Item Type: Microphone Amplifier Module Description: 1. This carefully designed electret microphone amplifier can add a lot to your project 2. Fully assembled and tested circuit board with soldered 20-20KHz electret microphone 3. Has excellent power supply noise suppression 4. Most suitable for projects using FFT, such as voice converters, audio recording / sampling and audio response projects 5. On the back, we include a small trimmer potentiometer to adjust the gain. You can set the gain from 25 times to 125 times 6. Drop to about 200mVpp (normally, about 6 inches away), ideal for connecting to something that requires "line level" input without clipping, or up to about 1Vpp 7. Very suitable for reading from microcontroller ADC. The output is rail-to-rail, so if the sound gets louder, the output can reach 5Vpp! Use: Connect GND to ground and connect VCC to 2.4-5VDC. For best performance, use the quietest power supply available. The audio waveform will be output from the OUT pin. The output will have a DC bias of VCC / 2, so when it is completely quiet, the voltage will be a stable VCC / 2 volts (DC coupled). If the audio device you use requires AC-coupled audio, place a 100uF capacitor between the output pin and the input of the device. If you are connecting to an audio amplifier with a differential input or including decoupling capacitors, you do not need a 100uF capacitor. The output pins are not designed to drive speakers or the smallest in-ear headphones, but to connect them directly to the speakers, so you need an audio amplifier (for example, a 3.7W stereo amplifier). If connected to a microcontroller pin, no amplifier or decoupling capacitor is needed-connect the OUT pin directly to the microcontroller ADC pin