Abstract: A highly efficient class-B current source audio amplifier with little heat generation having one amplifier half fixedly biased with the other amplifier half slave biased to the first. Each amplifier half contains a tandem chain of unmatched transistors. The first amplifier half has separate ambient and load temperature controls to substantially minimize distortion due to any change in the operating characteristics of the transistor chains and to substantially minimize the possibility of power transistor failures due to overheating.