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

[triod750]

This gets to the heart of the mystery of why tubes sound good. As you say, the engineers designing tubes had numbers they were going for, not something as nebulous as "sound quality." The 300b is a great example. It was designed specifically as a low distortion amplifier for compressed voices in telephone repeaters. Is low distortion the key to great sound? Debatable... In any case, when they started to use it with amplifiers for speakers it gained a warmth and midrange glow that people fell in love with. The lack of great drivers and output transformers played a very key role in that sound. As it turns out, modern amplifier design can give you a much more accurate and less distorted sound with 300b tubes. I prefer the new designs personally...

Point is, the 300b "sound" is very different depending on the application. And the same thing goes with every other tube. The only criteria that engineers used for "sound quality" was distortion and power. I've said it before, I'm convinced that the idea that different tubes sound different comes from guitar players. The classic manufacturers of hifi tube gear would be appalled at the idea of tube rolling. Certainly they would cringe at the idea of dropping in a totally different tube type like we so cavalierly do here. If you owned McIntosh, Marantz, Scott, Leak, Quad, etc. the only reason you'd change tubes would be when you wore them out. I have a strong suspicion that tube rolling only really started becoming popular when boutique tube amps and especially single ended ones came on the scene in the 90s.

I also don't think that speakers/heaphones were good enough back in the day to pick up on a lot of the stuff we talk about here. Sure, if you had the original Quad electrostatic speakers you could but approximately nobody owned those. Plus, Peter Walker would come over and beat you personally if you used anything other than the KT66 his amps were designed for. Headphones have dramatically changed for the better over the last 20 years.

So yeah, not only were engineers not worried about sound quality of tubes themselves, but neither were amp designers and consumers until recently.

And yet we get so much satisfaction from what we are doing, playing with our toys. What is wrong here? By changing tubes I can enjoy the same musical piece in several different ways. Maybe I should be put in jail, with just solid state?

 

[Isaacc7]

And yet we get so much satisfaction from what we are doing, playing with our toys. What is wrong here? By changing tubes I can enjoy the same musical piece in several different ways. Maybe I should be put in jail, with just solid state?

Oh yeah, me too. This community has brought about a lot of enjoyment and a lot of money spent lol. I wrote my post late at night and wasn't thinking as clearly as I'd like. The mystery I alluded to was more about how it doesn't seem to align with the pure engineering mindset. This group tends towards tweakability in their amps rather than pure engineering precision. I know that one contributor in the thread uses Audio Research amps for their speakers. I'm curious if anyone else has engineering centered amps like McIntosh, Quad, AR, Dynaco, or the like.

 

[Isaacc7]

Here's an example of an engineered, tweakable amp though not with the tubes. https://alexsoundtech.com/takatsuki/products/ta-s01

I wish more designers would approach their amps like this.

Anyway, let's get back to single triodes! Sorry to derail the thread!

 

[mordy]

Oh yeah, me too. This community has brought about a lot of enjoyment and a lot of money spent lol. I wrote my post late at night and wasn't thinking as clearly as I'd like. The mystery I alluded to was more about how it doesn't seem to align with the pure engineering mindset. This group tends towards tweakability in their amps rather than pure engineering precision. I know that one contributor in the thread uses Audio Research amps for their speakers. I'm curious if anyone else has engineering centered amps like McIntosh, Quad, AR, Dynaco, or the like.

I have an amp engineered by old school principles- the Ultimate by Eric McChanson.

 

[triod750]

His mind doesn't seem old though.

 

[leftside]

As it turns out, modern amplifier design can give you a much more accurate and less distorted sound with 300b tubes. I prefer the new designs personally...

VMT. If anyone can get the chance to listen to a Glenn 300B amp (with C3g drivers), one would not call this a warm sounding amp. The most neutral sounding amp was always Glenn's goal.

I still have McIntosh amps for my main speakers, but IF I were ever to replace these, I'd be contacting Supratek for some custom amps.

 

[leftside]

It's probably time to post this again

 

[LostControl85]

A little tubey goodness. This forum has been a great resource. Much thanks to you guys.

 

[reg66]

A little tubey goodness. This forum has been a great resource. Much thanks to you guys.

Assuming the dual tube adapter isn't already one... It looks as though you need a good looking adapter from @Deyan! Prices, including shipping, are most reasonable. I'll upload a pic in a mo of mine. 2 in aluminium to match the Lyr+ chassis and another dual adapter (dual 6J5 to 6SN7). No doubt he can accomodate your erm... NEEDS!!!

NOTE: the flush underside of the dual adapter, not being raised, was a request of mine. Oh, and Deyan also allows extra length on the internal wiring, so that you can adjust/rotate the base socket gently to your preference/requirements

 

[raindownthunda]

Langrex added a bunch of really nice L63 to their stock recently. If anyone is looking and has the budget.

https://www.langrex.co.uk/products/6j5g-cv1067-l63-gec-nos-valve-tube/


https://www.langrex.co.uk/products/l63-6j5g-gec-shouldered-grey-glass-oval-print-nos-valve-tube/


https://www.langrex.co.uk/products/l63-marconi-metal-base-nos-valve-tube-lc42/

 

[Designsfx]

Langrex added a bunch of really nice L63 to their stock recently. If anyone is looking and has the budget.

https://www.langrex.co.uk/products/6j5g-cv1067-l63-gec-nos-valve-tube/


https://www.langrex.co.uk/products/l63-6j5g-gec-shouldered-grey-glass-oval-print-nos-valve-tube/


https://www.langrex.co.uk/products/l63-marconi-metal-base-nos-valve-tube-lc42/

Ha Ha! I took screen shots of all of those the other day as well. They have some cool stuff.

 

[Designsfx]

I just saw an ad for these- guy is asking a little over $30 each. Not sure if that’s good, bad or worth it- can anyone provide insight on these?

 

[nwavesailor]

Langrex added a bunch of really nice L63 to their stock recently. If anyone is looking and has the budget.

https://www.langrex.co.uk/products/6j5g-cv1067-l63-gec-nos-valve-tube/


https://www.langrex.co.uk/products/l63-6j5g-gec-shouldered-grey-glass-oval-print-nos-valve-tube/


https://www.langrex.co.uk/products/l63-marconi-metal-base-nos-valve-tube-lc42/

I have all but the Marconi. The GEC 10E /348 are truly Top Tier tubes with a beautiful sound as well as very nice detail! One of my favorites.

 

[reg66]

Morning all. Bit of advice needed if poss...
Which of the following 2 sets would be the warmest sounding - or are they going to be very similar? 1st pic is STC 6J5G, 2nd is Brimar 6J5G

I ask as I'm after warmer sounding tubes at the mo. I have actually purchased the STC ones but might be able to change to the Brimar if you guys think they would be better suited. Are they much of a muchness in sound ie pretty much the same?

 

[LobalWarming]

Morning all. Bit of advice needed if poss...
Which of the following 2 sets would be the warmest sounding - or are they going to be very similar? 1st pic is STC 6J5G, 2nd is Brimar 6J5G


I ask as I'm after warmer sounding tubes at the mo. I have actually purchased the STC ones but might be able to change to the Brimar if you guys think they would be better suited. Are they much of a muchness in sound ie pretty much the same?

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.