Is it only when using Roon that you get the pops?
So if you use something live VLC it works fine?
The C510 is not a Roon tested device but neither is the Denafrips so it should make no difference as long as you are connected from the Mac mini to the DAC via USB.
Check the volume as well. Fix the system volume in Roon at 100% and use the NAD's volume control (if you use the NAD as pre-amp).
Ok, so I was not much looking into battling with this unit, so the second the seller heard I had an issue, he offered to refund in full.
All I really wanted was to fill a gap in a rack of a NAD system I have. To stream, I have LSB for HiRes audio.
So may I thank you for the advice but this one is solved.
No to start the Roon ROCK project. calling all NUC users. Going to set up a NUC and run Roon ROCK on it for my DAC.
I think taking the Mac Mini out of the equasion is a good idea as it has other uses to me it can perform besides doing jusy music playback.