacc7 said:


> I'm pretty sure Sylvania built all of the US made Loctals regardless of the branding. I have heard that NU made some early 7n7, round plate no less, but I've never actually seen any.


From everything I've read, both Sylvania and National Union made the 7N7's.  But they were the only two.  NU only made them for a short time, so the majority of what's out there were made by Sylvania.  I haven't done a lot of research on the 7A4's, but it would be logical that Sylvania was the main (if not only) manufacturer, and perhaps NU as well.

Sylvania even OEM'd for NU at times.  All in the pic are Sylvania, and the NU on the left is a Sylvania too...it has T-plates and is identical to the others internally.


----------



## Isaacc7

gibosi said:


> As I recall the NU 7N7 has the same round plates as the NU 6F8G and sounds about the same.


Oh, I have one of those! Somewhere... I've used the round plate KEN RAD 6f8g in my preamp, very open sounding. I only have one NU 6f8g round plate so I could put it as the input tube in my amp. Currently using a Raytheon 6f8g there now. Might try swapping it out if I can find the NU.


----------



## bcowen

Isaacc7 said:


> Oh, I have one of those! Somewhere... I've used the round plate KEN RAD 6f8g in my preamp, very open sounding. I only have one NU 6f8g round plate so I could put it as the input tube in my amp. Currently using a Raytheon 6f8g there now. Might try swapping it out if I can find the NU.


The one on the left is a National Union branded as Hytron.  Sylvania on the right.  The NU is labeled on both the box and the tube as a 7F7, but it's a 7N7 (tube testers don't lie ). Must have been made on a Friday afternoon...


----------



## pravous

Hard to get good pictures but I have a pair of Philco (assuming Sylvania) and Hytron 7A4.  They both seem to be round plate. 
Philco




Hytron


----------



## Isaacc7

I knew I had one floating around here somewhere...





If I come up with any grand opinions on it I'll talk about it in the 6sn7 thread.


----------



## les24preludes

I have a pair of 7A4 coming, together with CV6 and E1148. I'll report when they arrive. 

Meantime I rigged up a pair of 7193/2C22 and was disappointed. I have a hard time liking the ladder plates and this had the same grainy treble, despite being very clear and detailed. So not a keeper. 

I do like loctals - I have 7N7 T plates and 7AF7, and the 7N7 is in my system right now.


----------



## therremans

les24preludes said:


> Meantime I rigged up a pair of 7193/2C22 and was disappointed. I have a hard time liking the ladder plates and this had the same grainy treble, despite being very clear and detailed. So not a keeper.


I agree. I preferred the NU version over the KenRad. But they remain as you described.


----------



## bcowen

therremans said:


> I agree. I preferred the NU version over the KenRad. But they remain as you described.


I did a comparison between them, and at the end wasn't much turned on by either.  Not to say they can't be excellent in another amp or system, just that they didn't do it for me.


----------



## pravous

I absolutely love the 7193 in the Airmid.  Could be that having a circuit designed for 6J5 plays better with these?  The GEC cv1135 and vr135 versions of the 7193 have round plates and are fantastic.  I will try and take some pictures tonight.  The Hytron e-1148 seem to be similar but not exactly equivalent.  They have less gain than the 7193/CV1135.   When I tested this family I found that with the settings used in the 7193 data sheet the results in terms of gm were 7193>cv1135>e-1148.   7193 @ 100% cv1135 @ 60-70% and the e-1148 were @ 50%.  Sound wise the Ken Rad 7193 has the meaty low end.  GEC versions are a little more nuetral with great treble details.  The Hytron are very neutral with a slight emphasis on the midrange.


----------



## CAJames

I just got my adapters the other day and have been listening to both Ken-Rad and National Union 7193s. In my WA22 it seems like both tubes have the "house sound": KR is crystal clear, fast and transparent. The NUs might need a little more burn but they have more of the soft, warm yumminess. Both sound good in my system. Good enough I probably ought to investigate some of the UK models.


----------



## CAJames

So I rolled in mellower power tubes and I'm really enjoying the KR 7193. The bass is kickin', the mids are nice and liquid, but also detailed and highs might be a little rolled off but I don't mind. Just ordered kind of a grab bag of UK made DET20/CV6/VR135/etc I imagine it will take a while before they arrive.


----------



## triod750

https://www.ebay.com/itm/255476601206?hash=item3b7b979176:g:lksAAOSwPU5iTxZc

Same code? And 'item specifics':

Item specifics​Condition:
Seller refurbished:

Seller Notes:
“GOOD & STRONG ON FUNKE W19S. LOT OF 2 PCS.”
Model:
12AU7A ECC82 5814 6189 5963

Country/Region of Manufacture:
Germany
Type:
Vacuum Tube

Brand:
TELEFUNKEN"

At least they are refurbished. Good to know!


----------



## jonathan c

triod750 said:


> https://www.ebay.com/itm/255476601206?hash=item3b7b979176:g:lksAAOSwPU5iTxZc
> 
> Same code? And 'item specifics':
> 
> ...


How? Fresh ink on the logo?


----------



## Monsterzero

triod750 said:


> https://www.ebay.com/itm/255476601206?hash=item3b7b979176:g:lksAAOSwPU5iTxZc
> 
> Same code? And 'item specifics':
> 
> ...


I almost snagged those the other day, until I saw the shipping cost. He must hire a private jet to get them to you.


----------



## triod750

*"Due to the fact that by certified mail for the United States and Canada, the tracking and shipping update is very slow and was sent out of time, the shipment from now on will be sent through a Fedex affiliate, so the shipment It is more expensive. But it meets the deadlines and maintains a tracking update, insured the content and delivered with signature to the recipient".*

In spite of this, shipping cost is steep even in Europe. Maybe he ships them via US/Canada...?


----------



## triod750

jonathan c said:


> How? Fresh ink on the logo?


Or maybe a new roof?


----------



## bcowen

jonathan c said:


> How? Fresh ink on the logo?


The photos are dated 7/4/22, so dude has a time machine too.


----------



## triod750

bcowen said:


> The photos are dated 7/4/22, so dude has a time machine too.


That is European dating practise. Today is 11/5 -22. At least he got something right  .


----------



## bcowen

triod750 said:


> That is European dating practise. Today is 11/5 -22. At least he got something right  .


If he's listing on US Ebay, then he should be using US dates.  The nerve.  That's terribly confusing to those of us that are easily confused.  🤣🤣


----------



## jonathan c

bcowen said:


> If he's listing on US Ebay, then he should be using US dates.  The nerve.  That's terribly confusing to those of us that are easily confused.  🤣🤣


….but wouldn’t you like to buy, say quad NIB NOS of XYZ, on May 11th and pay on November 5th…🤷🏻‍♂️💸🤣…?


----------



## bcowen

jonathan c said:


> ….but wouldn’t you like to buy, say quad NIB NOS of XYZ, on May 11th and pay on November 5th…🤷🏻‍♂️💸🤣…?


Ugh.  XYZ's sound even worse than Philips ECG's.  Bet you didn't know that was even possible.


----------



## jonathan c

bcowen said:


> Ugh.  XYZ's sound even worse than Philips ECG's.  Bet you didn't know that was even possible.


At least a quad would (should) cost less than a single…🤪


----------



## triod750

Who made these? And when? Langrex is selling them and I am listening to a (borrowed) pair right now as input with a pair of genuine Tung Sol 6BX7GT (not GE made) as output and I don't dislike them at all. They seem to be very neutral.

https://www.langrex.co.uk/products/6c5g-cv581-cossor-nos-valve-tube/

It seems as if I have a preference for 6C5 to 6J5 in my amp. I am probably a lesser kind of person.


----------



## triod750

Since I don't speak electric I don't understand the practical relevance of this in our application http://amfone.net/Amforum/index.php?topic=13691.0;wap2

_"Although the 6J5 and 6J5G have the same amplification factor as the 6C5 and 6C5G, the mutual conductance has been increased, with a consequential reduction in plate resistance.  The output capacitance of the 6J5 is about a third that of the 6C5, and the design of the tube is such that the 6J5G is especially adapted to function in equipment at very high frequencies"._

Please enlighten me.


----------



## L0rdGwyn

triod750 said:


> Since I don't speak electric I don't understand the practical relevance of this in our application http://amfone.net/Amforum/index.php?topic=13691.0;wap2
> 
> _"Although the 6J5 and 6J5G have the same amplification factor as the 6C5 and 6C5G, the mutual conductance has been increased, with a consequential reduction in plate resistance.  The output capacitance of the 6J5 is about a third that of the 6C5, and the design of the tube is such that the 6J5G is especially adapted to function in equipment at very high frequencies"._
> 
> Please enlighten me.



For a typical audio circuit, this doesn't mean much.  In any reasonably designed and coupled output stage, the difference in transconductance and plate resistance between the 6J5 and the 6C5 will be negligible.  In radio frequency applications, it is more significant as the plate resistance can affect high frequency roll off points, don't want to attenuate the radio frequency you are attempting to amplify.


----------



## L0rdGwyn

Where plate resistance and transconductance do have an impact in single ended tube amplifiers is when the input tube is driving the grid of an output tube with a relatively high Miller capacitance, like the 300B.  The tube must provide the voltage swing to drive the output to clipping, but must also charge the Miller capacitance of the output tube.  This forms a low pass filter with the output impedance of the input stage, which is predominantly determined by the plate resistance of the input tube.  Long story short, for output tubes with a high Miller capacitance, like 300B, you must use a driver with a relatively low plate resistance or you will roll off the high frequencies.


----------



## triod750

L0rdGwyn said:


> Where plate resistance and transconductance do have an impact in single ended tube amplifiers is when the input tube is driving the grid of an output tube with a relatively high Miller capacitance, like the 300B.  The tube must provide the voltage swing to drive the output to clipping, but must also charge the Miller capacitance of the output tube.  This forms a low pass filter with the output impedance of the input stage, which is predominantly determined by the plate resistance of the input tube.  Long story short, for output tubes with a high Miller capacitance, like 300B, you must use a driver with a relatively low plate resistance or you will roll off the high frequencies.


Exactly as I thought! 

Thank you mylord!


----------



## L0rdGwyn

triod750 said:


> Exactly as I thought!
> 
> Thank you mylord!



No worries.  There are other specific situations where the plate resistance / transconductance come into play, I won't get into all of the technicalities, but usually it is a matter of not adversely affecting the frequency response of the amplifier.

But if you have an audio amplifier where using a 6J5 won't roll off the audible high end and a 6C5 will, you probably shouldn't be using either one if its that marginal.


----------



## triod750

L0rdGwyn said:


> But if you have an audio amplifier where using a 6J5 won't roll off the audible high end and a 6C5 will, you probably shouldn't be using either one if its that marginal.


In my case it seems more to be the other way around. Maybe, and if so, just slightly.


----------



## L0rdGwyn

triod750 said:


> In my case it seems more to be the other way around. Maybe, and if so, just slightly.



My guess is this perceived rolloff is due to distortion characteristics of the tubes.  If measured, they would likely show a similar high frequency response.  When people say "X tube is rolled off on top" or "Y tube is warm", if the tubes are the same model these perceived changes are not measurable, they are more likely due to psychoacoustic effects of each tube's distortion characteristics.  If rolling tubes in an amplifier measurably altered the frequency response - and assuming the tubes being used are all compatible with the amplifier - then there is something wrong with that amplifier's design.


----------



## leftside

triod750 said:


> Who made these? And when? Langrex is selling them and I am listening to a (borrowed) pair right now as input with a pair of genuine Tung Sol 6BX7GT (not GE made) as output and I don't dislike them at all. They seem to be very neutral.
> 
> https://www.langrex.co.uk/products/6c5g-cv581-cossor-nos-valve-tube/
> 
> It seems as if I have a preference for 6C5 to 6J5 in my amp. I am probably a lesser kind of person.


347 in stock. Langrex never fail to amaze me how they keep finding so many amazing NOS tubes.


----------



## Isaacc7

Langrex also has these GEC L63. I'm trying really hard not to spend more money but if the brain trust tells me these are great I might break down.





https://www.langrex.co.uk/products/l63-cv1067-gec-kbz-nos-valvetube/


----------



## raindownthunda

triod750 said:


> Who made these? And when? Langrex is selling them and I am listening to a (borrowed) pair right now as input with a pair of genuine Tung Sol 6BX7GT (not GE made) as output and I don't dislike them at all. They seem to be very neutral.
> 
> https://www.langrex.co.uk/products/6c5g-cv581-cossor-nos-valve-tube/
> 
> It seems as if I have a preference for 6C5 to 6J5 in my amp. I am probably a lesser kind of person.


My best guess is probably Brimar (but maybe Mullard?). If you image search for Brimar 6c5g there are some examples with the solid shield that look pretty much identical. Also, you inspired me to listen to these now with the often overlooked Tung-Sol 6080 that I've been trying (and failing) to find a good pairing for, and the combo is surprisingly fantastic. Nice warmth, decay, airy details.


----------



## jonathan c

Isaacc7 said:


> Langrex also has these GEC L63. I'm trying really hard not to spend more money but if the brain trust tells me these are great I might break down.
> 
> 
> 
> https://www.langrex.co.uk/products/l63-cv1067-gec-kbz-nos-valvetube/


They are great. As for me, no return to 6SN7 for the Lyr 3:


----------



## triod750

L0rdGwyn said:


> My guess is this perceived rolloff is due to distortion characteristics of the tubes.  If measured, they would likely show a similar high frequency response.  When people say "X tube is rolled off on top" or "Y tube is warm", if the tubes are the same model these perceived changes are not measurable, they are more likely due to psychoacoustic effects of each tube's distortion characteristics.  If rolling tubes in an amplifier measurably altered the frequency response - and assuming the tubes being used are all compatible with the amplifier - then there is something wrong with that amplifier's design.


I'm a strong believer in psychoacoustic effects. When I follow these forums that belief becomes strengthened. I also find that it is very difficult to describe what one is actually hearing, both for me and other people. Interpreting these descriptions is challenging and a lot of guesswork. An interesting way of keeping one's brain occupied.


----------



## whirlwind

leftside said:


> 347 in stock. Langrex never fail to amaze me how they keep finding so many amazing NOS tubes.



I know, right.

They always seem get  motherlode's, and right when you thought you were out...they pull you back in.


----------



## L0rdGwyn

triod750 said:


> I'm a strong believer in psychoacoustic effects. When I follow these forums that belief becomes strengthened. I also find that it is very difficult to describe what one is actually hearing, both for me and other people. Interpreting these descriptions is challenging and a lot of guesswork. An interesting way of keeping one's brain occupied.



Yes it is difficult, it becomes even more difficult when people are making comparison or placing value judgments on tubes that are being used differently in two different circuits.  I think people drastically underestimate how the circuitry outside of the tubes themselves affect the end result.  People tend to judge a circuit based on the tubes it uses alone, but there is more to it than that.



leftside said:


> 347 in stock. Langrex never fail to amaze me how they keep finding so many amazing NOS tubes.



If you look at Langrex's generic stock list, there are tons and tons of valuable tubes that they haven't put up for sale in dedicated listings.  My impression is they have a massive warehouse of tubes they've collected and they pick and choose what and when they will release them for sale, so I wouldn't be surprised if they've had these 6C5G on hand for years.  Just a hunch though!


----------



## triod750

L0rdGwyn said:


> Yes it is difficult, it becomes even more difficult when people are making comparison or placing value judgments on tubes that are being used differently in two different circuits. I think people drastically underestimate how the circuitry outside of the tubes themselves affect the end result. People tend to judge a circuit based on the tubes it uses alone, but there is more to it than that.


'My' amp designer always says "it's not about the tubes used, it's about the design". His opinion is that the tubes just have to be 'good enough' for their intended purpose. But since we 'normal users' can't change the design, we play around by changing the tubes. And sometimes to a good effect. But that effect might be less good when we also change the music...


----------



## L0rdGwyn

triod750 said:


> 'My' amp designer always says "it's not about the tubes used, it's about the design". His opinion is that the tubes just have to be 'good enough' for their intended purpose. But since we 'normal users' can't change the design, we play around by changing the tubes. And sometimes to a good effect. But that effect might be less good when we also change the music...



He's absolutely right.  The tubes are just another circuit element, they need to be chosen well for the application, if so the sound will be good.  Linear tubes will always be a good choice, the reason directly-heated triodes are highly favored in audio circuits; they are very linear, as such they do not necessarily require negative feedback.  The same goes for triode-strapped audio pentodes, like EL34.  Biasing and loading of gain stages is also critical, but sadly most commercial amplifier makers are using resistive loading and cathode bias, the worst choice.

What followed was a rant on the crap circuits commercial amplifier makers are using, picking on the amazingly overpriced Ampsandsound Red October in particular after reading this on the product page:

"Like the Nautilus, the Red October started as a personal project. It was not confined to a price point, and was not built for the masses, but instead the Red October was built to be the very best amplifier we were capable of building."

I deleted most of my rant, but I'll summarize: that 300B amplifier costs $12,000.  It doesn't even use a DC filament supply, and it is supposed to power headphones?  It will be noisy.  It also uses a 12AX7 input, a terrible choice as a 300B driver with its extremely high plate resistance.  Worse, it is resistively loaded and cathode biased, so it will be a high distortion gain stage.  Not built for the masses?  The very best amplifier they are capable of building?  It is as simple a circuit as you can get, there is nothing innovative happening in that box, it's the same basic single-ended 300B circuit that has been around for 80 years.

People hear this and probably think it is the height of tube amplifier design.  I interpret it as taking advantage of the lack of knowledge by audiophiles and using the sought after 300B as a marketing technique.  Maybe it really is the best amplifier he can make, if so that is disappointing as it is a great example of how to misuse tubes.  $12,000 in the right hands would get you a truly world class 300B amplifier with plenty left over for the designer as profit.  Sorry for the rant and I know it is off topic, going through a bit of Head-Fi disillusionment at the moment...I should probably hold my tongue so I don't offend.


----------



## jonathan c

L0rdGwyn said:


> He's absolutely right.  The tubes are just another circuit element, they need to be chosen well for the application, if so the sound will be good.  Linear tubes will always be a good choice, the reason directly-heated triodes are highly favored in audio circuits; they are very linear, as such they do not necessarily require negative feedback.  The same goes for triode-strapped audio pentodes, like EL34.  Biasing and loading of gain stages is also critical, but sadly most commercial amplifier makers are using resistive loading and cathode bias, the worst choice.
> 
> What followed was a rant on the crap circuits commercial amplifier makers are using, picking on the amazingly overpriced Ampsandsound Red October in particular after reading this on the product page:
> 
> ...


Don’t. I always learn something from a post of yours.


----------



## Xcalibur255

L0rdGwyn said:


> He's absolutely right.  The tubes are just another circuit element, they need to be chosen well for the application, if so the sound will be good.  Linear tubes will always be a good choice, the reason directly-heated triodes are highly favored in audio circuits; they are very linear, as such they do not necessarily require negative feedback.  The same goes for triode-strapped audio pentodes, like EL34.  Biasing and loading of gain stages is also critical, but sadly most commercial amplifier makers are using resistive loading and cathode bias, the worst choice.
> 
> What followed was a rant on the crap circuits commercial amplifier makers are using, picking on the amazingly overpriced Ampsandsound Red October in particular after reading this on the product page:
> 
> ...


If you're sure you are never going to seek MOT status then keep speaking truth to power my man.  Anything worth talking about is going to inevitably ruffle some feathers.


----------



## leftside

Xcalibur255 said:


> If you're sure you are never going to seek MOT status then keep speaking truth to power my man.  Anything worth talking about is going to inevitably ruffle some feathers.


Especially when they've spent 12k.


----------



## leftside

L0rdGwyn said:


> He's absolutely right.  The tubes are just another circuit element, they need to be chosen well for the application, if so the sound will be good.  Linear tubes will always be a good choice, the reason directly-heated triodes are highly favored in audio circuits; they are very linear, as such they do not necessarily require negative feedback.  The same goes for triode-strapped audio pentodes, like EL34.  Biasing and loading of gain stages is also critical, but sadly most commercial amplifier makers are using resistive loading and cathode bias, the worst choice.
> 
> What followed was a rant on the crap circuits commercial amplifier makers are using, picking on the amazingly overpriced Ampsandsound Red October in particular after reading this on the product page:
> 
> ...


Plenty of nice off the shelf amps out there, but my experience (now with 3 custom amps so I'm a little (tube) biased), is that if you have the patience to wait, custom amps from one of the skilled builders on here is the way to go. Quality parts, quality design, hand crafted, etc. 

Not a chance the major amp builders are going to be able to match this quality as they have sales and marketing expenses, people they need to employ, etc. To build amps like this would be far too costly for them to be able to still make a reasonable profit.

Just a shame that some of the smaller amp builders have seen a niche market, thrown in a fancy tube, put together some nice heavy transformers, but neglected the circuit design.


----------



## CaptainFantastic

L0rdGwyn said:


> He's absolutely right.  The tubes are just another circuit element, they need to be chosen well for the application, if so the sound will be good.  Linear tubes will always be a good choice, the reason directly-heated triodes are highly favored in audio circuits; they are very linear, as such they do not necessarily require negative feedback.  The same goes for triode-strapped audio pentodes, like EL34.  Biasing and loading of gain stages is also critical, but sadly most commercial amplifier makers are using resistive loading and cathode bias, the worst choice.
> 
> What followed was a rant on the crap circuits commercial amplifier makers are using, picking on the amazingly overpriced Ampsandsound Red October in particular after reading this on the product page:
> 
> ...



Your mostly deleted "rant" is appreciated. You know, what I find disconcerting is that unless one runs into comments like this from a very knowledgeable person like you, pretty much all the information out there would suggest that this company and its products are the bee's knees.


----------



## L0rdGwyn

Xcalibur255 said:


> If you're sure you are never going to seek MOT status then keep speaking truth to power my man.  Anything worth talking about is going to inevitably ruffle some feathers.



I'm not eager to go saying that stuff on the Ampsandsound thread lol not sure I have the energy to argue with any Red October owners, there would be no convincing them.  And if it is the best amplifier they've ever heard, that that's what they will say, even if it can be improved upon in many ways.  Maybe if I don't have an industry affiliation or MOT status in the works by the end of the year, I'll spend my time critiquing commercial tube designs publicly.



leftside said:


> Plenty of nice off the shelf amps out there, but my experience (now with 3 custom amps so I'm a little (tube) biased), is that if you have the patience to wait, custom amps from one of the skilled builders on here is the way to go. Quality parts, quality design, hand crafted, etc.
> 
> Not a chance the major amp builders are going to be able to match this quality as they have sales and marketing expenses, people they need to employ, etc. To build amps like this would be far too costly for them to be able to still make a reasonable profit.
> 
> Just a shame that some of the smaller amp builders have seen a niche market, thrown in a fancy tube, put together some nice heavy transformers, but neglected the circuit design.



Yes, no doubt about it.  There are certain aspects of custom building that can be addressed on an individual basis that are impractical at higher volumes.  For example, finding a custom transformer winder who can produce them in volume at low cost would be challenging.  Going back to Ampsandsound, their transformers are being wound by Transcendar.  Transcendar has completely shut down their website and no longer takes outside orders.  This is speculation on my part, but I assume that is due to their partnership with Ampsandsound, they likely can only support their needs.

Using more complex ancillary circuitry (e.g., power supply regulators) also becomes somewhat impractical - more complexity means more opportunity for parts failure, as well as increasing supply chain issues, especially with an international semiconductor shortage.  Even so, active loading can be accomplished in many ways with more widely available parts - Bottlehead has been doing it for over a decade and it has significant benefits, and yet very few manufacturers seem to pursue it.

I have been thinking about these things while designing that pentode amp I have in the works, designing from the standpoint of commercial manufacture is not easy.  I understand why many don't pursue these improvements - they cut into profit margins, make for a more complex design, more opportunities for parts failure, supply chain complexity, etc.  But IMO, then the product should be priced accordingly rather than adding a popular tube and price gouging.  The Red October has to be the most egregious I have come across in that department.


----------



## Xcalibur255

Companies invest so much energy into marketing because it works and gets them a return on the investment.  I think the audiophile community is especially easy to influence this way for a long list of reasons.  That sentence about the Red October and it's "personal project" roots is very likely ad copy and you see the same rosy grass roots style stories on most of those websites.  Of course it isn't necessarily bad in and of itself, but a large goal of advertising is to set a mood or instill a desire.  They want you to make a purchasing decision with the part of your brain that _feels _not the part that _thinks_.  It's inherently manipulative by nature.


----------



## Xcalibur255

L0rdGwyn said:


> I'm not eager to go saying that stuff on the Ampsandsound thread lol not sure I have the energy to argue with any Red October owners, there would be no convincing them.  And if it is the best amplifier they've ever heard, that that's what they will say, even if it can be improved upon in many ways.  Maybe if I don't have an industry affiliation or MOT status in the works by the end of the year, I'll spend my time critiquing commercial tube designs publicly.



Oh, no, and I wouldn't suggest you do so unless you want to get in touch with your inner masochist.   

I mean continue to do exactly what you did earlier today:  saw an opportunity to offer an insight to an audience that was likely to find it valuable and share that insight.


----------



## L0rdGwyn

CaptainFantastic said:


> Your mostly deleted "rant" is appreciated. You know, what I find disconcerting is that unless one runs into comments like this from a very knowledgeable person like you, pretty much all the information out there would suggest that this company and its products are the bee's knees.



Maybe not all of their products fall into this category, I haven't looked at each individually and they have other more budget-friendly options, I'm sure people are very happy with them.  But the Red October to me is clearly trying to capitalize on the reputation of that tube and is very over priced.


----------



## CaptainFantastic

Xcalibur255 said:


> Companies invest so much energy into marketing because it works and gets them a return on the investment.  I think the audiophile community is especially easy to influence this way for a long list of reasons.  That sentence about the Red October and it's "personal project" roots is very likely ad copy and you see the same rosy grass roots style stories on most of those websites.  Of course it isn't necessarily bad in and of itself, but a large goal of advertising is to set a mood or instill a desire.  They want you to make a purchasing decision with the part of your brain that _feels _not the part that _thinks_.  It's inherently manipulative by nature.



Well put. There is a recent interview in which I believe the word brand (hence marketing for it) is used in excess of 100 times. I think I stopped watching when I heard it mentioned three times in one sentence.  

[added the space to avoid the video icon display in the thread]
youtube.com /watch?v=_t3jEmIr2Ss


----------



## triod750

“The first principle is that you must not fool yourself, and you are the easiest person to fool.”
Richard Feynman

You see people breaking this rule over and over. Not least with us tube people or audio people. I'm not completely innocent.


----------



## bcowen

Xcalibur255 said:


> *Companies invest so much energy into marketing because it works and gets them a return on the investment.*  I think the audiophile community is especially easy to influence this way for a long list of reasons.  That sentence about the Red October and it's "personal project" roots is very likely ad copy and you see the same rosy grass roots style stories on most of those websites.  Of course it isn't necessarily bad in and of itself, but a large goal of advertising is to set a mood or instill a desire.  They want you to make a purchasing decision with the part of your brain that _feels _not the part that _thinks_.  It's inherently manipulative by nature.


So true.  Think Bose.  Prime example of how savvy marketing can make total junk highly desirable to the unwashed masses.


----------



## Isaacc7

leftside said:


> Plenty of nice off the shelf amps out there, but my experience (now with 3 custom amps so I'm a little (tube) biased), is that if you have the patience to wait, custom amps from one of the skilled builders on here is the way to go. Quality parts, quality design, hand crafted, etc.
> 
> Not a chance the major amp builders are going to be able to match this quality as they have sales and marketing expenses, people they need to employ, etc. To build amps like this would be far too costly for them to be able to still make a reasonable profit.
> 
> Just a shame that some of the smaller amp builders have seen a niche market, thrown in a fancy tube, put together some nice heavy transformers, but neglected the circuit design.


Absolutely right about customer amp builders. When I got the quote for the amp I wanted to have built for me I just shook my head. But it was still going to be less than a lot of used Audio Research and McIntosh amps and it was going to be exactly what I wanted. Custom tube amps and preamps are not cheap but they can come in less than the usual suspects in the amp world and not give up anything sound or build quality wise.


----------



## bcowen

jonathan c said:


> Don’t. I always learn something from a post of yours.


+1.  Me too.


----------



## Monsterzero

triod750 said:


> Who made these? And when? Langrex is selling them and I am listening to a (borrowed) pair right now as input with a pair of genuine Tung Sol 6BX7GT (not GE made) as output and I don't dislike them at all. They seem to be very neutral.
> 
> https://www.langrex.co.uk/products/6c5g-cv581-cossor-nos-valve-tube/
> 
> It seems as if I have a preference for 6C5 to 6J5 in my amp. I am probably a lesser kind of person.


 Did we ever figure out who made these tubes?


Isaacc7 said:


> Absolutely right about customer amp builders. When I got the quote for the amp I wanted to have built for me I just shook my head. But it was still going to be less than a lot of used* Audio Research and McIntosh amps* and it was going to be exactly what I wanted. Custom tube amps and preamps are not cheap but they can come in less than the usual suspects in the amp world and not give up anything sound or build quality wise.


I was chatting with an unnamed person recently and he referred to the exobitant prices on some of these boutique amps as "genius tax". Found that to be funny, but true.


----------



## L0rdGwyn

Monsterzero said:


> Did we ever figure out who made these tubes?



Most likely they were made by Brimar.


----------



## triod750

Did we have a guess as to when they most likely were made? By whoever made them...
Accurate year would suffice.


----------



## jonathan c

bcowen said:


> So true.  Think Bose.  Prime example of how savvy marketing can make total junk highly desirable to the unwashed masses.


Exhibit A:


----------



## Monsterzero

BOSE, an acronym for Buy Other Stereo Equipment


----------



## bcowen

jonathan c said:


> Exhibit A:


Problem is you need a trash can big enough to fit the speaker in. 

Of course, it *is* possible that filling that up with trash might make it sound better.


----------



## jonathan c

bcowen said:


> Problem is you need a trash can big enough to fit the speaker in.
> 
> Of course, it *is* possible that filling that up with trash might make it sound better.


…it’s called grunge…🤪


----------



## leftside

Monsterzero said:


> Did we ever figure out who made these tubes?
> 
> I was chatting with an unnamed person recently and he referred to the exobitant prices on some of these boutique amps as "genius tax". Found that to be funny, but true.


I've owned a number of McIntosh amps from 1960's vintage to amps from 10 years ago, and have always been very impressed. There aren't too many 1960's amps that are selling today for twice what they sold back then, and still work and still sound great (maybe a recap is in order).

Having said that, if I knew then what I know now regarding amps, I would probably have got Mick from Supratek or Mischa to have built me my main mono tube amps. I still might go that route that one day, but it's tough to give up amps that you like so much and also know will hold their value.


----------



## Monsterzero

leftside said:


> I've owned a number of McIntosh amps from 1960's vintage to amps from 10 years ago, and have always been very impressed. There aren't too many 1960's amps that are selling today for twice what they sold back then, and still work and still sound great (maybe a recap is in order).
> 
> Having said that, if I knew then what I know now regarding amps, I would probably have got Mick from Supratek or Mischa to have built me my main mono tube amps. I still might go that route that one day, but it's tough to give up amps that you like so much and also know will hold their value.


 Yeah, I wasnt really referencing McIntosh specifically at all. I'm a big fan of vintage McIntosh gear. 

Was more about an amp I recently reviewed and it's crazy price tag vs. Keenan's amp, which is half the price and sounds significantly better


----------



## triod750

Looking for tubes?

https://www.ebay.ie/itm/284365833934?hash=item42358646ce:g:CG0AAOSwhVJg6JZz

https://www.ebay.ie/itm/284365876532?hash=item423586ed34:g:ERAAAOSwYZtg6KGC

https://www.ebay.ie/itm/284641403224?hash=item4245f32158:g:8LwAAOSwaT1h~5zb

You can save on combined shipping...


----------



## leftside

triod750 said:


> Looking for tubes?
> 
> https://www.ebay.ie/itm/284365833934?hash=item42358646ce:g:CG0AAOSwhVJg6JZz
> 
> ...


The latter two are actually not a bad deal. Especially the second auction as I don't believe those are 6C5G. I think they are mislabeled 6J5G. The 3rd auction is about the going rate these days for NOS 1949 GEC 6J5G - but perhaps there should be a discount for buying 10


----------



## Marutks (May 21, 2022)

leftside said:


> I think they are mislabeled 6J5G.



Here is the same tube which looks like 6C5G to me.
https://www.head-fi.org/threads/the...c5-12j5-6p5-etc.934653/page-146#post-16971564

What are those tubes doing in Pakistan?


----------



## Xcalibur255

jonathan c said:


> Exhibit A:


I mean people could certainly be forgiven for making the mistake.


----------



## Xcalibur255

triod750 said:


> Looking for tubes?
> 
> https://www.ebay.ie/itm/284365833934?hash=item42358646ce:g:CG0AAOSwhVJg6JZz
> 
> ...


I feel like that last one is doable if people here wanted to organize a group buy and divy them up.


----------



## raindownthunda (May 21, 2022)

triod750 said:


> Looking for tubes?
> 
> https://www.ebay.ie/itm/284365833934?hash=item42358646ce:g:CG0AAOSwhVJg6JZz
> 
> ...


The second one is actually GEC L63. They are definitely different than the Cossor 6C5G rebrands Langrex has. The seller sent me an offer for 385 GBP a few months ago when a group buy fell through. Even with shipping at 65 GBP + tax it comes out to roughly $62 USD per tube / $124 USD per pair. If someone is interested in trying to organize another group buy I’d be in for a pair. They’ve been up for sale forever so maybe the seller would negotiate down further...


----------



## triod750

Is it actually GEC L63 or is it probably/most likely GEC L63? I noticed that it is different from the Cossor branded pair I am listening to but couldn't see the internals.


----------



## maxpudding

bcowen said:


> I did a comparison between them, and at the end wasn't much turned on by either. Not to say they can't be excellent in another amp or system, just that they didn't do it for me.



Are those adapters from deyan?


----------



## bcowen

maxpudding said:


> Are those adapters from deyan?


Yes.  I added the labeling, but the rest is his work.


----------



## les24preludes (May 22, 2022)

The mood seems to be going towards the L63 types.... I have a pair ST shape, used, and I was quite disappointed with the sound.

I have a pair of Raytheon 6J5WGT and these are rather good - very clear. 

The one I'm liking is the CV6. I have box plates, not round plates. Not so keen on the E1148 though and even less on the 7193.

Anyone still using CV6?


----------



## maxpudding

bcowen said:


> Yes.  I added the labeling, but the rest is his work.


I like the lead caps  Did you experience any microphonic/feedback noise with the 7193/2C22 tubes in your amp?


----------



## triod750

I have a pair of these as loaners and have tried to love them in different combinations without success. They have left me cold.






Now I have found a pair that is changing my feelings. With these as output tubes both the violin and grand piano sounds natural.





(Both photos borrowed).


----------



## bcowen

maxpudding said:


> I like the lead caps  Did you experience any microphonic/feedback noise with the 7193/2C22 tubes in your amp?


No microphonic issues at all.  Very quiet too.  I was expecting a little more noise with the exterior leads like that, but no such problem.


----------



## triod750

The truth, the whole truth and nothing but the truth about tube date and manufacturer coding?

"The letters in the box containing the arrow are the date code,
the first two being the year and the latter two the month or in
an alternative scheme the week using calendar date format.
*They show the date when the lettering was applied which may
not be the same date as when the valve was manufactured.*
In the other box the first letter is the approval status and the
second the qualification level. There may be one or two letters
following the oblique stroke. *These show the valve supplier;
being defined as the place where the pumping process was
completed i.e. the electrode assembly could have been
manufactured elsewhere or even by another manufacturer*.
This scheme was often used by members of the BVA for
commercial valves and by semiconductor manufacturers e.g".

From http://www.vmarsmanuals.co.uk/newsletter_articles/cv_valves
Don't remember where I got it from.


----------



## JazzVinyl

triod750 said:


> I have a pair of these as loaners and have tried to love them in different combinations without success. They have left me cold.
> 
> 
> 
> ...



Very nice to be able to find out they did not have synergy with your amp...as loaners, rather than to find out, after having purchased them


----------



## mordy

triod750 said:


> The truth, the whole truth and nothing but the truth about tube date and manufacturer coding?
> 
> "The letters in the box containing the arrow are the date code,
> the first two being the year and the latter two the month or in
> ...


It has to be added that some date codes on tubes are neither manufacturing dates nor shipping dates but instead the date when the warranty on the tube expires. Go figure…


----------



## triod750

JazzVinyl said:


> Very nice to be able to find out they did not have synergy with your amp...as loaners, rather than to find out, after having purchased them


Well, with the Brimar tubes as output they have synergy with my amp. Several 'lesser' tubes have become good in the right combinations. Experimenting is interesting and sometimes rewarding. Trying before buying is a blessing but rarely possible. Generous friends are a blessing too.

Nothing wrong with buying a well designed amp and use the tubes intended for it, but...


----------



## Velozity

triod750 said:


> Is it actually GEC L63 or is it probably/most likely GEC L63? I noticed that it is different from the Cossor branded pair I am listening to but couldn't see the internals.



It is actually GEC L63.  I bought 10 of them from that seller about 2 years ago and can verify from first-hand knowledge and comparison with other correctly labeled L63 in my collection that they have identical internals and sound signature.  Literally the only difference between the tubes in the second and third links from above is the labeling on the glass.  I'm about to buy some more because I need a matched quad for my new amp.  If anybody wants in let me know.


----------



## Xcalibur255

I personally am needing just a single tube because one of my L63s has a short and is not usable.  I've been hoping that a NOS single shows up that would match reasonably well so I can make it a working pair again but no luck so far.  So if you guys happen to end up with an oddball single lying around that would work I'd be grateful for a PM.


----------



## jonathan c (May 25, 2022)

Xcalibur255 said:


> I personally am needing just a single tube because one of my L63s has a short and is not usable.  I've been hoping that a NOS single shows up that would match reasonably well so I can make it a working pair again but no luck so far.  So if you guys happen to end up with an oddball single lying around that would work I'd be grateful for a PM.


What about this? - 185 in stock:


----------



## triod750

triod750 said:


> I have a pair of these as loaners and have tried to love them in different combinations without success. They have left me cold.
> 
> 
> 
> ...


Another pair of output tubes give more details/better definition, not least in both ends. Makes me think of C3g, but easier on my ears/brain. The tubes in question are genuine Tung Sol 6BX7GT. I suppose these 'L63GT' (as I call them in my mind) are much better than I thought. I judged them too early, without running them/myself in enough.


----------



## CAJames

So my "grab bag" of UK 7193 types turned out to be a bunch of these honeys:





Still in the factory paper. Labeled CV1135, Hammersmith Factory , Feb '54 date codes, at least for the ones I opened. And wow do they sound good: Strong bass, big beautiful mids and crystal clear highs. Interestingly the caps are backwards compared to the US tubes, the grid cap is the one closest to the guide pin. I have more than I need and would sell a few pairs if there is any interest, you can PM for the details.


----------



## Xcalibur255

@jonathan c

My bad, I should have specified that I need the grey glass ST style tube.  I have a pair of the clear straight glass and IMO they're not as good.  Very different presentation from the grey glass tubes.


----------



## triod750

Xcalibur255 said:


> @jonathan c
> 
> My bad, I should have specified that I need the grey glass ST style tube.  I have a pair of the clear straight glass and IMO they're not as good.  Very different presentation from the grey glass tubes.


I agree with you that these different L63 give a very different presentation. I am supposed to like the grey glass 'L63G' more since it is supposed to be more refined, but in the combinations I have tried them in my amp (not designed for them) this has not been the result. My brain has to work harder to extract the information from 'L63G' and this makes me tired. With 'L63GT', the music is easier to follow. Eventually I will probably compare them in a better amp.

I really like to believe in that 'older is better' but in reality I think that better is better, regardless of age and that it is mostly synergy dependent. (I hope gibosi doesn't read that last sentence  ).


----------



## gibosi

triod750 said:


> I really like to believe in that 'older is better' but in reality I think that better is better, regardless of age and that it is mostly synergy dependent. (I hope gibosi doesn't read that last sentence  ).



Usually, older is better, but not always.


----------



## pravous

CAJames said:


> So my "grab bag" of UK 7193 types turned out to be a bunch of these honeys:
> 
> 
> 
> Still in the factory paper. Labeled CV1135, Hammersmith Factory , Feb '54 date codes, at least for the ones I opened. And wow do they sound good: Strong bass, big beautiful mids and crystal clear highs. Interestingly the caps are backwards compared to the US tubes, the grid cap is the one closest to the guide pin. I have more than I need and would sell a few pairs if there is any interest, you can PM for the details.


So far of all the 7193 variants the cv1135 has been my favorite as well.  Hard to tell from the picture but is the base black or brown?


----------



## CAJames

The base is dark brown.


----------



## triod750

gibosi said:


> Usually, older is better, but not always.


In my naturally limited experience you are absolutely right!!


----------



## CAJames

gibosi said:


> Usually, older is better, but not always.


 
Yes. _A foolish consistency is the hobgoblin of little minds, _Ralph Waldo Emerson.


----------



## pravous

Old age and treachery will always beat youth and exuberance.

David Mamet


----------



## jonathan c

While we are at it, another RWE gem: _idea and execution are seldom found in the same head._


----------



## triod750

I have a lot of ideas...

But coming up with ideas is an execution in itself, not?


----------



## jonathan c

triod750 said:


> I have a lot of ideas...
> 
> But coming up with ideas is an execution in itself, not?


👎


----------



## triod750

jonathan c said:


> 👎


----------



## jonathan c

triod750 said:


>


👍


----------



## Monsterzero

pravous said:


> So far of all the 7193 variants the cv1135 has been my favorite as well.  Hard to tell from the picture but is the base black or brown?


 Are these drop ins on the Airmid or is an adapter needed?


----------



## pravous

Monsterzero said:


> Are these drop ins on the Airmid or is an adapter needed?


Requires adaptor.  Got my set from Deyan and then modified the top caps.


----------



## les24preludes

jonathan c said:


> While we are at it, another RWE gem: _idea and execution are seldom found in the same head._


I wouldn't agree with this. As a psychologist my specialisation has been performers, people in the arts and creativity in general. The creative mind is very good at generating ideas, but it is also good at getting results from these ideas. What it isn't so good at is steady-state administration which creatives find boring, since they like to jump from one new idea to another and then see the results in practice. So it depends what you mean by "execution". Ideas people are good pioneers but once a project is up and running you need different kinds of people to actually run it, since the creatives will have already moved on or even been sacked from things they started.


----------



## les24preludes

pravous said:


> So far of all the 7193 variants the cv1135 has been my favorite as well.  Hard to tell from the picture but is the base black or brown?


Yes, the CV1135 is very good. It's the one that's in my system at the moment, though I'm still tempted by my TDD4 line stage. Mine are black base.


----------



## TLO

Has anyone compared L63 (GT or ST) to ECC31? Please share your thoughts if you do, TIA!!!


----------



## BottleFred

TLO said:


> Has anyone compared L63 (GT or ST) to ECC31? Please share your thoughts if you do, TIA!!!


This one is interesting.
L63 ST (smoked) sounds spacious and warm.
L63 GT (brownbase) adds more musical timbre and liveliness.
ECC31 sounds more ‘upfront’, solid with nice live feel and timbre.
If you like space and real sound, go for L63GT.
If you like a solid live sound, try the ECC31.


----------



## TLO

BottleFred said:


> This one is interesting.
> L63 ST (smoked) sounds spacious and warm.
> L63 GT (brownbase) adds more musical timbre and liveliness.
> ECC31 sounds more ‘upfront’, solid with nice live feel and timbre.
> ...


Thank you!!! I have the ECC31 and like them a lot, looking to try the L63 now


----------



## TLO

BottleFred said:


> This one is interesting.
> L63 ST (smoked) sounds spacious and warm.
> L63 GT (brownbase) adds more musical timbre and liveliness.
> ECC31 sounds more ‘upfront’, solid with nice live feel and timbre.
> ...


Unfortunately, my amp Line Magnetic LM508, doesnt have enough space for the ST bottle, guess I will just look into the GT bottle with the new smaller adapter. Have checked with the adapter maker and it's a no go for ST bottle. Again, thanks a lot for the input


----------



## BottleFred

TLO said:


> Unfortunately, my amp Line Magnetic LM508, doesnt have enough space for the ST bottle, guess I will just look into the GT bottle with the new smaller adapter. Have checked with the adapter maker and it's a no go for ST bottle. Again, thanks a lot for the input


👍👍 happy hunting!


----------



## TLO

BottleFred said:


> 👍👍 happy hunting!


@mordy has just shared a solution, you can use a socket saver on one of the ST bottle, hence you can insert 2 ST bottles on the smaller new adapter


----------



## les24preludes

Revisiting this thread after buying a pair of metal base Sylvania round plates very cheap untested on ebay. Fortunately both are very strong and equal emissions. 

They are very clear and quite bright. I'll leave them in for a while to see if the brightness is too much. My recent favourites have been the CV6 types e.g. CV1135. They may go back in. Has anyone else tried these Sylvania metal base VT-940?


----------



## mordy

les24preludes said:


> Revisiting this thread after buying a pair of metal base Sylvania round plates very cheap untested on ebay. Fortunately both are very strong and equal emissions.
> 
> They are very clear and quite bright. I'll leave them in for a while to see if the brightness is too much. My recent favourites have been the CV6 types e.g. CV1135. They may go back in. Has anyone else tried these Sylvania metal base VT-940?


The same tube but a later production is one of my favorite tubes. You need to look for metal base 1950-53 tall glass Sylvania or rebranded (plenty of them) 6J5GT tubes. 




Tall glass, round plate, top mica bigger than bottom mica, clip heat radiator on top. If you shop carefully not expensive.
IMHO sounds better than the earlier ones.
Don't know which amp you are using, but you need a tube combination that doesn't accentuate brightness.


----------



## Nerfkevin

Hello fellow tube people! Im just getting in the realms of tube and have a little question.
If my amp has 2-6sn7 preamp and i want to use an arapted for 2 pairs of 6j5 tubes (2 for each side), does both pair has to be matching? 
Furthermore, how important is it for each pair to be matching, as long as it is the same model? 
Im looking towards trying my luck on some new untested tubes for a good price lol. I know for power tubes they have to be well matched but just need more info for preamp tubes!


----------



## mordy

Nerfkevin said:


> Hello fellow tube people! Im just getting in the realms of tube and have a little question.
> If my amp has 2-6sn7 preamp and i want to use an arapted for 2 pairs of 6j5 tubes (2 for each side), does both pair has to be matching?
> Furthermore, how important is it for each pair to be matching, as long as it is the same model?
> Im looking towards trying my luck on some new untested tubes for a good price lol. I know for power tubes they have to be well matched but just need more info for preamp tubes!


You do not need matching tubes. Which amp are you using?


----------



## Nerfkevin (Jun 23, 2022)

I got a custom amp from eufonika, it will arrive soon they come with some russian tube but of course i would like to experiment with stuff!
As for the tubes you mentioned above, are they these:



Edit: also, if i wasnt clear enough in my previous post, i was wondering tubes within the pair have to match “matched pair”, even though they're the same model.


----------



## Slade01

Nerfkevin said:


> I got a custom amp from eufonika, it will arrive soon they come with some russian tube but of course i would like to experiment with stuff!
> As for the tubes you mentioned above, are they these:
> 
> Edit: also, if i wasnt clear enough in my previous post, i was wondering tubes within the pair have to match “matched pair”, even though they're the same model.



As @mordy said, they do not have to be "matched".  It's a nice to have, but not necessary kind of thing.  

As far as the Russian stock tubes - Wieslaw has the skills to really tune the hell out of his (eufonika) amps to really get everything out of even the stock tubes.  It's one of the first tube amps I have ever encountered that I didn't feel the need to throw away the stock tubes.  Lol.  But it's a great amp to have - he makes all of his amps dead silent and work extremely well with tube rolling.


----------



## mordy (Jun 23, 2022)

Nerfkevin said:


> I got a custom amp from eufonika, it will arrive soon they come with some russian tube but of course i would like to experiment with stuff!
> As for the tubes you mentioned above, are they these:
> 
> Edit: also, if i wasnt clear enough in my previous post, i was wondering tubes within the pair have to match “matched pair”, even though they're the same model.


It looks like the right kind. There is usually a date code on the base on Sylvania labeled tubes and a second date code under the rhomboid GT designation on the glass. An example would be 126 on the base (numbers in a vertical row) meaning 26th week 1951, and on the glass under the tube designation the symbols K0M.
Count the ABC on your fingers and skip I (looks like 1) and K is finger #10=October.
0 = 1950.
M don't know, but probably a factory code.
Why the discrepancy between October and June? I assume manufacturing and shipping dates.
Come to think about it, it makes sense that the date on the glass is earlier. The factory could make a batch of tubes, and when they get an order, they can put Sylvania or a rebranded name like Motorola, Philco or FOMOCO (Ford Motor Co) on the base with a shipping date.


----------



## mordy

mordy said:


> You do not need matching tubes. Which amp are you using?


Re the Eufonika amp, please ask if the two 6SN7 tubes are wired in parallel. As you know, the 6SN7 is a double triode and technically one such tube can be used to drive both channels. 
I have a Feliks Euforia with two sockets for 6SN7 drivers. For whatever reason the designer chose two 6SN7 tubes wired in parallel to drive the two channels R&L.
By using two 6SN7 to 6N7 adapters I only need one 6J5GT triode per channel. The results are excellent; the only drawback (if it even is a drawback) is that I need a little more volume than with a pair of 6SN7 tubes. Using dual adapters 6SN7 to 6SN7 with two tubes each did not work at all - just terrible hum. But I do not know if your amp is wired the same way as the Euforia.


----------



## Nerfkevin

Thanks @mordy for that! I have asked eufonika about this and will keep that in mind when i tube roll. 
I just got these trio of i believe gec tubes for 50 gbp, looks arent too perfect but they tested well on amplitrex. Dont know if thats a great price but they seem to be quite expensive on the market😮


----------



## TLO (Jun 24, 2022)

mordy said:


> By using two 6SN7 to 6N7 adapters I only need one 6J5GT triode per channel. The results are excellent; the only drawback (if it even is a drawback) is that I need a little more volume than with a pair of 6SN7 tubes. Using dual adapters 6SN7 to 6SN7 with two tubes each did not work at all - just terrible hum. But I do not know if your amp is wired the same way as the Euforia.


Correct me if I am wrong. Each section of 6SN7 has a gain of 20, so a tube has 40 into each channel and two tubes have 80 into each channel. That is double perhaps that is why you are getting hum with two tubes. As for a single 6J5GT, you are only getting 20 with a single triode, half of what the amp is designed for each channel.


----------



## mordy

TLO said:


> Corect me if I am wrong. Each section of 6SN7 has a gain of 20, so a tube has 40 into each channel and two tubes have 80 into each channel. That is double perhaps that is why you are getting hum with two tubes. As for a single 6J5GT, you are only getting 20 with a single triode, half of what the amp is designed for each channel.


This is beyond my pay grade, but I do know that one 6SN7 tube has a total gain of 20 and a 6J5 tube is half of a 6SN7 and two 6J5 tubes equal one 6SN7.
The question is how the parallel wiring affects the gain. My gut feeling is that if you combine two tubes it is not like adding the gain of one tube to the gain of the second one. And if you combine two different tubes of different gain the resulting gain is not the sum of the gain of the two - maybe more like the lowest gain of the two tubes.
Perhaps somebody could weigh in and explain this.
Some amps allow for three or more drivers. What is the total gain when you combine different tubes?


----------



## TLO

mordy said:


> This is beyond my pay grade, but I do know that one 6SN7 tube has a total gain of 20 and a 6J5 tube is half of a 6SN7 and two 6J5 tubes equal one 6SN7.
> The question is how the parallel wiring affects the gain. My gut feeling is that if you combine two tubes it is not like adding the gain of one tube to the gain of the second one. And if you combine two different tubes of different gain the resulting gain is not the sum of the gain of the two - maybe more like the lowest gain of the two tubes.
> Perhaps somebody could weigh in and explain this.
> Some amps allow for three or more drivers. What is the total gain when you combine different tubes?


Perhaps someone can enlighten us. I have always thought that 20 is each section (one triode) of the 6SN7 and not as in a single tube with dual triodes....and if both triodes are connected in parallel in the circuit, you get more than 20 if not 40.
I have always wondered what is the total gain in each channel in my amp, with one 6SL7 (one triode for each channel) and two 6SN7 (one tube for each channel)...


----------



## Slade01 (Jun 24, 2022)

TLO said:


> Perhaps someone can enlighten us. I have always thought that 20 is each section (one triode) of the 6SN7 and not as in a single tube with dual triodes....and if both triodes are connected in parallel in the circuit, you get more than 20 if not 40.
> I have always wondered what is the total gain in each channel in my amp, with one 6SL7 (one triode for each channel) and two 6SN7 (one tube for each channel)...



Also above my paygrade but to my understanding, 20 is the max gain for the entire tube, not per triode section.  When the circuit/topography has tube wired in parallel, you allow the tubes to achieve the same gain while operating at a lower current (essentially reducing noise).  This is as far as I understand it.

So if you had two tubes in parallel for the one channel, those tubes are splitting the work - nothing is doubled gain wise, it's the same as if it were a single tube on that single channel.  But as @mordy stated - it really all depends on how your amp was designed.   There are pros and cons to each type (parallel, push-pull, etc.).


----------



## gibosi (Jun 24, 2022)

TLO said:


> Perhaps someone can enlighten us. I have always thought that 20 is each section (one triode) of the 6SN7 and not as in a single tube with dual triodes....and if both triodes are connected in parallel in the circuit, you get more than 20 if not 40.
> I have always wondered what is the total gain in each channel in my amp, with one 6SL7 (one triode for each channel) and two 6SN7 (one tube for each channel)...



It's my understanding that when the two sections are connected in parallel, output resistance is halved, but mu stays the same. If the two sections are connected in series, output resistance stays the same, but mu is doubled. But as they say, you should take this with a grain of salt. My knowledge is very limited.


----------



## mordy

gibosi said:


> It's my understanding that when the two sections are connected in parallel, output resistance is halved, but mu stays the same. If the two sections are connected in series, then mu is doubled. But as they say, you should take this with a grain of salt. My knowledge is very limited.


Perhaps L0rdGwyn could clarify the above, and also what happens to the mu when you combine tubes of different gain as drivers.


----------



## CAJames (Jun 24, 2022)

A quick perusal of some data sheets indicate the gain is anywhere from 13 to 20 per triode. I think that is the difference between the original 6SN7 and the later GTA and GTB versions. FWIW/YMMV/&c. I’ll also go with gains add in series, connecting in parallel it stays the same but output impedance drops.


----------



## Xcalibur255

CAJames said:


> A quick perusal of some data sheets indicate the gain is anywhere from 13 to 20 per triode. I think that is the difference between the original 6SN7 and the later GTA and GTB versions. FWIW/YMMV/&c. I’ll also go with gains add in series, connecting in parallel it stays the same but output impedance drops.


All versions of the 6SN7 have a mu of 20.  What changes is the plate voltage max and total max dissipation rating.  You can run a GTB tube a little harder without frying it.  All 6J5 tubes should also be mu 20, it's the older 76 that has a mu of 13.  The 6P5 is also 13.


----------



## Xcalibur255 (Jun 24, 2022)

Maybe Keenan will chime in, but he did say he wasn't going to spend as much time on Head-fi as he used to.  This is a very incomplete subject for my knowledge too, but my understanding aligns with gibosi.  It probably comes down to what you are needing to do with the tube.  If the 6SN7 is driving a 300B for example it's probably going to be wired in parallel because the lower resistance will help it overcome the Miller resistance in the 300B.  In a different application you might need more gain in order to drive the output stage to full output so you would wire in series.  In an OTL amp like the Glenn if you were to use two 6SN7 it would even be possible to wire each triode as a separate gainstage, effectively making a 3 stage amp (though you wouldn't want to do this in this application).

Where I start to get lost is when terms like white cathode follower start to pop up when discussing tube gain stages.  I understand a *little* bit but that knowledge is very rough and learning more is an exercise in hunting and pecking across the internet.


----------



## CAJames (Jun 24, 2022)

Xcalibur255 said:


> All versions of the 6SN7 have a mu of 20.



You’re right I was looking at the wrong part of the data sheet.


----------



## mordy

Xcalibur255 said:


> Maybe Keenan will chime in, but he did say he wasn't going to spend as much time on Head-fi as he used to.  This is a very incomplete subject for my knowledge too, but my understanding aligns with gibosi.  It probably comes down to what you are needing to do with the tube.  If the 6SN7 is driving a 300B for example it's probably going to be wired in parallel because the lower resistance will help it overcome the Miller resistance in the 300B.  In a different application you might need more gain in order to drive the output stage to full output so you would wire in series.  In an OTL amp like the Glenn if you were to use two 6SN7 it would even be possible to wire each triode as a separate gainstage, effectively making a 3 stage amp (though you wouldn't want to do this in this application).
> 
> Where I start to get lost is when terms like white cathode follower start to pop up when discussing tube gain stages.  I understand a *little* bit but that knowledge is very rough and learning more is an exercise in hunting and pecking across the internet.


I do own a Glenn OTL amp and it only has one 6SN7 socket. Each channel of the amp is driven by one side of the 6SN7.


----------



## Xcalibur255

mordy said:


> I do own a Glenn OTL amp and it only has one 6SN7 socket. Each channel of the amp is driven by one side of the 6SN7.


That's right, all of the Glenn OTL amps were single 6SN7.  I'm just saying if you were to build an amp with that circuit but implement two 6SN7 sockets you could do what I was describing.  It would be a bad idea too, I was just trying to highlight some examples of what's possible in terms of implementation.


----------



## Velozity

Velozity said:


> It is actually GEC L63.  I bought 10 of them from that seller about 2 years ago and can verify from first-hand knowledge and comparison with other correctly labeled L63 in my collection that they have identical internals and sound signature.  Literally the only difference between the tubes in the second and third links from above is the labeling on the glass.  I'm about to buy some more because I need a matched quad for my new amp.  If anybody wants in let me know.



I've got two of these left if anyone is interested pm me.  Figured I'd post here before classifieds.


----------



## mordy

Continuing my audiossey with the 6-pack - tonight it is a pair of Brimar labeled 6J5GT tubes made by Ken-Rad in the 40's.
Ken-Rad's house sound is strong bass and these don't disappoint in that realm, but to soon to have a more nuanced opinion. I have four of these tubes from a bulk pack from an old movie theater. They must be hand-made because each tube is a different size!
Can you see a foggy shadow over the heater in the bottom tube in the picture?


Sometimes you see a tube that has a black mark inside the glass above the heater - I think it is called anode boil-off. It is not supposed to be a major problem but it certainly shows that the tube has been used. I wonder if this little foggy shadow is the beginning of anode boil-off; does somebody know?
Here is a picture of a tube with anode boil-off:


----------



## jgwtriode (Jul 6, 2022)

Grabbed a pair of National Union 6J5GT's and am burning them in place of my burned in GEC L63's.  Paid 48$ for the pair, NOS never used and pretty much identically matched.   Running them with Tungsol 5998's in LOrdGywn's Airmid OTL.    As musical a combo as I have ever heard.  They are a lot like the GEC's but sweeter and more
satisfying through the mids and all the way into the highs.  Actually a larger slightly more diffused soundstage, least at the edges, but equally detailed, with more ambiance
and overtones that seem more integrated and an absolutely gorgeous decay that is a bit more than the L63's.  Focus and layering maybe better as well and certainly just as solid images with a hint more air around them.   I think bass has a bit more kick and slight more weight and extension on the GEC's, that may change with more burn in. They may be a hint darker and slightly softer tonally but not certain of that.   But these are the best thing I have heard on female voices, stringed instruments and horns.  Wow!  Monsterzero was kind enough to send a download of the 6J5 guide and I saw the write up for these.  So had to have a pair and have been enjoying them and will throw a couple hundred hours before I do a critical comparison..   I had not heard about these prior to that.    Any additional info or thoughts would be much appreciated.   I did find it odd the bottles are slightly different heights but identically constructed otherwise.


Happy listening,
jgwtriode


----------



## CAJames

jgwtriode said:


> Grabbed a pair of National Union 6J5GT's and am burning them in place of my burned in GEC L63's....



Yes, I love these tubes as well. They are neck and neck with the GEC straight glass L63 as my favorite.


----------



## g0ldl10n (Jul 10, 2022)

So I just came across a pair of RCA "Tall Bottle" 6C5 (and I think I see 'VG' below the 6c5 label).

Have googled and searched these forums for any information on these tubes and literally coming up with nothing. I can't even find other picture in google of 6C5 Tall Bottles.. anyone ever seen these before and have any info on them?

Edit: Actually, upon checking my eyesight that says 'MG'


----------



## maxpudding

g0ldl10n said:


> So I just came across a pair of RCA "Tall Bottle" 6C5 (and I think I see 'VG' below the 6c5 label).
> 
> Have googled and searched these forums for any information on these tubes and literally coming up with nothing. I can't even find other picture in google of 6C5 Tall Bottles.. anyone ever seen these before and have any info on them?



Those are the 6C5MG’s, usually come in silver bottles. Never seen a black one before, nice find!


----------



## g0ldl10n (Jul 10, 2022)

maxpudding said:


> Those are the 6C5MG’s, usually come in silver bottles. Never seen a black one before, nice find!


Honestly, since I was coming up with such limited info, I went ahead and just bought them for $11 a piece. Here's to hoping they sound great!


----------



## TLO

g0ldl10n said:


> So I just came across a pair of RCA "Tall Bottle" 6C5 (and I think I see 'VG' below the 6c5 label).
> 
> Have googled and searched these forums for any information on these tubes and literally coming up with nothing. I can't even find other picture in google of 6C5 Tall Bottles.. anyone ever seen these before and have any info on them?
> 
> Edit: Actually, upon checking my eyesight that says 'MG'


FYI, Silvertone is a brand by Sears. Most of their tubes were made by either Sylvania or National Union. I bet these tall bottle 6C5 were made by Sylvania.


----------



## g0ldl10n

I also picked up a pair of Hytron 6C5GT tubes after reading good things about them here, specially about them being warm, which is actually the sound signature I always look for as I enjoy it the most. These were marketed as being produced in 1943, but am unsure how to verify this, as the only other marking I see is '3A5'. 

Now, it is a waiting game for the adapter and the tubes.. I do have high hopes the wait will be worth it though.


----------



## g0ldl10n

TLO said:


> FYI, Silvertone is a brand by Sears. Most of their tubes were made by either Sylvania or National Union. I bet these tall bottle 6C5 were made by Sylvania.


I'm guessing you could be right.. the Silvertone tubes I have were all made by Sylvania.


----------



## TLO (Jul 10, 2022)

g0ldl10n said:


> I'm guessing you could be right.. the Silvertone tubes I have were all made by Sylvania.


https://www.head-fi.org/threads/the-reference-6j5-thread-l63-6c5-12j5-6p5-etc.934653/post-16309820

Another one...Air Castle.. 
Well, could be by Arcturus...🤷‍♂️
https://www.radiomuseum.org/dsp_hersteller_detail.cfm?company_id=7208


----------



## g0ldl10n

TLO said:


> https://www.head-fi.org/threads/the-reference-6j5-thread-l63-6c5-12j5-6p5-etc.934653/post-16309820
> 
> Another one...Air Castle..
> Well, could be by Arcturus...🤷‍♂️
> https://www.radiomuseum.org/dsp_hersteller_detail.cfm?company_id=7208


I just messaged the seller asking them how they determined they were made by RCA, if there is an EIA number on them or something.. will let you know what they say.

With my limited tube rolling experience thus far, Sylvania and RCA have been my favorite sounding brands, so would definitely be okay with either.


----------



## g0ldl10n

TLO said:


> https://www.head-fi.org/threads/the-reference-6j5-thread-l63-6c5-12j5-6p5-etc.934653/post-16309820
> 
> Another one...Air Castle..
> Well, could be by Arcturus...🤷‍♂️
> https://www.radiomuseum.org/dsp_hersteller_detail.cfm?company_id=7208


Actually, i think we overlooked this here in the pictures.. they may just be RCA.. just not sure if that is correct still.. idk. Really just hoping they sound great!


----------



## TLO (Jul 10, 2022)

g0ldl10n said:


> Actually, i think we overlooked this here in the pictures.. they may just be RCA.. just not sure if that is correct still.. idk. Really just hoping they sound great!


Not necessary..it might be just a licensed notice. I have a Silvertone 6SN7GT made by National Union, with a printed notice stating Licensed by RCA patent.

https://www.head-fi.org/threads/the-reference-6sn7-thread.117677/post-16964948
A lot of tubes were developed and patented by RCA in those days. I believe 6C5 is also developed by RCA.


----------



## g0ldl10n

TLO said:


> Not necessary..it might be just a licensed notice. I have a Silvertone 6SN7GT made by National Union, with a printed notice stating Licensed by RCA patent.
> 
> https://www.head-fi.org/threads/the-reference-6sn7-thread.117677/post-16964948
> A lot of tubes were developed and patented by RCA in those days. I believe 6C5 is also developed by RCA.


Ah, this would make sense. Let's see what the seller says, I'm curious.


----------



## g0ldl10n

@TLO 
So this is what the seller said regarding their belief RCA manufacturered those 6C5MG


----------



## mordy

TLO said:


> https://www.head-fi.org/threads/the-reference-6j5-thread-l63-6c5-12j5-6p5-etc.934653/post-16309820
> 
> Another one...Air Castle..
> Well, could be by Arcturus...🤷‍♂️
> https://www.radiomuseum.org/dsp_hersteller_detail.cfm?company_id=7208


 I just discovered another early tube manufacturer from Pawtucket, Rhode Island - Triad:



https://www.radiomuseum.org/tubes/tube_6c5mg.html
This is what I found:
A second variation has been brought out by Triad Manufacturing Company, Inc., and is illustrated in Fig. D. These metal-glass tubes are known as the MG series and are not all-metal, there being a glass inner sleeve which is used for maintaining the vacuum. *Triad was licensed by RCA*.


The MG series at present, includes the following types: 5Z4MG, 6A8MG, *6C5MG*, 6D5MG, 6F6MG, 6H6MG. 6F7MG, 6K7MG; the characteristics of these tubes are said to parallel those of all-metal construction. 

It is very likely that Sears used other sources in addition to NU and Sylvania.
Now, the designation 6C5MG means metal/glass. I don't advise prying off the metal envelope, but most likely this is what you are going to find:



In short, my assumption is that these MG tubes were made by Triad for Arcturus and Sylvania.
https://www.radiomuseum.org/dsp_hersteller_detail.cfm?Company_id=7209


----------



## triod750

I cannot evaluate the significance of this input: https://groupdiy.com/threads/metal-vs-glass-tubes.19527/


----------



## g0ldl10n

mordy said:


> I just discovered another early tube manufacturer from Pawtucket, Rhode Island - Triad:
> 
> https://www.radiomuseum.org/tubes/tube_6c5mg.html
> This is what I found:
> ...


Ah, excellent information, thanks for sharing!


----------



## mordy

triod750 said:


> I cannot evaluate the significance of this input: https://groupdiy.com/threads/metal-vs-glass-tubes.19527/


This is what I gleaned from your link:

RCA and GE brought out the metal tube in 1934.
Developed in secrecy by GE, the new design used a steel shell with individual glass filled eyelets for the lead-in wires, on a new, convenient octal base. This product line gave GE and other radio makers a complete tube compliment for the 1935 line of sets.

The original nine were:

5Z4 rect
6A8 and 6L7, converters
6C5 and 6F5 triodes
6F6 power pentode
6H6 duodiode
6J7 and 6K7 pentodes
A tenth type, the 6D5 power triode, was withdrawn before major production.

The other tube makers were unhappy to have their product line obsoleted.
Some, like Raytheon, signed up to adopt the new line.
Others were unhappy with RCA's invention.
The multiple eyelet seals were sure to leak, so they hurried to repackage their big pin products with octal bases.
*Yet others like Arcturus and Triad quickly devised what they termed the "perfected" metal tube, the metal-glass (MG) design, where a small conventional stem sealed glass tube was hidden inside a steel shell, on the same octal waferbase as GE-RCA used.*

The MG push was short lived. The RMA issued registration in July, 1935 on the 5Z4MG, 6A8MG, 6C5MG, 6D5MG, 6F5MG, 6F6MG
6H6MG, 6J7MG, 6K7MG, copies of RCA's line, plus the 25Z5MG rectifier for AC/DC sets.


Later registrations thru MArch 1936 covered the 6M6MG, 6N7MG, 6Q7MG, and (today unknown) 6Z6MG rectifier.
For those wanting to collect this set today, eventual adders were the 6J5MG, 6Z5MG, 25A6MG, and 25Z6MG.

Metal-shell tubes were popular in the 1930's.
They were heavily marketed to the public who feared injuring their hands on broken glass, and to radio manufactures who, among other things, appreciated the fact metal tubes were less likely to break during shipping of the radio sets.
An added feature was the shielding effect of the metal envelope, which improved radio performance.

The steel envelope was more expensive to manufacture and had real problems dissipating heat, so the fad was virtually over by 1950.

PS: My own observation of all metal tubes is that they run hot and take considerable longer than glass tubes to warm up - at least 1/2 hour.
The metal shielding may have been a plus in shielding from RF and EMI noise - some later tubes had aluminum shields; some early tubes had a sprayed on metallic coating.
Bottom line: The 6C5MG tube above could have been manufactured by Arcturus or Triad. It is interesting that Visseaux in France (among others) manufactured MG tubes as well.



https://www.ebay.com/itm/125381759277?hash=item1d3155d12d:g:cfIAAOSwn2tisy-L


----------



## Tom-s

Here’s a link to my post on page 73.  
Showing the internals of such MG tubes.


----------



## g0ldl10n

Tom-s said:


> Here’s a link to my post on page 73.
> Showing the internals of such MG tubes.


Ah, this is great visual info on these tubes - interesting design you don't see often.


----------



## triod750

mordy said:


> This is what I gleaned from your link:
> 
> RCA and GE brought out the metal tube in 1934.
> Developed in secrecy by GE, the new design used a steel shell with individual glass filled eyelets for the lead-in wires, on a new, convenient octal base. This product line gave GE and other radio makers a complete tube compliment for the 1935 line of sets.
> ...


I just meant that I don't have an opinion of the opinions posted in that link. But I have both Ken-Rad and RCA 6C5 that I like a lot and I let them warm up at least for an hour before I listen to them. My amp benefits from being warm too.


----------



## g0ldl10n

mordy said:


> This is what I gleaned from your link:
> 
> RCA and GE brought out the metal tube in 1934.
> Developed in secrecy by GE, the new design used a steel shell with individual glass filled eyelets for the lead-in wires, on a new, convenient octal base. This product line gave GE and other radio makers a complete tube compliment for the 1935 line of sets.
> ...


So either Arcturus or Triad would have been the real manufacturer of these then?

I wonder if there is anyway I could ever tell - it's quite difficult getting detailed info or pictures of these tubes from each manufacturer in order to compare. Most pictures I am finding on Google seem to be French made.





I wonder if the shape of the tops provide any hints, as this picture shared by @Tom-s shows each with a slightly difference shape.


----------



## mordy

Reading up on anode boil-off - found the quote of the day:

_20th century tube "technology" was very much involved in the black magic of producing long-lived low temperature high current cathodes. Today, some of this old technology appears to be lost, like the technology of how to make
a decent mummy._


----------



## mordy (Jul 11, 2022)

Continuing my audiossey - tried a bunch RCA 6J5GT tubes; I have maybe 10 tubes. Most are metal base but almost every one has a different construction and I don't have more than maybe one or two real pairs.
Remember the Wizard tube with just one metal band on the top mica? Now I found a RCA with such a construction so I feel safe in saying that the Wizard one band tubes were made by RCA. Don't know how, but I ended up with a date matched pair of RCA/Wizard tubes with a date code PO.







Starting the alphabet over again at N for the months, P would be March (April?) and maybe the 0 is 1940 - just guessing.

Another RCA black base pair: Here is the one-banded RCA/Radiotron tube with a two band look alike tube labeled GE:



Except for the bands on the top mica they look identical - my feeling is that the GE labeled tube is an RCA.
The RCA tube has a code RE4 which may mean 1940 OEM July-Aug.
The GE labeled tube has a code XE5 which may mean 1939 OEM Sept-Oct. (RCA code)
All the RCA metal base tubes (mostly from 50's) sound too bright, but the black base oldies RCA/GE pictured here sound quite nice. Will have to compare with the Wizards but that's for another day...


----------



## mordy (Jul 11, 2022)

Now I have spent some time with the 6J5GT RCA black base tubes from 1939/1940. Labels on hand are RCA, WIZARD and GE.
This tube is a winner and sounds similar to the National Union triple mica top getter flash 6J5GT. The NU has a sweeter midrange and wider sound stage, and the RCA better bass and detail - your pick.
In addition to the names above I also saw one labeled Cunningham on eBay. If you want to try them, look for an X or R in the date code (1939-40).

Distinctive mica plates:




Did I say to look for an R in the date code ?



Ladder plate:



Here is a GE/RCA crazy glue special (loose bases):



https://www.ebay.com/itm/283976637337?hash=item421e539b99:g:H~wAAOSwvbRfNCqj
The ones pictured only have one band on the top mica, but there are others than have two bands; don't know if it makes a difference in sound.

This pair is almost identical to what I have - one tube has two bands and one only one band. And R and X in the codes:



https://www.ebay.com/itm/374088992080?hash=item5719710550:g:CbIAAOSwNxNh2ypv
However, if you are patient you can pick up these tubes for very little...
Actually, I am surprised how many of these very old tubes are available.


----------



## Isaacc7

Are there any single triode versions of the Tungsol 6sn7 round plate black glass? I've seen round plate 6j5g and 76 tubes from them but I'm not sure if they are the same as the much more expensive 6sn7. I can't see what kind of plate the 6c5 have nor do I know what metal ones have. Did they make a metal version? I can also use 12j5 as well if there is money to be saved going that route. Has anyone been able to compare the 6j5 with the 6sn7? Thanks.


----------



## mordy

Isaacc7 said:


> Are there any single triode versions of the Tungsol 6sn7 round plate black glass? I've seen round plate 6j5g and 76 tubes from them but I'm not sure if they are the same as the much more expensive 6sn7. I can't see what kind of plate the 6c5 have nor do I know what metal ones have. Did they make a metal version? I can also use 12j5 as well if there is money to be saved going that route. Has anyone been able to compare the 6j5 with the 6sn7? Thanks.


As far as I know there are no triode version of the TS BGRP. The Tung Sol metal base 6J5GT tubes I have all have ladder style flat plates. Because of the construction of the 6C5GT tubes with a screen it is not possible to see what kind of plate construction is used.
Regarding the black all metal 6C5/6J5 tubes, you can find Tung Sol labeled such tubes. Please bear in mind that almost all of the all metal tubes were made by RCA and Ken-Rad regardless of branding.
IMHO opinion, the 12V 12J5GT tubes may not sound the same as the 6V versions, but they offer a much less expensive option many times.
As far as comparing 6J5GT tubes to 6SN7 tubes, I think that the consensus is that a pair of 6J5GT tubes sound better, and usually at a much lower price. Several people sold off their 6SN7 tubes in favor of using 6J5GT tubes instead, and had their amps rewired for 6J5G or GT tubes.


----------



## jonathan c

And on that point, @mordy, I stopped using 6SN7 tubes (even ‘holy grails’) in the Schiit Lyr 3. The sonic vistas offered by double 6C5 / double 6J5 on @Deyan - built adapter are too captivating to surrender. 😊


----------



## mordy

jonathan c said:


> And on that point, @mordy, I stopped using 6SN7 tubes (even ‘holy grails’) in the Schiit Lyr 3. The sonic vistas offered by double 6C5 / double 6J5 on @Deyan - built adapter are too captivating to surrender. 😊


Shhhh - don’t let the secret out! Watch the prices go up on eBay….


----------



## CAJames (Jul 12, 2022)

jonathan c said:


> And on that point, @mordy, I stopped using 6SN7 tubes (even ‘holy grails’) in the Schiit Lyr 3. The sonic vistas offered by double 6C5 / double 6J5 on @Deyan - built adapter are too captivating to surrender. 😊



There are plenty of other options besides 6C5/6J5, depending on how far down the adapter rabbit hole you wish to go. I've had excellent results with Types 37 and 76 and most recently with 7193/CV1135.


----------



## Monsterzero

mordy said:


> Shhhh - don’t let the secret out! Watch the prices go up on eBay….


 That ship sailed quite awhile ago


----------



## TLO

Monsterzero said:


> That ship sailed quite awhile ago


Yes, that's why I havent tried this tube family as of now. I need 4 pieces as a pair of 6SN7 alternatives, that will cost me easily USD200-400 plus adapter. That takes away the thrill of finding amazing sound tubes at dirt cheap price...


----------



## maxpudding

Monsterzero said:


> That ship sailed quite awhile ago


And thus, the journey to find cheap good tubes continues...


----------



## mordy

CAJames said:


> There are plenty of other options besides 6C5/6J5, depending on how far down the adapter rabbit hole you wish to go. I've had excellent results with Types 37 and 76 and most recently with 7193/CV1135.


Of all these tubes, including 6J5 family tubes, which is your favorite? Also, using the double-horned 7193, are the anodes polarized or it doesn’t matter how you connect them?


----------



## Monsterzero

TLO said:


> Yes, that's why I havent tried this tube family as of now. I need 4 pieces as a pair of 6SN7 alternatives, that will cost me easily USD200-400 plus adapter. That takes away the thrill of finding amazing sound tubes at dirt cheap price...


 I do not recall who it was that started the 6/12J5 rush in the Glenn thread, but I got in pretty early. Since that time prices have shot up considerably.
That being said, they do sound significantly better than their 6/12SN7 relatives and while not as cheap as a few years ago, you can still find some great deals every now and then.


----------



## maxpudding

mordy said:


> Of all these tubes, including 6J5 family tubes, which is your favorite? Also, using the double-horned 7193, are the anodes polarized or it doesn’t matter how you connect them?



The 7193/CV6/E1148 etc. family tubes have polarized caps


----------



## mordy

maxpudding said:


> The 7193/CV6/E1148 etc. family tubes have polarized caps


Thanks - how do you know how to connect them? -Now I think I remember reading that connecting them wrong can have disastrous results.


----------



## CAJames

maxpudding said:


> The 7193/CV6/E1148 etc. family tubes have polarized caps



Yes, one is the plate the other the grid, so definitely not interchangeable. And even better the UK/GEC CV1135s were different than the US/Ken-Rad and NU. You need to check the datasheet to see which cap is closest to the centering pin on the base.


----------



## CAJames (Jul 12, 2022)

mordy said:


> Of all these tubes, including 6J5 family tubes, which is your favorite?



I'd say the top 3 are the GEC straight glass L63, National Union black base 6J5GT and the GEC CV1135. But close behind are the RCA "silver meatball" 76, Sylvania VT-37 and the humble Sylvania metal base 6J5GT and probably some others. I need 4 for the WA22 and so far have been unwilling to spend the money for UK coke bottle/grey glass types but if the GBP keeps getting cheaper I might give myself a present.


----------



## maxpudding (Jul 12, 2022)

mordy said:


> Thanks - how do you know how to connect them? -Now I think I remember reading that connecting them wrong can have disastrous results.


Check the tube datasheets and then triple check them to make sure every connections are correct. And to make things a bit more interesting, @CAJames correctly mentioned that the American and European tubes have different wirings lol

Edit: sorry I meant different mounting positions


----------



## CAJames

TLO said:


> Yes, that's why I havent tried this tube family as of now. I need 4 pieces as a pair of 6SN7 alternatives, that will cost me easily USD200-400 plus adapter. That takes away the thrill of finding amazing sound tubes at dirt cheap price...



You can get great sounding single triodes for a fraction of that.


----------



## TLO

mordy said:


> Thanks - how do you know how to connect them? -Now I think I remember reading that connecting them wrong can have disastrous results.


You will see one connection going into the center of the plate, that is the grid and one connecting to the edge of the plate, that is the anode.


----------



## TLO

CAJames said:


> I'd say the top 3 are the GEC straight glass L63, National Union black base 6J5GT and the GEC CV1135. But close behind are the RCA "silver meatball" 76, Sylvania VT-37 and the humble Sylvania metal base 6J5JT and probably some others. I need 4 for the WA22 and so far have been unwilling to spend the money for UK coke bottle/grey glass types but if the GBP keeps getting cheaper I might give myself a present.


I would probably just get the cheaper GEC L63 and get over it, UK ST are just too much.


----------



## maxpudding (Jul 12, 2022)

Here’s a very nice post describing the use of this type of tube, courtesy of @Tom-s

Post in thread 'Crack;Bottlehead OTL'
https://www.head-fi.org/threads/crack-bottlehead-otl.476650/post-15242293

You can see that the data sheets provided clearly show the positions of the caps.


----------



## jonathan c (Jul 12, 2022)

mordy said:


> Of all these tubes, including 6J5 family tubes, which is your favorite? Also, using the double-horned 7193, are the anodes polarized or it doesn’t matter how you connect them?


Excuse me for my interruption: my favourites are GEC L63 / CV1067 and Ken-Rad 6C5 / VT-65. (Raytheon 6J5 are incoming: TBA.)  Edit: ‘65’ in lieu of ‘94’.


----------



## mordy

jonathan c said:


> Excuse me for my interruption: my favourites are GEC L63 / CV1067 and Ken-Rad 6C5 / VT-94. (Raytheon 6J5 are incoming: TBA.)


I am a little bit confused now  -  VT-94 I thought was 6J5 family.
6C5 maybe VT-65.


----------



## mordy

CAJames said:


> I'd say the top 3 are the GEC straight glass L63, National Union black base 6J5GT and the GEC CV1135. But close behind are the RCA "silver meatball" 76, Sylvania VT-37 and the humble Sylvania metal base 6J5JT and probably some others. I need 4 for the WA22 and so far have been unwilling to spend the money for UK coke bottle/grey glass types but if the GBP keeps getting cheaper I might give myself a present.


_Sylvania metal base 6J5JT_ - I assume 6J5GT?


----------



## jonathan c

mordy said:


> I am a little bit confused now  -  VT-94 I thought was 6J5 family.
> 6C5 maybe VT-65.


Thank you, mordy! My mistake 🤦🏻 ! Post has been edited.


----------



## CAJames

mordy said:


> _Sylvania metal base 6J5JT_ - I assume 6J5GT?



Indeed, fixed. Thanks. Seems like an underserved market would be an audio tubes "spell check" plugin.


----------



## Isaacc7

mordy said:


> As far as I know there are no triode version of the TS BGRP. The Tung Sol metal base 6J5GT tubes I have all have ladder style flat plates. Because of the construction of the 6C5GT tubes with a screen it is not possible to see what kind of plate construction is used.
> Regarding the black all metal 6C5/6J5 tubes, you can find Tung Sol labeled such tubes. Please bear in mind that almost all of the all metal tubes were made by RCA and Ken-Rad regardless of branding.
> IMHO opinion, the 12V 12J5GT tubes may not sound the same as the 6V versions, but they offer a much less expensive option many times.
> As far as comparing 6J5GT tubes to 6SN7 tubes, I think that the consensus is that a pair of 6J5GT tubes sound better, and usually at a much lower price. Several people sold off their 6SN7 tubes in favor of using 6J5GT tubes instead, and had their amps rewired for 6J5G or GT tubes.


Yeah, we've discussed the same/different aspect of 12v tubes a few times before. I'm firmly of the opinion they are the same. Heaters in indirectly heated tubes really shouldn't have any impact on sonics as long as electron emissions are made to be the same. 

I'm surprised no one has opened up a 6c5 to look at its internals. Hmm, maybe I'll do that one of these days. I imagine it would be similar to a 76 tube no? I had not heard of the metal tube manufacturers being so limed before. Interesting. 

Better is a matter of opinion, with good quality tubes it is more of an issue of difference as opposed to a quantitive advantage. I have experimented with *j5 tubes in place of *sn7 with mixed results. I'll keep experimenting.


----------



## CAJames (Jul 12, 2022)

TLO said:


> ... UK ST are just too much.



Sure, but they are dead sexy.


----------



## TLO

CAJames said:


> Sure, but they are dead sexy.






Like this???


----------



## mordy

CAJames said:


> I'd say the top 3 are the GEC straight glass L63, National Union black base 6J5GT and the GEC CV1135. But close behind are the RCA "silver meatball" 76, Sylvania VT-37 and the humble Sylvania metal base 6J5GT and probably some others. I need 4 for the WA22 and so far have been unwilling to spend the money for UK coke bottle/grey glass types but if the GBP keeps getting cheaper I might give myself a present.


In the past I wrote that the metal base RCA 6J5GT sounded too bright. I have three such pairs; each pair has a different construction (see later about the third "pair). This was written after trying two different pairs and not having the patience to try the third, different, pair.
But this hobby is full of surprises, and the third "pair" sounds very good. In general, I cannot think of a tube with more variations in construction than the 6J5GT. Here are pictures of the four different RCA 6J5GT metal base tubes; the third/fourth tubes are the best sounding ones. All are short tubes with flat 2-hole ladder plates. The differences are in the shape of the micas and the presence/absence of the mica holder bands..
The first tube has the bands on both the top and lower micas:



The second tube has a round top mica and a rectangular bottom mica; no bands:



The third tube has cut-outs for the top bands:



The fourth tube has the bands on the top mica plate (no cut-outs) but no bands on the bottom one:



Confusing, eh? 
Undoubtedly there must be even more RCA versions but this is what I found in my collection from the eBay bargain bins.
Somehow I ended pairing the third and fourth tubes and this "near pair" sound much better than the first two tubes.
How should I describe the sound? Open, airy, musical, non-fatiguing.


----------



## g0ldl10n

maxpudding said:


> Those are the 6C5MG’s, usually come in silver bottles. Never seen a black one before, nice find!


Just got them in today - now waiting for the adapter, the long wait for the adapter, lol. Will provide thoughts on the sound once I listen to them.


----------



## jonathan c

Very clear presentation with scrumptious bass, palpable soundstage, and more…from Sylvania 6J5GT ☑️


----------



## Isaacc7

jonathan c said:


> Very clear presentation with scrumptious bass, palpable soundstage, and more…from Sylvania 6J5GT ☑️


I mentioned this in the 6sn7 thread… I just realized I own some of the vaunted Sylvania “Bad Boy” 12sn7. Popped them into my preamp and they sound very similar to the round plate Sylvania 12j5gt IMO. Using the 6j5gt and adapter is certainly much less than tracking down the hyped up 6sn7!


----------



## mordy

jonathan c said:


> Very clear presentation with scrumptious bass, palpable soundstage, and more…from Sylvania 6J5GT ☑️


These tall bottle Sylvania early 1950's 6J5GT is one of the few cases where the older 1940's VT-94D/6J5GT don't sound as good as the newer ones.


----------



## Isaacc7

mordy said:


> These tall bottle Sylvania early 1950's 6J5GT is one of the few cases where the older 1940's VT-94D/6J5GT don't sound as good as the newer ones.


Are there a lot of sylvania 6j5 variations? Any you’d recommend over these? I too was impressed with the sound of these but if there are better ones to be had…


----------



## Xcalibur255

By Sylvania standards there doesn't seem to be that many variants (Sylvania is rather infamous for having a million different designs for some of their tubes).  The major thing with them seems to be black vs. grey plate with most people seeming to prefer the black plate version.  I have an older G coke bottle style black plate and a grey plate metal base from the 50's and they sound totally different from one another.  I'm curious if the metal base black plates sound the same as the coke bottle tubes or if they are in fact a third distinct sound.  I don't know if we have had anybody here who has had all three variants on hand yet.


----------



## mordy (Jul 14, 2022)

Xcalibur255 said:


> By Sylvania standards there doesn't seem to be that many variants (Sylvania is rather infamous for having a million different designs for some of their tubes).  The major thing with them seems to be black vs. grey plate with most people seeming to prefer the black plate version.  I have an older G coke bottle style black plate and a grey plate metal base from the 50's and they sound totally different from one another.  I'm curious if the metal base black plates sound the same as the coke bottle tubes or if they are in fact a third distinct sound.  I don't know if we have had anybody here who has had all three variants on hand yet.


Checked my stash now - I do have one pair of ST type Sylvania 6J5G. Then I have another four-five variants of the GT style:
40's VT94/6J5GT metal base tall tubes
50's 6J5GT           metal base tall tubes/ short tube
40 - 50s 6J5GT    black base short tubes/tall tube
All the GT tubes have the same internal construction.
Around 15-20 tubes - a couple are rebranded as CBS/Hytron, Motorola, Philco, RCA etc. Did not yet check for black/grey plates.


----------



## Xcalibur255

Essentially at some point they switched from black to grey plates, the black plate tubes are older.  

I'm kind of an outlier when it comes to the coke bottle Sylvanias.  Most people who have them seem to really like them but they weren't to my liking due to too much energy in the upper mids.  My opinion of the tube did improve a lot when I finally tried it on my 1101 Audio amp.  It's the most dynamic and "fun" sounding tube in my 6J5 collection but I tend to go after a bit more of a mellow sound so it's not the right fit for me personally.  I definitely get why it is some people's favorite though.


----------



## g0ldl10n

jonathan c said:


> Very clear presentation with scrumptious bass, palpable soundstage, and more…from Sylvania 6J5GT ☑️


Hey, I keep seeing these nice looking dual adapters for this amp and the Darkvoice.. can I ask, where are you getting these from?


----------



## bcowen

g0ldl10n said:


> Hey, I keep seeing these nice looking dual adapters for this amp and the Darkvoice.. can I ask, where are you getting these from?


@Deyan , a fellow HeadFi'er.  Just send him a PM if you're interested.


----------



## mordy

bcowen said:


> @Deyan , a fellow HeadFi'er.  Just send him a PM if you're interested.


There are Chinese made adapters as well, but Deyan's adapters are much better made and his customer service is excellent which I can't say about the main Chinese manufacturer.
If you have unusual or special requests, Deyan will work with you and make what you need. He also responds quickly to any questions you may have.


----------



## g0ldl10n

mordy said:


> There are Chinese made adapters as well, but Deyan's adapters are much better made and his customer service is excellent which I can't say about the main Chinese manufacturer.
> If you have unusual or special requests, Deyan will work with you and make what you need. He also responds quickly to any questions you may have.


ah, very cool - will definitely consider reaching out him - can't beat the clean look of those adapters.


----------



## raindownthunda

g0ldl10n said:


> ah, very cool - will definitely consider reaching out him - can't beat the clean look of those adapters.


One cool and not often mentioned feature with Deyan’s adapters is that you can rotate/spin them by design. I found that turning them 90 degrees fit my amp better.


----------



## bcowen (Jul 15, 2022)

g0ldl10n said:


> ah, very cool - will definitely consider reaching out him - can't beat the clean look of those adapters.


He can also custom make single tube adapters.  Below is one he made for my Schiit Vali 2 amp, 6922 on bottom and 7N7 on top.  He made it exactly to the dimensions I requested and it's one piece (versus having to add a socket saver at the bottom to a China adapter due to the Vali's recessed socket).  Even for highly customized adapters like this his prices are very reasonable.


----------



## Isaacc7

Seeing that the Sylvanias impressed me so much I decided to dig through my 12j5 box. I've got plenty of NOS JAN Tungsol but I found them overly "tubey" before. What else do I have? I need 4 at a time. 2 KenRad, 3 NU, a bunch of GE (no thanks), 2 Raytheon, aha! I have 7 RCA 12j5gt! They break down into 4 of one kind of label and 3 of another. But I have my quad!

I popped them into the adapters and HUMMMMMMMMMMMMM. Rats. Maybe they'll calm down if I let them cook a little. So while the hum was going on I was treated to a variety of pops, clicks, and noise. I just got the preamp back from repair so I'm a little paranoid about messing it up. Oh well, back to the 12sn7 game. 

I did order quads of NU and KenRad to try out. We'll see what they're about once I get them.


----------



## Monsterzero

Isaacc7 said:


> Seeing that the Sylvanias impressed me so much I decided to dig through my 12j5 box. I've got plenty of NOS JAN Tungsol but I found them overly "tubey" before. What else do I have? I need 4 at a time. 2 KenRad, 3 NU, a bunch of GE (no thanks), 2 Raytheon, aha! I have 7 RCA 12j5gt! They break down into 4 of one kind of label and 3 of another. But I have my quad!
> 
> I popped them into the adapters and HUMMMMMMMMMMMMM. Rats. Maybe they'll calm down if I let them cook a little. So while the hum was going on I was treated to a variety of pops, clicks, and noise. I just got the preamp back from repair so I'm a little paranoid about messing it up. Oh well, back to the 12sn7 game.
> 
> I did order quads of NU and KenRad to try out. We'll see what they're about once I get them.


I dunno about your other tubes but my collection of 6j5 Sylvanias are very prone to hum, pops, etc.
It's one of the many reasons I sold my previous amp and bought a new amp that takes 6j5 without an adaptor.
No noise now.


----------



## Isaacc7

Monsterzero said:


> I dunno about your other tubes but my collection of 6j5 Sylvanias are very prone to hum, pops, etc.
> It's one of the many reasons I sold my previous amp and bought a new amp that takes 6j5 without an adaptor.
> No noise now.


Yeah, I had zero problems with either the Sylvanias or the Tungsols. Since I'm using two per side I have twice as much an opportunity for bad tubes compared to most on this board.


----------



## Isaacc7

Got lucky and not only found the tube causing problems but it was only one! I probably broke some audiophile rule but I replaced the bad one with another RCA with a lightly different logo. The rest of the tube looks the same and the logo is the same silver so <shrug>. 

Anyway, right off these sound like they have a bit of glare to them. Will need to give them some time to settle in.


----------



## Isaacc7

So there doesn't appear to be much bass with the RCA in my system. It sounds open and clear but very very bass shy. Think I'm going to bail.


----------



## Isaacc7

So here's the RCA I wasn't impressed with




Like I said, open and clear but almost zero bass. I've experienced tubes mellowing out over time but never suddenly getting bass. So that was a disappointment but wait! I remembered that I have a smattering of 6j5 tubes too! A little digging and I came up with 4 Radiotron made in Australia. They have some curious markings...











The extra support rod reminds me of the Raytheon 12j5gt I have. Anyone know what the various letters and numbers mean? 

Right off the bat they have brought back the bass I was missing with the last set plus they seem to have quite good clarity. These are used tubes, tested at around 70% according to the box. Will settle in for the night with these and see how they stack up with some of my other tubes.


----------



## mordy

Just received a pair of coke bottle 6J5G tubes. Both tubes are of identical construction but one is labeled WARDS AIRLINE and the other WIZARD.
The date code on the Wards tube is N 8 which I think means January 1938; the other date code is illegible.
Are these tubes made by Sylvania?
Black round plate with two holes:



The top mica is very distinct with shiny mica; everything, including the metal wires, are flat:


----------



## triod750

At least they are older than we are (by a few years).


----------



## Isaacc7

So the Radiotron tubes are winners in my system. Was up way later than I should have been listening. They are both better balanced and more natural sounding than the Sylvanias. I am now exploring other 6j5 and 6c5 tubes. This site has done it again! My wallet weeps...

SInce I need 4 at a time I will not be exploring the British tubes, they just cost too much. I went through and read this entire thread looking for recommendations. Most of it ended up being discussions about various British tubes but there were multiple people vouching for metal versions and a few other American tubes. I've sent off an email to one of my usual suppliers of American stuff and I'll see what he has. Anticipating more than a few quads coming my way...


----------



## Velozity

Isaacc7 said:


> So the Radiotron tubes are winners in my system. Was up way later than I should have been listening. They are both better balanced and more natural sounding than the Sylvanias. I am now exploring other 6j5 and 6c5 tubes. This site has done it again! My wallet weeps...
> 
> SInce I need 4 at a time I will not be exploring the British tubes, they just cost too much. I went through and read this entire thread looking for recommendations. Most of it ended up being discussions about various British tubes but there were multiple people vouching for metal versions and a few other American tubes. I've sent off an email to one of my usual suppliers of American stuff and I'll see what he has. Anticipating more than a few quads coming my way...




Find a quad of the metal Ken-Rad 6J5.  Should be available for a good price and they punch waaaay above their weight.


----------



## Isaacc7

Velozity said:


> Find a quad of the metal Ken-Rad 6J5.  Should be available for a good price and they punch waaaay above their weight.


I'm working on a big order of both metal and g 6j5 and 6c5. KenRad is definitely one of the ones I'm looking forward to. Doh, almost forgot, I'm supposed to be getting a bunch of 12j5gt today and tomorrow. Raytheon, KenRad, and NU. 

I have spent the last several days using the JAN Tungsol 12j5gt. They have been a good combo with my more open output tubes like the Cossor 807 or EL38. They have a bit of midrange harshness as compared to my standard Tungsol round plate black glass 12sn7. I'm back to the 12sn7 today and I'm noticing a little bit better lower midrange which helps out voices in particular.


----------



## Isaacc7 (Jul 22, 2022)

Got all my tubes in! All of them are JAN, that was unexpected. First set into the preamp is the Raytheon 12j5gt. Still rocking the cv1102 and Cossor 807 in the amp. So so good! Right out of the gate the word that comes to mind is transparent, it reminds me of using my passive preamp. A few hours in the image seems to have deepened and the bass has extended. I think the Tungsol 12sn7 is richer sounding but that sticks out as a coloration in comparison. Really digging these.

Took a quick look at the National Union and KenRad tubes. The plates look identical though everything else (mica, getter, etc.) is different. It might be a while before the Raytheons come out of my system but I am curious how different they will sound with such similar plates.


----------



## jgwtriode

Well after about 4 or 5 weeks of listening I have definetly concluded that I slightly but definetly prefer my new NU 6J5GT's.  The Herbie tube dampers made their differences even slightly more apparent.  Main reasons.  They have a slightly sweet character with no loss of neutrality..  They are a hint faster and slightly more spacious.  I thought the Bass quality of the GEC L63 might be better!  But after Burn in and the dampers the NU's are at least just as good. Ah but that subtle sweetness extends top to bottom.  So. need to look at other 6J5's.   If anyone is interested in my very low use GEC L63's PM me.  I run them with Tungsol 5998's on LOrdGywn's Airmid.  Its.sounding the best I have heard it running my Leopardwood ZMF VCs.

Happy listening,

Jgwtriode


Happy listening


----------



## g0ldl10n

g0ldl10n said:


> Just got them in today - now waiting for the adapter, the long wait for the adapter, lol. Will provide thoughts on the sound once I listen to them.


So these do sound quite good - my main pair of headphones right driver bit the dust a couple weeks ago, and currently getting a replacement shipped to me via warranty, thankfully, so haven't been able to hear them to their potential yet. But so far, they sound very good, looking forward to hearing them with my other pair of headphones once they get in - only downside is they are microphonic, but quiet if the desk the amp is on doesn't have vibrations going through it for w/e reason, like typing on a keyboard. Guess that could be solved by relocating the amp. 

Anyways, so far so good and well worth what I spent on them, that's for sure.


----------



## raindownthunda

jgwtriode said:


> Well after about 4 or 5 weeks of listening I have definetly concluded that I slightly but definetly prefer my new NU 6J5GT's.  The Herbie tube dampers made their differences even slightly more apparent.  Main reasons.  They have a slightly sweet character with no loss of neutrality..  They are a hint faster and slightly more spacious.  I thought the Bass quality of the GEC L63 might be better!  But after Burn in and the dampers the NU's are at least just as good. Ah but that subtle sweetness extends top to bottom.  So. need to look at other 6J5's.   If anyone is interested in my very low use GEC L63's PM me.  I run them with Tungsol 5998's on LOrdGywn's Airmid.  Its.sounding the best I have heard it running my Leopardwood ZMF VCs.
> 
> Happy listening,
> 
> ...


The eBay seller in India just doubled the prices for their NU 6J5GT pairs & quads. They must be reading head-fi


----------



## Monsterzero

raindownthunda said:


> The eBay seller in India just doubled the prices for their NU 6J5GT pairs & quads. They must be reading head-fi


The prices on many of the 6J5s have gone over the 100 dollar mark. A few years ago it was like 20 bucks.


----------



## raindownthunda (Jul 27, 2022)

Monsterzero said:


> The prices on many of the 6J5s have gone over the 100 dollar mark. A few years ago it was like 20 bucks.


Seriously, glad I got into them a couple years ago. It seems like they are also getting harder to come by. I think buying singles and making your own pairs is the smart way to save a few bucks. Takes a lot of patience, luck, and detective skills to find matched construction with all the rebrands and variations. Also makes some of the “expensive” sellers like Langrex look more affordable as time goes on…


----------



## mordy

Monsterzero said:


> The prices on many of the 6J5s have gone over the 100 dollar mark. A few years ago it was like 20 bucks.


I must be living in a different world but I don't mind buying used tubes. Very recently I paid $11 shipped for one NU 6J5GT and I have been able to buy odd lots of 6J5GT tubes for $4-5 each and found a couple of the NU tubes there. 
Take a look at the first three items of what is available today:
https://www.ebay.com/sch/i.html?_fr...m570.l1313&_nkw=National+Union+6J5GT&_sacat=0


----------



## Xcalibur255

raindownthunda said:


> The eBay seller in India just doubled the prices for their NU 6J5GT pairs & quads. They must be reading head-fi


The chances of that are honestly pretty high.  Places like this create buying trends for those sellers so they do keep tabs on it.

I personally don't buy anything from that seller anymore anyway since they sold me a a bad L63 grey glass with loose pins and a short and didn't want to make it right.


----------



## mordy

Xcalibur255 said:


> The chances of that are honestly pretty high.  Places like this create buying trends for those sellers so they do keep tabs on it.
> 
> I personally don't buy anything from that seller anymore anyway since they sold me a a bad L63 grey glass with loose pins and a short and didn't want to make it right.


Did eBay/PayPal reimburse you?


----------



## maxpudding

We need to stop making good reviews lol


----------



## Xcalibur255

mordy said:


> Did eBay/PayPal reimburse you?


No, I had to eat it.


----------



## TLO

Xcalibur255 said:


> No, I had to eat it.


Read the long and detailed negative feedback, that was from me. After almost 2 weeks with no clear resolution, I left them that and moved on, not worth my time.


----------



## robo24

raindownthunda said:


> Seriously, glad I got into them a couple years ago. It seems like they are also getting harder to come by. I think buying singles and making your own pairs is the smart way to save a few bucks. Takes a lot of patience, luck, and detective skills to find matched construction with all the rebrands and variations. Also makes some of the “expensive” sellers like Langrex look more affordable as time goes on…


Not knowing a whole lot about tubes, I've been relying on Langrex and other places with good reputations. Had a few bad tubes from them lately and immediately replaced without having to send back the originals. Replacements have all been great. That's definitely worth something to me and I'm willing to pay a premium over finding lower prices without the security of reputation and great past experiences when there are problems.


----------



## Xcalibur255 (Jul 27, 2022)

TLO said:


> Read the long and detailed negative feedback, that was from me. After almost 2 weeks with no clear resolution, I left them that and moved on, not worth my time.


Yeah, as a general rule I prefer not to air dirty laundry but sometimes it's in the public interest to say something so people are aware of the risk they may be taking.  That's why I didn't say anything when it happened to me (which was months ago), but I see a number of people showing interest in getting NU tubes from this source so it felt necessary to mention something at this point.


----------



## raindownthunda

Xcalibur255 said:


> Yeah, as a general rule I prefer not to air dirty laundry but sometimes it's in the public interest to say something so people are aware of the risk they may be taking.  That's why I didn't say anything when it happened to me (which was months ago), but I see a number of people showing interest in getting NU tubes from this source so it felt necessary to mention something at this point.


I’ll pile on with my negative experience when attempting to use the “make an offer“ with this seller. The button was enabled yet the seller refused a very reasonable offer only a few dollars below list price with no counter. I get that prices can be firm but why have the make an offer button enabled If you won’t entertain or counter any offers? They also refused to consider slow/economy shipping to help reduce the $30 shipping fee. Right now there is a UK seller with the same NOS NU tubes for a more reasonable cost with reasonable shipping.


----------



## TLO

Xcalibur255 said:


> Yeah, as a general rule I prefer not to air dirty laundry but sometimes it's in the public interest to say something so people are aware of the risk they may be taking.  That's why I didn't say anything when it happened to me (which was months ago), but I see a number of people showing interest in getting NU tubes from this source so it felt necessary to mention something at this point.


Precisely, I left that feedback to warn others and not care about the money. Less than a day or two, he sent me a message offering a replacement if I would to remove the feedback, which I dont even bother to reply....  
Now, you know why I have a single piece of TS 6C8G dated Mar 1945 when I always buy in pairs.


----------



## whirlwind

Xcalibur255 said:


> No, I had to eat it.



Sorry to hear. I have been there.


----------



## whirlwind

Monsterzero said:


> The prices on many of the 6J5s have gone over the 100 dollar mark. A few years ago it was like 20 bucks.



Yeah, they were really cheap.


----------



## CAJames

raindownthunda said:


> The eBay seller in India just doubled the prices for their NU 6J5GT pairs & quads. They must be reading head-fi



Wow, I’m glad I got mine when I did. Disappointing to hear so many of you had problems with that seller. I’ve bought several tubes from them with no problems, but just shows yet again that past performance doesn’t guarantee future results.


----------



## jgwtriode (Jul 28, 2022)

Just supply and demand basic economics.  But next time wont be so enthusiastic about sharing my opinions about tubes I get!  Hard to believe how quickly a few comments and a couple sales got him all wound up.  But that's the arena we play in. We want value if we cant get a deal, he wants a tidy profit,. but would prefer a killing!  I have found him reputable, tubes are well packed and they arrive in a fairly timely fashion.  Both sets I have bought seem to be excellent.  I suspect he wont be selling any more NU's for awhile at that price.  As I see it he has sold one set to me and a quad to someone who saw me talking about them on @LOrdGwyn.  Both purchased at the lower price.  So now he has a matched quad and 3 matched pairs.  Nothing has been sold at the doubled price and he is not likely to anytime soon. I would like a backup set.  But I can wait!

Just my few cents worth.  No reason not to buy tubes from him, just not those right now.  Let em' sit in inventory

Happy listening,

jgwtriode


----------



## whirlwind

TLO said:


> Precisely, I left that feedback to warn others and not care about the money. Less than a day or two, he sent me a message offering a replacement if I would to remove the feedback, which I dont even bother to reply....
> Now, you know why I have a single piece of TS 6C8G dated Mar 1945 when I always buy in pairs.





TLO said:


> Precisely, I left that feedback to warn others and not care about the money. Less than a day or two, he sent me a message offering a replacement if I would to remove the feedback, which I dont even bother to reply....
> Now, you know why I have a single piece of TS 6C8G dated Mar 1945 when I always buy in pairs.


You will live happily ever after with those Mullards


----------



## Xcalibur255

whirlwind said:


> Sorry to hear. I have been there.


At least I did okay on the one that really counted (my dead KR KT150).  That would have been a huge bummer to eat at that price.  Seller did not do the right thing in that case either, but when I filed my paypal dispute (first time I have ever had to do one) they never responded so it was closed in my favor by default.


----------



## Xcalibur255 (Jul 28, 2022)

jgwtriode said:


> Just supply and demand basic economics.  But next time wont be so enthusiastic about sharing my opinions about tubes I get!  Hard to believe how quickly a few comments and a couple sales got him all wound up.  But that's the arena we play in. We want value if we cant get a deal, he wants a tidy profit,. but would prefer a killing!  I have found him reputable, tubes are well packed and they arrive in a fairly timely fashion.  Both sets I have bought seem to be excellent.  I suspect he wont be selling any more NU's for awhile at that price.  As I see it he has sold one set to me and a quad to someone who saw me talking about them on @LOrdGwyn.  Both purchased at the lower price.  So now he has a matched quad and 3 matched pairs.  Nothing has been sold at the doubled price and he is not likely to anytime soon. I would like a backup set.  But I can wait!
> 
> Just my few cents worth.  No reason not to buy tubes from him, just not those right now.  Let em' sit in inventory
> 
> ...


I think there's absolutely nothing wrong with sharing your enthusiasm about something you are liking.  That's mostly why we are here after all.

In the world of tubes there is really only one behavior that kind of bothers me.  Maybe I'm about to lose some friends over what I'm about to say, but I'm going to say it anyway.  That thing is extreme hoarding.  It's okay to buy multiple examples of something you really like.  It's okay to have a backup of something that may be hard to find in the future.  IMHO it is not okay to just buy and buy and buy until you clearly have more of a single tube than you could ever possibly use in your entire lifetime.  There are definitely some folks who do this for whatever reason.

Is it a person's right to do so?  Absolutely yes, but is that kind of behavior enviable?  We are all working with a dwindling and finite supply of something we love here and love is meant to be shared.

By the way this sentiment excludes a few specific examples such as folks who buy because they are motivated to preserve the history.  That's a far more noble goal than just simple hoarding.


----------



## Xcalibur255

This one's kind of interesting:

https://www.ebay.com/itm/374185787460?hash=item571f360044:g:7zsAAOSwy0xi2tBD

These have the same construction style, both plate and mica supports, as the WWII vintage VT-231 Raytheon 6SN7GT which is a highly regarded tube by most.  Most of the Raytheon 6J5 I have seen do not use this style of construction.


----------



## Isaacc7

Xcalibur255 said:


> This one's kind of interesting:
> 
> https://www.ebay.com/itm/374185787460?hash=item571f360044:g:7zsAAOSwy0xi2tBD
> 
> These have the same construction style, both plate and mica supports, as the WWII vintage VT-231 Raytheon 6SN7GT which is a highly regarded tube by most.  Most of the Raytheon 6J5 I have seen do not use this style of construction.


My Raytheon 12j5gtw have the same plate but different mica and the extra support rod.


----------



## Xcalibur255

Good point about the extra support rod.  VT-231s usually have that and these do not.


----------



## Velozity (Jul 28, 2022)

Speaking of Raytheons, these are my favorites.  Buying in singles and matching best you can is a good strategy for tubes that are 90 years old, Lol.


----------



## mordy

Velozity said:


> Speaking of Raytheons, these are my favorites.  Buying in singles and matching best you can is a good strategy for tubes that are 90 years old, Lol.


When I saw your picture of the Raytheons they looked familiar - could they be same as these tubes?



The right one is labeled GM from 1938 and the left one is labeled Philco from 1937. Both tubes have the support rod on one side, but the bottom mica is different in the right tube.


----------



## Xcalibur255 (Jul 29, 2022)

Velozity said:


> Speaking of Raytheons, these are my favorites.  Buying in singles and matching best you can is a good strategy for tubes that are 90 years old, Lol.


These are one of my favorites too.  I've come to think of their sound as the 'default' or 'house' sound for my 1101 Audio amp.  Their tone is almost perfectly matched to my tastes.  The round plate version is nice too.  A bit more soft and vintage sounding with a deeper and more ethereal soundstage.  I enjoy both flavors a lot.


----------



## Velozity

mordy said:


> When I saw your picture of the Raytheons they looked familiar - could they be same as these tubes?
> 
> The right one is labeled GM from 1938 and the left one is labeled Philco from 1937. Both tubes have the support rod on one side, but the bottom mica is different in the right tube.




Yes same tube.  I also have the GM, PHILCO, and ZENITH branded ones.  A total of 9 I think.  They are my oldest tubes also from the late 1930's.  Can't go wrong with these.


----------



## Velozity

Xcalibur255 said:


> These are one of my favorites too.  I've come to think of their sound as the 'default' or 'house' sound for my 1101 Audio amp.  Their tone is almost perfectly matched to my tastes.  The round plate version is nice too.  A bit more soft and vintage sounding with a deeper and more ethereal soundstage.  I enjoy both flavors a lot.



I too find the ladder plate a little better to my liking than the round plate, but I like both a lot.  When I'm not listening to L63 it's a toss up between these or Tung Sol VT-94A.  These usually win out, lol.


----------



## Monsterzero

The first time I tried the Fivre 6J5 I do not recall being very impressed with them, but tonight they sound fantastic, albeit a bit weak (neutral?) in the bottom end. Excellent air and separation, very nice mids and they seem to have an extra bit of non fatiguing shimmer in the top end.

Running them in the Glacier with a pair Western Electric 421a, and Gold Lion KT77s and a USAF 596 in the DAC.


----------



## mordy

Velozity said:


> I too find the ladder plate a little better to my liking than the round plate, but I like both a lot.  When I'm not listening to L63 it's a toss up between these or Tung Sol VT-94A.  These usually win out, lol.


The right tube does not have the round bottom mica which your Raytheon tubes have; it is rectangular. Is it still a Raytheon?


----------



## mordy

Xcalibur255 said:


> The chances of that are honestly pretty high.  Places like this create buying trends for those sellers so they do keep tabs on it.
> 
> I personally don't buy anything from that seller anymore anyway since they sold me a a bad L63 grey glass with loose pins and a short and didn't want to make it right.


Got a good laugh today - the Indian seller referenced above changed his eBay name! Must be reading the flattering reviews...
New name is electronicsmen...


----------



## TLO

mordy said:


> Got a good laugh today - the Indian seller referenced above changed his eBay name! Must be reading the flattering reviews...
> New name is electronicsmen...


No point changing the name, those pictures in his listings is a trademark I can recognize 100 feet away...  
OK, let see whether he changes all of the pictures after this post....


----------



## maxpudding (Aug 1, 2022)

Electronicsemen is the Indian wegehighguy? 😅

Just did a quick search, seems like yitry has a bunch of 6C5Vs. The price per unit is about 3 times more than when I bought them a year ago from another seller.


----------



## jonathan c

TLO said:


> No point changing the name, those pictures in his listings is a trademark I can recognize 100 feet away...
> OK, let see whether he _up_changes all of the _prices _after this post....


FTFY…[Reg. TM; © bcowen: 2021]


----------



## Xcalibur255

mordy said:


> Got a good laugh today - the Indian seller referenced above changed his eBay name! Must be reading the flattering reviews...
> New name is electronicsmen...


Stuff like this is classic.  People put so much energy into dodging damage to their reputation, and if they just conducted their business honestly their reputation would take care of itself and they wouldn't have to worry about it.


----------



## bcowen

maxpudding said:


> Electronicsemen is the Indian wegehighguy? 😅
> 
> Just did a quick search, seems like yitry has a bunch of 6C5Vs. The price per unit is about 3 times more than when I bought them a year ago from another seller.


No, the wege_high_tubes guy is shipping from Italy.  Never bought anything from him ‘cause his prices are consistently stupid, so can’t comment on the quality of what he is peddling.


----------



## jonathan c

bcowen said:


> No, the wege_high_tubes guy is shipping from Italy.  Never bought anything from him ‘cause his prices are consistently stupid, so can’t comment on the quality of what he is peddling.


Here is the (assumed) deal:  high price, ?? tubes, and ‘wedgie’ 😳😵‍💫…


----------



## maxpudding

bcowen said:


> No, the wege_high_tubes guy is shipping from Italy.  Never bought anything from him ‘cause his prices are consistently stupid, so can’t comment on the quality of what he is peddling.



😂 And yet there are still suckers who bought tubes from wegehighguy! Either they had no idea there are cheaper options or perhaps they are crazy rich suckers who don’t know what to do with their moneys.

I just hope the Indian seller won’t pull a wege-move, price wise.


----------



## mordy

Is this tube a fake?







Hmmm - Made in Germany? 
Yup, Russian made:



I should have figured it out already, but I forgot to look at the inverted saucer getter in the first picture.


----------



## jonathan c

mordy said:


> Is this tube a fake?
> 
> 
> Hmmm - Made in Germany?
> ...


…and the OTK inspection imprimatur…


----------



## TLO

mordy said:


> Is this tube a fake?
> 
> 
> Hmmm - Made in Germany?
> ...


Well, let me guess by the hand writing, seller by the name, lapisseadog?  
He is another one on my blacklist. There are two long detailed negative feedbacks from me, a really nasty seller, IMO. Beware.


----------



## mordy

jonathan c said:


> …and the OTK inspection imprimatur…


The "Sylvania" tube did not have an OTK stamp - the last picture I posted as a comparison with the real thing.


----------



## maxpudding

TLO said:


> Well, let me guess by the hand writing, seller by the name, lapisseadog?
> He is another one on my blacklist. There are two long detailed negative feedbacks from me, a really nasty seller, IMO. Beware.


I bought a pair of TS 6J5Gs from them. The tubes are in good condition, no hum at all. Did you ask for a refund? 🤔


----------



## TLO

maxpudding said:


> I bought a pair of TS 6J5Gs from them. The tubes are in good condition, no hum at all. Did you ask for a refund? 🤔


No becos I'm kind of pissed that time..  They were apparently not tested or inspected as described. How do I know? Before opening the plastic wrap, I noticed something is not quite right already, I could see cement compound all over in the transparent wrap. Yes, the cement compound has fallen off almost entirely. Both bases were loose, with one really bad that you could rock the glass tube in all directions easily. Basically the glass tube was left attached only by the wires to the pins.


----------



## Xcalibur255

mordy said:


> Is this tube a fake?
> 
> 
> Hmmm - Made in Germany?
> ...


I can't imagine sellers thinking that this type of 6J5 is valuable enough now to fake US markings on 6S2S tubes.  Having people think this tube is a Sylvania doesn't even really add that much value to it over what it would sell for as a 6S2S.

I'm trying to think of a reason why a tube made in East Germany during the cold war era would possibly end up with Sylvania licensing on it, therefore making these markings legitimate, but I can't see any reason for why such a thing would happen.  So....... the most reasonable answer is that the markings have been faked and that dishonest sellers have too much time on their hands.


----------



## Monsterzero

Since we are airing our eBay tube peddlars greivances, I bought a pair of Hytron 6C5G from Greengirl a few days ago. The listing had 7 tubes available, yet they cancelled the sale claiming items were out of stock or damaged.

Now, I've bought from Greengirl before with mixed results. Some tubes arrived okay, but a couple were DOA. GG refunded my $ both times, but it makes me suspicious as to how all 7 tubes could magically become damaged.....not pleased.

If anyone has a good pair of Hytron 6C5 available drop me a message. Heck any 6C5 im interested in


----------



## jonathan c

Monsterzero said:


> Since we are airing our eBay tube peddlars greivances, I bought a pair of Hytron 6C5G from Greengirl a few days ago. The listing had 7 tubes available, yet they cancelled the sale claiming items were out of stock or damaged.
> 
> Now, I've bought from Greengirl before with mixed results. Some tubes arrived okay, but a couple were DOA. GG refunded my $ both times, but it makes me suspicious as to how all 7 tubes could magically become damaged.....not pleased.
> 
> If anyone has a good pair of Hytron 6C5 available drop me a message. Heck any 6C5 im interested in


See PM


----------



## JazzVinyl

Monsterzero said:


> The prices on many of the 6J5s have gone over the 100 dollar mark. A few years ago it was like 20 bucks.



Seems to happen to all the popular "talked up" tubes.  

Long live, the 12v versions


----------



## Isaacc7

JazzVinyl said:


> Seems to happen to all the popular "talked up" tubes.
> 
> Long live, the 12v versions


I mentioned this on the 6sn7 thread and I guess I should mention it here. 12v versions of tubes really are cheap but unless your amp is custom made or you do modifications to your amp you typically can't take advantage of the cheaper prices. I had my Supratek Cabernet customized so that I can use 12v tubes and my upcoming Ultrasonic Labs amp can for both input and output. I have stocked up on some of the better regarded American *sn7 variants like the round plate black glass Tungsol and the "bad boy" Sylvania. And I am now exploring the world of 12j5 tubes. But my Dennis Had amp can't use 12v tubes and I am not going to spend the money buying the 6v versions. 

I'm sure by now everyone on this thread knows about the adapters that @Deyan makes. What a lot of people don't know is that he also makes external power supplies and special tube adapters so that you can use tubes with different heater voltages. He makes both fixed voltage versions as well as variable. I got the variable version because I have a vague ambition to try some of the various 4v tubes one day. Anyway, this is what it looks like:






As you can see, it can handle up to 6 tubes and up to 10 amps of heater current. Right now I am only using to adapt the input tube on my amp to 12v. Alas, there isn't room to use a 6j5 adapter but I can use my 12sn7 and I will also get some 12sl7 at some point I'm sure. The fixed voltage one is cheaper than the variable. I think he originally came up with this so that people could use the GU50. Drop him a line if you want to get into the 12v world.


----------



## mordy (Aug 9, 2022)

Isaacc7 said:


> I mentioned this on the 6sn7 thread and I guess I should mention it here. 12v versions of tubes really are cheap but unless your amp is custom made or you do modifications to your amp you typically can't take advantage of the cheaper prices. I had my Supratek Cabernet customized so that I can use 12v tubes and my upcoming Ultrasonic Labs amp can for both input and output. I have stocked up on some of the better regarded American *sn7 variants like the round plate black glass Tungsol and the "bad boy" Sylvania. And I am now exploring the world of 12j5 tubes. But my Dennis Had amp can't use 12v tubes and I am not going to spend the money buying the 6v versions.
> 
> I'm sure by now everyone on this thread knows about the adapters that @Deyan makes. What a lot of people don't know is that he also makes external power supplies and special tube adapters so that you can use tubes with different heater voltages. He makes both fixed voltage versions as well as variable. I got the variable version because I have a vague ambition to try some of the various 4v tubes one day. Anyway, this is what it looks like:
> 
> ...


If you want to try 12V tubes it is possible to go a different route and get octal adapters with wires for external power and the amp power disconnected. I have had good luck with power supplies from old PC computers using the 12V wires.
You can then get an inexpensive 15A voltage regulator with a set screw to adjust the voltage from 4 to 25V, using a voltmeter.
There are 7V, 8V and 25V tubes available in addition to the 4 and 12V tubes…


----------



## Isaacc7

mordy said:


> If you want to try 12V tubes it is possible to go a different route and get octal adapters with wires for external power and the amp power disconnected. I have had good luck with power supplies from old PC computers using the 12V wires.
> You can then get an inexpensive 15A voltage regulator with a set screw to adjust the voltage from 4 to 25V, using a voltmeter.
> There are 7V, 8V and 25V tubes available in addition to the 4 and 12V tubes…


That's essentially what @Deyan is making. His box and adapters are far nicer than anything I would whip up lol. The one that he made me can go up to 13v I think. I like the idea of using some of the really old 4v tubes from the likes of MOV from before they adapted the octal socket. I bought some n43 tubes by accident and the thought of using them just won't go way.  They look great but I'll have to see if it's worth the effort.


----------



## Isaacc7

Does anyone have any experience with Visseaux tubes? They have asking prices even higher than the British tubes I'm used to looking at. Are they a worthy marque?


----------



## mordy

Isaacc7 said:


> Does anyone have any experience with Visseaux tubes? They have asking prices even higher than the British tubes I'm used to looking at. Are they a worthy marque?


I have just a couple Visseaux tubes - 6N7G and 6N7GT. They are nice tubes and are worthwhile if the prices aren't very inflated.


----------



## Isaacc7

mordy said:


> I have just a couple Visseaux tubes - 6N7G and 6N7GT. They are nice tubes and are worthwhile if the prices aren't very inflated.


Aha! That was the tube I was thinking about. The 6n7g is being offered for crazy prices. I've seen the 6n7gt for as low as $100 each. The 11n7g on the other hand... I know you don't subscribe to the different heater tubes sounding the same but you do think the 6n7 tubes sound good? I already have the adapter to use it in my amp and with the external power supply I can use the 11v tube. For $33 a tube I might take a chance on them.


----------



## JazzVinyl

We should all shut up, before the 12v versions go sky high, too   

I do what @mordy said, octal saver with amp heaters not connected, wires out to a fine external regulated DC supply that is voltage adjustable...

Shutting up, now.


----------



## mordy

Isaacc7 said:


> Aha! That was the tube I was thinking about. The 6n7g is being offered for crazy prices. I've seen the 6n7gt for as low as $100 each. The 11n7g on the other hand... I know you don't subscribe to the different heater tubes sounding the same but you do think the 6n7 tubes sound good? I already have the adapter to use it in my amp and with the external power supply I can use the 11v tube. For $33 a tube I might take a chance on them.


Sometimes you can find these rebranded but you have to familiarize yourself with how they look. I think that my Visseaux 6J5GT has the name Neotron on it. Possibly some Mazda 6N7G tubes were made by Visseaux.
The fins above the top mica (heat radiators?) are unique to these tubes.


----------



## mordy

Isaacc7 said:


> Aha! That was the tube I was thinking about. The 6n7g is being offered for crazy prices. I've seen the 6n7gt for as low as $100 each. The 11n7g on the other hand... I know you don't subscribe to the different heater tubes sounding the same but you do think the 6n7 tubes sound good? I already have the adapter to use it in my amp and with the external power supply I can use the 11v tube. For $33 a tube I might take a chance on them.


I have good results with the metal 6N7 RCA and K-R. Also have NU and GE and will listen to them as well. But I can't flip through tubes, listening to them a couple of minutes each pair, and then come up with an opinion how they sound. It takes time, and these metal tubes, in addition, need much more time to warm up than glass tubes - at least 1/2 hour.
Then I have some 6N7G (and GT) tubes to roll as well, But the all metal 6N7 sound surprisingly good in my set-up with a full meaty low range and good mid range; the bass has lots of detail. The sound  sort of reminds me of how old, well recorded 78s sound.


----------



## whirlwind

JazzVinyl said:


> We should all shut up, before the 12v versions go sky high, too
> 
> I do what @mordy said, octal saver with amp heaters not connected, wires out to a fine external regulated DC supply that is voltage adjustable...
> 
> Shutting up, now.



Ha ha.

That seems to be the way it goes.

12 volt tubes have always been a great option for me as it is much easier to find NOS pairs at much more reasonable prices.


----------



## mordy (Aug 12, 2022)

Here is a pair of rare birds - Arcturus 6N7G. These tubes were made when tubes were big and bold and innards were size XL. And when tube boxes were pieces of art:


----------



## mordy (Aug 12, 2022)

But...listening to the Arcturus tubes for a while they are not a good match in my system. Although the sound stage is very wide, the tubes sound thin and slow and they don't bring out the soul of the music.
For some reason they have lower gain than other 6N7 tubes I tried, and I need to crank up the volume more. However, since they are very quiet it is not a problem.
Verdict:
Pretty yes, but satisfying, no.


----------



## Isaacc7

mordy said:


> But...listening to the Arcturus tubes for a while they are not a good match in my system. Although the sound stage is very wide, the tubes sound thin and slow and they don't bring out the soul of the music.
> For some reason they have lower gain than other 6N7 tubes I tried, and I need to crank up the volume more. However, since they are very quiet it is not a problem.
> Verdict:
> Pretty yes, but satisfying, no.


It's always disappointing to have to give up on a tube. Most of the time a tube that doesn't work for me can be chalked up to being the wrong "flavor" for the equipment. Sometimes though, you just have bad tubes. I will say that having a sample of one can point an inaccurate picture of the tube in general. I've had that happen with both 14af7 and 14n7. The first time I tried them they sounded really bad. Got in some replacements and they sounded quite good. 

In other news, I pulled the trigger on the Visseaux 11n7 tubes. Got them for $25 a piece so worth a gamble. This is the first "weird" voltage tube I will try and it did give me pause cause I doubt I'd ever be able to sell them if I decided they weren't for me. But why deny myself the fun of using the external power supply? Does anyone else get a thrill from using tubes that would otherwise be thrown out? I love that I can take something made for tank radio gear in the 40s or a color TV in the 60s and bring it to life and enjoy it. No? Just me? Maybe I've just turned into a tube hipster, ugh.


----------



## bcowen

Isaacc7 said:


> It's always disappointing to have to give up on a tube. Most of the time a tube that doesn't work for me can be chalked up to being the wrong "flavor" for the equipment. Sometimes though, you just have bad tubes. I will say that having a sample of one can point an inaccurate picture of the tube in general. I've had that happen with both 14af7 and 14n7. The first time I tried them they sounded really bad. Got in some replacements and they sounded quite good.
> 
> In other news, I pulled the trigger on the Visseaux 11n7 tubes. Got them for $25 a piece so worth a gamble. This is the first "weird" voltage tube I will try and it did give me pause cause I doubt I'd ever be able to sell them if I decided they weren't for me. But why deny myself the fun of using the external power supply? Does anyone else get a thrill from using tubes that would otherwise be thrown out? I love that I can take something made for tank radio gear in the 40s or a color TV in the 60s and bring it to life and enjoy it. No? Just me? *Maybe I've just turned into a tube hipster,* ugh.


A tube _addict _would probably be more accurate. But you're in good company. 🤣 

I have a blast trying tubes that aren't normally in the mainstream, but I'm not quite to the level you are.  I remember being told by a couple people I'd blow up my Lyr 3 with a 7N7.  An ECC40?  Heresy!  ECC84?  Gotta be nuts....


----------



## Isaacc7

bcowen said:


> A tube _addict _would probably be more accurate. But you're in good company. 🤣
> 
> I have a blast trying tubes that aren't normally in the mainstream, but I'm not quite to the level you are.  I remember being told by a couple people I'd blow up my Lyr 3 with a 7N7.  An ECC40?  Heresy!  ECC84?  Gotta be nuts....


I can quit any time I want…


----------



## JazzVinyl

Isaacc7 said:


> I can quit any time I want…


lol


----------



## mordy

mordy said:


> I have good results with the metal 6N7 RCA and K-R. Also have NU and GE and will listen to them as well. But I can't flip through tubes, listening to them a couple of minutes each pair, and then come up with an opinion how they sound. It takes time, and these metal tubes, in addition, need much more time to warm up than glass tubes - at least 1/2 hour.
> Then I have some 6N7G (and GT) tubes to roll as well, But the all metal 6N7 sound surprisingly good in my set-up with a full meaty low range and good mid range; the bass has lots of detail. The sound  sort of reminds me of how old, well recorded 78s sound.


Continuing my journey rolling tubes. The Arcturus 6N7G was disappointing, but this tube pictured here is first class - a Visseaux 6N7G (labeled Mazda). The date code is III 8 and it was made for the French Air Force - don't know if the year is 1938 or 1948. - Notice the two streams of fire propelling this tube to audiophile heights!




Way back in our Little Dot MKIII days people referred to the sound stage of this tube as "a wall of sound." 
It may be difficult to find this tube but I came across a seller in Taiwan who has the straight glass GT version (same construction) for $35:
http://tubes.tw/shop/product_info.php?products_id=1119&language=en

PS: My PC says that this web site isn't secure but I believe that people bought from this seller in the past without any problems.


----------



## CAJames

mordy said:


> ...PS: My PC says that this web site isn't secure but I believe that people bought from this seller in the past without any problems.



I am one of those. FWIW/FYI the site itself doesn't have an encrypted connection (it is HTTP not HTTPS) but you pay with paypal or some other (secure) method, you don't enter a credit card number on the site so there is no problem. In fact, the unsecure connection avoids a lot of problems with old/expired security certificates that can cause headaches for site admins.


----------



## JazzVinyl

mordy said:


> Continuing my journey rolling tubes. The Arcturus 6N7G was disappointing, but this tube pictured here is first class - a Visseaux 6N7G (labeled Mazda). The date code is III 8 and it was made for the French Air Force - don't know if the year is 1938 or 1948. - Notice the two streams of fire propelling this tube to audiophile heights!
> 
> Way back in our Little Dot MKIII days people referred to the sound stage of this tube as "a wall of sound."
> It may be difficult to find this tube but I came across a seller in Taiwan who has the straight glass GT version (same construction) for $35:
> ...



I bought one of these for the GOTL and can assure you that the internals (and the sound) was exactly the same as the harder to source Visseaux 6N7G version.  Quite the bargain, too!


----------



## mordy

mordy said:


> Continuing my journey rolling tubes. The Arcturus 6N7G was disappointing, but this tube pictured here is first class - a Visseaux 6N7G (labeled Mazda). The date code is III 8 and it was made for the French Air Force - don't know if the year is 1938 or 1948. - Notice the two streams of fire propelling this tube to audiophile heights!
> 
> Way back in our Little Dot MKIII days people referred to the sound stage of this tube as "a wall of sound."
> It may be difficult to find this tube but I came across a seller in Taiwan who has the straight glass GT version (same construction) for $35:
> ...


Rolling along - (the next tube I couldn't even remember that I had); a pair of very early 1940's RCA 6N7G:



This pair sounds very good. It seems that very little is known about the French Visseaux tubes but I read that at some point in time they bought licensing rights from RCA.
If anybody has a link or knowledge about this old French company and their tube manufacturing, please post.


----------



## Isaacc7

Have finally finished cycling through my Raytheon, NU, and Ken Rad 12j5gt tubes in my preamp.  I haven't noticed a dramatic difference between them, would be happy with any of them. I think the Raytheons are a little more open, the NU a little richer, and I think I can hear more layers and depth with the Ken Rad as compared to my reference Tung Sol BGRP 12sn7. I doubt I'd be able to tell which ones I've got in with a blind test. I think those tubes are more similar than different. The Sylvania round plate 12j5gt tubes have more of an upward tilt and the Tungsol JAN 12j5gt are a bit warmer. 

Overall I'm really impressed with the value of the single triodes vs. the twin triode 6/12sn7. Clarity in particular seems to be a common improvement. The 12j5gt pairs won't  replace all of my 6/12sn7 or 6f8g tubes but they will allow me to ditch some of of them The only ones I haven't liked at all are the RCA though I really like the Radiotron 6j5gt from Australia and I think those are based on RCA tubes.


----------



## mordy

Isaacc7 said:


> Have finally finished cycling through my Raytheon, NU, and Ken Rad 12j5gt tubes in my preamp.  I haven't noticed a dramatic difference between them, would be happy with any of them. I think the Raytheons are a little more open, the NU a little richer, and I think I can hear more layers and depth with the Ken Rad as compared to my reference Tung Sol BGRP 12sn7. I doubt I'd be able to tell which ones I've got in with a blind test. I think those tubes are more similar than different. The Sylvania round plate 12j5gt tubes have more of an upward tilt and the Tungsol JAN 12j5gt are a bit warmer.
> 
> Overall I'm really impressed with the value of the single triodes vs. the twin triode 6/12sn7. Clarity in particular seems to be a common improvement. The 12j5gt pairs won't  replace all of my 6/12sn7 or 6f8g tubes but they will allow me to ditch some of of them The only ones I haven't liked at all are the RCA though I really like the Radiotron 6j5gt from Australia and I think those are based on RCA tubes.


Welcome to the 6/12J5GT club!


----------



## triod750

Stylish! http://totron.sakura.ne.jp/national_union_soundxtra_series_tubes.htm
Gimme five!


----------



## triod750

Triple mica - who made me?


----------



## triod750

And here; the opportunity of a lifetime: https://www.ebay.co.uk/itm/16538441...zvKnRiKLIWCJ0p9JCYHrkGMyM=|tkp:Bk9SR6yKpovcYA


----------



## bcowen

triod750 said:


> And here; the opportunity of a lifetime: https://www.ebay.co.uk/itm/165384419513?hash=item2681adf8b9:gdQAAOSwBJViL7Kx&amdata=enc:AQAHAAAAoNRZ2lY/Hv7ua5WON5wWmU/OoJub5EMhv9Z7NemI4lAGcfCdLP0VwdvxGXunj5ElXIcG0NA2A0apd7EOfmxkr9FtcXnZEIhbOGCa7OVz4mhDb9B2CcIA4ejYHxawhPSZafT5ETtkJiw9z9X/egLJ43hqsjAfw0+NUmDsfn2UT+EzTyIOsBHGkVSs4gIGZezvKnRiKLIWCJ0p9JCYHrkGMyM=|tkp:Bk9SR6yKpovcYA


LOL!   I think I paid $15 for the pair I have.   🤣


----------



## triod750

bcowen said:


> LOL!   I think I paid $15 for the pair I have.   🤣


Come on, be honest, send the seller the missing cash!!


----------



## bcowen

triod750 said:


> Come on, be honest, send the seller the missing cash!!


If I subscribe to that notion, I can't afford to hoard.   🤣


----------



## triod750

You just have to adapt!


----------



## mordy

triod750 said:


> Stylish! http://totron.sakura.ne.jp/national_union_soundxtra_series_tubes.htm
> Gimme five!


On page 31 there is an ad for Sound X/Tra tubes - did not here about them before. Maybe a 1940 thing?
https://worldradiohistory.com/Archive-Service-Magazine/40s/Service-1940-04.pdf


----------



## triod750

mordy said:


> On page 31 there is an ad for Sound X/Tra tubes - did not here about them before. Maybe a 1940 thing?
> https://worldradiohistory.com/Archive-Service-Magazine/40s/Service-1940-04.pdf


And they are 'Demonstrably better'! Not just good or better...
But where do I find my N.U. distributor...?


----------



## jonathan c

triod750 said:


> And they are 'Demonstrably better'! Not just good or better...
> But where do I find my N.U. distributor...?


And if you do, can you use…?


----------



## bcowen

triod750 said:


> And they are 'Demonstrably better'! Not just good or better...
> *But where do I find my N.U. distributor...?*


www.ebay.com

🤣


----------



## mordy

triod750 said:


> And they are 'Demonstrably better'! Not just good or better...
> But where do I find my N.U. distributor...?


NU went out of business around 1953 and was bought by Sylvania. The Lansdale,PA factory used to be NU.
And S&H stamps are just collectors items today.


----------



## jonathan c

mordy said:


> NU went out of business around 1953 and was bought by Sylvania. The Lansdale,PA factory used to be NU.
> And S&H stamps are just collectors items today.


PS…Long-plate Lansdale 12AU7 s are fantastic tubes !


----------



## MDR30

Have two 6J5GT tubes, unmarked, that I'll send to anyone interested free of charge, only asking for postage.


----------



## mordy

MDR30 said:


> Have two 6J5GT tubes, unmarked, that I'll send to anyone interested free of charge, only asking for postage.


Please PM me - thanks


----------



## gibosi

MDR30 said:


> Have two 6J5GT tubes, unmarked, that I'll send to anyone interested free of charge, only asking for postage.



I believe I see a "flying saucer" getter?


----------



## mordy

gibosi said:


> I believe I see a "flying saucer" getter?


Looks like NEVZ 6S2S


----------



## mordy

Here is a Sylvania 6SN7GTB tube:



But what is this?



Another Sylvania 6SN7GTB? No, as pointed out by Triod750, this is a single and not dual triode - it is a Sylvania 6J5WGT with extra (disconnected) hardware inside.



I am curious how this came about. You would expect a single triode to have just one plate:


----------



## jonathan c

mordy said:


> Here is a Sylvania 6SN7GTB tube:
> 
> But what is this?
> 
> ...


4pm Friday came before the ‘hardware’ could be connected…?🤪


----------



## mordy

jonathan c said:


> 4pm Friday came before the ‘hardware’ could be connected…?🤪


It looks like it was deliberate because the tube is labeled and functions as a single triode.


----------



## raindownthunda

mordy said:


> It looks like it was deliberate because the tube is labeled and functions as a single triode.


I have a pair of these as well and was mega-confused when inspecting the tube for the first time. I stumbled on a bit of info half-way down this page on why they might have done this: 

_“If you look closely, cathode and grid are only assembled inside one of the plates. It is better visible when the tube is lit up_



_Obviously the same tooling and internal structure as for the 6SN7 was used, they kept the second plate inside for mechanical stability, but left the cathode and grid out.”_

If I had to hazard a guess I would think it could also be related supply chain efficiency, with less unique parts to manufacture, stock, and assemble. Interesting tube but too bad they don’t sound very good…


----------



## Monsterzero

raindownthunda said:


> too bad they don’t sound very good…


 I used to have a pair of Sylvania 6j5s that sounded phenomenal, except for a pretty strong buzz. I tried to re flow the solder, but ended up killing the tubes instead. 
In my attempt to get another "magic" pair of Sylvanias, I mustve bought 8-10 pairs of 6 and 12j5s....all of them sounded pretty bad. 
To this day I have no idea what made that one pair sound so good and the rest were not. Oh well....


----------



## Xcalibur255

I'm sure towards the end demand for the 6J5 was very low and it made no sense to have dedicated tooling to make them so we get interesting things like this as a result.


----------



## Xcalibur255

Monsterzero said:


> I used to have a pair of Sylvania 6j5s that sounded phenomenal, except for a pretty strong buzz. I tried to re flow the solder, but ended up killing the tubes instead.
> In my attempt to get another "magic" pair of Sylvanias, I mustve bought 8-10 pairs of 6 and 12j5s....all of them sounded pretty bad.
> To this day I have no idea what made that one pair sound so good and the rest were not. Oh well....


This is why I don't attempt the solder re-flow on my buzzing tubes.  I feel that the solder joint isn't always the source of this type of noise, sometimes it's actually a tiny speck of debris lodged inside the grid from manufacturing and a good "thwack" in your palm can knock it out.  Other times it's a grid tolerance issue and the tube will technically work but will always buzz.  My last few 6J5 purchases have all turned out to have unfixable buzzing issues, I sort of feel like the world is telling me to stop.  You just can't stop being curious about the ones you haven't heard yet though!


----------



## Isaacc7

Xcalibur255 said:


> I'm sure towards the end demand for the 6J5 was very low and it made no sense to have dedicated tooling to make them so we get interesting things like this as a result.


Yup. I'm sure Sylvania had a contract to fulfill, probably with the government/military, and was not about to retool a whole production line when they already had a perfectly good tube being made. All they had to do was redo some connections and voila, a tube that worked just fine for whatever the government needed it for. 

Sylvania did a ton of this. Keep your eyes out for 807 or 6bg6ga with 7581a guts in them, often times labeled Philips. A 7581a rated tube could drop into a circuit designed for an 807 no problem. Don't try the other way around though! There are also lots of TV tubes that were upgraded over time. You'll see 6av5 with the guts of much more powerful 6fw4. The most notorious example of this is Sylvania using a 6av5 (probably actually a 6fw4), wiring it as a triode, and selling it as a 6b4ga. The 6b4 is a triode (an indirectly heated version of the 6a3, the 6v version of the 2a3), the 6av5 is a beam tetrode I think. Rewiring the 6av5 as a triode made it close enough to a 6b4 *for whatever purpose the government had for it* so that Sylvania didn't 't have to revive the ancient 6b4 tooling. I'm pretty sure they were being used as pass elements in voltage regulators. Some Techtronix equipment used them that way. Needless to say, audio quality wasn't the driving factor of fulfilling the contract!


----------



## mordy

The tube world is full of surprises. Here is a GE metal 6N7 pair from the 50's that sound excellent. - Maybe they are old Ken-Rad tubes with new logos and dates?




The days of $2 tubes are mostly over, but you can still find these for little money.
If you have the right amp and adapters for the 6N7 it is well worth trying.


----------



## Xcalibur255

Isaacc7 said:


> Yup. I'm sure Sylvania had a contract to fulfill, probably with the government/military, and was not about to retool a whole production line when they already had a perfectly good tube being made. All they had to do was redo some connections and voila, a tube that worked just fine for whatever the government needed it for.
> 
> Sylvania did a ton of this. Keep your eyes out for 807 or 6bg6ga with 7581a guts in them, often times labeled Philips. A 7581a rated tube could drop into a circuit designed for an 807 no problem. Don't try the other way around though! There are also lots of TV tubes that were upgraded over time. You'll see 6av5 with the guts of much more powerful 6fw4. The most notorious example of this is Sylvania using a 6av5 (probably actually a 6fw4), wiring it as a triode, and selling it as a 6b4ga. The 6b4 is a triode (an indirectly heated version of the 6a3, the 6v version of the 2a3), the 6av5 is a beam tetrode I think. Rewiring the 6av5 as a triode made it close enough to a 6b4 *for whatever purpose the government had for it* so that Sylvania didn't 't have to revive the ancient 6b4 tooling. I'm pretty sure they were being used as pass elements in voltage regulators. Some Techtronix equipment used them that way. Needless to say, audio quality wasn't the driving factor of fulfilling the contract!


I actually have a bit of experience with the whole 6AV5 6B4G thing.  The 6AV5 oscillated like crazy in the particular amp I tried it in.


----------



## triod750

I've only used genuine 6B4G in Triod750 .


----------



## Isaacc7

Xcalibur255 said:


> I actually have a bit of experience with the whole 6AV5 6B4G thing.  The 6AV5 oscillated like crazy in the particular amp I tried it in.


I wonder if using "snubbers" in an adapter would prevent that. I don't actually know what they are but I've seen people talk about using them to prevent oscillations. I have some 12av5 I'm interested in using In my next amp but am worried about problems.


----------



## bcowen

jonathan c said:


> PS…Long-plate Lansdale 12AU7 s are fantastic tubes !


So are the tall-bottle 7N7's.


----------



## raindownthunda (Sep 1, 2022)

I was planning on "just" cleaning the pins and giving these a quick test run, but I'm getting sucked into tonight's tube roll and having trouble taking off the headphones. Here are the Philips Miniwatt 6C5V. I believe these are manufactured by RT? Not the prettiest examples, but they are dead silent and sound quite nice. Spacious, detailed, full, and musical paired with the Chatham 6AS7G.


----------



## mordy

raindownthunda said:


> I was planning on "just" cleaning the pins and giving these a quick test run, but I'm getting sucked into tonight's tube roll and having trouble taking off the headphones. Here are the Philips Miniwatt 6C5V. I believe these are manufactured by RT? Not the prettiest examples, but they are dead silent and sound quite nice. Spacious, detailed, full, and musical paired with the Chatham 6AS7G.


Are these tubes glass tubes with an RF coating? There is a possibility that you could find the RFT logo on the bottom of the base near the tube pins if they were made by RFT.


----------



## raindownthunda

mordy said:


> Are these tubes glass tubes with an RF coating? There is a possibility that you could find the RFT logo on the bottom of the base near the tube pins if they were made by RFT.


Hey mordy - I just checked both tube bases and don’t see any markings at all. They are glass with a textured metallic coating. They look identical (other than the logo) to the ones pictured here: https://www.radiomuseum.org/tubes/tube_6c5v.html
Looks like Langrex also has them for sale.


----------



## mordy

Packed up the Cetron 6336B tubes, being mindful of the joint Army & Navy instructions:



According to the spec sheet, one pair of 6336B can take the place of 4 or 6 6AS7G tubes.
https://frank.pocnet.net/sheets/077/6/6336B.pdf

What about? Mrs Ling Xu did not plan for 6 x 6AS7 tubes in her adapter (not enough spacing to make room for 6 tubes) so we have to settle for four tubes.
Is it going to melt my voltage regulator? Make the listening room into a sauna? How will it sound compared to the 6336B?
Only one way to find out:



You know what they say about cars - you cannot have enough horse power. How many horsepower is 10A?
Common Amps to Horsepower Conversions

AmpsHorsepowerEfficiency10 A*1.45 HP*90%
Throw in another 1.6A for the driver tubes and we should have at least 1.5 HP.

It is getting warm in here - time to turn on the AC.                                 

So far everything is holding up. The sound is different than the 6336B - more background detail, less slam and the sound stage isn't as wide. The presentation is more laid back and distant compared to the Cetron's in your face sound. 
Need more volume - the amplification factor  for the RCAs is 2.2 and 2.7 for the Cetrons. 
The RCAs are supposed to be warm sounding tubes - need more time to form a clearer opinion of the sound in this setup. 
I don't own planar headphones but 1.5HP sounds like enough to drive them lol.


----------



## maxpudding

1.5HP AC is enough to cool down a hot room within minutes too lol


----------



## bcowen

mordy said:


> Packed up the Cetron 6336B tubes, being mindful of the joint Army & Navy instructions:
> 
> According to the spec sheet, one pair of 6336B can take the place of 4 or 6 6AS7G tubes.
> https://frank.pocnet.net/sheets/077/6/6336B.pdf
> ...


Love it!  Maybe some 6AS7GA's?  Then you could fit 6.   🤣


----------



## Xcalibur255

Isaacc7 said:


> I wonder if using "snubbers" in an adapter would prevent that. I don't actually know what they are but I've seen people talk about using them to prevent oscillations. I have some 12av5 I'm interested in using In my next amp but am worried about problems.


That's what I was trying for, but that amp is long gone now anyway.  It had grounding issues and when I sent it off for repairs I never got it back.


----------



## mordy

After listening to the quad of RCA 6AS7G tubes for a while my impression is that they sound fine. In comparison with the 6336B there is less slam but more detail and the upper frequencies come through very crisp and clear. Not as musical but still very enjoyable together with the GE 6N7 tubes.
I am re-tired - rolling along...
Next a Russian - American collaboration - Owensboro and Petersburg (GE 6N7 and Svetlana 6AS7G). The Russian tubes are new and not burned in. There was a time when you could buy the Svetlana tubes by the case of 50 or 100 for very little but not any more. Sometime ago I bought a small lot of these tubes with loose bases and with a little assistance of crazy glue they are in use now:

The second tube from the left has a resemblance to the leaning tower of Pisa - did not pay enough attention when I glued it together, but it works.
First impression is that these tubes have more bass than the RCAs in this setup. However, it is too early to describe the sound since the tubes are new - will need at least 30 hours; probably more.
But in this hobby the travel to reach the destination is also enjoyable...


----------



## mordy (Sep 4, 2022)

mordy said:


> After listening to the quad of RCA 6AS7G tubes for a while my impression is that they sound fine. In comparison with the 6336B there is less slam but more detail and the upper frequencies come through very crisp and clear. Not as musical but still very enjoyable together with the GE 6N7 tubes.
> I am re-tired - rolling along...
> Next a Russian - American collaboration - Owensboro and Petersburg (GE 6N7 and Svetlana 6AS7G). The Russian tubes are new and not burned in. There was a time when you could buy the Svetlana tubes by the case of 50 or 100 for very little but not any more. Sometime ago I bought a small lot of these tubes with loose bases and with a little assistance of crazy glue they are in use now:
> The second tube from the left has a resemblance to the leaning tower of Pisa - did not pay enough attention when I glued it together, but it works.
> ...


Maybe someone knows the answer: I am always on the lookout for any electrical acrid smell from my equipment - always scary when it happens. Now I smell something from the amp, but it is not an electrical smell, more like a smell from old cardboard boxes or old newspapers. Could it be from the old Russian tubes?
I should also add that the tubes suddenly changed from a bright sound to a more mellow sound - around 12 hours into the burn-in process.


----------



## bcowen

mordy said:


> Maybe someone knows the answer: I am always on the lookout for any electrical acrid smell from my equipment - always scary when it happens. Now I smell something from the amp, but it is not an electrical smell, more like a smell from old cardboard boxes or old newspapers. Could it be from the old Russian tubes?
> I should also add that the tubes suddenly changed from a bright sound to a more mellow sound - around 12 hours into the burn-in process.


I can't offer anything of help on the smell.  I have noticed that some old tubes smell kind of hot when first fired up.  And I can't exactly explain 'hot', other than similar to turning on the stove burner without having anything cooking on it at first (if that even makes any sense).

IME, most every truly new (as in never used) NOS Russian-made tube I've tried improves quite a bit over the first 15+ hours of play time. From Svetlanas to Fotons to Melz, they all sound a bit thin, lack harmonic depth and detail and some can have a treble edge to them compared to how they sound after getting some break in time. Just my experience, but I've heard it so many times I don't think it's just a figment of my imagination.


----------



## mordy

bcowen said:


> I can't offer anything of help on the smell.  I have noticed that some old tubes smell kind of hot when first fired up.  And I can't exactly explain 'hot', other than similar to turning on the stove burner without having anything cooking on it at first (if that even makes any sense).
> 
> IME, most every truly new (as in never used) NOS Russian-made tube I've tried improves quite a bit over the first 15+ hours of play time. From Svetlanas to Fotons to Melz, they all sound a bit thin, lack harmonic depth and detail and some can have a treble edge to them compared to how they sound after getting some break in time. Just my experience, but I've heard it so many times I don't think it's just a figment of my imagination.


Exactly my experience with these Svetlanas! Thin sounding, with a treble edge. Better sound to come....I am sure.


----------



## mordy

mordy said:


> After listening to the quad of RCA 6AS7G tubes for a while my impression is that they sound fine. In comparison with the 6336B there is less slam but more detail and the upper frequencies come through very crisp and clear. Not as musical but still very enjoyable together with the GE 6N7 tubes.
> I am re-tired - rolling along...
> Next a Russian - American collaboration - Owensboro and Petersburg (GE 6N7 and Svetlana 6AS7G). The Russian tubes are new and not burned in. There was a time when you could buy the Svetlana tubes by the case of 50 or 100 for very little but not any more. Sometime ago I bought a small lot of these tubes with loose bases and with a little assistance of crazy glue they are in use now:
> The second tube from the left has a resemblance to the leaning tower of Pisa - did not pay enough attention when I glued it together, but it works.
> ...


After some 15 hours suddenly there is a remarkable change for the better in sound. The only thing I can think of is this:



Becoming this:



The thin, harsh sound suddenly changed to a mellow, full sound. - They are people that claim that there is no such a thing as tube burn-in and that the tubes sound the same from being new to having been used for a while. IMHO they are wrong. However, I am used to a more gradual change than in this case.


----------



## Xcalibur255 (Sep 6, 2022)

Every NOS driver and power tube I've used has gone through this transformation from thin and flat to full and melodious.  Not always to the same degree or in the same period of time, but they all do it to some extent.  In fact one of the ways I'm confident that a tube I've just bought is truly NOS is if it sounds lifeless and has no bass the very first time I hear it.  I also find find many tubes go through this "swing" in sound several times before settling down, each successive one milder than the first big swing.  There's this weird 6th sense that kicks and you just "know" when it's finally settled down and this is what it's going to sound like.

I'm sure quite a few people think this is absolutely absurd and laughable, but if being a tube whisperer is crazy then it's my kind of crazy.


----------



## mordy

Xcalibur255 said:


> Every NOS driver and power tube I've used has gone through this transformation from thin and flat to full and melodious.  Not always to the same degree or in the same period of time, but they all do it to some extent.  In fact one of the ways I'm confident that a tube I've just bought is truly NOS is if it sounds lifeless and has no bass the very first time I hear it.  I also find find many tubes go through this "swing" in sound several times before settling down, each successive one milder than the first big swing.  There's this weird 6th sense that kicks and you just "know" when it's finally settled down and this is what it's going to sound like.
> 
> I'm sure quite a few people think this is absolutely absurd and laughable, but if being a tube whisperer is crazy then it's my kind of crazy.


Nothing crazy about it - this is the truth about what is happening when burning in new tubes. In some cases the tube will keep on changing for a hundred hours or even more, although the changes may become more subtle.
I chuckle when people do comparison tests of new tubes and take a bunch of them, play each one a few minutes, and then proclaim a winner.


----------



## triod750 (Sep 8, 2022)

My mystery 6C5G died on duty last night. First tube ever to do this. The heater stopped working.



I removed the metal shell by desoldering the tab connected to pin 1 (screen) and prying the 'lid' open and then separating the two halves. The tube had the marking SYLVANIA burnt into the socket. On the glass there was 6C5G in an oval.
I have one STC 6J5G that hums like crazy. It is beautiful but totally unlistenable. I dressed it in this metal shell and put it in the amp. It is now dead quiet.
The tab is now around the pin marked (m) on this link: https://www.radiomuseum.org/tubes/tube_6j5g.html It felt as the right thing to do.
When checking the 6C5G I found this source interesting regarding the metal shield: https://groups.io/g/tubecollectorsassociation/topic/66480356 My tube was intended for use in a radio. (Luxor was a Swedish company manufacturing radios and such items).

So if you have a tube that hums, you could try this solution...
I have a couple of L63 here that hums. Maybe....


----------



## DecentLevi

Hi guys, any opinions on these? It says Reflector 6C5S
https://www.ebay.com/itm/385077878640


----------



## maxpudding

DecentLevi said:


> Hi guys, any opinions on these? It says Reflector 6C5S
> https://www.ebay.com/itm/385077878640



That’s Russian 6X5GT, a rectifier tube.


----------



## mordy

mordy said:


> After some 15 hours suddenly there is a remarkable change for the better in sound. The only thing I can think of is this:
> 
> Becoming this:
> 
> The thin, harsh sound suddenly changed to a mellow, full sound. - They are people that claim that there is no such a thing as tube burn-in and that the tubes sound the same from being new to having been used for a while. IMHO they are wrong. However, I am used to a more gradual change than in this case.


After some time with the Svetlana 6H13C the verdict is that as a quad they acquit themselves well - nice sounding tubes with the 6N7 GE. But rollin' along...What's next? Dug out some 6080 tubes that haven't seen daylight for several years - bought when these tubes could be found used for $2 each in small lots, if you remember those days lol.
These RCA 6080 tubes put on a nice light show:






Two of the tubes are labeled Stromberg-Carlson. This company, founded by two enterprising Swedes, was a very large pioneer in communications equipment and consumer electronics. You can read about it here:
https://en.wikipedia.org/wiki/Stromberg-Carlson

Well, in comparison with the RCA 6AS7G, are these RCA 6080 New and Improved?
We'll give it a little time and see...


----------



## Isaacc7

If anyone is interested, a seller just put up a bunch of American 6j5g tubes on ebay. Looks like there's a bunch of Raytheons that a poster here said are really good. I'm trying to keep my tube spending down and I need 4 at a time so I won't be going for these.


----------



## mordy

mordy said:


> After some time with the Svetlana 6H13C the verdict is that as a quad they acquit themselves well - nice sounding tubes with the 6N7 GE. But rollin' along...What's next? Dug out some 6080 tubes that haven't seen daylight for several years - bought when these tubes could be found used for $2 each in small lots, if you remember those days lol.
> These RCA 6080 tubes put on a nice light show:
> 
> 
> ...


After using this combo for a little while I came to the conclusion that although the tubes have a nice mid-bass, they are too soft sounding and lack real slam and impact. They are OK, but in this combination they don't stand out.


----------



## mordy

Isaacc7 said:


> If anyone is interested, a seller just put up a bunch of American 6j5g tubes on ebay. Looks like there's a bunch of Raytheons that a poster here said are really good. I'm trying to keep my tube spending down and I need 4 at a time so I won't be going for these.


Same here - trying to keep spending and collecting tubes down. I think the same seller had another lot of 100 6J5GT tubes recently. 
I am not inclined to sell stuff and the few difficult buyers I have encountered in the past turned me off from selling.
It is tempting to buy a big lot cheap and keep the ones you want and sell the rest, but I know myself - it ain't happening...


----------



## CAJames

Isaacc7 said:


> If anyone is interested, a seller just put up a bunch of American 6j5g tubes on ebay. Looks like there's a bunch of Raytheons that a poster here said are really good. I'm trying to keep my tube spending down and I need 4 at a time so I won't be going for these.



I wonder how those sell. Thanks to this thread I've got plenty of single triodes for this life and most of the next so my interest is strictly academic.


----------



## Isaacc7

CAJames said:


> I wonder how those sell. Thanks to this thread I've got plenty of single triodes for this life and most of the next so my interest is strictly academic.


I will be getting more single triodes for sure but I'm going for less expensive. I've got a potential order for a bunch of metal 6c5 and 6j5 tubes in the works. I will also try out some 76 and 6l5 tubes at some point too. The only other large-ish tube purchase I can see myself doing is a bunch of different 6bg6 tubes. But once again, those are pretty cheap and like the 6l5 and 6c5, aren't particularly in demand so I can wait a little while.


----------



## CAJames

If you are looking at 76 tubes I can also recommend the type 37.


----------



## mordy

CAJames said:


> I wonder how those sell. Thanks to this thread I've got plenty of single triodes for this life and most of the next so my interest is strictly academic.


The 100 piece lot found a buyer.
https://www.ebay.com/itm/1753838761...=true&nordt=true&rt=nc&_trksid=p2047675.l2557


----------



## Isaacc7

CAJames said:


> If you are looking at 76 tubes I can also recommend the type 37.


Right, the 37 and 76 use the same adapter right? I've seen some of the globe 37 tubes and they look amazing. Might be worth having even if they don't sound great lol.


----------



## gibosi

Isaacc7 said:


> Right, the 37 and 76 use the same adapter right? I've seen some of the globe 37 tubes and they look amazing. Might be worth having even if they don't sound great lol.



In a different amp (Glenn OTL), most of the 37s I have tried were too noisy for me. However, 76s are fine.


----------



## CAJames

Isaacc7 said:


> Right, the 37 and 76 use the same adapter right? I've seen some of the globe 37 tubes and they look amazing. Might be worth having even if they don't sound great lol.


Yes and yes. I've been looking kinda half heartedly for 4 globe 37s but have only found a couple for what I'm willing to spend (which isn't very much). I've been using Sylvania VT-37s and really like the sound. They have less gain then pretty much any other type I've tried, if that matters at all.


----------



## pravous

I found all the type 37 I have tried to be noisy. I have a pair of Philco (assuming Sylvania manufacture) and Sylvania globes.  The Sylvania globes have an air to them that is quite unique.


----------



## gibosi (Sep 12, 2022)

pravous said:


> I found all the type 37 I have tried to be noisy. I have a pair of Philco (assuming Sylvania manufacture) and Sylvania globes.  The Sylvania globes have an air to them that is quite unique.



Surprisingly, I often found 27s to be quieter, but an external DC heater to provide 2.5 volts / 1.75 amps was too much of a hassle. But the early Westinghouse 27s were my favorites.


----------



## DecentLevi (Sep 13, 2022)

Look, I've found a new Westinghouse 27 and it really puts out a good glow 
'Guess they've really come full circle after all these years
https://www.bestbuy.com/site/westinghouse-27-full-hd-ips-led-monitor/6507358.p?skuId=6507358


----------



## CaptainFantastic

I had three L63 singles sitting around that "needed" to find their companions. I put needed in quotes because even I know that they are all GEC L63s (6J5Gs) so the matching is purely on an aesthetic level. Add the fact that half the time you can't even see the sticker when the tubes sit in the adapter, and this was really an idiotic enterprise. But nonetheless, after some months and waiting for strong testing tubes (at least advertised as such) + very reasonable prices, I hereby present the results. And the good news is that (so far) they are also nice and quiet and sound great.


----------



## leftside

CaptainFantastic said:


> I had three L63 singles sitting around that "needed" to find their companions. I put needed in quotes because even I know that they are all GEC L63s (6J5Gs) so the matching is purely on an aesthetic level. Add the fact that half the time you can't even see the sticker when the tubes sit in the adapter, and this was really an idiotic enterprise. But nonetheless, after some months and waiting for strong testing tubes (at least advertised as such) + very reasonable prices, I hereby present the results. And the good news is that (so far) they are also nice and quiet and sound great.


Singles definitely need to find their companions 

The clear glass ones are Mullards. All very nice. Congrats.


----------



## leftside

Big fan of the 37 tube here. Quiet in my amps. Definitely warmer sounding tubes. I imagine if more people knew about them, these would be very popular in modern tube gear.

I'll have to post up some pics if I get time. I have the globe version with mesh plates, silver plates and grey plates. Not sure if I can tell much difference between the three, but with winter coming I'll be heading back indoors soon and will try and compare.


----------



## CaptainFantastic

leftside said:


> Singles definitely need to find their companions
> 
> The clear glass ones are Mullards. All very nice. Congrats.



Excellent, thanks for pointing that out. I would have never figured it out myself.


----------



## Monsterzero

Has anyone tried these yet?


----------



## maxpudding

Monsterzero said:


> Has anyone tried these yet?


I think @chrisdrop has tried them before


----------



## raindownthunda (Sep 28, 2022)

Monsterzero said:


> Has anyone tried these yet?


I have these from Langrex. Not sure who actually made them but my guess is Mullard. Seems similar to some Mullard 6c5g, see here: https://mullard.org/products/copy-of-6c5g-tungsram-white-box-cv581 and here http://www.r-type.org/exhib/abv0021.htm

It’s been a while since I’ve listened to them but I remember them sounding pretty good. Maybe a little thicker/denser than the reference GEC L63 but with good clarity and bass extension? Need to give them a fresh listen but I recall them being enjoyable. EDIT: Yep, listening now... these are really good.


----------



## CAJames

Haven't tried them but I remember them being well liked. I've actually had my eye on them with the GBP practically free these days...


----------



## raindownthunda

Also where in the world does Langrex find 347 of these?!? Makes me wish they included an origin story in their listings to romanticize the history (like a fine bottle of vintage wine).


----------



## chrisdrop

maxpudding said:


> I think @chrisdrop has tried them before


I like those tubes


----------



## jonathan c

CAJames said:


> Haven't tried them but I remember them being well liked. I've actually had my eye on them with the GBP practically free these days...


With GBP = 1.0821 USD, I wonder if Langrex might raise their GBP prices to compensate for weaker exchange ratio…


----------



## CAJames

jonathan c said:


> With GBP = 1.0821 USD, I wonder if Langrex might raise their GBP prices to compensate for weaker exchange ratio…


Yeah, I’m not inclined to wait around to find out…


----------



## leftside

jonathan c said:


> With GBP = 1.0821 USD, I wonder if Langrex might raise their GBP prices to compensate for weaker exchange ratio…


Their prices are already high enough lol. Good tubes tho. I’m also amazed at how many tubes they seem to find. The story/history for sure would be interesting.


----------



## jonathan c (Sep 28, 2022)

leftside said:


> Their prices are already high enough lol. Good tubes tho. I’m also amazed at how many tubes they seem to find. The story/history for sure would be interesting.


I bet that they found boxes of tubes forgotten (not inventoried correctly / at all) in erstwhile military or research warehouses…🤷🏻‍♂️


----------



## Isaacc7

raindownthunda said:


> I have these from Langrex. Not sure who actually made them but my guess is Mullard. Seems similar to some Mullard 6c5g, see here: https://mullard.org/products/copy-of-6c5g-tungsram-white-box-cv581 and here http://www.r-type.org/exhib/abv0021.htm
> 
> It’s been a while since I’ve listened to them but I remember them sounding pretty good. Maybe a little thicker/denser than the reference GEC L63 but with good clarity and bass extension? Need to give them a fresh listen but I recall them being enjoyable. EDIT: Yep, listening now... these are really good.


I have got to stay off this forum! It’s too expensive! Lol. Bought 4 of these and a pair of the Fivre built 12sn7. Also have another big order being firmed up with Billington. I keep thinking I’m done but somehow I keep spending money. I can resist anything but temptation.


----------



## jonathan c

Isaacc7 said:


> I have got to stay off this forum! It’s too expensive! Lol. Bought 4 of these and a pair of the Fivre built 12sn7. Also have another big order being firmed up with Billington. I keep thinking I’m done but somehow I keep spending money. I can resist anything but temptation.**


** Oscar Wilde ☑️👍. Plus, “the only way to get rid of temptation is to yield to it.”


----------



## CAJames

Isaacc7 said:


> I have got to stay off this forum! It’s too expensive! Lol. Bought 4 of these and a pair of the Fivre built 12sn7. Also have another big order being firmed up with Billington. I keep thinking I’m done but somehow I keep spending money. I can resist anything but temptation.



Yeah, pass the candle...


----------



## CAJames

So, decided to get "vintage" L63s (from Langrex) and managed to hit the GBP at pretty close to the bottom. Internally they look very similar to the "regular" GEC L63s but they don't sound the same. More high end sparkle and dynamics.







P.S. These are the last single triodes I'm buying.... No, really.


----------



## alvin sawdust

raindownthunda said:


> I have these from Langrex. Not sure who actually made them but my guess is Mullard. Seems similar to some Mullard 6c5g, see here: https://mullard.org/products/copy-of-6c5g-tungsram-white-box-cv581 and here http://www.r-type.org/exhib/abv0021.htm
> 
> It’s been a while since I’ve listened to them but I remember them sounding pretty good. Maybe a little thicker/denser than the reference GEC L63 but with good clarity and bass extension? Need to give them a fresh listen but I recall them being enjoyable. EDIT: Yep, listening now... these are really good.


Do you prefer the Cossor or the GEC? On looks alone I like the Cossor. Langrex are also selling interesting looking brown and black base Fivre mesh anode 6c5g.


----------



## jonathan c

CAJames said:


> P.S. These are the last _single _triodes I'm buying.... No, really.


We know….. this leaves open the purchase of more than one at a time 🤣…..


----------



## triod750

alvin sawdust said:


> Fivre mesh anode 6c5g


Should be 'Fivre mesh screen' to be correct, not? But everybody knows what you mean.


----------



## leftside

alvin sawdust said:


> Langrex are also selling interesting looking brown and black base Fivre mesh anode 6c5g.


Those are good too


----------



## alvin sawdust

triod750 said:


> Should be 'Fivre mesh screen' to be correct, not? But everybody knows what you mean.


https://www.ebay.co.uk/itm/27467865...rentrq:ae64ca131830a2436f53d409fff62868|iid:1


----------



## CaptainFantastic

alvin sawdust said:


> https://www.ebay.co.uk/itm/274678650363?_trkparms=amclksrc=ITM&aid=111001&algo=REC.SEED&ao=1&asc=20160908105057&meid=b4f95f6dc445443aaded6a9980165ff9&pid=100675&rk=2&rkt=15&sd=313413940851&itm=274678650363&pmt=0&noa=1&pg=2380057&_trksid=p2380057.c100675.m4236&_trkparms=pageci:549e40d0-459e-11ed-82fa-9a6773729efb|parentrq:ae64ca131830a2436f53d409fff62868|iid:1



Be careful with those Fivre mesh tubes, as some here (including me) have reported issues with ones sourced from Langrex. I would like to hear from people who bought this tube type from Langrex and had a fully usable pair. Maybe it's just the issues that were reported.


----------



## raindownthunda (Oct 6, 2022)

alvin sawdust said:


> Do you prefer the Cossor or the GEC? On looks alone I like the Cossor. Langrex are also selling interesting looking brown and black base Fivre mesh anode 6c5g.


They are both excellent. Fantastic detail, imaging and timbre. The GEC ST has gotten the most play time as I think they are the most versatile, sounding great with just about every power tube in my BHC. If the GEC ST has more finesse and sweetness with a slight edge on the “magic” euphonic factor, the Cossor has more weight, density and slam while managing to also have great treble. I haven’t had nearly as much listening time with the Cossor but I’ve yet to be disappointed. Both top notch tubes IMO just different flavors. The cossor logo is pretty cool too. I prefer them both over the GEC GT Style with my ears and gear. If I could only own one it would probably be the GEC ST.

I dont have the fivre GT tubes but have the ST style and also really enjoy them. Not quite as detailed as either GEC or Cossor, but ultra smooth and creamy. My favorite with the Aeolous for blissed-out vocals. One pair I have had a noticeable elevated noise floor/hiss when music isn’t playing while the other pair is silent.


----------



## alvin sawdust

CaptainFantastic said:


> Be careful with those Fivre mesh tubes, as some here (including me) have reported issues with ones sourced from Langrex. I would like to hear from people who bought this tube type from Langrex and had a fully usable pair. Maybe it's just the issues that were reported.


Thanks for that,  would most likely go for the Cossor or GEC.


----------



## alvin sawdust

raindownthunda said:


> They are both excellent. Fantastic detail, imaging and timbre. The GEC ST has gotten the most play time as I think they are the most versatile, sounding great with just about every power tube in my BHC. If the GEC ST has more finesse and sweetness with a slight edge on the “magic” euphonic factor, the Cossor has more weight, density and slam while managing to also have great treble. I haven’t had nearly as much listening time with the Cossor but I’ve yet to be disappointed. Both top notch tubes IMO just different flavors. The cossor logo is pretty cool too. I prefer them both over the GEC GT Style with my ears and gear. If I could only own one it would probably be the GEC ST.
> 
> I dont have the fivre GT tubes but have the ST style and also really enjoy them. Not quite as detailed as either GEC or Cossor, but ultra smooth and creamy. My favorite with the Aeolous for blissed-out vocals. One pair I have had a noticeable elevated noise floor/hiss when music isn’t playing while the other pair is silent.


Thank you so much, that's good to hear. May go for a set of both, just have to decide which first 🤔


----------



## triod750

alvin sawdust said:


> https://www.ebay.co.uk/itm/274678650363?_trkparms=amclksrc=ITM&aid=111001&algo=REC.SEED&ao=1&asc=20160908105057&meid=b4f95f6dc445443aaded6a9980165ff9&pid=100675&rk=2&rkt=15&sd=313413940851&itm=274678650363&pmt=0&noa=1&pg=2380057&_trksid=p2380057.c100675.m4236&_trkparms=pageci:549e40d0-459e-11ed-82fa-9a6773729efb|parentrq:ae64ca131830a2436f53d409fff62868|iid:1


I still think that what we see are the screens, no matter what they call it. I have been wrong before...


----------



## robo24

CaptainFantastic said:


> Be careful with those Fivre mesh tubes, as some here (including me) have reported issues with ones sourced from Langrex. I would like to hear from people who bought this tube type from Langrex and had a fully usable pair. Maybe it's just the issues that were reported.


Mine are usable but noisy and in my Glenn I can't use them with higher gain tubes like 6 of the 6BX7. One of my favorites but would love them to be quiet.


----------



## leftside

CaptainFantastic said:


> Be careful with those Fivre mesh tubes, as some here (including me) have reported issues with ones sourced from Langrex. I would like to hear from people who bought this tube type from Langrex and had a fully usable pair. Maybe it's just the issues that were reported.


Fine for me in the amps from Mischa/1101 Audio.


----------



## triod750

What is the difference between CV1067 and CV1932?


----------



## pravous

Sparton 6p5gt. Round plates, dimpled foil getters.  From what little I have been able to find out they were a small Massachusetts company that made tubes and radios.




Show signs of use, not sure what you call it when the getter flashing leaks out above the filament tube.


Tested @ 98% of nos so no complaints.  Dead quiet, excellent separation and imaging.  The only other thing I have noticed is that the mica is chalky? like fivre 6j5gt.  My first 6p5 experiment. If anyone has recomendations for others in the 6p5 family let me know.


----------



## gibosi

pravous said:


> Sparton 6p5gt. Round plates, dimpled foil getters.  From what little I have been able to find out they were a small Massachusetts company that made tubes and radios.
> 
> Show signs of use, not sure what you call it when the getter flashing leaks out above the filament tube.
> Tested @ 98% of nos so no complaints.  Dead quiet, excellent separation and imaging.  The only other thing I have noticed is that the mica is chalky? like fivre 6j5gt.  My first 6p5 experiment. If anyone has recomendations for others in the 6p5 family let me know.



The 6P5G is essentially a type 76 with an octal base rather than the 5-pin UX base. Good tubes.


----------



## triod750

triod750 said:


> What is the difference between CV1067 and CV1932?


I still wonder this. Any suggestions? And don't tell me 865 - I have already done the math...


----------



## LobalWarming

That's one of the beauties of old tubes - lots of wondering between listens. 

The CV1067 and CV1932 are British military designations for 6J5G. http://www.r-type.org/exhib/abi0057.htm

While there can be construction differences between CV1067 and CV1932, probably no different than production differences over time within the same designation. 

Seems to me we sometimes forget that our precious NOS thermionic treasures were once disposable items built to the lowest possible cost. At least from the late 30s onward.


----------



## triod750

Yes, but why create/use a new CV number?


----------



## LobalWarming

triod750 said:


> Yes, but why create/use a new CV number?


You have to ask the British Military of the late 1930s...


----------



## triod750

LobalWarming said:


> You have to ask the British Military of the late 1930s...


Well, I thought that it was what I did, previously....


----------



## g0ldl10n

triod750 said:


> Yes, but why create/use a new CV number?


I am fairly confident that the British Valve Manufacturers Association (BVA) made their tube type numbers in this fashion to purposely make it hard for people to determine the US made equivalent, due to the US made tubes being a lot cheaper back then, to help kill competition.


----------



## triod750

You are not the only one. But with these two - who would benefit?


----------



## Isaacc7

triod750 said:


> Yes, but why create/use a new CV number?


I wonder if it is a similar situation as the 807 and British manufacturers?

http://www.r-type.org/addtext/add029.htm

The Brits had a slew of different designations for 807-ish tubes. For all audio uses they are equivalent to an 807 but in more demanding uses like RF not all of them would do well.


----------



## triod750

But those 807-ish tubes weren't equivalents as it seems, just close. These two 6J5G; http://www.r-type.org/exhib/abi0057.htm and http://www.r-type.org/exhib/abh0170.htm are. Or aren't they? And if they are not - in what way do they differ? This is the reference thread after all...


----------



## gibosi

triod750 said:


> But those 807-ish tubes weren't equivalents as it seems, just close. These two 6J5G; http://www.r-type.org/exhib/abi0057.htm and http://www.r-type.org/exhib/abh0170.htm are. Or aren't they? And if they are not - in what way do they differ? This is the reference thread after all...



The CV1932 is directly equivalent to a 6J5G.

https://www.radiomuseum.org/tubes/tube_cv1932.html

Whereas, the CV1067 can usually replace a 6J5G, but it's slightly different.

https://www.radiomuseum.org/tubes/tube_cv1067.html


----------



## Isaacc7

triod750 said:


> But those 807-ish tubes weren't equivalents as it seems, just close. These two 6J5G; http://www.r-type.org/exhib/abi0057.htm and http://www.r-type.org/exhib/abh0170.htm are. Or aren't they? And if they are not - in what way do they differ? This is the reference thread after all...


Well, they are equivalent for audio. And like those 807 variants I doubt there is a good explanation still around these days. I’m willing to bet the explanation is pretty du


triod750 said:


> But those 807-ish tubes weren't equivalents as it seems, just close. These two 6J5G; http://www.r-type.org/exhib/abi0057.htm and http://www.r-type.org/exhib/abh0170.htm are. Or aren't they? And if they are not - in what way do they differ? This is the reference thread after all...


Those pages both say those tubes are equivalent to the 6j5g. All the different names seem like they were for different divisions of the government.


----------



## CAJames

LobalWarming said:


> You have to ask the British Military of the late 1930s...



Seriously. The same people who gave you flammable and inflammable and they mean the same thing!


----------



## jonathan c

CAJames said:


> Seriously. The same people who gave you flammable and inflammable and they mean the same thing!


So you really need uninflammable !!


----------



## maxpudding

jonathan c said:


> So you really need uninflammable !!


Or non-uninflammable?


----------



## triod750

gibosi said:


> The CV1932 is directly equivalent to a 6J5G.
> 
> https://www.radiomuseum.org/tubes/tube_cv1932.html
> 
> ...


Thanks @gibosi . Unfortunately I can't see in what way they are different but if I could, I would probably not understand it anyway.


----------



## maxpudding

triod750 said:


> Thanks @gibosi . Unfortunately I can't see in what way they are different but if I could, I would probably not understand it anyway.


Probably this could help shed some light:

http://www.r-type.org/static/eqi-ex.htm


----------



## ARCXENOS

I got an amp that has 2 6SN7 driver sockets, I am wondering if I get the 6J5 adapters (that takes 2 tubes each channel), can I mix and match tubes (for example 1 RCA + 1 osram on each channel, matched against each other), or must I strictly get the 6J5 in a quad matched configuration?


----------



## CAJames (Oct 11, 2022)

ARCXENOS said:


> I got an amp that has 2 6SN7 driver sockets, I am wondering if I get the 6J5 adapters (that takes 2 tubes each channel), can I mix and match tubes (for example 1 RCA + 1 osram on each channel, matched against each other), or must I strictly get the 6J5 in a quad matched configuration?



What amp?

In general I'd say sure, no problem. You can even mix e.g. 6J5 and 6C5 if you want. Even "matching" (whatever that means, but that is a whole different discussion) is more a guideline than a rule in my experience.


----------



## ARCXENOS

CAJames said:


> What amp?
> 
> In general I'd say sure, no problem. You can even mix e.g. 6J5 and 6C5 if you want. Even "matching" (whatever that means, but that is a whole different discussion) is more a guideline than a rule in my experience.


The Cayin ha-300b mk2 is my current amp

and thanks for the info, glad I could try out different pairs!


----------



## CAJames

Nice! I just got a 300B amp myself (speakers only) and it uses 4 6SN7s for input and drivers. I'm currently enjoying it with pairs of Type 37 and CV1135 and it sounds fantastic.


----------



## triod750 (Oct 13, 2022)

I have one Brimar branded 6J5GT/G with shiny steel skirt that came in a lot of Brimar branded siblings made by KenRad with corroded skirts. This shiny one has round micas with four pairs of teeth and two small holes that aren't used. It has a clear top and a flash getter below bottom mica. It's a tall bottle tube. I have looked around for photos of similar mica 6J5GT/G and come up empty. And no, I still don't have a camera. Still waiting for my Kodak Instamatic to surface.

Could have added that the plates are flat and ribbed  with two holes (each side) just like the KenRad plates.

Looking again with better lighting I could see a sheet metal 'pill' getter at the bottom of the glass pinch. Previously I only saw the flash.


----------



## triod750

And the micas don't look like these: https://www.ebay.co.uk/itm/28499777...Qawjm0vKdFKpfFC/zuXosPWEA=|tkp:Bk9SR-iWtI77YA


----------



## triod750 (Oct 18, 2022)

These photos are from @leftside and taken from this document: https://docs.google.com/document/d/1BukZ-NuUqh4o_Z2ZOi6KrGavsw5EZNOLSvGa-l5cHLU/edit# I have previously posted a photo of a Philips branded 6J5GT with black plastic bottom marked PHILIPS MADE IN U.S.A. and nothing more, not even 6J5GT.
Well, the innards look exactly like these Raytheon tubes.

Edit. And going back to that post https://www.head-fi.org/threads/the-reference-6j5-thread-l63-6c5-12j5-6p5-etc.934653/post-16665414, I see that some of you found that out already. My RAM strikes again.


----------



## Isaacc7

Going through my tube stash and decided to compare the 14a4 tubes I have against the Sylvania 12j5wgt. I have 14a4 tubes labled Sylvania, International, and Raytheon and they are identical. They are also identical to the Sylvania 12j5wgt except the 14a4 silvering extends down most of the tube. I have every confidence that they will sound the same as the 12j5wgt.


----------



## nwavesailor (Nov 12, 2022)

I will have adapters today allowing me to use 4, 6J5G in an Envy amp.
I already have 4, GEC L63 straight bottle brown base and 4, Visseaux 6J5G to try.

_*EDIT: I forgot I had bought 2 matched pairs of Tung Sol VT-94A that @Xcalibur255 rated at his top pick *_and a quad of Super Silvertone 6P5G's!!!

I am eying 4, GEC 6J5G CV/1067 with smoked glass or Brimar/ STC L63 and wondered if these might be a very different tube and in the same ballpark as the Tung Sol, Visseaux and GEC quads I already own and worth snagging???


----------



## nwavesailor (Nov 13, 2022)

The Visseaux 6J5 sound really good in the Envy. I have only had a couple of hours with some of my favorite tracks but my initial impression is they are quite good and perhaps better than the TSRP 6SN7, TSRP 6F8G and Melz 1578.
 If the TS 6J5 are better than the Visseaux I will be stunned!


----------



## ColSaulTigh

nwavesailor said:


> The Visseaux 6J5 sound really good in the Envy. I have only had a couple of hours with some of my favorite tracks but my initial impression is they are quite good and perhaps better than the TSRP 6SN7, TSRP 6F8G and Melz 1578.
> If the TS 6J5 are better than the Visseaux I will be stunned!


You got me!

I'm in - ordered (4) Zenith 6J5G's and your adapters - should be here in a few weeks.  Now we'll see if I have a new tube type to obsess over....

May the Elrog gods smile upon me!


----------



## leftside

If you all end up liking 6J5 tubes as much as some of us on here, it might be worthwhile thinking about a custom amp that takes 6J5 natively. In the long run you might end up saving money by only having to use 2 tubes instead of 4.


----------



## ColSaulTigh

leftside said:


> If you all end up liking 6J5 tubes as much as some of us on here, it might be worthwhile thinking about a custom amp that takes 6J5 natively. In the long run you might end up saving money by only having to use 2 tubes instead of 4.


Right now, I'm doing this on a lark.  A custom amp is far down the line for me - but who knows what the future holds.


----------



## nwavesailor (Nov 14, 2022)

Are the STC / Brimar 6J5G worth pursuing if I already have TS VT-94A, GEC L63 straight bottle and Visseaux 6J5G?

The Brimar have a B code that may indicate Blackburn production. The GEC have a Z code for Hammersmith production?


----------



## raindownthunda

nwavesailor said:


> Are the STC / Brimar 6J5G worth pursuing if I already have TS VT-94A, GEC L63 straight bottle and Visseaux 6J5G?
> 
> The Brimar have a B code that may indicate Blackburn production. The GEC have a Z code for Hammersmith production?


The Brimar 6J5G and GT are both great tubes. From my experience they have have a thicker/richer sound than the tubes you mentioned. I’d say they and are worth pursuing if you want to mix it up and enjoy emphasized midbass.


----------



## pravous

Brimar 6c5g are worth checking out as well.  Currently enjoying some Ken Rad 6j5gt.  I call this pair old rusty.


----------



## raindownthunda

pravous said:


> Brimar 6c5g are worth checking out as well.  Currently enjoying some Ken Rad 6j5gt.  I call this pair old rusty.


There’s something ultra satisfying about a rusted out pair of tubes that sound glorious. I think we should have an ugly tubes we still love thread.


----------



## nwavesailor

I listened to the Tung Sol VT-94A tonight and it is another great 6J5G. I'll have the GEC L63 (GT shape) soon and try that quad before deciding to get another flavor or stay with the Visseaux, TS and GEC.

If the STC Brimar or GEC smoked glass 6J5G are a bit warmer (?) than the tubes I have tried I may not want a quad of those.


----------



## triod750

pravous said:


> Brimar 6c5g are worth checking out as well.  Currently enjoying some Ken Rad 6j5gt.  I call this pair old rusty.


How did you identify them as Ken-Rad? The left one looks the same as my Brimar branded Ken-Rads but the right one has a different bottom mica, with no slits. Can be Ken-Rad in spite of this, I just wonder. On my tubes - I have several of them - there is codes in white on the glass pinch. Can you see these on your's too?


----------



## whirlwind (Nov 15, 2022)

pravous said:


> Brimar 6c5g are worth checking out as well.  Currently enjoying some Ken Rad 6j5gt.  I call this pair old rusty.


That should sound pretty glorious   

Those old Ken Rad 6J5GT metal base tubes are known for the rusty metal base, not sure why, something in the chemical process I presume.

You can find shiny base ones, but they are a little rare.

I find myself listening to these Arcturus 6J5G's a lot....I believe them to be rebranded RCA, but I could be wrong.

I really think most 6/12 J5 tubes are really nice sounding.
Much easier to find NOS tubes than the 6SN7.

I much like them, even when paired with much less known outputs.

Great with some bluesy stuff.


----------



## JTbbb

Tubes have arrived! Couple of queries? Z = Hammersmith, but I’m struggling with dates. I’m used to the letter codes. Are these 1967? Finally, a couple of getters have chromed the glass, and a couple haven’t. Does this mean the chromed have been powered up, and the other pair not? And how fast do tubes chrome up? Cheers


----------



## whirlwind

I think you are just seeing the getter flash, that is normal.     

Nice tubes, enjoy


----------



## JTbbb

What are the thoughts on these. I think I could use them as a pair?

CV1932, GEC, MILITARY SPEC 6J5G, HAMMERSMITH POSTWAR PRODUCTION​



6J5G, OSRAM, AIR MINISTRY, 10E/348, L63, HAMMERSMITH, GREY GLASS, ETCHED CARTOUCHE, WARTIME PRODUCTION​


----------



## leftside

JTbbb said:


> Tubes have arrived! Couple of queries? Z = Hammersmith, but I’m struggling with dates. I’m used to the letter codes. Are these 1967? Finally, a couple of getters have chromed the glass, and a couple haven’t. Does this mean the chromed have been powered up, and the other pair not? And how fast do tubes chrome up? Cheers


1973. The earlier straight glass have D getters.


----------



## leftside

nwavesailor said:


> I listened to the Tung Sol VT-94A tonight and it is another great 6J5G. I'll have the GEC L63 (GT shape) soon and try that quad before deciding to get another flavor or stay with the Visseaux, TS and GEC.
> 
> If the STC Brimar or GEC smoked glass 6J5G are a bit warmer (?) than the tubes I have tried I may not want a quad of those.


I’m one of the few who don’t really find GEC tubes to be warm, but I do find Brimar to be on the warmer side. Both are definitely worth getting, but it’s going to cost a bit to get 4 of those - especially the grey glass GEC.

To be honest I don’t think I’ve come across a bad 6J5 unless it was on its last legs/testing very low.


----------



## pravous

whirlwind said:


> That should sound pretty glorious
> 
> Those old Ken Rad 6J5GT metal base tubes are known for the rusty metal base, not sure why, something in the chemical process I presume.
> 
> ...


I have one shiny base Ken Rad 6j5gt.  It has round instead of flat ladder plates.  I’ll keep searching for a second.


----------



## triod750

pravous said:


> I have one shiny base Ken Rad 6j5gt.  It has round instead of flat ladder plates.  I’ll keep searching for a second.


A second won't do. You will have to spend days...


----------



## pravous

leftside said:


> I’m one of the few who don’t really find GEC tubes to be warm, but I do find Brimar to be on the warmer side. Both are definitely worth getting, but it’s going to cost a bit to get 4 of those - especially the grey glass GEC.
> 
> To be honest I don’t think I’ve come across a bad 6J5 unless it was on its last legs/testing very low.


The only 6j5s I have ever had a problem with are some noisy metal shell ones.  I agree with the GEC not being warm, I like them best with the Tungsol 5998 in the power slot.  For Gec 6as7g I prefer Fivre 6j5gt or 76.  Same with the 421a.  I really like the Visseaux paired with the Bendix 6080wb or the 7802wb. So many great choices in the 6j5 family.


----------



## nwavesailor (Nov 15, 2022)

Has anyone heard the GEC L63 (GT glass) and compared them to the GEC 6J5G grey glass?
If the grey glass version are significantly different and perhaps better in clarity and detail I may snag a quad.
Thanks!


----------



## triod750

To my ears clarity and detail describes GEC L63 clear GT very well, similar to Siemens C3g in that department.


----------



## nwavesailor (Nov 15, 2022)

I will have the GEC L63 clear GT soon.
Most find the L63 GT version to be  fantastic but, being a tube kook, I am wondering about the GEC ST shape grey glass 6J5G version in comparison.

I know...........I could spend the BIG $$$ and see for myself!


----------



## ColSaulTigh

nwavesailor said:


> I will have the GEC L63 clear GT soon.
> Most find the L63 GT version to be  fantastic but, being a tube kook, I am wondering about the GEC ST shape grey glass 6J5G version in comparison.
> 
> I know...........I could spend the BIG $$$ and see for myself!


You might have some competition if these impress me as much as this thread leads me to believe...I might even part with one of my spare sets of Melz


----------



## nwavesailor

Yup! I've been thinking the same thing..........

I may be in the honeymoon phase and need to revisit the true greats, TSRP 6SN7, TSRP 6F8G and yes the 1558 before letting them go to new homes.


----------



## nwavesailor

ColSaulTigh said:


> You might have some competition if these impress me as much as this thread leads me to believe...I might even part with one of my spare sets of Melz


Great! 
I sure you have seen the almost universal praise of the GEC L63 (GT). It seems like an affordable no brainer. I have one pair and the second in route from Langrex.
With the TS, Visseaux and 2 incoming L63 to have a quad I'm in fairly good shape..............


----------



## leftside

pravous said:


> The only 6j5s I have ever had a problem with are some noisy metal shell ones.  I agree with the GEC not being warm, I like them best with the Tungsol 5998 in the power slot.  For Gec 6as7g I prefer Fivre 6j5gt or 76.  Same with the 421a.  I really like the Visseaux paired with the Bendix 6080wb or the 7802wb. So many great choices in the 6j5 family.


Great combos


----------



## leftside

nwavesailor said:


> Yup! I've been thinking the same thing..........
> 
> I may be in the honeymoon phase and need to revisit the true greats, TSRP 6SN7, TSRP 6F8G and yes the 1558 before letting them go to new homes.


I wouldn't sell those


----------



## leftside (Nov 15, 2022)

nwavesailor said:


> Has anyone heard the GEC L63 (GT glass) and compared them to the GEC 6J5G grey glass?
> If the grey glass version are significantly different and perhaps better in clarity and detail I may snag a quad.
> Thanks!


There's a 20-25 year difference in construction, different materials used, etc, so both are definitely worth getting. I like them both, but have slight preference for the earlier tubes.

Also don't forget the tall grey glass, black base, cup getter tubes that came inbetween the ST grey glass and the GT clear glass. Often these will have a MWT sticker on the glass.  And then there's the metal base 6J5 as well. Earlier have inverted cup getter, later have D getter. Expensive, but significantly cheaper than the metal base B65/6SN7 tube.


----------



## nwavesailor (Nov 15, 2022)

Thanks for your advice and great pics, @leftside!

It's only money and they say ya can't take it with you!!! 
I keep meaning to put some stickers on my tubes of value so they don't wind up at my estate sale for $1


----------



## pravous

On a bit of a Kenrad kick lately.  188-5 means GE tube manufactured in the Kenrad Owensboro factory?  Does that mean it was still the Kenrad design, just under new ownership?  I am guessing it probably is not that simple?   Anyone have good pictures of known Kenrad 6j5g and 76.  It seems at one point the 76 were also produced under the “Crosley” brand.


----------



## nwavesailor (Nov 16, 2022)

I snagged 2 pairs of the GEC grey glass 6J5G / CV1067. 
Unless I go off the deep end for the STC Brimar, I think I'm DONE!

Thanks, @leftside !


----------



## whirlwind

leftside said:


> There's a 20-25 year difference in construction, different materials used, etc, so both are definitely worth getting. I like them both, but have slight preference for the earlier tubes.
> 
> Also don't forget the tall grey glass, black base, cup getter tubes that came inbetween the ST grey glass and the GT clear glass. Often these will have a MWT sticker on the glass.  And then there's the metal base 6J5 as well. Earlier have inverted cup getter, later have D getter. Expensive, but significantly cheaper than the metal base B65/6SN7 tube.



As always, great pics !     








nwavesailor said:


> Yup! I've been thinking the same thing..........
> 
> I may be in the honeymoon phase and need to revisit the true greats, TSRP 6SN7, TSRP 6F8G and yes the 1558 before letting them go to new homes.


I agree with @leftsides advice....I would not get rid of the above mentioned tubes, those are all fantastic sounding tubes, some of the best.
If they are good tubes, they would be hard to replace and very hard to find.


----------



## JTbbb

JTbbb said:


> What are the thoughts on these. I think I could use them as a pair?
> 
> CV1932, GEC, MILITARY SPEC 6J5G, HAMMERSMITH POSTWAR PRODUCTION​
> 
> ...


Hmm, no reply from anyone. I guess it’s because no one is sure if they could go together as a pair? Would it be worth getting them anyway, then keeping my eyes out for matching valves? Is £50 each too much?


----------



## Somatic

ColSaulTigh said:


> You might have some competition if these impress me as much as this thread leads me to believe...I might even part with one of my spare sets of Melz


Dibs on your spares  .. lol


----------



## pravous

JTbbb said:


> Hmm, no reply from anyone. I guess it’s because no one is sure if they could go together as a pair? Would it be worth getting them anyway, then keeping my eyes out for matching valves? Is £50 each too much?


You could look at Langrex and Billington and see what their prices are for the grey glass 6j5g.  The two you listed seem to be from different periods of manufacture.   Still might sound good together but personally I would be hesitant to recommend in case it doesn’t work out.


----------



## Xcalibur255

nwavesailor said:


> I snagged 2 pairs of the GEC grey glass 6J5G / CV1067.
> Unless I go off the deep end for the STC Brimar, I think I'm DONE!
> 
> Thanks, @leftside !


Hopefully you have better luck with that seller than I did.


----------



## leftside

JTbbb said:


> Hmm, no reply from anyone. I guess it’s because no one is sure if they could go together as a pair? Would it be worth getting them anyway, then keeping my eyes out for matching valves? Is £50 each too much?


Could always ask the seller if the tubes have the same construction


----------



## JTbbb

leftside said:


> Could always ask the seller if the tubes have the same construction


Yes done that, but with no reply as yet. Thanks for the advice though.


----------



## gibosi (Nov 16, 2022)

pravous said:


> On a bit of a Kenrad kick lately.  188-5 means GE tube manufactured in the Kenrad Owensboro factory?  Does that mean it was still the Kenrad design, just under new ownership?  I am guessing it probably is not that simple?   Anyone have good pictures of known Kenrad 6j5g and 76.  It seems at one point the 76 were also produced under the “Crosley” brand.



A pair of Ken-Rad Type 76. The date codes, T2 and U2 are warranty dates. That is, T2 indicates that the warranty expired in May, 1943 and U2, June, 1943. Unfortunately, it's not clear how long the warranty period lasted. But I think it is safe to say that these tubes were manufactured in the early 1940's, one month apart. So the taller bottle is about a month older than the shorter bottle. And the wire spacers attached to the top mica can be used to identify Ken-Rad Type 76 from this period. Sorry, I can't help you with the 6J5G. I have avoided diving down that rabbit hole. lol


----------



## pravous

gibosi said:


> A pair of Ken-Rad Type 76. The date codes, T2 and U2 are warranty dates. That is, T2 indicates that the warranty expired in May, 1943 and TU, June, 1943. Unfortunately, it's not clear how long the warranty period lasted. But I think it is safe to say that these tubes were manufactured in the early 1940's, one month apart. So the taller bottle is about a month older than the shorter bottle. And the wire spacers attached to the top mica can be used to identify Ken-Rad Type 76 from this period. Sorry, I can't help you with the 6J5G. I have avoided diving down that rabbit hole. lol



Thanks for the pictures!  I wanted confirmation of the wire spacers, mica and plates before I acquired any of the Kenrad 76.


----------



## pravous

What do the getters look like if you don’t mind me asking?   Most of my 76 have the dimple foil getters.


----------



## gibosi

pravous said:


> What do the getters look like if you don’t mind me asking?   Most of my 76 have the dimple foil getters.



My Ken-Rads also have dimple foil getters.


----------



## pravous

gibosi said:


> My Ken-Rads also have dimple foil getters.


Thanks for the info!


----------



## raindownthunda (Nov 26, 2022)

Enjoying a late night session with these these Motorola 6J5GT that just arrived today. I took out the TS BGRP 6SN7 I've been listening to for the past few weeks and somehow I'm enjoying these more?? Defies logic. More expansive, less congested, great warm tone. Hard to believe these cost about as much to my door as the shipping alone for the 6SN7.

Despite matching boxes, I was surprised to see a number of minor differences in both print and construction. One tube has codes 247 50-44 and the other 322042. Does anyone know who made these and if those are date codes? They both have the same dimpled foil getter.


----------



## nwavesailor

Perhaps just coincidental but a 322 code usually denotes Tung Sol production


----------



## nwavesailor

247 may be National Union


----------



## OctavianH

That's a good resource on that:
https://www.tubemuseum.org/SearchResults.asp?Cat=30


----------



## bcowen (Nov 26, 2022)

raindownthunda said:


> Enjoying a late night session with these these Motorola 6J5GT that just arrived today. I took out the TS BGRP 6SN7 I've been listening to for the past few weeks and somehow I'm enjoying these more?? Defies logic. More expansive, less congested, great warm tone. Hard to believe these cost about as much to my door as the shipping alone for the 6SN7.
> 
> Despite matching boxes, I was surprised to see a number of minor differences in both print and construction. One tube has codes 247 50-44 and the other 322042. Does anyone know who made these and if those are date codes? They both have the same dimpled foil getter.


The codes as @nwavesailor noted are Tung Sol and National Union.  Motorola never made tubes, they just had their brand put on them by other manufacturers so it's highly likely you have a Tung Sol and a National Union.  Would be very interesting to listen to them for a while and get a good handle on the sound and then swap places between them and see if you can detect any difference.  If they have similar emission levels, maybe there's a discernable sonic difference...and maybe not?


----------



## JTbbb

bcowen said:


> The codes as @nwavesailor noted are Tung Sol and National Union.  Motorola never made tubes, they just had their brand put on them by other manufacturers so it's highly likely you have a Tung Sol and a National Union.  Would be very interesting to listen to them for a while and get a good handle on the sound and then swap places between them and see if you can detect any difference.  If they have similar emission levels, maybe there's a discernable sonic difference...and maybe not?


I’ve been amazed how you can mismatch different makes of 6sn7, where one drives each channel, and discern no difference!


----------



## triod750

raindownthunda said:


> Enjoying a late night session with these these Motorola 6J5GT that just arrived today. I took out the TS BGRP 6SN7 I've been listening to for the past few weeks and somehow I'm enjoying these more?? Defies logic. More expansive, less congested, great warm tone. Hard to believe these cost about as much to my door as the shipping alone for the 6SN7.
> 
> Despite matching boxes, I was surprised to see a number of minor differences in both print and construction. One tube has codes 247 50-44 and the other 322042. Does anyone know who made these and if those are date codes? They both have the same dimpled foil getter.


Looks like XT on the glass on the left tube, below 6J5GT. What does that mean? And it isn't a GT/G. Most of mine are. Did they mark them like this later?


----------



## Xcalibur255 (Nov 26, 2022)

bcowen said:


> The codes as @nwavesailor noted are Tung Sol and National Union.  Motorola never made tubes, they just had their brand put on them by other manufacturers so it's highly likely you have a Tung Sol and a National Union.  Would be very interesting to listen to them for a while and get a good handle on the sound and then swap places between them and see if you can detect any difference.  If they have similar emission levels, maybe there's a discernable sonic difference...and maybe not?


It's worth nothing that there have been plenty of verifiable instances of the manufacturer code on the tube not denoting the real manufacturer.  It seems like US tube makers played it fast and loose with these codes.  Being able to see the tubes from more angles would help to confirm, but at first glance both tubes seem to match the Tung-Sol construction details for an early 50's metal base 6J5.  I can see the tube with the NU code has additional heat dissipation fins on it, but details like this come and go on tubes of same brand/make all the time.

There are a number of sleeper 6J5 that are inexpensive but sound awesome and this particular era of TungSol is one of them IMO.


----------



## raindownthunda

Thanks all - super helpful. The plates and getters look identical but there are a bunch of minor internal differences I can spot after staring at these for far too long: top fins, top+bottom mica, straight vs flared bottom supports. Here are a few more pics of the codes/internals:


----------



## Xcalibur255 (Nov 26, 2022)

Those actually are two different plate styles.  The center ribs give it away the most.  I don't think the tube with the yellow print is a Tung Sol after all, but I haven't seen enough NU tubes from this time period to verify for you that the factory code is correct and it is in fact NU.  NU seems the most likely though.  Sylvania and Raytheon 6SN7 from this time period often had mica and plate styles similar to this too, it all kind of blurs together after a while.......

I'd be curious if you can hear a tonal disparity between the left and right channels.  Tung Sol and NU are different enough sounds, but comparing left/right I think is much harder than comparing pairs when rolling.  Your brain does a lot of normalizing and blending of what it gets from your ears.  I guess if it sounds good it is good.


----------



## raindownthunda

Xcalibur255 said:


> Those actually are two different plate styles.  The center ribs give it away the most.  I don't think the tube with the yellow print is a Tung Sol after all, but I haven't seen enough NU tubes from this time period to verify for you that the factory code is correct and it is in fact NU.  NU seems the most likely though.  Sylvania and Raytheon 6SN7 from this time period often had mica and plate styles similar to this too, it all kind of blurs together after a while.......
> 
> I'd be curious if you can hear a tonal disparity between the left and right channels.  Tung Sol and NU are different enough sounds, but comparing left/right I think is much harder than comparing pairs when rolling.  Your brain does a lot of normalizing and blending of what it gets from your ears.  I guess if it sounds good it is good.


Oh wow - have to admit I missed the subtle difference in the plates. My mere-mortal ears can't discern any obvious difference between tone L/R channels. 

Digging through my stash searching for answers has gotten me even more confused. Time to shut off the analytical brain and get back to the music 

From L->R: Tung-Sol, Ken-Rad, Ken-Rad


----------



## Xcalibur255

I have found the small rectangular bottom mica with the little notch outs on the corners to be a good identifier for the Tung Sol 6J5, and the plate style seems to stay consistent across a number of years too.  The other can of worms is harder to help with.  Something I've been unable to confirm is if these KenRad 6J5 are actually made by KenRad, because I bought a pair and to my ears they didn't have the KenRad house sound.  The older NU tubes with the round plates definitely have the NU house sound, but NU was probably getting out of making these by the early 50's so it's hard to say whether the metal base tubes are made by NU or a rebrand.  By this point the KenRad assets would have been owned by GE too and who knows what difference that makes?

IMO Tung Sol and Sylvania 6J5 are easy to positively ID, once you get into the other brands it becomes more of a crap shoot.  Raytheon has been especially fun, they seem to have half a dozen different styles with their name on them all within a short time period.


----------



## Marutks (Nov 26, 2022)

mordy said:


> The tube world is full of surprises. Here is a GE metal 6N7 pair from the 50's that sound excellent.



I have a pair of 6N7 GE tall metal tubes.   They work in the BlueHalo amp without adapters.

I am listening to  on my Atriums 👍


----------



## mordy

Marutks said:


> I have a pair of 6N7 GE tall metal tubes.   They work in the BlueHalo amp without adapters.
> 
> I am listening to  on my Atriums 👍



Do you think that these tubes were manufactured in 1972 or 1978?
My theory is that there were large stocks left over from the 50s and the tubes were just relabeled.
It would be remarkable for a tube to be in production from the late 30s to the 70s - over 40 years!
As far as I know the all metal tubes were abandoned because glass tubes were cheaper to make.


----------



## triod750

mordy said:


> As far as I know the all metal tubes were abandoned because glass tubes were cheaper to make.


Reminds me of what I read about Philips company. It was organized in different technical departments and two of them had a disagreement about the best way to design a special tube. There was a meeting where the head of the company attended an he listened to the technical arguments from both sides and then asked "which of these is cheapest to manufacture"? "There you have your answer". He picked up his hat and left.


----------



## LobalWarming

Indeed. In the late 40s the development of the kiddie's tubes (miniature novals) was another cost down revolution. 

We 21st century tube hoarders collectors forget that vacuum tubes were once considered cheap throw-away commodity items, not museum quality 'holy grail' artifacts to over-pay for.


----------



## mordy (Nov 27, 2022)

LobalWarming said:


> Indeed. In the late 40s the development of the kiddie's tubes (miniature novals) was another cost down revolution.
> 
> We 21st century tube hoarders collectors forget that vacuum tubes were once considered cheap throw-away commodity items, not museum quality 'holy grail' artifacts to over-pay for.


I am not so sure that all tubes were that cheap way back then. I have some boxes with price markings and on some Mullard 9pin tubes it says 13 shilling. That would translate to around $2,20 today(?) but it is very difficult to get an idea of the real buying power of currencies way back then - in the 1940s the average British annual salary was 3700 shilling.
The Siemens C3g tubes for long distance transatlantic phone calls were priced at approximately 200 DM around 1960 which would translate to around $800 today.
- Not sure if the above calculations are correct; maybe somebody else can chime in.

OK - found a video of a guy who has a Tung Sol 1965 price list. Here I am going to list a couple of tubes with the 1965 price and then show that price converted into today's 2022 dollars.
12AX7  $2.55              $24.12
12SN7  $2.70              $25.54
6SN7    $2.60              $24.60
6N7      $5.40              $51.09
6BX7    $5.55              $52.51
6550    $6.90              $65.28
6AS7    $6.95              $65.75

Definitively some discrepancies in the list - maybe some older tubes were in short supply and were priced higher. In any case, maybe we shouldn't complain so much about today's tube prices, at least in some cases? It seems to me that some re-issues are cheaper than what's listed here.
This is a retail price list and we don't know what the wholesale prices were, special deals etc.
But a little food for thought...


----------



## Isaacc7

mordy said:


> I am not so sure that all tubes were that cheap way back then. I have some boxes with price markings and on some Mullard 9pin tubes it says 13 shilling. That would translate to around $2,20 today(?) but it is very difficult to get an idea of the real buying power of currencies way back then - in the 1940s the average British annual salary was 3700 shilling.
> The Siemens C3g tubes for long distance transatlantic phone calls were priced at approximately 200 DM around 1960 which would translate to around $800 today.
> - Not sure if the above calculations are correct; maybe somebody else can chime in.
> 
> ...



I’m sure that both the 6as7 and the C3g tubes were government prices. The 6as7 was really only used as a pass element of a voltage regulator. Not sure how many consumer devices needed that but I do know that the government/military ordered them by the millions both for current usage and for spares. Not sure when people started using them for audio, probably when OTLs were being experimented with. The 6bx7 and 6n7 prices surprise me. Think both were used in TVs. In any case, they have certainly come down in price quite a bit!


----------



## LobalWarming

Isaacc7 said:


> I’m sure that both the 6as7 and the C3g tubes were government prices. The 6as7 was really only used as a pass element of a voltage regulator. Not sure how many consumer devices needed that but I do know that the government/military ordered them by the millions both for current usage and for spares. Not sure when people started using them for audio, probably when OTLs were being experimented with. The 6bx7 and 6n7 prices surprise me. Think both were used in TVs. In any case, they have certainly come down in price quite a bit!


I grew up around broadcasting... while designed for TV, 6BX7/6BL7s were used in audio broadcast boards, like McCurdy - as well as 6C5/6J5 and EF86s. Recall seeing cases of them in the dark basements of radio/tv stations. They didn't pay retail - not anywhere near it. 

And neither did we when dumpster diving at the end of the tube board era.


----------



## Marutks

Slade01 said:


> I'll throw crazy into the mix.  take a look at these tubes below.  I'm guessing these are ken rads for sure.



I have a pair of 6J5 Kenrads with painted bases.


----------



## triod750 (Nov 28, 2022)

I can almost see the code inside, on the glass pinch. I have a pair of these that sound different from the others I have. They look the same inside, only the metal skirt is different. One of them has the code W17 and the other W41. They are both marked 'Distributed by BRIMAR'. The others only say 'BRIMAR'.


----------



## triod750

If W is supposed to mean week, I wonder what A on others is supposed to mean.


----------



## Marutks

my tubes have codes C41 and D32


----------



## triod750

Marutks said:


> my tubes have codes C41 and D32


Too far apart - you've got to toss them   . They must make you feeling weird...?


----------



## Marutks

haha,  no,  they sound excellent to me.


----------



## mordy

Marutks said:


> I have a pair of 6J5 Kenrads with painted bases.


Are these tubes unusually heavy? There were some with lead bases I assume for less microphonics


----------



## ColSaulTigh

Things are starting to get a bit crowded in the ol' Woo Audio WA5-LE...

My adapters finally arrived, and seem to be working just fine.  Tubes are Zenith 6J5G.  Looking forward to this new experiment!


----------



## JTbbb

ColSaulTigh said:


> Things are starting to get a bit crowded in the ol' Woo Audio WA5-LE...
> 
> My adapters finally arrived, and seem to be working just fine.  Tubes are Zenith 6J5G.  Looking forward to this new experiment!


I have adapters imminent, along with a quad of Brimar 6J5G’s. And a quad of GEC L63’s waiting. Looking forward to trying them in Envy, plus I can use both in my Crack.


----------



## ColSaulTigh

JTbbb said:


> I have adapters imminent, along with a quad of Brimar 6J5G’s. And a quad of GEC L63’s waiting. Looking forward to trying them in Envy, plus I can use both in my Crack.


Where are you finding your tubes?  Ebay is getting a bit sparse.


----------



## Marutks

mordy said:


> Are these tubes unusually heavy? There were some with lead bases I assume for less microphonics



They seem to be heavier than other tubes.   Although I am not sure if it is because of lead base or just thick metal base.


----------



## nwavesailor

Langrex still has pretty good stock.

Tube World $$$$ but they are as advertised !


----------



## JTbbb

ColSaulTigh said:


> Where are you finding your tubes?  Ebay is getting a bit sparse.


GEC’s we’re from LANGREX and Brimars from a friend.


----------



## ColSaulTigh

Thanks!  Looks like it's off to Langrex I go with what's left of my wallet...


----------



## ColSaulTigh

Anybody ever deal with "Vintage Electronics"?


----------



## JTbbb (Nov 28, 2022)

ColSaulTigh said:


> Anybody ever deal with "Vintage Electronics"?


Yes. I have bought valves from them. Top money, but top valves.

 I presume you mean the uk company?


----------



## nwavesailor

Nice!
‘Top $$$ top valves’ is how I’d describe Tube World too.


----------



## Isaacc7

JTbbb said:


> Yes. I have bought valves from them. Top money, but top valves.
> 
> I presume you mean the uk company?


Interestingly, they had the best prices I had seen on the Cossor 807 tubes. Haven’t checked recently but they were cheaper than Billington’s “wholesale” price and of course much less than eBay.


----------



## whirlwind

I have never been disappointed with my experience with Langrex, I always received very nice tubes.


----------



## nwavesailor

whirlwind said:


> I have never been disappointed with my experience with Langrex, I always received very nice tubes.


+1


----------



## ColSaulTigh

JTbbb said:


> Yes. I have bought valves from them. Top money, but top valves.
> 
> I presume you mean the uk company?


Correct.


----------



## pravous

Finally found a matching Tung Sol 76. Construction and sound very close to the 37 but no background noise.  The TS 6j5g/vt-94a has so far eluded me but if the sound is similar I can see why they are so highly spoken of.


----------



## pravous

ColSaulTigh said:


> Things are starting to get a bit crowded in the ol' Woo Audio WA5-LE...
> 
> My adapters finally arrived, and seem to be working just fine.  Tubes are Zenith 6J5G.  Looking forward to this new experiment!



Zenith 6j5g are one of my guilty pleasures.  I got my pair cheap and they are my default inputs in my Bottlehead crack in my shop.  I believe they were manufactured by Sylvania and rebranded Zenith?


----------



## ColSaulTigh

pravous said:


> Zenith 6j5g are one of my guilty pleasures.  I got my pair cheap and they are my default inputs in my Bottlehead crack in my shop.  I believe they were manufactured by Sylvania and rebranded Zenith?


Not sure -- my first jump into the 6J5's, I've still got some research to do.


----------



## analogTubeSound

Having some 6J5 Fun... Yes i realize the kenrads are not absolutely identical but i am using them as a pair none the less.


----------



## nwavesailor

ColSaulTigh said:


> Thanks!  Looks like it's off to Langrex I go with what's left of my wallet...


Snag any L63 / 6J5G from Langrex?


----------



## Xcalibur255

pravous said:


> Zenith 6j5g are one of my guilty pleasures.  I got my pair cheap and they are my default inputs in my Bottlehead crack in my shop.  I believe they were manufactured by Sylvania and rebranded Zenith?


Quite a few are, I would say the majority in the case of the coke bottle tubes, but not all.  Some of them are Raytheons, and the late 30's Sylvania and Raytheon 6J5 tubes are pretty much on opposite ends of the spectrum from each other in terms of sound so it might be good to watch out for mis-matched pairs here.  I've seen quite a few that are too, it's easy to tell by looking at the top mica support.  The Raytheon are cross shaped and the Sylvania are rectangular with rounded ends and are held against the glass with a pair of thin steel tension wires.


----------



## triod750

analogTubeSound said:


> Having some 6J5 Fun... Yes i realize the kenrads are not absolutely identical but i am using them as a pair none the less.


The left tube there, Crosley Ken Rad, is the first where I have seen the typical notches in the top mica. On all I have handled they are in the bottom mica. Interesting. Early Monday morning at the factory?


----------



## whirlwind

All of my Ken Rad 6/12J5GT's have the notches in the bottom mica also.


----------



## triod750

And we saw, a while ago, one tube supposed to be Ken-Rad, without any notches at all. The other one in the photo had them in bottom mica as usual. https://www.head-fi.org/threads/the-reference-6j5-thread-l63-6c5-12j5-6p5-etc.934653/post-17243921


----------



## ARCXENOS

Hi gents, I have been using my quad GEC L63 for sometime, I quite enjoy them but the itch to get more tube pairs is real and well, since I already bought the converter....

I am wondering if its ok to mix a 6J5WGT with a regular 6J5G as a mix of a 6SN7 substitution? I think there were different characteristics between the 2 classes, would there be issues?


----------



## Xcalibur255

Perfectly safe to mix a 6J5WGT and a 6J5G together, they are electrically identical.  It's not OK to run one 6J5 and one 6SN7 in the adapter though, just in case that's what you're asking here.  The pin connections are different.


----------



## nwavesailor

I need to thank @Xcalibur255 for suggesting that the GEC L-63 6J5GT and GEC 6J5G / CV1067 may sound different and worth pursuing.  Both are Hammersmith production and I like them both but favor the earlier ST version with the grey glass. Well worth the cost.


----------



## ARCXENOS

Xcalibur255 said:


> Perfectly safe to mix a 6J5WGT and a 6J5G together, they are electrically identical.  It's not OK to run one 6J5 and one 6SN7 in the adapter though, just in case that's what you're asking here.  The pin connections are different.


That was what I was asking, thank you.

Gonna be interesting to try the 6J5WGTs out!


----------



## ARCXENOS (Nov 30, 2022)

Its not the WGT stuff I am getting from the surplus store, but I chanced upon a quad from my local dealer at a low price, are these white labels? Will be getting a couple of other 6j5gs to mix and match for fun
,


----------



## nwavesailor (Nov 30, 2022)

We'd all love to find a 'surplus' store like that one.
I  look forward to your thoughts compared to the GEC. I have both and lean towards one.


----------



## Xcalibur255 (Nov 30, 2022)

ARCXENOS said:


> Its not the WGT stuff I am getting from the surplus store, but I chanced upon a quad from my local dealer at a low price, are these white labels? Will be getting a couple of other 6j5gs to mix and match for fun
> ,


This is the tube that nobody seems to be able to identify with any certainly.  You commonly see this labeled as Raytheon with the British 10E markings on them, and they've also appeared as Philcos, Brimars, Ken-Rads and now these Tung Sols.  Everybody who's gotten a pair says they sound great but their true manufacturing origins is a mystery.  There seem to be a lot of them in Europe and they're commonly found with European tube sellers.

My personal theory is that Raytheon is the actual manufacturer and that they had two distinct production lines for their 6J5 tubes tubes, a regular line that produced the cross shaped mica tubes for private industry and automotive, and these which were intended primarily for military contract fulfillment.  If you compare the plates on this tube to the Raytheon 6J5WGT metal base with the brown bottom cap the plates themselves are identical, the top mica structure has changed to accommodate the new smaller glass bulb.


----------



## pravous

Xcalibur255 said:


> Quite a few are, I would say the majority in the case of the coke bottle tubes, but not all.  Some of them are Raytheons, and the late 30's Sylvania and Raytheon 6J5 tubes are pretty much on opposite ends of the spectrum from each other in terms of sound so it might be good to watch out for mis-matched pairs here.  I've seen quite a few that are too, it's easy to tell by looking at the top mica support.  The Raytheon are cross shaped and the Sylvania are rectangular with rounded ends and are held against the glass with a pair of thin steel tension wires.


My pair are the rounded end rectangular mica.  Is the cross shape top mica an indicator of Raytheon manufacture?   I have seen pictures in this thread of coke bottle 6j5g under the “wizard” brand with that distinctive cross shaped mica.


----------



## gibosi

pravous said:


> My pair are the rounded end rectangular mica.  Is the cross shape top mica an indicator of Raytheon manufacture?   I have seen pictures in this thread of coke bottle 6j5g under the “wizard” brand with that distinctive cross shaped mica.



For what it's worth, I have Raytheon 76 from the mid 1930's and they have cross-shaped top mica.


----------



## g0ldl10n

Xcalibur255 said:


> This is the tube that nobody seems to be able to identify with any certainly.  You commonly see this labeled as Raytheon with the British 10E markings on them, and they've also appeared as Philcos, Brimars, Ken-Rads and now these Tung Sols.  Everybody who's gotten a pair says they sound great but their true manufacturing origins is a mystery.  There seem to be a lot of them in Europe and they're commonly found with European tube sellers.
> 
> My personal theory is that Raytheon is the actual manufacturer and that they had two distinct production lines for their 6J5 tubes tubes, a regular line that produced the cross shaped mica tubes for private industry and automotive, and these which were intended primarily for military contract fulfillment.  If you compare the plates on this tube to the Raytheon 6J5WGT metal base with the brown bottom cap the plates themselves are identical, the top mica structure has changed to accommodate the new smaller glass bulb.


I may be wayyyyy off base here, but the top structure of this tube looks very very similar to the type of structure RCA used in one of their 6G6G designs. Idk, just food for thought I suppose, as the 6G6G is a pentode, and 6J5 obviously triode. Just thought it looks similar enough that there's a possibility RCA was the manufacturer, and used a similar design here.


----------



## Tom-s (Dec 1, 2022)

Yes. The cross top mica is a remnant of the 1930’s Raytheon four pillar series tubes.

Also selling their tubes to third parties was common for Raytheon.
See this post by Mordy and my reply below.

https://www.head-fi.org/threads/the...c5-12j5-6p5-etc.934653/page-107#post-16474871


I applaud to @Xcalibur255 as he’s totally right about these Tung Sol being Raytheon tubes from the ‘40s. More rebranding going on.
Here’s more posts on this discussion.

https://www.head-fi.org/threads/the...6c5-12j5-6p5-etc.934653/page-92#post-16294978

Edit. Forgot an important part! Do look closely at the anode shape for both 1930’s and 1940s tubes discussed here. It will reveal the same form / press was used.

Edit:
Here’s some 6J5s anode plate details all Raytheon. Only one of these three is branded Raytheon. 
Four pillar carbon non branded; WWII era carbon black VR67 Raytheon, 1948 shiny and more broad labeled as GEC L63 but a Raytheon.


----------



## ARCXENOS (Dec 1, 2022)

I found the tungsol-theons a little bit too aggressive sound for my tastes, I think it doesn't meshes well with the elrog er300b

I would be using my GECs now but it appears my right channel converter is somehow dead after removal of the tungsol-theons  . Not really a brightside since I didn't expect anything to be gone today, but at least I managed to confirm the L63s are all safe with the left channel. phew, guess I only need to replace 1 converter than the precious gecs.


----------



## ColSaulTigh

LOL, so thanks to Ambien, I'm now the proud owner of *7* pairs of NOS NIB JAN-CKR 6J5GT/G VT-94D KEN-RAD tubes!

Apparently I submitted two offeres on two separate auctions, and both were accepted.  So I imagine I'll have some extras for sale here shortly...


----------



## triod750

ARCXENOS said:


> I found the tungsol-theons a little bit too aggressive sound for my tastes, I think it doesn't meshes well with the elrog er300b
> 
> I would be using my GECs now but it appears my right channel converter is somehow dead after removal of the tungsol-theons  . Not really a brightside since I didn't expect anything to be gone today, but at least I managed to confirm the L63s are all safe with the left channel. phew, guess I only need to replace 1 converter than the precious gecs.


In order to protect tubes an sockets I always use a screwdriver to separate them, wiggling it a little at a time on opposite sides. It's worth the trouble.


----------



## Xcalibur255

Tom-s said:


> Yes. The cross top mica is a remnant of the 1930’s Raytheon four pillar series tubes.
> 
> Also selling their tubes to third parties was common for Raytheon.
> See this post by Mordy and my reply below.
> ...


That last photo with the "Made in England" markings is the part that is probably most misleading for many people.  It's understandable that country of origin markings were probably pretty loose during WWII but it IS a country of origin marking and you should be able to trust it.


----------



## Xcalibur255

ARCXENOS said:


> I found the tungsol-theons a little bit too aggressive sound for my tastes, I think it doesn't meshes well with the elrog er300b
> 
> I would be using my GECs now but it appears my right channel converter is somehow dead after removal of the tungsol-theons  . Not really a brightside since I didn't expect anything to be gone today, but at least I managed to confirm the L63s are all safe with the left channel. phew, guess I only need to replace 1 converter than the precious gecs.


If they were NOS testing them give them some more time.  These settle down a lot over the course of 50 hours or so.  My WGTs went from being one of the brightest sounding 6J5 in my collection to being the most mellow up top as they settled in.  They're actually a little too mellow now for the headphones I'm using, but the synergy with my Omega speakers was sublime.


----------



## nwavesailor

ColSaulTigh said:


> LOL, so thanks to Ambien, I'm now the proud owner of *7* pairs of NOS NIB JAN-CKR 6J5GT/G VT-94D KEN-RAD tubes!
> 
> Apparently I submitted two offeres on two separate auctions, and both were accepted.  So I imagine I'll have some extras for sale here shortly...


Good thing the Ambi induced bids were on 14 inexpensive tubes. It could have been for 7 MO pairs!


----------



## ARCXENOS

Xcalibur255 said:


> If they were NOS testing them give them some more time.  These settle down a lot over the course of 50 hours or so.  My WGTs went from being one of the brightest sounding 6J5 in my collection to being the most mellow up top as they settled in.  They're actually a little too mellow now for the headphones I'm using, but the synergy with my Omega speakers was sublime.



Will definitely run them more, whenever I sort my converter issue out.

Another unlucky incident for me, the surplus store ran out of WGTs! Might be a blessing, as I was eyeing some cv1934 too, but 9 dollars per WGT was too good to be true (and readily in stock)


----------



## ColSaulTigh

nwavesailor said:


> Good thing the Ambi induced bids were on 14 inexpensive tubes. It could have been for 7 MO pairs!


I've had someone like that happen.  Bought a custom art knife collection for around $6k.  Had no idea until they showed up a few days later...lol!


----------



## nwavesailor

🤪


----------



## leftside

Xcalibur255 said:


> That last photo with the "Made in England" markings is the part that is probably most misleading for many people.  It's understandable that country of origin markings were probably pretty loose during WWII but it IS a country of origin marking and you should be able to trust it.


The marking was made in England


----------



## leftside

Tom-s said:


> Yes. The cross top mica is a remnant of the 1930’s Raytheon four pillar series tubes.
> 
> Also selling their tubes to third parties was common for Raytheon.
> See this post by Mordy and my reply below.
> ...


Some good info there. I've been wondering if some of my "Marconi" 6J5G were in fact another brand.


----------



## nwavesailor (Dec 8, 2022)

I have been wondering why my Langrex order stalled out 7 days ago in Langley UK after clearing for shipment.
I'll guess it is the Royal Mail strike days planned for December!

_EDIT: My Langrex shipment of STC Brimar have finally arrived in LA so I should have them in a few days_


----------



## ColSaulTigh

So the UPS Fairy showed up today with my latest Ambien purchase...


----------



## triod750

These are pretty good with some tubes. I have bought them, branded Brimar, for less than $4 without boxes. They were spare parts for a cinema and the box contained 50 pieces. Not all of them were still there...


----------



## LobalWarming

ColSaulTigh said:


> So the UPS Fairy showed up today with my latest Ambien purchase...


Very nice... but oh man... what sort of pricey dental work do you have you put under the pillow for the UPS fairy to stop by?


----------



## ColSaulTigh

LobalWarming said:


> Very nice... but oh man... what sort of pricey dental work do you have you put under the pillow for the UPS fairy to stop by?


I steal dentures from the local Old Folks Home.


----------



## JTbbb

Adapters are on the way! Wartime & just post war time, Hammersmith.


----------



## nwavesailor

I think you will really like these Hammersmith production valves in your Envy w/ Elrogs


----------



## g0ldl10n

JTbbb said:


> Adapters are on the way! Wartime & just post war time, Hammersmith.


I have some Marconi Hammersmith beam tetrodes that I strap as triodes that sound spectacular. I really appreciate the SQ from European tubes, and all Marconis that ive heard have sounded very, very good! 

I bet these are gonna sound great, nice pick up!


----------



## JTbbb

nwavesailor said:


> I think you will really like these Hammersmith production valves in your Envy w/ Elrogs


All bought separately and with identical internals. Can’t wait to try them. In my modded Crack too!


----------



## nwavesailor (Dec 10, 2022)

You are wise, patient and no doubt saved a ton of $$$ as well as insuring that these are pretty much the same tube!
I do not have your patience and bought quads and pairs of the 1950's Hammersmith 6J5G. 
Not cheap but all tested as advertised and sound fantastic.




they


----------



## JTbbb (Dec 10, 2022)

nwavesailor said:


> You are wise, patient and no doubt saved a ton of $$$ as well as insuring that these are pretty much the same tube!
> I do not have your patience and bought quads and pairs of the 1950's Hammersmith 6J5G.
> Not cheap but all tested as advertised and sound fantastic.
> 
> ...


I paid £50 each for three of them and £60 for the Marconi. Probably somewhere near market value I guess!

Edit: yours look superb!


----------



## CaptainFantastic

JTbbb said:


> I paid £50 each for three of them and £60 for the Marconi. Probably somewhere near market value I guess!
> 
> Edit: yours look superb!



You are lucky being in the UK in this respect. It seems like all sellers of these tubes are in the UK, which makes sense since that's where they were produced. But I remember hating seeing these good deals and then paying another 25-30 euros for the import fees.


----------



## nwavesailor (Dec 16, 2022)

A new favorite 6J5G, STC Brimar. As strong testing as any quad of 6J5G I have ever bought.



Very detailed and not what you may tend to think of with some 'polite' British tubes. @Xcalibur255 was right on the mark with his take on this version.
It's right up there with the TS and GEC and Visseaux ST's


----------



## LobalWarming

Yes, those STC/Brimars are beauties... picked up a pair a few years ago and they're still in my Top 5 - with the other dozen 6J5s - it's so crowded at the top.


----------



## leftside

nwavesailor said:


> A new favorite 6J5G, STC Brimar. As strong testing as any quad of 6J5G I have ever bought.
> 
> 
> 
> ...


Agreed. Slightly warmer I find. 'D' or 'O' getter? No difference in sound between the earlier and later in my setup tho. Langrex had a whole bunch for sale not so long ago. I daren't go onto their site to check


----------



## whirlwind

leftside said:


> Agreed.  I daren't go onto their site to check


LOL!


----------



## ARCXENOS (Dec 17, 2022)

Gents, may I pick your brains for these





vs





I have a quad of the 2nd one, I believe the top one will sound different as there are differences in the construction, but there are some similarities that makes me think they might sound same-ish. Any experience with these? FWIW I really love the quad that I have, just don't want more of the same

Or should I look at some other pair/quads to diversify


----------



## raindownthunda (Dec 17, 2022)

ARCXENOS said:


> Gents, may I pick your brains for these
> 
> 
> 
> ...


the first two tubes are the Brimar 6J5G (both made by Brimar despite the GEC logo). You can tell by the oval plate and hole the mica (edit: without the metal straps the GEC L63 ST has). these were just being discussed a few posts back. They will definitely sound different than the straight tube GEC L63 at the bottom. I think the Brimar’s are warmer and thicker maybe with more decay while still being very detailed. Both top tier tubes IMO.


----------



## TLO

raindownthunda said:


> the first two tubes are the Brimar 6J5G (both made by Brimar despite the GEC logo). You can tell by the oval plate and hole the mica. these were just being discussed a few posts back. They will definitely sound different than the straight tube GEC L63 at the bottom. I think the Brimar’s are warmer and thicker maybe with more decay while still being very detailed. Both top tier tubes IMO.


Could anyone please verify if the second and third pic are indeed Brimar? I will be very interested to know as I always thought that the 2 big round holes on the top mica is the trademark that we always see in GEC / Marconi tubes.


----------



## raindownthunda

TLO said:


> Could anyone please verify if the second and third pic are indeed Brimar? I will be very interested to know as I always thought that the 2 big round holes on the top mica is the trademark that we always see in GEC / Marconi tubes.


Good call, GEC L63 ST shape also has holes. The oval plates are the biggest give away as GEC are flat. As far as I know the GEC will also had two metal straps on the top In addition to the holes.

(not my photos)
GEC:




Brimar:


----------



## OctavianH

I can add 2 photos for those interested:

1) my pair of GEC L63 grey glass bought from Langrex:





2) a pair of Brimar CV1932 I bought from another source:





In my opinion the one labelled GEC in the posts above is actually Brimar.


----------



## TLO

OctavianH said:


> I can add 2 photos for those interested:
> 
> 1) my pair of GEC L63 grey glass bought from Langrex:
> 
> ...


Hmm...perhaps the small rings for the supporting rods in the Brimar is a give away. I only see these small rings in mostly Brimar tubes and perhaps some Mullard like the Mullard EL32.


----------



## Xcalibur255

The plate itself is a good giveaway for Brimar because of the uncommonly wide width, with the wire supports bracing the top mica being a final feature that can confirm because none of the Marconi tubes used this style of support for their top mica.  There are other details you can use too, but these two will let you ID the tube at a glance.


----------



## ARCXENOS

Thank you all for the informative posts, I have never owned anything from Brimar before so I guess this is a great starting point!


----------



## TLO

Xcalibur255 said:


> The plate itself is a good giveaway for Brimar because of the uncommonly wide width, with the wire supports bracing the top mica being a final feature that can confirm because none of the Marconi tubes used this style of support for their top mica.  There are other details you can use too, but these two will let you ID the tube at a glance.





OctavianH said:


> I can add 2 photos for those interested:
> 
> 1) my pair of GEC L63 grey glass bought from Langrex:
> 
> ...





raindownthunda said:


> Good call, GEC L63 ST shape also has holes. The oval plates are the biggest give away as GEC are flat. As far as I know the GEC will also had two metal straps on the top In addition to the holes.
> 
> (not my photos)
> GEC:
> ...


Thank you for the enlightenment....


----------



## leftside (Dec 18, 2022)

OctavianH said:


> I can add 2 photos for those interested:
> 
> 1) my pair of GEC L63 grey glass bought from Langrex:
> 
> ...


What makes you believe the first pictures are Brimar? I believe those to be very early 1948 GEC 6J5 with the holes in the micas parallel and opposite to each other and with the metal straps as pointed out by @raindownthunda

Both of those pairs of tubes you have are pretty rare.


----------



## YungOmbat

chrisdrop said:


> *"New logo" RCA CV1932 *
> 
> Radio Museum seems to denote CV1932 as = 6J5*G* but clearly this one is not a shoulder-type glass tube.
> 
> ...


those are the most intersting tubes ive ever seen, looks like a capacitor


----------



## nwavesailor

The black painted metal can 6J5's would have to be sound pretty darn spectacular for me to use. 
I find part of the experience of using tubes is the visual of the ST glass envelope and yes, the glow. 
There is NO glow in the grey or black smoked 6J5G (yes, an inconsistency in my thinking) but they still look very nice!


----------



## maxpudding

YungOmbat said:


> those are the most intersting tubes ive ever seen, looks like a capacitor



These metal tubes mostly sound amazing too, the uglier they look (especially rusty ones), the better they sound 😆


----------



## jonathan c

nwavesailor said:


> The black painted metal can 6J5's would have to be sound pretty darn spectacular for me to use.
> I find part of the experience of using tubes is the visual of the ST glass envelope and yes, the glow.
> There is NO glow in the grey or black smoked 6J5G (yes, an inconsistency in my thinking) but they still look very nice!


Head straight for Ken-Rad 6C5 and 6J5 metals! Fantastic! A pair on a @Deyan adapter in lieu of a 6SN7 in Schiit Lyr 3: even more fantastic!


----------



## nwavesailor

Yeah, I get that the sound is paramount but personally I gotta have a nice visual as well. 

4 metal cans would not do it for me 

 Here is tonight's GEC's


----------



## OctavianH

leftside said:


> What makes you believe the first pictures are Brimar?


I was referring to the ones presented here, sorry for confusion.


----------



## g0ldl10n

nwavesailor said:


> Yeah, I get that the sound is paramount but personally I gotta have a nice visual as well.
> 
> 4 metal cans would not do it for me
> 
> Here is tonight's GEC's


What amp is this? It is very nice looking!


----------



## nwavesailor (Dec 18, 2022)

Thanks
It is a Feliks Envy


----------



## Xcalibur255

The metal can tubes can actually sound better because the can provides EMI/RFI shielding.  The only reason I'm not a fan is because you cannot verify that both tubes have the same construction.  If you get ones that have the same date/lot code though then I wouldn't hesitate to buy them as they'll probably sound nice.


----------



## ARCXENOS

Xcalibur255 said:


> The metal can tubes can actually sound better because the can provides EMI/RFI shielding.  The only reason I'm not a fan is because you cannot verify that both tubes have the same construction.  If you get ones that have the same date/lot code though then I wouldn't hesitate to buy them as they'll probably sound nice.



Their individual prices seem rather fair, but I guess getting the same factory batch might be a challenge.... maybe another thing on the checklist

6J5MG variants also look pretty cool, but commands a higher price, a shiny metal premium tax or do they sound as much as the entry fee?!


----------



## maxpudding

ARCXENOS said:


> Their individual prices seem rather fair, but I guess getting the same factory batch might be a challenge.... maybe another thing on the checklist
> 
> 6J5MG variants also look pretty cool, but commands a higher price, a shiny metal premium tax or do they sound as much as the entry fee?!


The 6J5MGs for me can produce a better overall “soundstage” than the 6J5 metal cans. I bought a few of them a couple of years ago when they are cheaper. Not as good as the GECs or the Tung Sols, but they have their own flavor. YMMV though.


----------



## Xcalibur255

ARCXENOS said:


> Their individual prices seem rather fair, but I guess getting the same factory batch might be a challenge.... maybe another thing on the checklist


It's not as tough as you might think, they do pop up from time to time.


----------



## bcowen

jonathan c said:


> Head straight for Ken-Rad 6C5 and 6J5 metals! Fantastic! A pair on a @Deyan adapter in lieu of a 6SN7 in Schiit Lyr 3: even more fantastic!


Just be sure the Ken-Rads are pre-1945 to assure they weren't made by GE.   🤣  🤣


----------



## triod750

jonathan c said:


> Head straight for Ken-Rad 6C5 and 6J5 metals! Fantastic! A pair on a @Deyan adapter in lieu of a 6SN7 in Schiit Lyr 3: even more fantastic!


Me too like Ken-Rad 6C5 - a good performer in my amp!!


----------



## triod750

Xcalibur255 said:


> The metal can tubes can actually sound better because the can provides EMI/RFI shielding.  The only reason I'm not a fan is because you cannot verify that both tubes have the same construction.  If you get ones that have the same date/lot code though then I wouldn't hesitate to buy them as they'll probably sound nice.


You might listen and then trust you ears. I doubt they have the same frequency response anyway


----------



## jonathan c

triod750 said:


> You might listen and then trust you ears. I doubt they have the same frequency response anyway


… the metal tubes or the ears?… 🤔😜


----------



## ARCXENOS

ARCXENOS said:


> Gents, may I pick your brains for these



I placed an order for these, I think these will be my last quad of 6J5 variants for awhile.

heck maybe even all tubes (not counting the sylvanias 22de4 + 2x 6j5 package that seems to be missing in the usps system!!), because I am considering to get a new pair of 300b or stc cv1988 next


----------



## triod750

jonathan c said:


> … the metal tubes or the ears?… 🤔😜


The ears. I doubt that many of us have the same FR in both ears. I expect this to be very rare.


----------



## JTbbb

bcowen said:


> Just be sure the Ken-Rads are pre-1945 to assure they weren't made by GE.   🤣  🤣


Just so that newbie’s to tubes don’t get confused. Yes the Ken Rad factory was taken over by GE, was it 1943 gents? But did they not still produce genuine Ken Rads up to 1948? Albeit with GE labelling, but without the dots on the glass? An example below 1948?


----------



## nwavesailor

ARCXENOS said:


> I placed an order for these, I think these will be my last quad of 6J5 variants for awhile.


NICE!

 I find those to be a very nice pairing with the ER300B


----------



## jonathan c

triod750 said:


> The ears. I doubt that many of us have the same FR in both ears. I expect this to be very rare.


It could be worse: suppose L and R ears were 180’ out of phase…😳🙉 …?


----------



## triod750

jonathan c said:


> It could be worse: suppose L and R ears were 180’ out of phase…😳🙉 …?


I would just get a different circuit to correct this. Maybe a phasequalizer?


----------



## gibosi

JTbbb said:


> Just so that newbie’s to tubes don’t get confused. Yes the Ken Rad factory was taken over by GE, was it 1943 gents? But did they not still produce genuine Ken Rads up to 1948? Albeit with GE labelling, but without the dots on the glass? An example below 1948?



Also, with respect to 6SN7GT, if the plates are installed at an angle, "staggered", with respect to the micas, they are still "KenRad." When the plates are installed parallel, they are "GE".


----------



## bcowen

JTbbb said:


> Just so that newbie’s to tubes don’t get confused. Yes the Ken Rad factory was taken over by GE, was it 1943 gents? But did they not still produce genuine Ken Rads up to 1948? Albeit with GE labelling, but without the dots on the glass? An example below 1948?


GE took over in 1945.  I've never seen anything that shows when any particular tube type was changed from a Ken-Rad to a GE design, but I think it's quite safe to assume that everything didn't change on Day 1.  Might have taken several years for their bean counters to ruin _everything_.     The construction detail as @gibosi notes is certainly a good way to tell though.


----------



## JTbbb

bcowen said:


> GE took over in 1945.  I've never seen anything that shows when any particular tube type was changed from a Ken-Rad to a GE design, but I think it's quite safe to assume that everything didn't change on Day 1.  Might have taken several years for their bean counters to ruin _everything_.    The construction detail as @gibosi notes is certainly a good way to tell though.


Well, we have established that for the 6sn7 (ones you can see internals) tubes, they were still producing the KenRads in 1948. But your advice above for 6C5 & 6J5 metals certainly holds true!


----------



## triod750

Xcalibur255 said:


> The metal can tubes can actually sound better because the can provides EMI/RFI shielding.  The only reason I'm not a fan is because you cannot verify that both tubes have the same construction.  If you get ones that have the same date/lot code though then I wouldn't hesitate to buy them as they'll probably sound nice.


Then here is a matched pair for you @Xcalibur255  where you can see the construction: https://www.ebay.co.uk/itm/40404912...vrCbEms7JXQjAGekDSOTIsVwQ=|tkp:Bk9SR8D0vuumYQ


----------



## triod750 (Dec 21, 2022)

I have here a pair of Tung-Sol branded metal base tubes with 322 DT3 on the metal socket and the same innards as these: https://www.ebay.co.uk/itm/374270574028?hash=item572443bdcc:g:OFgAAOSwb4Rh2ymH&amdata=enc:AQAHAAAAoFO0Kl82BUf9wX4vHbo6Gi2cDRQMeFPNYKm9M2dHBbsztQukQQ1y3B9Y5RYAh2OcxFBu2hjNOYKNAy6wNI1He/ubM09c28pluRDJMx8ALiN50DwPVEpvjl/CCB+DC8uhuH1lc9WrATBZqAEaHlzDPk19ulCi+I288dsp5TT30a4F98Un6wPmRGr/p8KCTU2+X/xGRE8KPowGJUclDsn6TjU=|tkp:Bk9SR6SQ4_GmYQ
Who might be the manufacturer?









Just found a Philco branded pair looking the same as these Westinghouse and Tung-Sol 6J5GT. This 'Philco' pair has the codes 274 63-19 and 274 64-09. 274 for RCA but did they manufacture them?


----------



## triod750 (Dec 21, 2022)

And what manufacturer coded their tubes like this?









 "Brimar 6J5GT, Made in USA". As per: https://www.ebay.co.uk/itm/304610555167?hash=item46ec34351f:g:wEUAAOSw29FjCf6e&amdata=enc:AQAHAAAAkLFP4uobktvyC3+THbboozzkfv2RzhGP9SnH+Rgh975eN9HfhX6NgeQZJaggWSofeILjA3WX6YgWjK6TbUnqYXOtQ14IQJBBXRUYwOAf3bC+id2PFOOVtM1g9wei+Utj+DiwmvgzsQoMUCxrS2hFFvrmz18XO3hZPQLRyfdCcoOgl4dHlqaLrtfGY5uVBNJ5Sw==|tkp:Bk9SR6bI7_KmYQ

I have here a Brimar branded 6SL7GT with similar coding on top of glass (379 and 1K1) and the same kind of bottom ring getter. But this is "Made in England".


----------



## triod750

triod750 said:


> I have here a pair of Tung-Sol branded metal base tubes with 322 DT3 on the metal socket and the same innards as these: https://www.ebay.co.uk/itm/374270574028?hash=item572443bdcc:g:OFgAAOSwb4Rh2ymH&amdata=enc:AQAHAAAAoFO0Kl82BUf9wX4vHbo6Gi2cDRQMeFPNYKm9M2dHBbsztQukQQ1y3B9Y5RYAh2OcxFBu2hjNOYKNAy6wNI1He/ubM09c28pluRDJMx8ALiN50DwPVEpvjl/CCB+DC8uhuH1lc9WrATBZqAEaHlzDPk19ulCi+I288dsp5TT30a4F98Un6wPmRGr/p8KCTU2+X/xGRE8KPowGJUclDsn6TjU=|tkp:Bk9SR6SQ4_GmYQ
> Who might be the manufacturer?
> 
> 
> ...


And here another: https://www.ebay.co.uk/itm/18522311...PI3G1NifwUR4x+xzDMN2SdLA==|tkp:Bk9SR7Tgr_emYQ
RCA this time, and cheap as chips!


----------



## ARCXENOS

ARCXENOS said:


> Thank you all for the informative posts, I have never owned anything from Brimar before so I guess this is a great starting point!





Early christmas present arrived, the smoothness 

definitely different from the GEC straight tube L63, I am enjoying its bass presentation alot

My last quad of drivers for awhile, a pair of 300b next, as my driver + rectifier box is reaching its limit


----------



## nwavesailor

ARCXENOS said:


> Early christmas present arrived, the smoothness
> 
> definitely different from the GEC straight tube L63, I am enjoying its bass presentation alot
> 
> My last quad of drivers for awhile, a pair of 300b next, as my driver + rectifier box is reaching its limit


Looks GREAT!

Now you just need a pair of Elrog ER300B🤪


----------



## ARCXENOS

nwavesailor said:


> Looks GREAT!
> 
> Now you just need a pair of Elrog ER300B🤪







Oh they are there , I was just cycling all my drivers with the gold lions for this holiday season


----------



## nwavesailor

Ah, so you already have the Elrog's


----------



## JTbbb

Not sure if you guys across the pond know of this place? I’ve not had a bad tube from them, and they refresh stock fairly regularly.


----------



## CAJames

Yes, I've bought a few tubes from Mullard Magic and been very happy.


----------



## Isaacc7

JTbbb said:


> Not sure if you guys across the pond know of this place? I’ve not had a bad tube from them, and they refresh stock fairly regularly.


I have ordered from them before and liked the service. Problem is that they frequently only have singles available.


----------



## CaptainFantastic

JTbbb said:


> Not sure if you guys across the pond know of this place? I’ve not had a bad tube from them, and they refresh stock fairly regularly.



Fully agree. I bought some nice 6SN7s from them last year and they were so nice making sure the VAT forms were filled out correctly to avoid double tax with the new system, etc. Tubes were exactly as described too and perfectly quiet in my BHC.


----------



## JTbbb

Isaacc7 said:


> I have ordered from them before and liked the service. Problem is that they frequently only have singles available.


This is true, but you keep going back every couple of days or so, and something suitable will turn up to match what you have.


----------



## triod750

https://www.ebay.co.uk/itm/26513757...dfWbiU841iB1xYtHi42p/yBw==|tkp:Bk9SR8yAtMmnYQ


----------



## LobalWarming

triod750 said:


> https://www.ebay.co.uk/itm/265137572608?hash=item3dbb6e4b00:g:a8QAAOSwmXtghc8e&amdata=enc:AQAHAAAAkBNCYlPgoUo0ZDm0otv/qno9wMgcnaexhazxoT590dvkufG85h9XLMYLWDKArEmMDIg/2+H2+PjD4UUUIY/Ae8lxA6RO0afV5CFxsbOkLl+LbKqGFkltN39gqx8xYiGKffFY5LgTb/sYArJU9UWFnncoMUtT2nG9RteSagXrDJdfWbiU841iB1xYtHi42p/yBw==|tkp:Bk9SR8yAtMmnYQ


Oh.. possibly made in that Soviet factory on that far northern island in Japan.


----------



## g0ldl10n

Anyone have a pair of Raytheon JAN-CRP-12J5WGT? 





If so, how do you like them?


----------



## Isaacc7

g0ldl10n said:


> Anyone have a pair of Raytheon JAN-CRP-12J5WGT?
> 
> 
> 
> If so, how do you like them?


I have some that I really like. Mine are the brown base. A quad of them are currently the input tubes on my amp.


----------



## LobalWarming

g0ldl10n said:


> Anyone have a pair of Raytheon JAN-CRP-12J5WGT?
> 
> 
> 
> If so, how do you like them?


Have both their 12J5 and 6J5 editions - enjoy them both. Clean and analytical - not a very romantic twin. I like to use them as a palette cleanser before rolling over to the lush romantic and spacious side of the tracks.


----------



## g0ldl10n

Isaacc7 said:


> I have some that I really like. Mine are the brown base. A quad of them are currently the input tubes on my amp.





LobalWarming said:


> Have both their 12J5 and 6J5 editions - enjoy them both. Clean and analytical - not a very romantic twin. I like to use them as a palette cleanser before rolling over to the lush romantic and spacious side of the tracks.


Thanks for the input - they were inexpensive enough to order a pair, which were supposed to be here today, however, that winter storm in the US hit my area today and the wind chill is nearly -40f and the USPS mail carriers did not deliver mail today - looking forward to giving them a try!

Also ordered a pair of NU 12J5GT tubes as well - I seem to like almost everything NU made, so hopefully these are no different.


----------



## triod750

LobalWarming said:


> Oh.. possibly made in that Soviet factory on that far northern island in Japan.


You mean Kamjapanchatka? My thought too...


----------



## nwavesailor

I’ve heard they made some of the absolute best tubes EVER there 🙄


----------



## triod750

Well, they were the best tubes they ever made there...


----------



## Xcalibur255 (Dec 23, 2022)

g0ldl10n said:


> Anyone have a pair of Raytheon JAN-CRP-12J5WGT?
> 
> 
> 
> If so, how do you like them?


I like the 6J5WGT version quite a bit.  IMO it's in the same lane as the GEC L63 GT glass tube but trades a bit of resolution for a bit of added wetness and smoothness up top.  Really good bass speed and control in my system but it can be a bit soft up top at times.  Considering they sell for well under half the price of the GECs I consider them a bargain and a worthy substitute.

In my amps I don't hear them as analytical like LobalWarming does.  A good reminder that the amp is a big part of how these tubes sound.  In fact this is one of the most lush sounding 6J5 in my collection and they have really nice synergy with my speakers which can be a bit spicy in the lower treble region sometimes.  The only 6J5 that has ever struck me as outright dry sounding or analytical is the National Union 6J5G roundplate from the late 30's which is a very different animal from the later vintage tubes GT tubes it turns out.  Much like the difference between NU 6SN7 black glass and the much more rare (and older) grey glass version of that tube they're radically different sounds with the older tube being detailed and dry sounding where as the later vintage tube has a softer and wetter presentation.


----------



## triod750

I'm looking at a non-working 6J5GT that came in one lot of Ken-Rad made, Brimar branded tubes. This one is however silkscreened BVA, Amerty, Mullard, Made in USA. What is interesting is the silkscreened code on the metal skirt; F1G. I haven't seen this on any of the other Ken-Rad made tubes. On the glass pinch I can see the code R43, similar to the code in the 'Brimar' versions. The metal skirt seems to be heavier than on the others, except for a pair that has the text 'Distributed by' above BRIMAR on the metal skirt.


----------



## Marutks

I have a pair of short 6j5mg tubes.


----------



## triod750

922; is that an EIA code?


----------



## triod750

http://www.nostalgiaair.org/Tubes/6J5.htm
Anybody tried 6AE5G type tubes?


----------



## Isaacc7

triod750 said:


> http://www.nostalgiaair.org/Tubes/6J5.htm
> Anybody tried 6AE5G type tubes?


Apparently it is lower gain than the 6j5. That's all I could find with a quick google. That and it was used in a radio lol.


----------



## nwavesailor

Merry Christmas!


----------



## triod750

Sylvania leaf 6J5G-RC:
https://ehscott.ning.com/forum/topics/sylvania-6j5g-tube-variants
https://antiqueradios.com/forums/viewtopic.php?f=19&t=295256


----------



## g0ldl10n

Quick question I hope someone that is more knowledgeable than I can answer. Did USSR/Russia make equivalent 6J5 or 12J5 tube? If so, what is the tube type?


----------



## nykobing

g0ldl10n said:


> Quick question I hope someone that is more knowledgeable than I can answer. Did USSR/Russia make equivalent 6J5 or 12J5 tube? If so, what is the tube type?


6s2s and 6s5s (6c5 type) are two of them.


----------



## maxpudding (Jan 2, 2023)

As far as I know they only produced the 6S2S and the 6S5S. I bought the 6S2S, they sound decent. Haven’t tried the 6S5S.


----------



## g0ldl10n

g0ldl10n said:


> Anyone have a pair of Raytheon JAN-CRP-12J5WGT?
> 
> 
> 
> If so, how do you like them?


Well, these RT 12J5WGT tubes are actually my favorite RT tube I have heard. Definitely worth the $12.50 price tag in NIB/NOS condition.


----------



## Isaacc7 (Jan 3, 2023)

g0ldl10n said:


> Well, these RT 12J5WGT tubes are actually my favorite RT tube I have heard. Definitely worth the $12.50 price tag in NIB/NOS condition.


I wonder if there is any difference between the metal and brown base tubes. I don’t have any of the metal ones to compare. I really like the ones I have a lot but they don’t always work well with every output tube. Sometimes you can have too much clarity and transparency lol.


----------



## triod750

Isaacc7 said:


> Sometimes you can have too much clarity and transparency lol.


Amen!


----------



## g0ldl10n

Isaacc7 said:


> I wonder if there is any difference between the metal and brown base tubes. I don’t have any of the metal ones to compare. I really like the ones I have a lot but they don’t always work well with every output tube. Sometimes you can have too much clarity and transparency lol.


Not sure either - I just have the metal base tubes.. if you can find the brown base 12j5wgt for decent price, I'd gladly pick up a pair and let you know my thoughts, lol.


----------



## g0ldl10n

Isaacc7 said:


> I wonder if there is any difference between the metal and brown base tubes. I don’t have any of the metal ones to compare. I really like the ones I have a lot but they don’t always work well with every output tube. Sometimes you can have too much clarity and transparency lol.


Well, an offer I sent to a seller with a pair of brown bases was accepted, so soon I will be able to compare them to the ones with the metal bases I currently own, and will share what I find here.


----------



## Somatic

These Tung-Sol 6J5GT are too good ... feels like the audio gods have came to visit. Amazing vocals. Clear, precise like Melz 1578. Amazing bass authority while remaining clean.

Susvara's are flying to DMT hyperspace with this combo. See you on the other side.


----------



## leftside

Somatic said:


> These Tung-Sol 6J5GT are too good ... feels like the audio gods have came to visit. Amazing vocals. Clear, precise like Melz 1578. Amazing bass authority while remaining clean.
> 
> Susvara's are flying to DMT hyperspace with this combo. See you on the other side.


6J5's are the spirit molecule.


----------



## LCMusicLover

Weird question: I bought this _Extremely modded bottlehead crack w/ speedball_. One of the mods was to add 2 6J5 sockets as alternatives to the 12AU7 input tube. I have a bunch of 12AU7/5814A/4003 tubes, but would like to try something from the 6J5 family. Seller included a pair of Cunningham 6J5s, but said they were noisy— he was right. Also included a pair of these RCA JAN CRC-6J5 (VT-94 code):





Since I have no experience with those tubes I have no idea how ‘good’ those RCAs are, so I’m hoping somebody here can make a recommendation. Hoping for something in the less than $100/pair range. Or, alternatively, you could tell me that there’s no significant improvement to be found over those RCAs. I’m looking for a ‘wetter’ sound.

While the Mullard 6J5G in the second post here are gorgeous, they’re not in the budget


----------



## raindownthunda (Yesterday at 6:41 PM)

LCMusicLover said:


> Weird question: I bought this _Extremely modded bottlehead crack w/ speedball_. One of the mods was to add 2 6J5 sockets as alternatives to the 12AU7 input tube. I have a bunch of 12AU7/5814A/4003 tubes, but would like to try something from the 6J5 family. Seller included a pair of Cunningham 6J5s, but said they were noisy— he was right. Also included a pair of these RCA JAN CRC-6J5 (VT-94 code):
> 
> 
> 
> ...


The RCA’s are a good value but there are definitely better sounding tubes out there for <$100 / pair. The Ken Rad 6J5 metal tubes are another budget/value option much less than $100.

Some top contenders for warmer/wetter sound in your price range: Brimar 6J5GT or 6C5G, Sylvania 6J5G/GT, Ken Rad 6J5G/GT, Raytheon 6J5WGT, National Union 6J5GT.

I wouldn’t call these super warm, but these GEC L63 are probably one of the best all-around tubes out there in that price range: https://www.langrex.co.uk/products/l63-cv1067-gec-kbz-nos-valvetube/

The American tubes especially have a lot of rebrands, so if you’re trying to match singles it’s important to pay attention to the construction of the tubes. Lots of discussion in this thread on tube identification if you search


----------



## LCMusicLover

raindownthunda said:


> The RCA’s are a good value but there are definitely better sounding tubes out there for <$100 / pair.
> 
> A few contenders on the warmer side worth exploring: Brimar 6J5GT or 6C5G, Sylvania 6J5G/GT, Ken Rad 6J5G/GT, Raytheon 6J5WGT, National Union 6J5GT.
> 
> The American tubes especially have a lot of rebrands, so if you’re trying to match singles it’s important to pay attention to the construction of the tubes. Lots of discussion in this thread on tube identification if you search


Thanks for the starting points! The challenge of  exploring a new tube family is that, in the beginning, you don’t even know what to look for, don’t know what you don’t know. Hopefully, after a lot of reading & some searches I’ll have a better sense of what I’m looking for.


----------



## ColSaulTigh

LCMusicLover said:


> Weird question: I bought this _Extremely modded bottlehead crack w/ speedball_. One of the mods was to add 2 6J5 sockets as alternatives to the 12AU7 input tube. I have a bunch of 12AU7/5814A/4003 tubes, but would like to try something from the 6J5 family. Seller included a pair of Cunningham 6J5s, but said they were noisy— he was right. Also included a pair of these RCA JAN CRC-6J5 (VT-94 code):
> 
> 
> 
> ...


Glad to see you're exploring the wonders of your new amp!

In the 6J5 family in your price range, I've got some Zenith's that are nice and neutral sounding, and some Ken Rad 6J5G's that are extremely bold and crisp.  Having said that, both are a touch microphonic, which I think is a characteristic of the 6J5 in general.  In order to better make recommendations, could you give us an idea of what kind of sound you're looking for?


----------



## Monsterzero

GEC L63
National Union 6j5
Fivre L63
Zenith 6j5

Are my favs on the Airmid. I have some Tung Sols but haven't had a chance to listen to them yet, but supposedly they're very good as well.

Did you get the 6j5 database link yet? If not lemme know and I'll send you the link


----------



## raindownthunda

LCMusicLover said:


> Thanks for the starting points! The challenge of  exploring a new tube family is that, in the beginning, you don’t even know what to look for, don’t know what you don’t know. Hopefully, after a lot of reading & some searches I’ll have a better sense of what I’m looking for.


You’re off to a great start having an amp that can take 6J5 tubes natively! I also have a Bottlehead Crack and use my dual 6J5 adapter 95% of the time. The beauty of 6J5 is you really don’t need to spend mega bucks on the most rare/exotic varieties. I‘ve come to the conclusion most of them sound pretty damn good


----------



## LCMusicLover

ColSaulTigh said:


> Glad to see you're exploring the wonders of your new amp!
> 
> In the 6J5 family in your price range, I've got some Zenith's that are nice and neutral sounding, and some Ken Rad 6J5G's that are extremely bold and crisp.  Having said that, both are a touch microphonic, which I think is a characteristic of the 6J5 in general.  In order to better make recommendations, could you give us an idea of what kind of sound you're looking for?


Sure — the whole point of this amp purchase was to hear the _vaunted_ ZMF/tube amp synergy w/ my Atrium and Auteur (OG upgraded to Classic).

I’m looking for a wetter/tube-y sound. I understand that the Speedball reduces the gooey-ness of the Crack, so looking to ‘add back’ w/ tubes. I’ve just got two power tubes, but have several more coming.  I honestly don’t know much about them either, although one will be a Western Electric 421A, so high hopes there!

Part of the deal is that I have some other very good SS amps, especially my DSHA-3F, as well as a cap-modded Liquid Platinum. Really I just wanted a different flavor. I like what I’ve been hearing thus far, so of course my _audio.nervosa_ insists that I go further 



Monsterzero said:


> .
> .
> .
> Did you get the 6j5 database link yet? If not lemme know and I'll send you the link


No Sir!

And 

Yes please!


----------



## LCMusicLover

raindownthunda said:


> You’re off to a great start having an amp that can take 6J5 tubes natively! I also have a Bottlehead Crack and use my dual 6J5 adapter 95% of the time. The beauty of 6J5 is you really don’t need to spend mega bucks on the most rare/exotic varieties. I‘ve come to the conclusion most of them sound pretty damn good


Got any favorites to recommend?


----------



## raindownthunda

LCMusicLover said:


> Got any favorites to recommend?


See my list a few posts up 

ill just add that if you’re looking for that wetter sound the 421a is not it IME. More analytical and detail forward. If I were to recommend just one magic combo with the BHC w/ SB + ZMF it would be Chatham / Tung-Sol 6AS7G with the Brimar 6J5GT.


----------



## Monsterzero

raindownthunda said:


> ill just add that if you’re looking for that wetter sound the 421a is not it IME.


Agreed. To my ears and in my amp, the 421a are_ slightly_ warmer than the 5998s, but not enough to feel the wetness. Check out some RCA 6AS7g...dirt cheap and warm &  gooey


----------



## ColSaulTigh

LCMusicLover said:


> Sure — the whole point of this amp purchase was to hear the _vaunted_ ZMF/tube amp synergy w/ my Atrium and Auteur (OG upgraded to Classic).
> 
> *I’m looking for a wetter/tube-y sound. I understand that the Speedball reduces the gooey-ness of the Crack, so looking to ‘add back’ w/ tubes.* I’ve just got two power tubes, but have several more coming.  I honestly don’t know much about them either, although one will be a Western Electric 421A, so high hopes there!
> 
> ...


You might want to look at getting a 6SN7-to-6F8G adapters and find some nice Tung Sol Black Glass Round Plates.  Those are possibly the most wet, slick, and well-rounded drivers I've heard.


----------



## LCMusicLover

raindownthunda said:


> See my list a few posts up
> 
> ill just add that if you’re looking for that wetter sound the 421a is not it IME. More analytical and detail forward. If I were to recommend just one magic combo with the BHC w/ SB + ZMF it would be Chatham / Tung-Sol 6AS7G with the Brimar 6J5GT.


Thanks! Good news is that I also have a Chatham 6AS7G coming.

Missed that you had posted earlier.


Monsterzero said:


> Agreed. To my ears and in my amp, the 421a are_ slightly_ warmer than the 5998s, but not enough to feel the wetness. Check out some RCA 6AS7g...dirt cheap and warm &  gooey


Actually, I had noticed a _TON_ of those RCAs available on eBay … and reasonably priced. And I also have one of those incoming.

For driver tubes, right now I have two 6080s — one Raytheon, and one Sylvania. But, more coming — between folks here and some _over there_, a bunch of tubes are going to magically show up in my PO Box


----------



## leftside

LCMusicLover said:


> Weird question: I bought this _Extremely modded bottlehead crack w/ speedball_. One of the mods was to add 2 6J5 sockets as alternatives to the 12AU7 input tube. I have a bunch of 12AU7/5814A/4003 tubes, but would like to try something from the 6J5 family. Seller included a pair of Cunningham 6J5s, but said they were noisy— he was right. Also included a pair of these RCA JAN CRC-6J5 (VT-94 code):
> 
> 
> 
> ...


Start with the US metal base 6J5 (TungSol, KenRad, Sylvania, Raytheon, etc) and go from there. Should still be reasonably priced even though a lot were made in the 1940's or 1950's with the black plates that make their early 6SN7 brothers so sought after.

Welcome to the club. Getting amps that take 6J5 natively was one of the best decisions I made.


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## Xcalibur255

The most lush sounding 6J5 in my collection, to my ears, is the Raytheon WGT brown base.  Very forgiving top end without going overboard into veiled territory, and really lovely midrange tonality.  Each amp is different though and what sounds lush in one setup may not sound that way in another, something I never tire of mentioning because it's so true.

Probably the safest bet all around would be any of the Ken-Rads, but like so many Ken-Rad tubes they're the most prone to being noisy so there's a risk/reward equation to them.


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## LCMusicLover

Thanks to all for the fast and helpful responses!


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## JTbbb

Have got these Visseaux 6L5’s in the 6sn7 position in my Bottlehead Crack. Smooth and Tubey, I like a lot. I will now need to get in touch with Feliks Audio, see if they are ok for the Envy! Ugly looking brutes though aren’t they 😀.


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