Even when both a digital audio signal and an analog audio signal are inputted, a type of inputted digital audio signal is identified, and an internal signal path is automatically switched based on the result of the identification operation and previously set content. A main storage of a host microcomputer 12 stores signal path information indicating a signal path to be selected for each type of digital audio signal inputted from each external AV apparatus. A DIR 3 identifies the type of digital audio signal inputted from a digital input terminal 1. The host microcomputer 12 switches an A/D switching selector 4 and an analog direct/DSP process switching selector 7 respectively so that a signal path corresponding to the type of signal shown in the result of an identification operation of the DIR 3 is selected, based on the signal path information.