12AX7WA Versus 12AX7WB

[admin]

I understand that the 12AX7WB is substituted for the 12AX7WA when wanting to provide more gain. To what extent do you consider the difference to be audible. I ask this because I have made this swap and did not notice any appreciable change in gain or tonality in my Fender Twin reverb. Your comments would be appreciated.

[triode]

It depends on where you put the tube in the circuit. In a Fender Twin, V1 or V2 will give you the most noticeable difference. These tubes are very similar in that they are both made by Sovtek at the Reflector Tube Factory in Russia. Internal materials are similar such as the cathode, filament, grid wire and plate materials. Sovtek tubes have a "house" sound which is generally flat, uninvolving and neutral. If you are looking for more gain, I would try the new Re-issue Tung-Sol 12AX7 from New Sensor. This tube really rocks. We have them in stock.

[soundmasterg]

Peter, I only use 12AX7WA's and 12AX7WB's for function tubes myself...such as a tremelo tube. They don't sound all that great is the reason why. They do function for a long time however, and are usually very reliable. They're also a little lower gain than most 12ax7's. so they can sometimes tame a too active tremelo. If you want gain, the JJ ECC83S has a lot of gain. Remember though that gain and distortion aren't the same thing. If you want high gain out of one stage in your amp, then a high gain tube can do that. If you want the amp to have more distortion, well that gets into how the amp was designed and what parts were used to shape the tone. You can get part way there with tubes, but often, you have to revoice the amp.

I guess the new Tung Sols are good, though I haven't tried them yet myself. The new JJ ECC803S's are VERY nice. The Sovtek 12AX7LPS and Electro Harmonix 12AX7 are pretty good too. The EI 12AX7 sounds especially nice in a Vox AC30, but they are often microphonic. I've heard the Mullard copy Groove Tubes 12AX7C that is made in China is supposed to be good too, but they cost too much for me to try one.

Anyway, the best way to see the difference between tube types is to try them out yourself. It can cost a bit to do so but its worth it once you find the ones you like. NOS stuff generally lasts longer than modern manufacture stuff, but NOS stuff is getting more scarce and more expensive every day.

[admin]

Charlie: I very much appreciate your suggestion of the Re-issue Tung-Sol 12AX7 and your comments on V1 and V2.