AUDIO POWER AMPLIFIER

摘要

PROBLEM TO BE SOLVED: To surely prevent a pop noise caused at application of power and at releasing mute without relying on a capacitive element for use of time constant formation having difficulty in semiconductor integrated circuit processing in an audio power amplifier that attached importance to environment in a listening sense. SOLUTION: The audio power amplifier has an amplifier circuit 11 that amplifies power of an audio signal to drive a loudspeaker, a sequential circuit 21 that is digitally stepped with a pulse signal given externally for mute release control and a variable impedance circuit 12 that stepwise changes an equivalent impedance in response to the stepping of the sequential circuit 21. This variable impedance circuit is interposed in a transmission path for the audio signal as a gain control element to conduct mute release control by a pulse signal.