Electret Microphone Amplifier - MAX9814 with Auto Gain Control
Give your project excellent listening skills with this useful Electret Microphone Amplifier - MAX9814 with Auto Gain Control from PMD Way
This board arrives fully assembled, however inline header pins are included they aren't soldered to the board.
You will find an elecret microphone with a 20~20kHz range amplified by the useful MAX9814 - which has an automatic gain control, ideal for use when you can't predict the loudness of noise being amplified.
Automatic gain control takes care of turning the recording level down when things get noise, and up when things get quiet.
The default 'max gain' on the board is 60dB, however you can change this to 40dB or 50dB by connecting the Gain pin to VCC or ground respectively.
You can also change the Attack/Release ratio, from the default 1:4000 to 1:2000 or 1:500. The ouput from the amp is about 2Vpp max on a 1.25V DC bias, so it can be easily used with any Analog/Digital converter has an input rated up to 3.3V.
If you want to pipe it into a Line Input, just use a 1-100uF blocking capacitor in series (100uF sounds best).
For audio-reactive projects, use an FFT driver library which can convert audio input into frequencies.