Abstract: To reduce errors due to the on-resistance of the switches. The electronic volume includes a first attenuator 2 whose input is connected to a signal input terminal 1, first switch S1 connected between an output of the first attenuator 2 and input of a output buffer 8, second switch S2 connected to a second attenuator 3 and between an output of the second attenuator 3 and an input of the output buffer 8, and a switching unit 7 connected to three attenuators 4, 5, 6 connected in series to the signal input terminal 1 and between respective outputs of the attenuators 4, 5, 6 and the second attenuator 3. The switch 7 includes a series circuit including a resistor whose one end is connected to the output of the attenuators 4, 5, 6 and the other end is connected to the input of the second attenuator 3 and three switches in series (R1 and S3, R2 and S4, R3 and S5) and a series circuit including a resistor connected in series between the other end of the three switches in series and ground (R4 and S6).

Abstract: A bass boost circuit of the present invention changes simultaneously the amplification gain in the voltage-controlled amplifier, and the cut-off frequency of the low-pass filter according to level of bass component of incoming signal. It does not become over boost state, and sound such as “flop” or “overshoot” is canceled, it will further be hard being fallen out by middle range of frequency, and there is advantage that vocal and the like can tend to be heard, even when small signal is inputted.