$7000 preamp vs $700 receiver - Is the difference THAT significant?

@scottscottsdale and @vinylshadow The AVR does NOT have a good DAC, as I understand it.  The Bluesound has a much more evolved DAC, so I'm running unbalanced line out (relying on the Bluesound DAC) with some "TIMBRE" series Kimber interconnects.

I also have an AppleTV4K, and Tidal sounds like garbage thru that source device.  I don't waste my time there.  

You said: ignore the multichannel but you have an AVR in there. What exactly is its function?
The AVR is a poor source and a poor preamp / amp. You don’t even have the top of the line which is somewhat better. You also have a underwhelming source (Bluesound). 
To hit both on the head you should indeed look for a multichannel pre/pro. The 8805 would be a good place to start. But you are stuck with Audyssey. Better still - a NAD M17. You draw two benefits from the NAD: you stay in the Bluesound ecosystem (V2 comes with a pretty decent streamer so you can forget about the separate box) and you get Dirac. You will further benefit from the balanced outputs, if your stereo supports them. 
The NAD will give you a flavour of what good stereo sounds like. You’re not quite there yet but will get you a bit closer. 

And why do you need Tidal MQA? I have a pretty decent DAC. And I prefer Qobuz for sound quality. 

Yes it is... But I would not buy McIntosh. There are better preamplifiers on the market in 7.000$ price tag. You may want to check Ear Yoshino 912 or Atma Sphere MP-3.

This thread has probably long since been exhausted...but has anyone here spoken about receivers made by Outlaw Audio? Curious how those might compare to the others mentioned. I’ve heard nothing but great things in terms of SQ.