Abstract: A D-class power amplifier of two channels in which an increase in power voltage due to a regenerative current is prevented and a high efficiency in utilization of electric power is attained. Two D-class power amplifying circuits included in the D-class power aymplifier of the two channels are constructed by opposite phases. A preprocess is performed only to low frequency components of input signals so that they have a substantially equal amplitude in the two channels, and the resultant low frequency components are supplied to the D-class power amplifying circuits, respectively. The other ends of loads connected to the D-class power amplifying circuits are connected to a neutral potential point of the power voltage.