To improve voice sound quality using a vacuum tube amplifier. A reactive load that has impedance characteristics, in which impedance characteristics in a first frequency band includes a first impedance characteristic pattern selected from a plurality of first impedance characteristic pattern candidates on the basis of a type of a vacuum tube amplifier, and impedance characteristics in a second frequency band includes a second impedance characteristic pattern selected from a plurality of second impedance characteristic patterns on the basis of the type of the vacuum tube amplifier, outputs a signal that responds to a sound signal output from the vacuum tube amplifier in accordance with the impedance characteristics and performs correction on an output signal of the reactive load.