The microphone board adopts karaoke special chip PT2399, SMD process, stable performance. The power supply adopts a single power supply, with a rectifier circuit, which can be used for both AC and DC. The microphone board front and rear amplification uses AD828 fever-grade op amp chips, By setting the jumper cap, both electret microphones and dynamic microphones can be used. Working voltage: DC7-24V Potentiometer spacing: 25mm (potentiometer fixed version) Distance between two microphone sockets: 28mm JP1, JP2 function description: If the microphone type is set, by setting JP1, JP2, two types of dynamic microphones and electret microphones can be used. There are matching shorting caps. When the shorting cap is plugged in, the electret microphone is used. circle microphone. Color: Red Material: Plastic+Metal Package Contents: 1 x Microphone Board 2 x Cables