Best PC to use as a Server

It sounds like you’ve mastered some inexpensive workarounds and I salute you.  Unfortunately my IT skills are very limited, and I  don’t understand the bulk of your post.  I know what Raspberry Pi is but you lost me after that.  I do have a question about Audacious, however.  When you say it handles Classical Music, do you mean that it does a better job organizing Metadata than iTunes, et al?
And how do you rip CDs?
Regarding Linux—my understanding is that most Server/renderers, such as Bluesound, are Linux Computers.  Is that correct?
i

I can appreciate you wanting a Windows-based system. I use Ubuntu Linux on a $14 computer I bought at Goodwill (I use a $39 SSD in that).

I have 10 Tb of external drives and use that as my 'server'.

I use Raspberry Pi ($35) computers as endpoints on an SSH-network. (One has Allo-DigiOne SPDIF card, and another has Allo Boss DAC.)

 The music player, Audacious is small, uses between 2-4% of the RasPi processor to play music. And it handles Classical music just fine.
 
Most folks are afraid of Linux, but for my 'bang for the buck', free open-source is the way to go.

The newer macs all use USB C for connections i bought a $8 connector to run hdmi out of my macbook pro

look at small green computer, the inexpensive i5 linked should do what you need but they also have a more powerful i7 variant in a couple of configurations.  Using these for Roon core and then using the ultraRendu, Metrum's Ambre, or something similar as the endpoint should be a very satisfying sonic solution.
https://www.smallgreencomputer.com/products/sonictransporter-i5?variant=20893269700

for mac type solutions, you might also look at Mojo Audio
https://www.mojo-audio.com/

@jsd52756 
Thanks, I had never heard of eluktroniks.  The offerings look interesting and yes it does look like there are some sales going on.

Take a look at the audio specific pc's, headless, controlled from your phone, iPad, or laptop. 

I have, over time, used three of Small Green Computer's models. 

There are other pre-built and supported options or you can build your own.

I asked this myself in late 2016 https://forum.audiogon.com/discussions/looking-for-laptop-windows-10-for-music-only Folks recommended Eluktronics as a laptop and they seemed like a good choice as the mfg says they are loaded with basic Windows and no bloatware.  Looks like they have a good discount on now. 
I ended up just running my old Samsung series 9, upgraded to Windows 10 & Jriver 24 as my program.  It works really well.  If you've never used Jriver the learning curve is huge.  (For me anyway.)
Good luck, John

@jaybe  i’m New to that forum.  Every forum has it’s share of Aholes, but at least they can stimulate useful discussions.
@whart  I think you may have misunderstood me about Audirvana.  It loaded and works just fine, but my Computer is a 2011 Mac Air with a limited HD, and A+ and dbpoweramp seem to have gobbled up the what was left of my HD.  I couldn’t do the last Apple update because it was out of room.  Apple has increased the size of their programs and I recently had to get a new iPhone for the same reason.
  Audirvana + is a significant improvement over iTunes, but A+ from the Air still doesn’t compete with the same files played from my NAS via Bluesound or the Oppo.  I am looking to replace A+ and dbpoweramp with MusiCHI, which is reportedly much better for Classical Music.  In CM most of us want the Metadata listed in a very different way than is traditional for other genres.

@mahler123-- You said you had issues with Audirvana, but attributed that to the maxed out hard drive in your computer. Apparently, Audirvana now has a Windows-based program.
I’m using the Audirvana for Mac-- it sounds good, but I haven’t really compared it to much. I did have an Oppo 95 and found that the transport was a ’choke point’, i.e. there wasn’t a huge difference between the Oppo full on (using it both to spin the disc and using its DAC) vs Oppo as transport into a Border Patrol DAC. But, when I swapped out the Oppo for a better, Redbook only transport, that made a difference.
I’ve been reading as much as I can, but obviously, none of that is a substitute for listening to the set up in one’s own system.
As a long time vinyl guy, I’m pretty impressed with how good some of these Redbook CDs and files (even though I’m only processing them at Redbook resolution via the Border Patrol) sound. SACD sounded good via the Oppo, but my main interest is in obscure stuff, which I’m more likely to find on old CDs.
Again, no statement of absolutes here--I’m still just getting my feet (or ears) wet.
PS: this thread bears on the issue: [url]https://forum.audiogon.com/discussions/better-cdp-or-network-player/post?postid=1597772#1597772[/url]

I have used Macs as a source, but also Bluesound (Vault2 and Node)
and also my Oppo disc spinners will recognize my NAS.  Sonically, I prefer the Bluesound and the Oppo.  If you think about it, renderers such as Bluesound should sound better than a PC, since they have much bigger Power supplies and their parts are optimized for music replay, instead of general purpose computing.
  I think that you will find that the quality of the experience of file based listening (i.e., Computer Audio) is largely determined by the quality of the App that organizes the files.  Most of the apps are terrible for Classical Music, which is what I listen to.  The best is MusiCHI, but it’s Windows based.  I have no interest in using a program such as Parallels, that splits a Mac OS into a Windows and Mac environment, having had a bad experience with that before.
  We may not get a lot of responses here.  I might ask the same question on the Computer Audiophile Forum, which you might want to investigate as well.

I’m really new to digital, though an old analog hand. My impression is that a lot of folks think that general utility computers are not going to sound as good as purpose built audiophile type servers, even though those are computers too.
I’m still in the early throes of exploring all this for the first time. I have gotten a good Redbook transport, which most people seem to think is unnecessary, a modest NOS DAC, and set up a Mac Mini, tried to strip it down and adjust the settings according to some ’best practices’ I found on the web.
In the course of my research, which is continuing, I saw that HDPLEX offers builds that are meant for audio-- linear power supply, SSD and no excess stuff (though I can’t remember the operating system, if it is Windows, it’s gonna have a lot of bloat in it- how that impacts sound, I dunno). NB- a quick look disclosed some use a Windows server system, which is probably stripped down.

 Be interested to see what the responses are to this. So count me in on your side of the question, rather than providing any good answer.