A class-A amplifier is defined as an amplifier that is biased so that the output current flows at all times. Thus, the input signal-drive level to the amplifier is kept small enough to avoid driving ...

The almost universal choice in semiconductor power amplifiers is for a unity gain output stage, and specifically a voltage follower. Output stages with gain are not unknown, 1 but they are not common.

The circuit in Figure 1 sinks a constant current (ICE3) through Q3’s collector and emitter. This design is balanced so changes in Q3’s base-emitter voltage (VBE) don’t affect the current sink’s ...