I have just added a 2nd hand XPS DR to my system which otherwise consists of a 272, ATC actives, Rega Aria and Michell Tecnodec.
After connecting it up all worked well and straight away could hear the positive impact the XPS had on the 272. I played some digital music and was impressed.
We also have a TV connected to the 272 via optical toslink. When I turn the TV on a strange thing occurs: when the picture on the TV is mostly dark, such as a black background or a dark scene in a movie, the XPS buzzes loud. When the screen goes bright again, the buzzing dies away. I can replicate the behaviour over and over.
Now I am used to Naim amps and PSUs “humming”, I used to own a NAP250.2 which was a little noisy. The noise coming off the XPS is something else entirely. It is super loud, you can hear it over music and from the next room. It sounds broken, but only when the TV is on and the picture is dark.
I have tried moving the XPS to different positions and unplugging items to troubleshoot.
How on earth can a TV interfere with the XPS based upon what it is showing on screen? There is no option to not have the TV as this is in my lounge.
Naim transformers are sensitive to noise on the mains. The TV will draw more or less current from the mains depending on screen brightness and I suspect the switching supply in the TV is putting noise back into the mains which varies with current draw. Can you plug the TV into another socket , even temporarily using an extension lead, to see if this helps ?
Have just tried plugging the XPS into a separate double socket via an extension lead and get the same result. It is quiet until the TV comes on at which point it buzzes in sync with how bright the picture is.
Both double sockets will be on the same mains ring as they are in the same room.
If you have a separate ring in another part of the house, upstairs maybe, try running a long extension lead so that you can connect the TV elsewhere. If that kills the buzz you’ll know there is an issue on the TV. I think I read somewhere that you can get a DC blocker thingy. Maybe one for the TV would work. It all sounds very strange.
I assume you would attach the DC blocker to the wall connected to your stereo equipment and the tv directly to the wall not being in the loop. But it might very well be interfering noise with your tv being to close to the XPS to meaning it’s not getting into the XPS from the grid?