Description: The MAX4466 is a micro power operational amplifier optimized for use as a microphone preamplifier. Add an ear to your project with this well-designed which has excellent power supply noise rejection. On the back, we include a small trimmer pot to adjust the gain. You can set the gain from 25x to 125x. That's down to be about 200mVpp (for normal speaking volume about 6" away). Using introduction: Connect GND to ground, VCC to 2.4-5VDC. The audio waveform will come out of the OUT pin. The output will have a DC bias of VCC/2 so when it's perfectly quiet, the voltage will be a steady VCC/2 volts (it is DC coupled). If the audio equipment you're using requires AC coupled audio, place a 100uF capacitor between the output pin and the input of your device. If you're connecting to an audio amplifier that has differential inputs or includes decoupling capacitors, the 100uF cap is not required. Features and benefits: Power supply voltage: + 2.4V to + 5.5V (can be directly connected to STM / ARDUNIO / Raspberry Pi and other development board) Power supply rejection ratio: 112dB Common mode rejection ratio: 126dB AVOL: 125dB (RL = 100kΩ) rail-to-rail output Static supply current: andlt;24μA Gain bandwidth: 600kHz Size: 20.8mm x 13.8mm x 7.5mm/0.8 x 0.5 x 0.3inch Applications: Cellular phone Digital repeater Headphones Hearing aids Microphone preamplifier Portable computer Speech recognition system Package included: 5 x MAX4466 Electret Microphone Amplifier Module 5 x 3pin 1 x 15pin DuPont Wire Female to Male