dale and all, There are now high power amplifiers on a chip, except that the large capacitors required for input/output D.C. blocking are still external.
The last one I saw was a 50 wat per chanel unit on a board that measured maybe 3 by 3 by 2 inches including several large condensors. The chip was maybe 1 by 2 by 1/4th inch these use an amplification mode called Class E which I don't understand but it involves modulating the power to the amp at a very high frequency and changing the duty cycle to produce the appropriate output levels after condensor filtering. Very low noise, very low distortion etc. and pretty cheap. As for power supplies, they're all switchers, they rectify the 110 volts and turn it back into high frequency A.C. then can transform it up wor down and rectify it again. Then they charge a condensor with a pulsed voltage that varries in its duty cycle just enough to keep the cap charged up to the desired voltage. No large components except a few electrolytic caps. As for transistors on a chip, they'rre pretty much doing this at the nearly atomic level now, nothing "moves" except "holes" or charge carriers. Take a course in advanced solid state physics! Tom
