Did I find the perfect 12at7 for v1?

[KellyBass]

I recently bought a lot of 20 12at7s off of ebay for $20. Gt's, Fender USA, a couple old RCAs, Sylvania etc. I figured at least one of them might make the cut for V1 on my express. One of them was simply labeled "M". When I popped it in I couldn't believe how dead quiet this thing was. No microphonics at all! Even tapping the tube itself was dead quiet! I looked them up and they are Mühlhausen Kuhl? Some sort of RTF brand??

Does anyone else have any experience with these? Where can I get more?

[CaseyJones]

There's no such thing as a "perfect 12AT7 for V1".

12AT7s were designed for RF applications not audio which is why they're cheap. If they were a good audio tube the audiophools would drive the prices out of sight, there's yer big clue. I expect you're using 12AT7s to tame the gain of an uncontrollable Wreck. There are better ways to do it.

Track down a 5751. Less gain than a 12AX7 and a more appropriate 12AX7 sub for audio applications. You can tell it's a good tube when the audiophools are climbin' all over it.

[Cliff Schecht]

SRV preferred 5751's in his amps. I've got a few nice looking black plate RCA ones but I've never put 'em to use..

[KellyBass]

I'll have to grab a couple of 5751's and give them a shot. Thanks for the tip. I really do miss the "bite" of a 12ax7 in V1, but it's very hard to find one that doesn't ping everytime I breathe.

[Firestorm]

I tried 5751s for a different reason: to try to reduce the hiss. I just can't get past it -- the thing always sounds like a Marshall on 10. Wound up liking some low noise/low microphonic 6702s (12AY7). But that's probably heresy.

SRV often used the 5751s in the PI of a blackface amp (more gain than the stock 12AT7). Might be worth a try there for the opposite reason.