CLEAN-FEEDS TO C203
An outside source is any contribution to a programme that is not coming from the same studio as the main production. Three common examples are the telephone 'phone in' sources, programmes which have an interviewee in a different (remote) studio, and/or an IDSN link.

Most circuits outside the studio buildings will cause a time delay to signals passing over them. With some microwave international links the delay may be significant amounting to several seconds. If remote contributors hear the delayed signal, sounding like an echo, conversation can become impossible. Even without delays, feedback problems can arise when the remote contributor uses a loudspeaker to hear the interviewer-instead of headphones. Sending a clean feed avoids all time delays and feedback problems.

A clean feed is a mix of all channels EXCEPT the remote source. If three remote sources are to be used in the same programme three clean feeds and three C203's may be needed. Clean feeds are therefore associated with input channels of the console and the C203 module(s) to be assigned for a clean feed(s). Selection is by internal jumpers on all input channels, audition and sub-groups.

Clean feeds can be produced using subgroups or auxillary sends but the CAD 200 is provided with four busses designated as 'clean feeds'.Channels are selected to these busses by internal jumpers. The four busses allowing up to four different clean feed routings to be created.
                                                                                                                                     

The clean feed output is sent to the outside source. The incoming audio from the outside source brought in through the C203 channel associated with that clean feed. This means the remote contributor hears every channel in the console -which is faded up- except his/her own.
Many system will not need four clean feeds. The number is determined by the number of outside sources that are to be used simultaneously. If more than four are required, external switching of the outside source is required.