PURPOSE: To improve the connection easiness of AV connection cables by providing terminals indicating various source device codes, and determining and displaying a source device connected to a connector on the side of an AV selector.

CONSTITUTION: A discrimination terminal is provided, setting one for an RCA pin and the other for a multiple connector pin 4, indicating device codes. An AV signal 6 inputted to the multiple pin connector 4 is inputted to a selector 9 to be selected by a selection signal from a microcomputer 8. In the meanwhile, discrimination signals set as in a figure (c) are inputted to the microcomputer 8 to be determined according to the connectors for determining a connected device. Need of inserting the connecting connector into a designated position can thus be eliminated, the device can be determined if it is inserted into a desired position, and by adding and changing the discrimination signal, increase of the sorts of the connection cables can be restricted.