| 摘要 |
In the circuit arrangement for boosting low audio frequencies of a sound reproduction, e.g. in the form of a broadcast programme, a tape or cassette playback, the volume control normally provided is bypassed by tapping part of the audio frequency voltage on or upstream of the volume control, forwarding it via a chain comprising RC components and a potentiometer and then feeding it back in downstream of the volume control but upstream of an audio-frequency output amplifier, e.g. a broadcast receiver, tape recorder or cassette recorder. In order to prevent a short-circuit of the removed part of the audio frequencies or the part which is to be fed back in, a decoupling resistor is provided in each case between the potentiometer and the output amplifier or between the volume control and the output amplifier. By means of this circuit arrangement, the volume of low frequencies can be set independently of the general volume control due to the fact that the normal volume control is bypassed, the signal level in the diverted part of the audio frequency voltage increasing as the signal audio frequency decreases.
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