Recommend me a new production 12AX7

[MrSparkle]

Great information, thanks! We must know...what is the secret variant?

6Н2П-ЕP!

[JackFawkes]

Functionally, the two 6Н2П's are the same. Most people recommend the ЕВ for guitar amp use over the 6Н2П, but as usual there's dissenters. Realistically the PI is maybe not the best place for them, but you'll probably be fine - especially if you get the milspec variant (or the secret extra-mil-spec variant I didn't mention).

Great information, thanks! We must know...what is the secret variant?

I'm gonna guess -ER (or -EP)?
For the most part the dash-letter(s) at the end identified that the particular tube was rated for certain duration/durability/shock resistances; I believe ER/EP would mean something like "long life, vibration & radiation resistant".

EDIT: I was correct! But didn't look at the second page to see the answer was already posted

[DaddyDom]

As a non-scientific valve-tube nerd, here's my experience.

Pretty much every old amp or piece of kit I've bought cheap (meaning, needs looking at) has had its original 12AX7s of many and varying brands. Some Mullard, some Zaerix, some Mazda, some Philips, some RCA, some Hammond, etc etc.

In 40+ years I've had about 3 die on me - so my advice would be that old ones last well, buy NOS but don't sweat the brand one iota. And then forget about them.
Hope that helps.

[øøøøøøø]

I gave up on old stock 12AX7s

Just too hard to get much value for money in 2024

I buy Tung Sol branded reissues now

[therizzla]

I gave up on old stock 12AX7s

Just too hard to get much value for money in 2024

I buy Tung Sol branded reissues now

This is the direction I'm leaning. I read a lot about failures from the Tung Sol reissues but that seems to be in cathode follower positions so I should be good with my SFTR.

[øøøøøøø]

Yep

Selected applications, paying up for a good tube can still be worth it

Microphones, tube compressors, that sort of thing—and applications that are very demanding for the tube—I might still pay 3 figures for a good true NOS example

But for a plate follower in a guitar amp?

Pssssh. Not anymore, for me. It’s just not a big enough deal.

It’s too much money and/or too much work (to repeat the seller’s test to verify their numbers and/or send it back when it’s noisy or otherwise not-as-advertised)

Or the time troubleshooting the *rest* of the amp to make sure in fact it’s the new tube that’s noisy and not that one of the others has suddenly failed…

At this point just plugging something in and having it work right away is worth a lot to me

10 years ago was different

20 years ago, way different

Now I operate as though NOS stocks are totally used up. Squeezing the last bit of juice out of an old lemon is too much work for me.

[JSett]

At this point just plugging something in and having it work right away is worth a lot to me

This is the motto of any working/gigging guitarist (or should be). That's why certain amps become standard backline, why certain pedals become board-staples, why certain IEM systems become the go-to.

Not having to worry about a gear failure under the heat of the lights, or during expensive studio time, is worth its weight in gold.

[MrSparkle]

This is the motto of any working/gigging guitarist (or should be). That's why certain amps become standard backline, why certain pedals become board-staples, why certain IEM systems become the go-to.

Not having to worry about a gear failure under the heat of the lights, or during expensive studio time, is worth its weight in gold.

I recognise, understand and accept everything you say here. I'll still never be convinced by the Tonemasters.

FET (With OT!) Showman Now!

[-JB-]

Can’t go wrong with JJs. I’m a fan of always having access to replacements when you need them right away.

[therizzla]

UPDATE: I finally ordered some new tubes for my SFTR and installed them last night and the results were much more noticeable than I had anticipated!

V1: Mesa labelled 12AX7 (was installed when I got the amp, I don't use the normal channel for guitar)
V2: Tung-Sol RI 12AX7
V3: JJ ECC81
V4: Tung-Sol RI 12AX7
V5: Mesa labelled 12AX7 (same as V1, already installed and nothing fancy needed here)
V6: NOS JAN Philips 12AT7WC (matched triodes)

I also ordered a JAN Philips for V3 too, but I decided against using a tube I paid a little more for matched triodes in a position that doesn't require it so I left the JJ in there that came with the amp for now. I ordered a set of Tube Store Preferred Series 6L6WGCs but the JJ 6L6GCs in it now are fine, no reason to change at the moment. JJs and TAD/Preferred Series 6L6s are some of the only ones I can find that can take the high plate voltage of the ultralinear set-up.

With the two new Tung-Sols and the NOS 12AT7 PI the amp is quieter at idle and the overall tone seems a bit richer or more complex if that makes sense. OD and fuzz also sound a bit smoother through the amp now too, less sterile. The amp is a little brighter than it was before but a quick EQ adjustment brought it back to where I like it. I really enjoyed learning about each position and what to look for and where to spend and where to save money, interesting stuff.

Thanks to everyone for the recommendations, it was money well spent!

[OffYourFace]

you're gambling with all new tubes. A friend just a got a new set of Tung Sol 12ax7s and one died in a day.

When I worked at Matchless, I'd get a box of 100 Ruby (Magic Parts) tested JJ 12ax7s and there'd be one or two bad ones, same with the Apex tested (tubesandmore.com). It is what it is. But most companies have a good return policy.

[therizzla]

you're gambling with all new tubes. A friend just a got a new set of Tung Sol 12ax7s and one died in a day.

So far, so good! The Tung-Sols definitely made it past a day though I’ve read that they die almost immediately in a cathode follower position so in the Twin’s V2 and V4 they should be fine. I know the reliability in new tubes won’t be what it was in old glass but it already had new tubes when I got it, I didn’t pull any old ones in favor of new.

The PI is now a NOS 12AT7 and I plan on doing the same in the reverb driver position soon too.

The tone and background noise is improved and time will tell on reliability but I’m satisfied with the end result so far.

[øøøøøøø]

you're gambling with all new tubes. A friend just a got a new set of Tung Sol 12ax7s and one died in a day.

When I worked at Matchless, I'd get a box of 100 Ruby (Magic Parts) tested JJ 12ax7s and there'd be one or two bad ones, same with the Apex tested (tubesandmore.com). It is what it is. But most companies have a good return policy.

I wonder if this is unique to our current era?

Like, tubes have kind of an “infant mortality” phenomenon and I think maybe they always have. Some percentage die really early but once you get past that, it becomes a lot more predictable (not telling you anything new, this is why “burn-in” is a thing, of course)

Were the “better” old-stock tubes less likely to have early failures? I’m not sure there’s good data on that!

But it is interesting.

[therizzla]

Were the “better” old-stock tubes less likely to have early failures? I’m not sure there’s good data on that!

But it is interesting.

I can say for sure that they didn’t have a zero percent early failure rate. That is an interesting thought though.

[OffYourFace]

Good question. I’m sure there were bad tubes back in the day. You’d buy a couple at the drug store and if they were bad you return them. The salesperson probably put them on a tube tester to make sure it wasn’t user error.

I guess getting defective tubes stings a bit more now when you’re paying $20 for a 12ax7 online. You have to wait days for it to arrive in the mail and if it dies in 12 hours, it’s a total PITA to deal with it.