Item Type: Microphone Amplifier Module_x000D_ Description: _x000D_ 1. This carefully designed electret microphone amplifier can add a lot to your project_x000D_ 2. Fully assembled and tested circuit board with soldered 20-20KHz electret microphone_x000D_ 3. Has excellent power supply noise suppression_x000D_ 4. Most suitable for projects using FFT, such as voice converters, audio recording / sampling and audio response projects_x000D_ 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_x000D_ 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_x000D_ 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!_x000D_ Use: _x000D_ 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._x000D_ 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