| 摘要 |
PURPOSE: To prevent a shock noise from being generated when canceling the muting of power source ON. CONSTITUTION: A muting signal is generated from a muting signal generating circuit 17 while muting amplifiers 8 and 9 with which stereo signals L and R are amplified and output signals are impressed to loads 10 and 11 to be grounded through a capacitor 12. Then, the muting of the amplifiers 8 and 9 is operated by turning off switches 15 and 16 corresponding to the muting signal. While the muting signal is generated, a charging circuit 18 is operated and the capacitor 12 is charged corresponding to the output signal of the charging circuit 18 so that its terminal voltage can be almost equal with the output midpoint voltage of the amplifiers 8 and 9. Therefore, the capacitor can be prevented from being rapidly charged when muting is canceled. |
