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

[shwnwllms]

The pair you salvaged sounded good?

I have one matched pair. It sounds sublime. Listening to them now.

Then I have 3 singles. 1 from different factory and earlier time period (different construction). The other two are from different sellers, no idea if they are closely matched so I can’t make another pair, basically have a reject pile in case one of my good ones go out.

I’ve never run across this with any other single triode. Luckily they aren’t very expensive and the sellers have worked with me.

 

[mordy]

I have one matched pair. It sounds sublime. Listening to them now.

Then I have 3 singles. 1 from different factory and earlier time period (different construction). The other two are from different sellers, no idea if they are closely matched so I can’t make another pair, basically have a reject pile in case one of my good ones go out.

I’ve never run across this with any other single triode. Luckily they aren’t very expensive and the sellers have worked with me.

Is it necessary to have both triodes closely matched in your amp? I once used two triodes 6J5 where one was marked barely good and the other NOS and I could not hear any difference.
In terms of the Russian 6C2C triodes I could not hear any difference when pairing a 1966 tube with a 1974 tube.

 

[shwnwllms]

Is it necessary to have both triodes closely matched in your amp? I once used two triodes 6J5 where one was marked barely good and the other NOS and I could not hear any difference.
In terms of the Russian 6C2C triodes I could not hear any difference when pairing a 1966 tube with a 1974 tube.

I’ve heard it doesn’t matter, but I still try to match whenever possible. That said, with the 50’s and 60’s 6S5S they are totally different construction in different factories so I wouldn’t make a pair out of those

 

[nwavesailor]

I'm with @shwnwllms on not mixing tubes of different construction and factories.
Can I hear it? Maybe not, but I still like my pairs or quads to be the same and test reasonably close as well.

 

[Isaacc7]

I'm with @shwnwllms on not mixing tubes of different construction and factories.
Can I hear it? Maybe not, but I still like my pairs or quads to be the same and test reasonably close as well.

Eh, I’ve loosened up over the years about this. If it sounds good then I’m good

 

[mordy]

I’ve heard it doesn’t matter, but I still try to match whenever possible. That said, with the 50’s and 60’s 6S5S they are totally different construction in different factories so I wouldn’t make a pair out of those

In the above example of the NEVZ 6C2C tubes the tubes looked identical - I am not advocating using dissimilar tubes or different manufacturers, but if the internals look the same, even though the tubes were made at different times, there is a possibility that they will sound similar. And based on experience, when you have a tube measuring 70% paired with a tube measuring 100% you may not hear a difference.

 

[nwavesailor]

For me it is also a visual thing. If they look different my brain knows it and then tells my ears!!!!

 

[shwnwllms]

Three different types of 6S5S (earliest on the left) for comparison

Photo courtesy of @Wes S as I’ve only seen the middle 50’s and 60’s on the right

 

[CAJames]

I'm with @shwnwllms on not mixing tubes of different construction and factories.
Can I hear it? Maybe not, but I still like my pairs or quads to be the same and test reasonably close as well.

I don't (necessarily) have a problem with mismatched tubes. I look at it like blended Scotch vs. Single Malt. JMO/YMMV and all that.

 

[nwavesailor]

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

I have some in transit and I am hoping for Q U I E T
It took a while to find some 6S5S and hopefully mine are OK!

 

[Designsfx]

For me it is also a visual thing. If they look different my brain knows it and then tells my ears!!!!

That’s what the light switch is for!

 

[Designsfx]

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

For those who have or are currently using the 37 tube- @CAJames brings up the point of it being low gain. What are the strong points of this tube and is the lack of gain what accentuates its overall character? Does it pair better/worst with specific rectifiers?

 

[leftside]

For me it is also a visual thing. If they look different my brain knows it and then tells my ears!!!!

Yeah if my brain knows then it will be impossible to relax and listen to the music. It's just the way it is. I've learn to live with it.

 

[leftside]

For those who have or are currently using the 37 tube- @CAJames brings up the point of it being low gain. What are the strong points of this tube and is the lack of gain what accentuates its overall character? Does it pair better/worst with specific rectifiers?

Adds another weapon to the tube arsenal. Warmer tube. My amps that can use 37 don't use a tube rectifier, so can't help you there.

 

[CAJames]

For those who have or are currently using the 37 tube- @CAJames brings up the point of it being low gain. What are the strong points of this tube and is the lack of gain what accentuates its overall character? Does it pair better/worst with specific rectifiers?

My experience is they are warm but still detailed and has good bass while the treble is a little rolled off. They can take the edge off other tubes that are a little to hot in the treble but have other desirable characteristics. And they look good and are still (relatively) inexpensive.