Hi johnziomas, the Gungnir dac has async USB and the Auralic Aries Mini has a usb dac out. The Aries Mini usb out is significantly better than both my (c. 2008) mac mini usb out and sonos coax out (which sounded quite different from each other, btw) To me it just sounds more like music: less harsh, more tonally balanced , more detailed and with better layering and imaging. Even my wife noted the improvement (fairly rare) As to why, I can only speculate. I only thought to try it because of the interest around this sort of thing on the forums (computer audiophile, DAR, etc) At any rate it solved some long standing issues that I'd been trying to address through preamps, DACs, cabling, tubes, etc., wish I would've looked into it sooner.