Dsloger 5V DIY Active Speaker Kit With Black Case Circuit Rationale:APS-2 active speaker is mainly composed of amplifier circuit and a level indication circuit. The amplifier circuit uses class D audio power amplifier chip PAM8403, with Class D amplifiers can provide AB class amplifier power efficiency. Stereo audio signal from J1, because the left and right channels are completely symmetrical. -Working voltage: 5V -Amplifier power: 3W * 2