Sorry to go back more than a year...
The noise I was referring to in my post was the one mentioned by Rob Watts
HERE.
When redoing the electrical system at home I was trying to take any measures to isolate my HiFi gear from the rest of the house, so I asked the electrician to dedicate a separate switch on the panel only for my expensive boxes, which he did. Also, the earthing of the system has been redone following the latest safety rules.
All of this, as I understand now, has nothing to do with the kind of RF noise mentioned by Rob Watts in this old post.
My Dave is feeding directly the Omega CAM Speakers; no amp needed in my close range setup.
The signal path is UpTone Audio EtherREGEN > Lumin U1 Mini > Dave, so technically I have 3 boxes with their own mains power.
Now, will an electrical connection among the metal housing of the 3 boxes help, as you wrote?
Or I have to first get rid of the ground for all the 3 of them?
Sorry, I am confused...