| 摘要 |
PURPOSE:To eliminate a variable resistor which necessitates mechanical operation and to obtain a sound output with high quality by providing a circuit to change a sound output level before a digital signal is converted to an analogue signal when the sound signal is reproduced. CONSTITUTION:The sound output signal from a pre-amplifier 3 is converted into the digital signal by FM demodulation circuit 4, passes through a correction circuit 5 and an output level is changed by a sound output level variable circuit 12, and then converted into the analogue signal at an AHD sound signal circuit 13 and outputted from an output terminal 15. Since the output level of the sound signal is changed digitally, it becomes unnecessary to provide the variable resistor, etc. which entail mechanical operation, and high quality sound out put without noise, etc. is obtained. |
