| 摘要 |
PURPOSE:To improve the S/N using the dynamic range widely to a low level signal by providing a gain adjusting device to a pre-stage of an A/D converter and using the gain adjusting device for sound volume adjustment. CONSTITUTION:After an inputted analog sound signal is subjected to level adjustment by the gain adjusting device 4, the result is inputted to the A/D converter 1, where the signal to converted into a digital signal. The digital signal is subjected to control of proper sound quality by a digital signal processing section 2. A microcomputer 3 applies gain control of the gain adjusting device 4 and control for sound quality or the like in the digital signal processing section 2 through a bus line. Thus, the input adjustment of the A/D converter 1 is applied by the gain adjusting device 4 and sound control is applied also so as to improve the dynamic range by increasing the sound volume. |
