Hi, I am running a sonicTransporter i5 with the stock smps. I play music (much of it hi res) that is either locally stored on i5’s internal SSD or streamed from Qobuz via Roon. The i5 is connected to a Synology RT2600ac by ethernet. The router is powered by its own stock smps. A Naim ND5 XS2 streamer is connected to the Synology router via ethernet. All of the above are located in my living room (the only option in my NYC apartment) but the Naim streamer gets its electricity from a Furman 15-i plugged into a different outlet (not sure if it is a separate circuit from i5). The i5 and router are plugged into the same power strip, as is my Fios modem and an air purifier.
While the system sounds wonderful, the nature of this hobby is to explore whether it can be improved and if so, at what cost. With that in mind, I would appreciate any thoughts as whether there would be potential benefits to upgrading power supply for i5 and, if necessary, the router as they are plugged into the same outlet. If there are benefits, how significant? Please keep in mind that I have no or limited flexibility in resituating equipment.
Personally (and I know I’m going to be in trouble here… ) I don’t think it will make any difference at all… but a couple of zero-cost things to try (if you’ve not already) are not using the Furman (Naim generally advise not using mains filters but I can see it might be a safety issue in a city) and using the ND5 XS2 wireless (eliminates the possibility of electrical noise on the ethernet).
I’m using the Furman not to purify AC but as a surge protector (I have had an air conditioning unit fried by power surge). I tested setup with and without Furman and found it to be completely neutral (neither better nor worse).
I agree with @AndyR it sounds like you have done a good job of isolating everything. Switching power supplies like the one that powers the sonicTransporter do put noise back into the outlet. So using a Llinear supply will keep that from happening. But there are probably a lot of other noise sources on your power lines. The Furman is a good way to filter all this out.