PURPOSE: To save number of DC blocking capacitors into one by connecting one input terminal of the 2st and 2nd speaker loads to an output terminal of the 1st and 2nd power amplifier sections whose output terminal DC potential is equal to each other, connecting the other input terminal of each speaker and connecting a capacitor between the connected part and ground.

CONSTITUTION: The 1st and 2nd power amplifier sections 2, 4 are conventional power amplifiers provided with complementary output stages 10, 11 and the DC potential at the output terminal is nearly 1/2Vcc. Thus, the DC potential of each output stage gives no effect on the current flowing from the output terminal of the 1st power amplifier section 2 to the output terminal of the 2nd power section 4 through the 1st speaker load 6 and the 2nd speaker load 8. Similarly, the converse flowing gives the same effect. The connecting point between the 1st speaker load 6 and the 2nd speaker load 8 is grounded in terms of AC and only the AC signal is driven by the speaker loads 6, 8.