My advice is do one thing at a time. Don't buy a V-Link or any other USB/SPDIF converter until you live with the Mini (or Bluesound Node) stock as it were. Your reply post reminded me...yes, I had tried digital coax out of the Mini into the Gungnir first. It just sounded kinda thin to me. I had a hunch about trying things with the V-Link (my Gungnir was purchased withOUT a USB port; previously I used the V-Link between my MacBook and the Gungnir). The V-Link turned the sound around...from disappointment to happy. Not saying that'll be true for anyone else though I am pretty certain about what I heard. Haven't looked back since. Anyway, don't spend your money unless you have a connectivity issue or a performance problem you think a converter will fix. Get it from some place (Audio Advisor, Music Direct that has a return option; the V-Link is no longer made by the way). Because I am a stubborn cheapskate about audio, I opted for an iFi iPower AC/DC converter. It is still a switching supply but supposedly has a ton of filtering to make it quiet and prevent contaminating your AC circuits with noise (or so the dogma goes about the evils of switching power supplies). Anyway, there's a lot of discussion on Computer Audiophile about the iFi wall wart. ALSO - check out Audio Asylum, "Duster" has posted some good looking linear power supply stuff from China. Another option for you.
ONE FINAL THING - in the interest of full disclosure, my CDs were ripped as ALAC files into an iTunes library. The Mini plays them fine and displays correct metadata for all (track sequencing, times, etc.) BUT for whatever reason, album art is hit or miss. Some covers show. Some don't. Tidal is perfect. Stuff streamed from there shows everything. Just an issue with my iTunes ripped CDs. Have fun.