Yesterday I got a couple new Tungsol 12AX7 tubes.

I replaced the stock Sovtek preamp tube in my Hartke GT60c hybrid amp with a Tungsol and it cleaned up the tone quite a bit. It gave more clarity, definition, "hollowness", and more bass response but did take away a little warmth. I expected a subtle difference but there is a pretty major difference in tone after the swap. There is a window on the front of the amp to see the preamp tube, and I always assumed the tube itself was glowing. It's not ... there is actually an orange LED under the tube socket to make the body of the tube glow when the amp is on

I also pulled both Chinese preamp tubes in my Peavey Classic 20, and replaced the one closest to the input with a Tungsol and the one closer to the power tubes with a Sovtek. It made the amp quite a bit warmer and less trebly but did make it quieter. The new tubes also make it break up faster and it's harder to get a clean tone. The Chinese tubes must have been slightly microphonic because the am used to hum a little, now it's silent after the tube swap. May try swapping the Sovtek and Tungsol and see what changes.

Anyways ... how can I tell which pre-amp tube is which in the Peavey? (V1,V2) They aren't labeled. I have a PDF schematic of the amp but it doesn't make much sense. Also the Chinese tubes have stickers on them that say "made in China" ... does a sticker on the outside of a tube hurt tone in any way?
well first off your gonna get a much better sound using matched tubes instead of two random tubes from different companies. the best way to see whats in your peavey would be to look online or contact peavy and ask them.
Quote by Thepoison92
Go as a tampon
White shirt, white hat, white trousers (cheap ones) and cover the bottom half in fake blood, also have to write 'Tampax' on the shirt, so people know what you are and can then be disgusted.