Electret Microphone Amplifier Module MAX4466 with Adjustable Gain, 4 Pack

Electret Microphone Amplifier Modules with Adjustable Gain This set includes four MAX4466 electret microphone amplifier modules, each supplied with a pin header for straightforward connection. These compact boards are designed for audio capture and signal conditioning, making them well suited to voice conversion, audio recording and sampling, and audio-reactive projects that use FFT analysis. Each module arrives with a 20–20kHz electret microphone already soldered in place, so you can begin experimenting without additional assembly. Simple Wiring and Power Requirements Connecting the modules is straightforward. Ground the GND pin and supply VCC with 2.4–5V DC; for the best performance, use the quietest available supply, such as a 3.3V rail. The audio waveform appears on the OUT pin, biased at VCC/2 when idle, which means the output is DC coupled. If your audio device requires AC-coupled audio, place a 100µF capacitor between the output pin and the device input. When connecting to an amplifier with a differential input or a built-in decoupling capacitor, the extra capacitor is not needed. Output Flexibility for Different Setups The output pins are not intended to drive speakers directly, but they can drive the smallest in-ear headphones. For louder playback, use an audio amplifier such as a 3.7W stereo amplifier. Alternatively, you can connect the OUT pin straight to a microcontroller ADC pin without any amplifier or decoupling capacitor, which keeps the setup simple for direct sampling. Adjustable Gain and Audio Performance Each module includes a small trimmer potentiometer on the back to set the gain from 25x to 125x, giving you control over sensitivity for different input levels. The board offers a power supply rejection ratio of 112dB, a common mode rejection ratio of 126dB, and an open-loop voltage gain of 125dB with rail-to-rail output. Quiescent supply current stays below 24µA, and the gain bandwidth is 600kHz, supporting clean capture of the 20–20kHz audio range. Ideal for Audio-Reactive Projects For audio response work, the FFT driver library is recommended, as it takes the audio input and translates it into frequency data. This makes the modules particularly useful for projects that respond to sound, such as visualisers or spectrum analysers. Please note that the output is not designed to drive speakers or earphones directly, so keep the signal path within the intended amplifier or ADC setup.