To provide an audio signal amplifier and an audio apparatus having the same that automatically set the output level to an optimum level depending on power supply voltage and so on. The audio signal amplifier of the present invention has an input terminal for receiving an audio signal from outside; a...http://www.google.de/patents/US20050047615?utm_source=gb-gplus-sharePatent US20050047615 - Audio signal amplifier and audio apparatus having the same
