| 摘要 |
PURPOSE:To reduce a cross talk in a switch circuit by muting a voice signal system which is not used among the voice signals of two systems. CONSTITUTION:Muting signals MUT1, MUT2 are respectively supplied from a system controller 90 to sound intermediate frequency amplifiers 14, 24 and voice detecting circuits 15, 25. According to the execution of a sub-routine, when a VTR 40 is in a picture recording mode, the muting of the respective circuits is prohibited and when it is not in the picture recording mode, the switching position of a switch circuit 83 is discriminated, and at the time of a contact C or D, the muting of the respective circuits is carried out. Further when the circuit 83 is brought into a contact A, the muting of the circuits 14, 15 is prohibited by the signal MUT1 and the muting of the circuits 24, 25 is carried out by the signal MUT 2. At the time of a contact B, the circuits 14, 15 are muted and the muting of the circuits 24, 25 is prohibited. In such a way, at the time of operating the VTR 40, a speaker 57, and a color picture tube 53, an unnecessary voice signal can be muted.
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