| 摘要 |
PURPOSE:To avoid noise and to prevent sound volume from being changed by controlling the characteristic of an equalizer means according to the correction characteristic moved toward the cut processing if the setting characteristic includes boost and applying level control so as to cancel the change in the sound volume. CONSTITUTION:When the user applies boost setting, a microcomputer 24 controls electronic volumes VR0, VR1... toward the cut side as much as possible while keeping the similarity of the characteristic. Moreover, the input to an equalizer circuit 28 is varied by an electronic volume 22 so as not to change the level of the middle frequency of an output audio signal. Thus, the S/N is not deteriorated in the boosting and the high impedance design to decrease the capacitance of capacitor of a semiconductor inductor is attained. Since the sound volume change in the sense of listening is suppressed even if the setting characteristic is changed by the user, extra care such as sound volume adjustment after the equalizer characteristic setting is not required. |
