An audio signal amplification device for amplifying an audio signal, comprising: an amplifier circuit configured to amplify an audio signal; a clock generation circuit configured to generate a clock signal for use in operations of the amplifier circuit; and a power supply circuit configured to receive input power, which is supplied from a power supply, and to generate direct current power, which is supplied to the clock generation circuit and to the amplifier circuit, wherein the power supply circuit includes: a constant voltage power generation circuit configured to generate the direct current power of a constant voltage from the received input power; a first capacitor; a first charging circuit configured to receive the input power as an input and to charge the first capacitor by using the input power; and a selection circuit configured to receive the direct current power generated in the constant voltage power generation circuit and the direct current power output by the first capacitor, to select one of the direct current power generated in the constant voltage power generation circuit and the direct current power output by the first capacitor on the basis of a charging state of the first capacitor and to supply the selected direct current power to the clock generation circuit, in order that when the clock generation circuit receives the direct current power output by the first capacitor, propagation of noise from the power supply circuit to the clock generation circuit can be suppressed. an amplifier circuit configured to amplify an audio signal; a clock generation circuit configured to generate a clock signal for use in operations of the amplifier circuit; and a power supply circuit configured to receive input power, which is supplied from a power supply, and to generate direct current power, which is supplied to the clock generation circuit and to the amplifier circuit, wherein the power supply circuit includes: a constant voltage power generation circuit configured to generate the direct current power of a constant voltage from the received input power; a first capacitor; a first charging circuit configured to receive the input power as an input and to charge the first capacitor by using the input power; and a selection circuit configured to receive the direct current power generated in the constant voltage power generation circuit and the direct current power output by the first capacitor, to select one of the direct current power generated in the constant voltage power generation circuit and the direct current power output by the first capacitor on the basis of a charging state of the first capacitor and to supply the selected direct current power to the clock generation circuit, in order that when the clock generation circuit receives the direct current power output by the first capacitor, propagation of noise from the power supply circuit to the clock generation circuit can be suppressed. a constant voltage power generation circuit configured to generate the direct current power of a constant voltage from the received input power; a first capacitor; a first charging circuit configured to receive the input power as an input and to charge the first capacitor by using the input power; and a selection circuit configured to receive the direct current power generated in the constant voltage power generation circuit and the direct current power output by the first capacitor, to select one of the direct current power generated in the constant voltage power generation circuit and the direct current power output by the first capacitor on the basis of a charging state of the first capacitor and to supply the selected direct current power to the clock generation circuit, in order that when the clock generation circuit receives the direct current power output by the first capacitor, propagation of noise from the power supply circuit to the clock generation circuit can be suppressed.