Use one of the latest chips on the block to produce an audio pre-amp with AGC compression, limiting, and noise reduction.

Intended primarily as a means of processing microphone inputs to computers, the SSM2166P integrated circuit (IC) --manufactured by Analog Devices-- has a wider range of possible applications. Public address and surveillance systems immediately spring to mind, and the device will be of particular interest to radio enthusiasts, especially now that the popular Plessey 6270 IC mic/pre-amp, with voice gain, is no longer available.

This construction article describes how the new IC can be used for a variety of signal inputs, and additional circuitry is given for readers who require a signal-strength meter.