| 摘要 |
A control device for an FM car radio in which low frequency characteristics of the audio output signal are switched so that stereophonic music programs can be reproduced with enough bass sound and monaural speech or news programs can be reproduced without much bass sound but with desirable articulation. One embodiment of the device comprises a capacitor-resistor filter connected in series between the amplifier and the speaker for attenuating low frequency characteristics of an audio output signal only when monaural broadcasting is being received, a transistor for shorting the filter to send bass sound directly to the speaker only when stereophonic broadcasting is being received, and a pilot signal discriminator which outputs pilot signals to turn on the transistor only when stereophonic broadcasting is being received.
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