| 摘要 |
PURPOSE:To listen to a reproduced sound with excellent sound quality even when an operating position of a sound volume adjustment variable resistor by detecting the operating position of the sound volume adjustment variable resistor and an input audio signal level and varying the frequency characteristic of a filter circuit in response to each detection output so as to apply frequency characteristic compensation to the filter circuit. CONSTITUTION:A microcomputer 7 retrieves a detection level data read from an output register 6 and a filter coefficient data group depending on an operating position data from a ROM in the microcomputer 7 and transfers the retrieved data to an arithmetic processing section 3 as a 2nd control signal. The frequency characteristic of a filter circuit 44 is a characteristic in which its output level is higher in high and low frequency ranges than that of an intermediate frequency range as the operating position data of the sound volume adjustment variable resistor is close to the MIN position and the characteristic is flat as the operating position data of the sound volume adjustment variable resistor is close to the MAX position. Thus, even when the operating position data of the sound volume adjustment variable resistor is close to the MIN position, a more flat characteristic is obtained as an input signal level is increased. |
