"Kurt Albershardt" wrote in message
...
The more buses there are in the mixer (particularly subroups and other
buses which lie between the inputs and whatever outputs you are using) the
more potential gainstaging, noise, and grounding problems the designer has
to overcome.

I'm not sure why unused buses should add problems, switch them out of the
main mix.
OTOH if you really need them ...........

TonyP.