Power amplifier

摘要

A power amplifier which has a muting circuit bringing the power amplifier into a muting condition when an excessively large input signal is applied. The power amplifier comprises a preamplifying stage and a power amplifying stage. The preamplifying stage includes at least one transistor for driving the power amplifying stage. The collector of the transistor is coupled to one power source terminal. The emitter of the transistor is coupled to the other power source terminal through an electronic switch, and to the first power source terminal through a resistor. The electronic switch selectively connects the emitter of the transistor to one of the power source terminals.