In a multichannel amplifier according to the present invention, in a case where a headphone is not connected to a headphone output terminal, a switch IC and first to third switches are on/off controlled by a control unit so that an audio signal path for outputting a front channel signal FL/FR to a front speaker and extending from a first input terminal 1 to a front speaker output terminal 6 via a buffer circuit 10a, a switch IC 9, a first volume control unit 3a, a buffer circuit 10b, and a first amplifying unit 4a is not electrically connected to another audio signal path.