Class AB amplifiers

An amplifier in which the grid bias and alternating grid voltages are such that anode current in a specific tube flows for appreciably more than half but less than the entire electric cycle. A transistor amplifier whose operation is class A for small signals and class B for large signals. Combines Class A and B and current flows for 180º to 200º. Class AB designs are the most widely used for audio applications. Class AB amplifiers are typically about 50% efficient.

These amplifiers are usually 60-70% efficient.