PURPOSE: To switch an arbitrary mode by operating a changeover switch provided in a remote controller, varying a remote resistance value, and outputting a mode switching signal in desired combination from a plurality of comparators provided at a stereophonic body side.

CONSTITUTION: One side of a remote controller 12 is connected directly to a reference voltage output line of an audio signal line, and used as a reference voltage of a remote control circuit. On the other hand, a plurality of comparators 44, 45 are provided at a stereophonic body to compare remote terminal outputs with different remote reference voltages. The output of both the comparators 44, 45 are supplied to a mode selector 36, which outputs a desired mode output. Here, a comparator output responsive to the combination of the switches can be obtained by turning ON, OFF of changeover switches 41, 42. Thus, many modes can be selected by less switches.