Two of the most often used amplifier building blocks in audio amplifier design are the common emitter amplifier with emitter degeneration and the emitter follower using the same circuit biasing.

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 ...

Figure 1 The addition of a simple diode in the emitter circuit yields the symmetric waveform in Figure 4. Figure 2 This amplifier circuit produces the distorted waveform in Figure 3. Diode D 1 ...