VCA Group

A feature found on many high end live mixing boards. A VCA group provides the same type of control over signal levels that a mute group provides for muting. Basically, VCA groups allow the sound engineer to control the volumes of several independent sources through one control fader without having to route them all through a common subgroup. It is called a VCA group because Voltage Controlled Amplifiers are used. In fact every controllable channel in the desk has its volume controlled by a VCA (as opposed to audio passing through a resistive fader) in order for this to work. Some more modern (and expensive) designs have employed a motorized fader scheme (also known as Moving Fader), but these sometimes aren’t referred to as VCA groups since there may no longer VCA’s involved (see the Technical Tip of the Day from 04/09/2002 for more background on that).