Last night I found the answer as to why I love the compressor in Omni Channel so much:
It’s a coloring compressor. It adds harmonics to your signal depending on which type of compressor you choose: VCA, FET, or OPTO.
If you run a 1khz sine wav through the compressor and look at the result in a good spectrum analyzer, you’ll see some interesting behavior:
The VCA is the most subtle of the three, at least until you drive it, but FET and OPTO will add harmonics to your signal even before pulling down the threshold & adding compression. You get harmonics just by turning it on! This is separate and different from the saturation optionally added in the preamp section.
This makes the Omni Channel compressor considerably more interesting than expected and I think a lot of people don’t realize it has this functionality.
There’s more going on under the hood in this plugin than most people realize. Clearly, a lot of design & engineering went into it.
From the manual:
The Compressor module is made up of three different compressor units, each with very different characteristics.
• VCA is a very fast, transparent, linear compressor.
• FET is a slightly slower compressor. It has more distortion and color than the VCA, and it’s smoother.
• OPT (opto) is slow and very smooth, so transients are maintained.
Changing the compressor type does not alter the parameter settings, so you can efficiently compare the impact of
each compressor type on the signal.
PS. I don’t think many people use Scheps Omni Channel as a mix bus processor, but try it! I particularly love using the OPTO compressor on a full mix. It has similar harmonic addition as FET, but the response is slower and smoother, like the manual says.