| 摘要 |
PURPOSE:To freely set sound quality in response to the request of a user by providing a control voltage level variable means operating a 2nd sound quality control means and varying a control voltage fed to a 1st sound quality control means so as to vary the sound quality variable quantity freely. CONSTITUTION:A DC control voltage signal VCO in response to a level of an input signal Vi is given to a control terminal via resistors 6, 7, 8 in a voltage control sound quality variable circuit 4, which varies the sound quality of an audio signal automatically. The audio signal through the circuit 4 is inputted to the 2nd sound quality control means, that is, a sound quality adjusting circuit 5, where the frequency characteristic of the audio signal is controlled by adjusting a variable resistor 53 in the circuit 5. On the other hand, a control terminal of the circuit 4 is connected to a slider of the variable resistor 10 via a resistor 9. One terminal of the variable resistor 10 is connected to ground, the other terminal is connected to a power supply Vc and the slider is interlocked with the slider of the variable resistor 53. That is, in response to the operation of the variable resistor 10, the level of the control voltage signal VCO fed to the voltage control sound quality variable circuit 4 is changed. |
