Mac Mini as a music server

I use a Mac Mini with SSD to send files from Roon via ethernet to an Ayre QX-5 Twenty digital hub.  The interface to Roon is an iPad.  The sound quality is superb.

I recently re-purposed an old Mac mini (2010) to server duty and have been pretty happy with the outcome. I'm using Asset UPnP in conjunction with either Hi-Fi Cast or BubbleUPnP apps for control to a Chromecast Audio. Works and sounds great. Just ordered a Sonore microRendu (Christmas present to self) which should arrive next week. 

Thanks everyone for your input & Merry Christmas/Happy New Year to all of you.

From what I have read thus far, the Mac-mini music server seems like a very logical point of entry that also has substantial upgradeability.  In the fairly recent past, I used a Marantz N-7004 & was pleased with its sound, but not happy about its lack of upgradeability.  I currently run a Cambridge Audio Stream Magic 6, v2 in my home office vintage system [Carver + Theil].  It sounds much better than the Marantz did & does an excellent job as a DAC as well...but I am wanting more power & potential for my reference system in my 'Man Cave'.

Again, many thanks to all of you.  You have given me much to consider.  I hope this discussion continues!

Am also thinking about a new Mac mini or a iMac that also can handle my photo editing, thinking using Ethernet to a pro-ject endpoint into my Primare Dac 

I recently got the new 2018 Mac Mini to replace an old Macbook Pro and am considering returning it. I'm wondering if anyone else has tried it in their system. Maybe I got a lemon and I need to try a new unit? 

I'm using the i5 / 8GB / 256GB, 2018 Mac Mini to stream iTunes and Spotify (via airplay - AEX series g - Toslink or direct connect via USB) to my Peachtree Dac.it that's feeding a vintage McIntosh system.

When I A/B it against my 2017 Macbook pro, I lose a lot of detail and staging. The lows from the Mac Mini is sloppy and rounded with the mid's sounding thin.

I also A/B'd it using headphones and IEM's via audio jack and get same results. In fact, the Mac Mini sounds worse than my iPhone XS - how's this possible?

Would be interested in anyone else's thoughts who may have similar set up. I love the Mac Mini form factor and bought it with the idea that I would add RAM and external storage as needed. But the lacking sound output quality (maybe its the T2 chip that's causing the issue?) is a deal breaker.