AVC for PCs:

An annoying phenomenon (not restricted to PCs) is that each and every programme that produces sound does so at a different level. This means almost constant adjustment of the volume control to ensure audibility of one programme and protection of the ear drums with another one. The control circuit described in this article is designed to obviate this nuisance: it constantly monitors the signal even at the output of the soundcard and adjusts it when required. Use of the circuit is not restricted to PCs; it may also be used as a dynamic limiter in existing audio equipment.