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. <EOS>