Do you have a question about the Aiyima A03 and is the answer not in the manual?
Controls the amplifier's power state and selects audio input between Bluetooth and line-in.
Adjusts bass, treble, subwoofer frequency, subwoofer volume, and total volume for audio output.
Connects main left/right speakers, a subwoofer, and external audio sources via RCA jacks.
Includes a jack for the Bluetooth antenna and the DC power input port.