| 摘要 |
PURPOSE:To make it possible to perform sound volume adjustment and left and right sound volume balance adjustment by digital control by providing only each one-stage volume on the signal line of left and right channel CH. CONSTITUTION:Signals of left and right CH are inputted to terminals L21 and R21 and are outputted to output terminals L22 and R22 through volumes 21 and 22 which have the attenuation quantity controlled by switches A1-A16 and A17- A32. Volume control circuit 23 counts pulses of oscillator OSC on a basis of up/ down counters B1 and B2, and the counted output controls switches A1-A32 through decoders D1 and D2. Signals for sound volume increment and reduction and balance adjustement are applied to terminals 231-234. |
