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Adafruit Electret Microphone Amplifier - MAX9814 w/ Auto Gain Control

by Adafruit

This fancy microphone amplifier module is a step above the rest, with built in automatic gain control. The AGC in the amplifier means that nearby 'loud' sounds will be quieted so they don't overwhelm & 'clip' the amplifier, and even quiet, far-away sounds will be amplified.

This amplifier is great for when you want to record or detect audio in a setting where levels change and you don't want to have to tweak the amplifier gain all the time. 

The chip at the heart of this amp is the MAX9814, and has a few options you can configure with the breakout.

  • The default 'max gain' is 60dB, but can be set to 40dB or 50dB by jumpering the Gain pin to VCC or ground.
  • You can 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 that is up to 3.3V input. If you want to pipe it into a Line Input, just use a 1uF blocking capacitor in series. 


For audio-reactive projects, we suggest using an FFT driver library (such as the one in this library) which can take the audio input and 'translate' it into frequencies. If you just need to keep track of audio levels, see this sound-level meter tutorial for Arduino

Each order comes with one assembled and tested board, with an electret mic pre-soldered on, and a small piece of header. Adafruits tutorial will get you started with using and testing the microphone amplifier and you can check out their general-purpose microphone amplifier tutorial for other project ideas and code.

3 customer reviews

2 years ago
Works perfectly as advertised, good documentation and a nice set of example programs. I can take it from there. I have been thinking of but not actually buying it for literally years - the recent sale made me a buyer. Just the thing to amuse the piano-playing members of my family.
by Peter about Piano HAT via REVIEWS.io
5 years ago
Good fun to tinker with. Well built and of the highest quality.
by Daniel about Piano HAT via REVIEWS.io
9 years ago
Recently purchased one of these piano hat boards for my raspberry pi, as usual the service from Pimoroni was excellent and the board is of a really good quality. It's nicely laid out and the touch pads are a decent size. The board looks very classy with the black background and gold lettering and the software to go with it makes using the board very easy. Although it's laid out as a piano it could be used for anything which requires 16 capacitive touch pads and leds.
by Steve about Piano HAT via REVIEWS.io

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