Looking for low-gain 12AX7 variant

[chrisb]

Hi All,
I just had an amazing amp made based on the Vox AC4 schematic, and I really love it but it has a wee bit too much preamp gain for my taste. I put a 12AU7 in the preamp and that helped, but the tremolo is tied to that tube and it almost disappears now.

I'm hoping someone can tell me of a low-gain variant of the 12AX7 that I can put in....

Thanks for any advice,
Chris

[scott_s]

12AY7 would be my recommendation.

[chrisb]

Thanks, Scott.

Is there any reason in particular that you recommend that one?

[ken_j]

12AX7=100 12AT7=60 12AY7=45 12AV7=41 12AU7=20

[chrisb]

Yes, I see: middle of the road!
Perfect, I'll let you know how it goes...

[scott_s]

12AY7 was used in the front end of a LOT of Fender amps to keep the overall gain and noise down. You won't hurt anything by swapping in any of the above variants, but for each of the tubes to sound its best, you'll want to use the appropriate cathode resistor.