OP,
You are asking a lot of excellent questions regarding component selection and integration into an already well conceived system.
Here’s an analogy to think about, and in advance I’ll state there are additional layers that could be developed but that would take more time than I have right now.
Think about it like a multilevel chess game (or that game they played on STTNG). To get the equation or formula just right, you need to win on all of the levels. All levels involve compatibility.
One important level, and the one I was referring to in my first post regarding your Macs and why I thought pairing them with a warm dac would be bad is what I call the sound temperature level. I wrote about this recently on another thread but think about a sound spectrum from zero to 100, where 0 is cold, dull, boring, 100 is hot, hurts your ears, and 50 is neutral. 25-40 might be what some call “warm,” and 60-85 might be what some call “bright” (and you could fill rest of that spectrum in with any number of other descriptors but you get the point).
This is a good time to say there in no one right answer, even though some will claim there is. You might be a “20 person” and for you 20 is perfect on the temp chart. Or a 68 person, or a straight up 50 person. Like a sleep number bed. No right answer.
That said, we can think of each component as falling somewhere along the temp spectrum (though everyone hears differently and since no independent ratings org, we have to estimate).
Let’s say for sake of argument your Macs are 20-30 range. Just a guess I haven’t heard your stuff. Just illustrating the concept. And similarly let’s say your 800s are in the 75-85 range.
If that’s correct maybe that explains why Mc/BW historically a popular pairing ( since many people on sleep number scale may like a “final combined sound number” within 40-60.
I’m not saying final number a simple average (before someone jumps on me for that). This is discussional not scientific.
So anyway now you probably see why I implied adding a warm (20-30ish) dac might not be good synergistic addition.
Level two: Resolvability level. Not to be confused with cost level but somewhat related. You could also call this quality level but I like resolvability better. I’ll use my systems as example, and since dacs are topical here we’ll use them.
I own the Teac and Bluesound dacs/streamers and use both daily for multiple hours. For argument sake I’d say both of them fit within the 40-60 window above on the sound temperature scale described above (both fairly neutral). But on the resolvability scale of this level of the chess board they differ substantially. The former punches way above its $2k cost weight class to point I can comfortably use with my ARC/Spendor D series reference system (again, my reference is not at level of your reference, (but someday I will be hopefully)), and the Teac is not out of its league with the ARC and Spendor resolvability wise even though cost wise it is much lower cost (to my ears anyway).
The Bluesound, by contrast, no, it works in my much lower resolving system but that’s it. It can’t resolve at level of Teac and is like a C youth hockey player trying to fit in on the A team (everyone in the stands is like, wth is that kid doing on the A team, that’s a C player -I’m a youth hockey coach last 12 yrs, another reason explaining my 20 yr absence). The Bluesound would be out of place in my reference system (recall my earlier statements about where I can hear dramatic MQA improvements and where I can’t) and it would drag my reference system down in an unacceptable manner (like the C player pushed up to the A team).
A third level is cost and fitting everything within you budget and still winning at each level.
so those are three levels and you could extend it many more but I’m out of time for now .....
As with any analogy there will be infinite ways to poke holes in it. Offered as food for thought not as a holy grail of audio wisdom
