im looking at buying a stereo compressor/gate for my new rack setup, poss a behringer composer mdx2600 or similar, and i was wondering whether it is possible to use one channel before my preamp, to slightly compress and gate my guitar signal (pickups can be a little noisy), and use the other channel in the pre amps loop or after the outputs, without creating any sort of ground loop, which the preamp can be sensitive to.

cheers for any help
The Compressor is built to deal with a line level signal. Running it before the preamp it won't be nearly as effective, if at all.
Fender '72 Telecaster Deluxe Reissue -> Korg Pitchblack Tuner -> Boss PS-5 -> EHX Big Muff -> MXR EVH Phase 90 -> Menatone Pleasure Trem 5000 -> Line 6 Verbzilla -> MXR Carbon Copy -> Boss RC-2 -> Peavey Classic 50