Introduction

The board adopts the PAM8403 typical circuit design, the use of MICRO USB power supply (reserved welding wire interface), is very convenient to use universal mobile phone charger for the power supply, resistance container parts adopt standardized SMT process, simple and stable design special interface for Bluetooth audio receiver module, can easily DIY little Bluetooth speakers the board can pick up 8 ohms 4 ohm small speakers, suitable for all frequency horn or full frequency small speakers.
Single lithium battery or USB power supply is suitable, also can use 4 cells of 1.5V, but you must add a 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.
The output is CMOS BTL drive mode, all 4 wires are completely independent, don't connect together