stepped volume control

Conventional rotary or slider potentio-meters suffer from several disadvantages when used as volume controls in an audio system. The ganged, logarithmic potentiometers which are frequently employed in stereo amplifiers fre-quently suffer from poor matching of the two channels, so that the relative signal levels or balance of the left- and right channels vary as the control is operated. Carbon potentiometers also have a relatively limited life and soon become noisy in operation. One solution to these problems is to use a stepped volume control consisting of a switched, resistive potential divider, as shown in figure 1. This circuit has sev-eral advantages over a conventional potentiometer.