Returns accepted within 3 days, only for damaged or wrong products. Return offered in the form of Cash refund or Product exchange. Buyer is responsible for the shipping fees.
The Kit is using the audio amplifier chip LM386, a simple external circuit, the audio signal is amplified. Circuit is simple, less use of components, welding easy. Sound volume are good, high cost, widely used in small speakers and other equipment.
2. Circuit theory: The main circuit LM386 audio amplifier chip and audio input adjustment circuit. By potentiometer can adjust the size of the input audio signal, thereby controlling the size of the output audio outputs.