Allow me, as someone who has traveled the same road in digital source, to make a suggestion. You are not getting anywhere near the capacity of the speakers with the Mac Mini. I used one for about a year with enhanced software, but have moved on to different servers. The Mac Mini is a good starting point, but not suitable as a long term audiophile digital source; not if you really want to maximize a rig.
If you wish to read about my changes, see my articles at Dagogo.com on the Salk Audio StreamPlayer 3 and the latest, the SONORE Signature Rendu SE and Small Green Computer sonicTRansporter AP i7 4T. You will absolutely see huge improvements by upgrading the digital source, and power cable to it as well as USB cable. The SONORE/sonicTransporter combo is a stunning digital source, far, far outclassing the Mac Mini.
The cost to do so is well worth it. I wish you well on your journey. Do not let the deception that the sound cannot get any better dissuade you. There is always much room for change and better enjoyment.