operating system choice for mini-PC

I like jplay. Nearly as functional as Roon, but sounds more transparent. 

@magon 

I recently purchased a Berkeley Audio Design "Alpha USB Series 2" re-clocker (DDC), and it is amazing.  So perhaps I can offer some advice on what you are seeking, which is similar to my situation.

The short answer is to use an Apple product to feed your DDC.

I had been using a Window 10 laptop’s USB output to feed my DAC, via an Audioquest cable, and it sounded very good (night and day better than a mass produced USB cable).

When I discovered how much better my DAC would sound if I used its AES/EBU input, I discovered DDCs.  And so I purchased one, and put it between my laptop and my DAC.  And the results are very good.

There were other obstacles to overcome, such as using a short USB cable.  Those cables should be kept no longer than 9 or 10 feet (if I remember correctly).  So I purchased my Audioquest USB cable at 1.5 meters.

That meant that I had to keep my Windows 10 laptop very close to my DAC, which I did.  But that also meant that I needed a remote control, because I was not going to keep getting up to change songs.

My remedy was to use a second Windows 10 laptop, and remotely control the other one via Remote Desktop.  Remote Desktop allows for you to have the server laptop send video to the client laptop, but keep the audio local (and in this case, that meant the audio being fed to the DAC).

So far, so good.

Now I introduced my DDC between the server laptop and my DAC.  The server laptop feeds my DDC via my Audioquest USB cable, and the DDC feeds my DAC via an AES/EBU cable.  You should try to keep that cable short, too, but AES/EBU cables will not be problematic if you need a longer run.

I am using JRiver’s Media Center, and I love it.

Now, getting back to my short answer about using an Apple product:

The high-end store from where I purchased the DDC box recommended that I use Audirvāna and a Mac, for the best sound quality.  I plan on purchasing two Macs, once I can determine if I can do the Remote Desktop setup.  I know nothing about Macs, and do not know what remote control software comes with them, or can be downloaded / installed with 3rd party software.

Lastly, the store was adamant about using a quality USB cable (which I already had), and also a quality AES/EBU cable (which I did not have, and was expensive).

The store had no profit motive for recommending the Mac and Audirvāna (they sold neither).  They assured me that that combination would sound better than my Windows boxes.

So, I have a laptop (#1) on my lap, networked directly to the laptop (#2) near my stereo.  Laptop #2 runs JRiver’s Media Center.  Laptop #2 feeds my DDC, via an Audioquest USB cable.  The DDC feeds my DAC via an AES/EBU cable.

Laptop #1 is basically a glorified remote control.  The above set-up works great, and sounds great.

Note that I do no streaming.  Laptop #2 has all of my music stored on its internal SSD.  So I can’t speak to sound quality from a streaming service.  But it would probably sound very good.  But the store’s personnel told me that their digital sounds best when they download the songs and play them from their Mac’s local storage.  My two laptops are not connected to the internet.  They get no updates, which I do not need, because I never install anything or go on-line.  Those laptops serve a singular purpose.

It’s been a while but last time I messed with building my own audio PC, I liked Volumio best. If I was to do it again I would look into Euphony Stylus which looks very impressive. Volumio has the advantage of being free unless something has changed, Euphony involves a fee.