Use receiver pre-out and multi-ch inputs as processor loop?

I think you would set-up a feedback loop if you did that.

I suspect that whatever comes into the MC Inputs would go out through the Pre Outs, then back In........

You need one of those rare units with PreOut/Power In jumpers.

My old school Marantz SR96 has them, but I could not name a current unit that still does.

Brian

Unfortunately, I have to agree with Brian. I'm not aware of any modern AVR or integrated amp which provides a "processor loop".

[edited to add: they used to be almost common shortly after the first external Dolby processors became available.]

To use an external multichannel equalizer, you'll need to connect it between the AVR's preamp outputs and a complete set of external amplifiers. (I used to do just that, using a THX graphic equalizer between my pre/pro and multichannel amp. I did away with the equalizer when I got a pre/pro with Audyssey.)

Pre-outs in modern AVRs come after the multichannel inputs, not before them. That is, signals going into the receiver by way of the multichannel inputs come out both on the pre-outs and on the speaker outs.