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

[Xcalibur255]

@reg66

If you're trying to get warmer than the Brimar then a Raytheon 6J5WGT brown base would be a good bet. Or it's older cousin the VR67 version. The Ken-Rad made 6J5G are also quite warm though ones that are truly made by Ken-Rad and not just a re-label with their name on it are hard to find. If you want to play the adapter game basically any version of the 76 will be warmer than most 6J5 too.

 

[reg66]

@reg66

If you're trying to get warmer than the Brimar then a Raytheon 6J5WGT brown base would be a good bet. Or it's older cousin the VR67 version. The Ken-Rad made 6J5G are also quite warm though ones that are truly made by Ken-Rad and not just a re-label with their name on it are hard to find. If you want to play the adapter game basically any version of the 76 will be warmer than most 6J5 too.

Ahh cool, many thanks. I'll have a look what's around.
Admittedly although I own them I haven't really tried/let them burn in (yes, i am amassing a collection that's getting too big to roll effectively. Let alone wait for each set/tube to burn in [if you're a believer in tube burn]!!), but what about my KR VT-65's or 6J5's metal tops - would they be anywhere closer to pretty warm? KR VT-94?

i know the sound i'm after in my head, if that makes sense at all lol. But i'm gathering such a collection of 6SN7s, 6J5s, 13D8 etc etc that i now don't know where to begin haha!!

Basically i'm after a very real overall tone wih warmth, great mids a bit forward incl accurate/natural sounding guitar and vocals. i don't mind sacrifcing some detail but would like air (unless air gets lost the warmer you delve?). Am i wanting too much, too specific!?

Man, i need a couple of weeks off at least [work 6-7 days p/w] to really get stuck into rolling them all rather than just buying/collecting in my brief-ish spare time hahah

Cheers guys for helping/advising

EDIT: Fk it, no doubt even if i find what i'm looking for i'll probs start wanting detail and accuracy again. Such is the nature of the beast!!!

 

[raindownthunda]

Ahh cool, many thanks. I'll have a look what's around.
Admittedly although I own them I haven't really tried/let them burn in (yes, i am amassing a collection that's getting too big to roll effectively. Let alone wait for each set/tube to burn in [if you're a believer in tube burn]!!), but what about my KR VT-65's or 6J5's metal tops - would they be anywhere closer to pretty warm? KR VT-94?

i know the sound i'm after in my head, if that makes sense at all lol. But i'm gathering such a collection of 6SN7s, 6J5s, 13D8 etc etc that i now don't know where to begin haha!!

Basically i'm after a very real overall tone wih warmth, great mids a bit forward incl accurate/natural sounding guitar and vocals. i don't mind sacrifcing some detail but would like air. Am i wanting too much, too specific!?

Man, i need a couple of weeks off at least [work 6-7 days p/w] to really get stuck into rolling them all rather than just buying/collecting in my brief-ish spare time hahah

Cheers guys for helping/advising

The metal KR 6J5, GE 6J5, and especially the RCA 6J5 are all on the warm to very warm side. Luckily they are cheap enough to try without breaking the bank. They are not as resolving with detail. They also don’t have the most “air” from what I remember. My theory is that there is a correlation that the more clarity/resolving the tube is, the more sense of “air”. Not sure there is a super warm tube that is also super “airy”?

I think the Brimar 6C5G or 6J5G/GT, and also the Fivre 6C5G or 6J5GT will get you a moderately warm tilt, but also with more air and clarity. The 6C5G variants I think are more intimate and “creamy”. Love them both for vocals. I also agree with Xcalibur’s suggestion on the Raytheon 6J5WGT.

 

[reg66]

Yup, edited my post to assume warmth and air might not go together as you must've been typing... Seems to make sense logically (i'm still a learner!). Got a day off tomorrow for once, so, there's no time like the the present!! Time to tinker. I'd already inserted these when i saw your post.... will give the 6J5s a go shortly.

Cheers

 

[leftside]

I have both the STC and Brimar shown here. They're very close. STC is perhaps a bit more romantic, a tad warmer that the Brimar. But, it's really, really close. Can only suggest you get both and decide with your own ears - to keep them both. Later spring for a pair of ST bottle as show above by @raindownthunda.

Agreed. Very, very close.

 

[leftside]

Have you any experience with these GEC L63 10E/348? If so, are they warmer than the STC I have just bought - should I have gone with those instead... hmm!?

IMO the GEC are not warmer. In my setup, the Brimar 6J5 are as warm as it gets. Obviously other may say otherwise. The only other tube that I find warmer is the early type 37. Might be time to post some pics of variations of that tube. The 37 will work with 76 to 6J5 adapters if you have 6J5 sockets.

 

[leftside]

The metal KR 6J5, GE 6J5, and especially the RCA 6J5 are all on the warm to very warm side. Luckily they are cheap enough to try without breaking the bank. They are not as resolving with detail. They also don’t have the most “air” from what I remember. My theory is that there is a correlation that the more clarity/resolving the tube is, the more sense of “air”. Not sure there is a super warm tube that is also super “airy”?

I think the Brimar 6C5G or 6J5G/GT, and also the Fivre 6C5G or 6J5GT will get you a moderately warm tilt, but also with more air and clarity. The 6C5G variants I think are more intimate and “creamy”. Love them both for vocals. I also agree with Xcalibur’s suggestion on the Raytheon 6J5WGT.

Yeah forgot about those. Those US tubes like RCA are also on the warmer side.

 

[leftside]

I'm not sure when the first GEC 6J5 tubes were made. It's easy to identify the year for GEC tubes 1945 and later, but unfortunately the knowledge to identify earlier numbering schemes has been lost over the years. If there is a numbering scheme on a GEC tube that I don't recognize then I just accept it is "pre-1945".

For KT66, it's not so bad as it's known the earliest clear glass, grey glass and black glass larger ST type were only made during WWII, so 1939 - 1945. Not so easy with 6J5 tho unfortunately.

 

[Xcalibur255]

Ahh cool, many thanks. I'll have a look what's around.
Admittedly although I own them I haven't really tried/let them burn in (yes, i am amassing a collection that's getting too big to roll effectively. Let alone wait for each set/tube to burn in [if you're a believer in tube burn]!!), but what about my KR VT-65's or 6J5's metal tops - would they be anywhere closer to pretty warm? KR VT-94?

i know the sound i'm after in my head, if that makes sense at all lol. But i'm gathering such a collection of 6SN7s, 6J5s, 13D8 etc etc that i now don't know where to begin haha!!

Basically i'm after a very real overall tone wih warmth, great mids a bit forward incl accurate/natural sounding guitar and vocals. i don't mind sacrifcing some detail but would like air (unless air gets lost the warmer you delve?). Am i wanting too much, too specific!?

Man, i need a couple of weeks off at least [work 6-7 days p/w] to really get stuck into rolling them all rather than just buying/collecting in my brief-ish spare time hahah

Cheers guys for helping/advising

EDIT: Fk it, no doubt even if i find what i'm looking for i'll probs start wanting detail and accuracy again. Such is the nature of the beast!!!

What you're describing is pretty much what the older Raytheon 6J5 tubes sound like to my ears. Particularly the old 6J5G versions, but the WGT metal base with the brown bottom caps also sound this way, just a bit different flavor of it.

I have yet to hear a pre-WWII Raytheon tube of any type whose sound I didn't fall in love with. They really had it figured out back then.

 

[Xcalibur255]

I'm not sure when the first GEC 6J5 tubes were made. It's easy to identify the year for GEC tubes 1945 and later, but unfortunately the knowledge to identify earlier numbering schemes has been lost over the years. If there is a numbering scheme on a GEC tube that I don't recognize then I just accept it is "pre-1945".

For KT66, it's not so bad as it's known the earliest clear glass, grey glass and black glass larger ST type were only made during WWII, so 1939 - 1945. Not so easy with 6J5 tho unfortunately.

I think the first year for 6J5 was '37 or '38.

I honestly think when it comes to KT66 one can grab a pair of new production Gold Lions and they're missing out on very little. I'm usually not very impressed by new production tubes but these get it right, and the build quality is outstanding too. Unless you enjoy the hunt of course.

 

[leftside]

I think the first year for 6J5 was '37 or '38.

I honestly think when it comes to KT66 one can grab a pair of new production Gold Lions and they're missing out on very little. I'm usually not very impressed by new production tubes but these get it right, and the build quality is outstanding too. Unless you enjoy the hunt of course.

I have Gold Lion KT88 that I sometimes use in my main speaker amps. I have very few new production tubes in my collection, but yes Gold Lion seem to be quite good. Strong testing GEC KT88 with a decent amount of silver getter flashing are become very rare these days though. Still plenty of GEC KT66 - especially the later brown base/clear glass version.

 

[Designsfx]

Always remember that tubes can give different result in different circuits and audio chains...

Oh yes- I’m totally aware of that. Going tube dac to tube pre to tube amp brought the realization of how they all add up very quickly.

 

[CAJames]

IMO the GEC are not warmer. In my setup, the Brimar 6J5 are as warm as it gets. Obviously other may say otherwise. The only other tube that I find warmer is the early type 37. Might be time to post some pics of variations of that tube. The 37 will work with 76 to 6J5 adapters if you have 6J5 sockets.

Agree. I've been enjoying WWII vintage Sylvania 37s in my WA22 for months now. Note however they are probably the lowest gain tubes in my caddy if that matters. I bought a bunch of them from a guy on ebay a while ago, but you can get them today at Langrex, for a lot less than most 6J5s.

 

[shwnwllms]

Word of warning for anyone seeking out the elusive 6S5S, they have a high failure rate (I’m talking 50% or more) at least on the scraps @Wes S left for us to fight over.

I’ve bought 4 pairs so far and still only have 1 matched pair to my name (with three singles from different sellers and time periods that aren’t matched)

I’ve got one more replacement pair on the way and after that I’m done

I got lucky with the first pair I got, I should have quit while I was ahead (no one that I’ve come across is testing for noise, just reading a tube tester as they don’t have amps to run them in)

The ones I pitched were some of the worst, godawful sounding tubes I’ve heard in my life. Some even had visible signs of defect. I doubt the sellers were even testing them as it’s not an in demand tube

 

[JTbbb]

Word of warning for anyone seeking out the elusive 6S5S, they have a high failure rate (I’m talking 50% or more) at least on the scraps @Wes S left for us to fight over.

I’ve bought 4 pairs so far and still only have 1 matched pair to my name (with three singles from different sellers and time periods that aren’t matched)

I’ve got one more replacement pair on the way and after that I’m done

I got lucky with the first pair I got, I should have quit while I was ahead (no one that I’ve come across is testing for noise, just reading a tube tester as they don’t have amps to run them in)

The ones I pitched were some of the worst, godawful sounding tubes I’ve heard in my life. Some even had visible signs of defect. I doubt the sellers were even testing them as it’s not an in demand tube

The pair you salvaged sounded good?