So you have a great hi end stereo preamp, but

@millercarbon

"Oh, he can. For sure. Probably does. So what? Its still ruining the sound merely having the thing in the same room. People probably think I’m kidding, or exaggerating. I am not. I tried all this stuff, and with much better processors than any avr! HT is a wasteland. Guaranteed to bring down any system, any price, even just being in the room and turned on. Not even necessary to connect it to anything. Its that bad."

Nonsense.

There's plenty of products known to improve sound merely being plugged into an outlet. So we know for a fact things plugged in can affect the sound quality of other things that are plugged in. You seem to think this is a one-way street. That things connected to the grid cannot harm sound quality.

Nonsense.

It's pretty simple really, AVR's suck for 2 channel audio! They were designed for multi channel surround sound, and that's the domain that they should stay in. If you desire quality 2 channel sound, then you will need to open your wallet. Anything else is just a compromise. 

Its still ruining the sound merely having the thing in the same room.

With due respect, I suggest that musical enjoyment is not ruined by an AVR but rather by this type of attitude.

Besides, it's pretty easy. There are great preamps with HT bypass as mentioned above. 

My gear doesn't have that, but it does have balanced XLR outs - I use a preamp and a separate HT pre/pro (no amp stage).  I built a Neutrik connector patch bay and it works perfectly well and is basically the same as throwing a switch, probably better. Amps get the signal from the patch bay to their XLR inputs.  

The patch bay does more than this too - you can switch signals to different amps, easily patch in a piece of visitor gear, or whatever.  But of course that makes my listening room look more like a pro audio studio than a Temple to Sound.