Abstract: An electrical audio power amplifier is connected to receive an input informational signal from a pre-amplifying stage functioning with a transducer or pick-up device such as a magnetic phono cartridge or tape head and connected to supply a transformerless output to drive a speaker to create audio sound waves substantially free of distortion. An input differential amplifier includes a first input supplying the input informational signal and a second input supplying the output informational signal and providing a differential output signal to an output amplifying stage including a pair of intermediate amplifiers and a power amplifier to directly provide the output informational signal to the speaker.