AC/DC converter, large power output

[Chris Smith]

I see where you are going there. Transformer plus the variac.

[bobsRAC]

If you're not running the amp for hours at a time, you could put a 10 - 20A supply in parallel with a car battery and a large bypass cap.

[Phaelium]

That sounds like a plan, but how and why do you wire in a bypass cap? What size would you suggest?<p>Thanks