Should I upgrade from a Mac Mini to a dedicated server or should I upgrade my dac?

And I should have added to my original post that compared to my analog set up I always have a sense that my system has a certain digital "homogenous" sound, if that makes any sense,  This is something that bothers me about it and it doesn't sound right.  I have heard called digital glaze and other such descriptions and to my ears its there,  I am no way trying to suggest that one source is necessarily better than the other but with my current set-up I think there is room for improvement- but how?

IME a lowly Bluesound will be an improvement on the Mini. 
 

My CD player sounds much better than both into same Dac. I have not yet gone down the rabbit hole of all the different things you can apparently do to clean up all the internet crap. Maybe it’s worth it, I just don’t have the time or patience. Cds for me keep it simple. 

to get really excellent sound from a digital system, i think you need to do both - go to a roon nucleus or equivalent, and also, a high performing dac

in addition you will need noise filtration and management for the network feed... 

in my experience all are needed... 

One thing I'm not clear on. Are you connecting mini to ethernet switch or bridging thunderbolt out directly to Moon? Mini direct out to Moon would likely be preferable. You're doing well by doing no rendering with mini, could still benefit greatly with powering mini with lps, such as Uptone MMK and JS-2. So take thunderbolt bridge direct out to Moon with quality power supply, add operating system optimization and you have first rate non rendering server, essentially you have network device. Would take really top flight server to beat this setup. The issue with all this requires much diy work.

@pgastone

Keep the Mac Mini.I have one and hate the MAC OS but you d not need to replace it to get great sound.

Read the John Swenson white paper on streaming. If you want to try his approach, get a media converter such as a Sonore OpticalModule, Uptone EtherRegen (use reverse), etc.. Then get a Sonore OpticalRendu to take the FibreOptical from the media converter int the OpticalRendu and then tale USB into the DAC.

If you want to save some cash for a slight los in quality then get a network switch that has a Fibre Optical output. Take the Fibre directly into the OpticalRendu and then USB into your DAC.

Fibre cannot carry analog noise like Ethernet can and pollute your DAC. I was under the impression that the very best method to stream was Fibre directly into a DAC (like Lumin X1 DAC) or second best the Sonore OpticalRendu. However, after reading John Swenson’s comments about adding a media convertor in front of the OpticalRendu I tried it and my tunes sounded even more focused so now I also do that for 2 or my 3 OpticalRendu’s.

Ethernet streaming is easier but most DACs do not have this and the DACs that I have heard with it sound better streaming via an OpticalRendu to the USB input of a DAC.

All the Rendu’s are ROON READY.