29 Jun '14, 8am

Automatic Audio Leveling Circuit Makes Scanning More Fun

Automatic Audio Leveling Circuit Makes Scanning More Fun

Alan’s circuit is essentially an attenuator. It takes speaker level audio in (exactly what you’d have in a desktop scanner) and outputs a limited signal at about 50mv peak to peak, which is enough to drive an auxiliary amplifier. The attenuator is made up of a resistor and a pair of 1N34A Germanium diodes. The more bias current applied to the diodes, the more they will attenuate the main audio signal. The diode bias current is created by a transistor-based peak detector circuit driven off the main audio signal. But don’t just take our word for it, watch the video after the break.

Full article: http://hackaday.com/2014/06/29/automatic-audio-leveling-c...

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