| 摘要 |
PURPOSE:To realize a double response to a built-in volume circuit and an outside-installed volume circuit by a method wherein the volume circuit installed in a sound source tip which forms a computer game device is provided with sound volume control function and an external volume control mechanism. CONSTITUTION:In a sound source tip having two built-in channels of adaptation difference pulse code modifying decorders (ADPCM) and a programable sound generator (PSG) as a sound output part, for a volume/volume control circuit, a voltage controlling amplifier (VCA) is provided on both of the right hand and the left hand to control sound volume of PCM voice signal from an external sound source (compact disk). At an input terminal of the respective VCA, two output terminals are provided which correspond to the input terminal. These output terminals are provided as a VCA output terminal VCAR-OUT and a VCAL-OUT when they are used as a built-in circuit, and a VCA output terminal VCAR and a VCAL for the outside volume circuit. |
