Electret Microphone Amplifier - MAX4466 with Adjustable Gain
This fully assembled and tested board comes with a 20-20KHz electret microphone soldered on. For the amplification, we use the Maxim MAX4466, an op-amp specifically designed for this delicate task! The amplifier has excellent power supply noise rejection, so this amplifier sounds really good. This breakout is best used for projects such as voice changers, audio recording/sampling, and audio-reactive projects that use FFT.
A small trimmer pot to adjust the gain, lets you set the gain from 25x to 125x. That's down to be about 200mVpp (for normal speaking volume about 6" away) which is good for attaching to something that expects 'line level' input without clipping, or up to about 1Vpp, ideal for reading from a microcontroller ADC.
Using it is simple: connect GND to ground, VCC to 2.4-5VDC. For the best performance, use the "quietest" supply available (on an Arduino, this would be the 3.3V supply). The audio waveform will come out of the OUT pin. The output will have a DC bias of VCC/2 so when its 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.
- +2.4V to +5.5V Supply Voltage Operation
- Versions with 5nA Complete Shutdown Available
- Excellent Power-Supply Rejection Ratio: 112dB
- Excellent Common-Mode Rejection Ratio: 126dB
- High AVOL: 125dB (RL = 100kΩ)
- Rail-to-Rail Outputs
- Low 24µA Quiescent Supply Current