Does anyone have a circuit for a switchable power stage on an amp?

[BoomTexan]

Would this be possible at all? I've ruled out doing this on a push-pull, too much work. I've been pondering over a single ended design where I could cut one of two 6L6 or EL34 tubes to bring it down to 6-10ish watts from 15-20ish. How would I go about doing this? It surely can't be as simple as cutting off the voltage to a single tube, but I'm curious as to how this would work.

 

[dan40]

I suppose that you could use a switch on the control grid wire leading to pin 5 of the tube that you want to cut off. This way the bias does not get messed up on the other tube that is still operating and the OT still sees the same load. You are basically cutting the AC signal to that one tube so that it has nothing to amplify. I believe that Mesa Boogie does a similar thing on one of their push/pull amps that essentially makes it a pseudo single ended power amp.