This is a mini 2 channels 3w amplifier with PAM8403. It is perfect for MP3/MP4/small audio systems,DIY amps,etc. And you could also power the board with 5V USB power supply.
Power supply: DC2.5-5.5 V. Output power: 3W + 3W (4Ω). SNR: 90dB. Efficiency: > 90%. Size: 15.5×۲۴ mm.
Single lithium battery or USB power supply is suitable, also can use 4 cells of 1.5V , but you must add 5V regulator circuit, more than 6V will burn IC out. + and – of power supply can’t be reversed, power supply voltage can’t be more than 6V, otherwise it will damage the IC. There were high gain buffers, can’t change any board device parameters. Input: please use shielded wire to avoid any interference and eliminate cluttering sound. Output is CMOS BTL drive mode,all 4 wires are completely independent, don’t connect together!