Patent ID: 8270631

Claim:
A multichannel audio amplification apparatus comprising a speaker terminal group TA for connecting an A-type speaker group including at least one surround speaker for reproducing only a surround sound included in a multichannel sound and a speaker terminal group TB for connecting a B-type speaker group including no surround speaker; the multichannel audio amplification apparatus further comprising: an audio output circuit for outputting one of a multichannel audio signal and a stereo audio signal obtained by the multichannel audio signal subjected to a mixing process; an amplifier circuit including a plurality of amplifiers for amplifying one of the multichannel audio signal and the stereo audio signal; a selective output circuit for selectively outputting one of the amplified multichannel audio signal and the amplified stereo audio signal by switching to an arbitrary speaker terminal out of the speaker terminal groups TA and TB; a speaker detection circuit for detecting whether or not a speaker is connected to an arbitrary speaker terminal out of the speaker terminal groups TA and TB; a control circuit for controlling the audio output circuit, the amplifier circuit, the selective output circuit and the speaker detection circuit; and an operating circuit and a display circuit connected to the control circuit; wherein in a case where the speaker detection circuit detects that no speaker is connected to one of the speaker terminals of the speaker terminal group TB, the control circuit controls the audio output circuit and the selective output circuit in such a manner that output signals of the plurality of amplifiers are output to none of the speaker terminals of the speaker terminal group TB, and controls the display circuit to display that an operation for using the B-type speaker group by the operating circuit is impossible, while in a case where the speaker detection circuit detects that the speaker is connected to one of the speaker terminals of the speaker terminal group TB, the control circuit controls the display circuit to display that the operation for using the B-type speaker group by the operating circuit is possible.