Specification: Origin: Mainland China Type: Module Condition: New Model Number: Microphones Amplifier Board Operating voltage: DC 2.3V to 5.5V Board size: 25*20*3mm/0.98*0.78*0.12in 1. Using ST imported K472 electret microphone amplifier chip, the chip has low noise. Gain adjustable, wide power supply, can be differential output, can also be single-ended output 2. Microphone has been connected: microphone positive + negative -, GND on the board for shielding, do not need to connect the microphone (also can not meet, meet, but good to avoid interference) Output Connection: 1: Differential Output: Connect The Signal +, -, The Center Of The Gnd Grounded 2: Single-Ended Output: Connect The Signal +, The Middle Of The Gnd Connection To Ground 3: Dual-Channel Output: Signal + When The Channel, Signal - When The Track, Gnd Grounded Middle Three kinds of output connection, you can choose according to need. Note: Circuit board power supply is good not to use switching power supply, otherwise low noise, interference may be very serious.  Due to the different monitor and light effect, the actual color of the item might be slightly different from the color showed on the pictures. Thank you! Please allow 1-2cm measuring deviation due to manual measurement. Included: 1*Electret Microphones AMP 1.ST Imported K472 Chip: The K472 electret microphone amplifier board utilizes the high-quality ST imported K472 chip, known for its low noise and excellent amplification performance. 2.Easy Connection: The microphone is already connected to the microphones amplifier board, simplifying the setup process. Connect the microphone's positive and negative terminals, with the GND on the board serving as the shield (not required but recommended to avoid interference). 3.Multiple Output Options: The microphones amplifier module offers flexibility in output connections. For differential output, connect the signal positive and negative terminals, with the middle connection serving as the ground (GND). For single-ended output, connect the signal positive terminal, with the middle connection used as the ground. For stereo output, utilize different signal and ground connections for each channel. 4.Wide Power Supply Range: Whether you have a lower or higher voltage power supply, the end-electret microphone preamp can accommodate your needs. Its wide operating voltage range allows for flexibility in powering the board, ensuring compatibility with different setups or projects. 5.High-Quality Performance: Advantage from the ST imported audio amplification board, which guarantees exceptional audio amplification with low noise, adjustable gain, and reliable power supply support.