It is BS. That is they way I run my system! As noted, the only exception is if you get ground loops and such causing buzz/noise. In that case use Toslink and that should avoid it.
Let's remember that I test all the DACs with USB connection to my computer which is running my audio analyzer software which is a CPU pig and uses up an entire core just sitting there. Yet I am getting those excellent results from the well designed DACs.
I agree, mostly. I have heard “noise” or roughness from my PC after it has been on for a day or two. Also when I installed new software while and after playing music and when the CPU maxes out.
A dedicated low noise PC for Roon should be all that is needed. While I admire the Roon software, the design and implementation, I believe they go far overboard with the NUC and associated comments. A dead cheap motherboard with a 50$ processor will do, a couple of low turning huge fans that can be tuned to minimum rpm by soft- or hardware and a fan-less Grafik card for HDMI out ( or just the MB output or USB) is all. Mounted in a small enclosure and hidden away in a cabinet with all Ethernet connections is all you need (there were great low noise enclosure been sold for people that went crazy from the noise of their Sun workstations - they might still be around on EBay). Do nothing else on that PC. The Win10 license will be probably the most expensive single item for that project and it’s updating requirements will be the only upsetting thing but keeps you virus free.. Add USB Hdds as needed and possibly add an online backup service.