| 摘要 |
PURPOSE:To obtain a proper tone quality changing characteristic while using a voltage source by setting the changing characteristics of DC control voltages of outputs of Two D/A converters to be converse to a pulse width of the voltage source. CONSTITUTION:An output of a pulse width modulation voltage source 10 whose pulse width is controlled by a remote controller or the like is converted into a DC voltage by the D/A converter 11, outputted as a low frequency control voltage, and the output of the voltage source 10 is inverted by an inverter 13, converted into a DC voltage by the D/A converter 12 and outputted as a high frequency control voltage. Thus, the control of low/high tone is executed at the same time in opposite polarity by using one voltage source. |
