VARIABLE GAIN DEVICE

摘要

PURPOSE: To obtain a variable gain device comprising a DSP with less sound quality deterioration by combining a variable gain through multiplication processing by the DSP with a variable gain of a D/A converter output level. CONSTITUTION: A gain to minimize the reduction in an effective bit length of an input signal to a D/A converter 105 is secured in the multiplication processing of a DSP 104. Simultaneously in a variable output level device 106 comprising an analog circuit in which a gain of an output level of the D/A converter 105 is varied, one of plural setting gains is selected by switch operation by a digital control signal from an external output port of the DSP 104 and a desired gain is obtained by the sum of the gains. Then the gain is varied by changing regularly the gain.