The remote control cards are designed to provide remote control of audio levels in professional, fixed installations. Each card can be used with either a remote potentiometer, or a "Preset Board" option. Typical applications allow level control, combining, and switching of audio signals, from remote locations. On the single and dual channel units, each input has two outputs. There is a direct, transformer isolated output, and a link output for combining signals. The link output is designed to be fed to one of the remote level controls with mixed output. The link feature allows larger remotely controlled mixers to be created. Each of the two outputs can be configured independently, to be either PRE or POST VCA. This allows one output to be level controlled while the other output level is constant (for recording, etc.). Or, both may be level controlled.