Patent ID: 6970044

Claim:
An audio signal amplifier circuit comprising: a first, a second and a third differential amplifier which operate at a source voltage with respect to a reference potential or a voltage between the source voltage; an output stage having a first and a second transistor driven complimentarily; a first resistor connected to an input terminal; a second resistor connected to an output of the first differential amplifier circuit; and a first and a second feed back resistor connected to an output terminal of the output stage circuit, wherein the first differential amplifier circuit receives an input signal via the first resistor and inputs an output signal to the second and third differential amplifier circuit via the second resistor, the second differential amplifier circuit drives one of the first and the second transistor, the third differential amplifier circuit drives the other of the first and the second transistor, and an output signal of the output stage circuit is fed back to an input of the first differential amplifier circuit via the first feed back resistor and to inputs of the second and the third differential amplifier circuit via the second feed back resistor.