| 摘要 |
PURPOSE:To eliminate the need for a control signal line, by transmitting an operation start signal and an operation stop signal via an audio signal transmission cord. CONSTITUTION:As audio signal sources, e.g. a record player 2, a tape deck 3 and a tuner 4 are provided. When an operation start signal is transmitted from a desired audio signal source to an amplifier 1, the audio signal from the signal source is selected automatically based on it and outputted from the amplifier 1. The amplifier 1 transmits an operation stop signal to other audio sources in operation so as to stop automatically the operation. The operation start signal and the operation stop signal are transmitted via audio signal transmission cords 20L, 20R, 30L, 30R, 40L and 40R. The control signal line is not required, because the audio signal transmission cords are used in this way. |
