| 摘要 |
PURPOSE:To reduce a high frequency noise such as multi-path when an FM radio program is received. CONSTITUTION:A switching circuit 9 is turned on by an output of a control circuit 8 in modes such as an AM radio mode and a CD mode other than an FM radio mode, a capacity of C1+C2 is connected to an electronic attenuator 4 and a signal having a usual loudness characteristic is obtained. In the FM mode, the switching circuit 9 is turned off and only the capacity of C1 is connected to the electronic attenuator 4 and a median of a high loudness frequency is shifted toward high frequencies and a gain nearly 10kHz is reduced to reduce the effect of multi-path noise or the like. |
