[codefox1]

Some transistorized preamps have an output capacitor that can send a DC charge to the following amplifier, abd sometimes they shorted, and some power amps have no input capacitor that will nullify the defect. So, you can turn the preamp on first, then the amp and not get the thump which can still easily blow out a speaker. You can wire in a capacitor between the input jack of the power amp and it's first stage of amplifiation. And just what value should you use? The answer is "it depends." I would personnally start with an .05 mfd 620 volt and see how it sounds. I assume that both machines have, or have been converted to proper 3 wire grounded recepticles, and the "death capacitors" have been removed. Use crap speakers and resistive loads in parallel when trying out these tests, and let us know what you find.