Adafruit Stereo 2.8W Class D Audio Amplifier - I2C Control AGC
Adafruit Stereo 2.8W Class D Audio Amplifier - I2C Control AGC - A mini class D with AGC and I2C control? Yes please! Able to deliver 2 x 2.8W channels into 4 ohm impedance speakers (@ 10% THD) it has an i2c control interface as well as an AGC (automatic gain control) system to keep your audio from clipping or distorting.
Adafruit Electret Microphone Amplifier - MAX9814 w/ Auto Gain Control. 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.
Glomex Nashir AGC - the marine TV antenna with automatic gain control amplifier - Tronnixx in Stock - http://www.amazon.com/dp/B015MQEF2K - http://audio.tronnixx.com/uncategorized/glomex-nashir-agc-the-marine-tv-antenna-with-automatic-gain-control-amplifier/