PURPOSE: To obtain a sound volume control circuit having a proper sound volume characteristic meeting the operation of the user by using sound volume changing characteristics in combination for each of plural DC converting means and furthermore adjusting an output level of one DC converting means by a variable resistor.

CONSTITUTION: When a transistor (TR) 4 is turned off, an electric charge is charged to capacitors 10a, 10b respectively via resistors 5a, 5b and diodes 7a, 7b. When the TR4 is turned on next, the electric charge is discharged from the capacitor 10a via a resistor 8a, a diode 20a, a variable resistor 21, and a resistor 22, and the electric charge is discharged also from the capacitor 10b via a resistor 8b and a diode 20b. The voltage of the capacitors 10a, 10b decided by the charge/discharge in this way is attenuated for the former capacitor by the variable resistor 21 and applied to the cathode side of a diode 23a, and the voltage of the latter capacitor is applied to the cathode side of a diode 23b respectively. Thus, the base voltage of a TR11 depends on a higher voltage of the said cathode voltages and a sound amplifier 13 is controlled by an output voltage from the emitter of the TR11 depending on the said higher voltage.