Gear & technology
Class AB
Also called Class AB amplifier
A Class AB amplifier uses two output devices that each handle one half of the waveform, with a small overlap so neither switches fully off. It is the standard design for most solid-state and tube power amplifiers, balancing efficiency with low distortion.
A pure Class B stage, with no overlap, distorts as the signal crosses zero. Class AB biases both devices slightly on, which removes most of that distortion while keeping efficiency around 50 to 70 percent at full power, much less at typical listening levels. Most integrated amps and receivers use it.
Some amplifiers run in Class A for the first few watts and AB above that, which makers advertise as the best of both. Class D has taken over where efficiency and size matter most.