The module's anti-noise ability has been greatly increased, the sound is clear and identifiable, very quiet, without impact, and the sound is clean and no noise! Using dual-bridge power supply, each chip has a separate rectifier bridge and capacitor system power supply, of each other, without affecting each other, and further improving the channel separation of the left and right channels! The white 3P audio socket is a common standard socket in the industry, which can be connected to external audio modules such as decoder boards and Bluetooth modules, and is widely used! The blue 3P terminal can be directly modified with various pre-stage tuning boards and volume potentiometers, etc., which is convenient and quick to use! Regarding the power supply, we recommend using a 40W-80W dual power transformer 11V-15V. Remember: If the voltage is too high, it blow up, because this is a small and medium power design, it is a small board, it is best to measure the voltage before powering on! Product model: LM1875 dual-channel 2.0 stereo pure power amplifier board Module weight: 75 grams Power supply: dual power transformer 11-15V is recommended not to exceed 15V Output impedance: 4ohm 8ohm Power: 2X20W chip output Advantages: excellent material, simple structure, using classic power amplifier circuit, good effect, not picky Just find a small 50W transformer and you can easily up! colour:Black Material:abs size:Approximately 68 x 76mm Package Contents: 4 amplifier board Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.