Guitar amp 12ax7

[Tungsol]

NOS mullards, amperex and telefunkens are the usual list of characters recomended for audio applications. Are you looking for different characteristics in guitar preamp tubes compared to a typical audio 12ax7 linestage or phono application. Any recomendations for the best sounding 12ax7 tubes for guitar amps?

Thanks.

 

[seamas]

I keep hearing that guitarist like the rca short grey plates.

 

[dividebytube]

this is very informative:
http://www.guitaramplifierblueprinting.com/12ax7.html

 

[diamondsouled]

The RFT 12AX7-ECC83 is fairly highly regarded as a guitar amp tube. The plates look more like those on a 12AT7.

I bought an ARC active crossover which had some in it that were labeled RCA 12AX7.

Tubemongers library has some picts of some of the different varieties that are out there:

http://www.tubemongerlib.com/gallery2/v/12AX7/?g2_page=9

Cheers

Lar

 

[Rex Everything]

I always looked for Mullards and Telefunkens for there sweet break up in guitar amps. For clean stuff like Fender amps the RCA's are very nice.

 

[jrsh92]

If you need gain to overdrive a later stage or the poweramp, I've had some really good experience with an old (very old) Korean 12AX7. I didn't even know they made 12AX7 in Korea, but they do, and they sound amazing. The glass is thin enough to make me worry, though...
If you're using a high gain guitar amp that overdrives the preamp or that uses a tube preamp for distortion-- in the case of a Vox or Marshall Valvestate/Valvetronix amp-- I've found that the sound of a 12AU7 absolutely destroys any 12AX7 I've heard, even if it wasn't originally what the amp was designed to use.