Each power amplifier is biased from a common internal regulator to provide high power supply rejection, and output Q point centering. The LM1877 is internally compensated for all gains greater than 10 ...

TDA2003 is a cheap amplifier that is designed to run on single rail power supplies (unipolar). It provides a high output current capability (up to 3.5A), very low harmonic and cross-over distortion.

Notably, the MC601's extraordinary, distortion-canceling, quad-differential design consists of two complete amplifier circuits, whose outputs are combined in the unique McIntosh-crafted autoformers.