If you intend the Desk PC, PC to HP directly it's because with the HPs I can listen to the PC output with no need to switch on the Rotel; and Rotel to HP it's because that let's me listen to the all the other sources that goes to the Rotel, NUC included. One output of the Rotel goes to a Rotel RMB 1075 power amplifier that drives the hi-fi floor loudspeakers.
If you intend the NUC, yes I think it is not, as it is powered with a brick PS with a two poes plug.
Sorry but I don't understand this question.
To try to give you a better understang of my setup here's a "map":
View attachment 248415
My first goal is to be able to listen to the NUC via my headphones when I'm mixing at the desk PC, controlling the NUC with Remote desktop,
and the second goal is to be able to listen to the NUC through the room loudpeakers. Both goals with no noise, RFI/EMI or HUMs.
As a workaround, for the first goal I will try & use the "send sounds to the host" Desktop restore function, to see if there will be no quality degradation and no latency.
For the second I will try to use balanced cables from NUC to Rotel + a conveter.
But I can't think there's no way to track the source down and to tame it. Nobody have to use balanced cable in a house, haven't they?