Like everyone else, I’m always trying to find the weakest link in the system, the no.1 issue that keeps occupying my mind nowadays is the noise being generated from a normal router.
Right now I use an Ethernet cable for gaming (which is slightly fancier with nylon exterior and insulated conductors) to connect my Lumin U1 mini with LPS.
I wonder if using a WiFi bridge instead would further improve sound quality.
Some have had positive experiences with WiFi. You could consider an Uptone EtherRegen. Or a switch with a fiber SFP to something like a Sonore opticalModule Deluxe.
There’s a zillion opinions about all the above and more here on this forum and the Roon forum. Be prepared for paralysis by analysis.
You are showing the db for a wood router, not a wifi router!
1- One way to reduce noise, it to use a wifi extender, and use one of its cable connection to feed the streamer. Adding a linear power supply improves things.
2- Router noise can always be reduced by adding a linear power supply
3- An audiophile switch is a costly option, but it works better than fuses. Most switched come with a wall wart, so an LPS would improve them. This is the costliest option.
How much is this necessary if all the IT stuff runs at a separate power circuit from the Hi-Fi?
My whole system is fed by a single regenerator, the regenerator is fed by an independent circuit.
I have no scientific explanation, and I cannot say it is necessary. I totally accept that noise levels vary by location, susceptibility of devices to noise, etc. Analogue playback was never affected by all of this. The improvements are restricted to the digital domain.
Thanks…it’s probably true shared ground… but anyway strange…at least we know what lengths we have to go with digital getting right…more mess than with vinyl it seems and getting similar expensive 
Nothing gets past you, @Palouse.
Academicians keeps things in check 
I found if your router is also the switch a good LPS can power both and no audiophile switch is needed. A roon endpoint and matrix to the DS all on LPS helps. Any other video/streamer device like apple TV or fire TV improve if on ethernet or getting separate wifi and are run as Roon endpoint. Or if you strip audio through a HDMI converter run it on a LPS and use power generator on any AC. It all improves.
I suppose we should have asked the make and model of the router. None of the gear in my network core can use an LPS.
Absolutely. Assuming all things are equal, LPS will produce less noise than a wall SMPS. I know there are five star SMPS that come with gear worth thousands, but these are rare. Moreover, I am not qualified to recommend specific routers 
Why?
All of our network gear at home has internal power supplies running around ~100W, 120V, xx Amps. A Security Gateway (Threat management: DPI, IPS/IDS, and firewall) Management plane (web-based real-time network and device insights and analytics), 24 Port PoE switch (powers access points, doorbells and some cameras), a Network Video Recorder, and three downstream fiber backbone managed switches (8 Port PoE). None of which runs on DC.
Geeking doesn’t stop with HiFi.
Given they run 24/7, 90 - 240V SMPS are highly likely. They do not overheat and save energy. You must have a serious power backup system.
Everything except the downstream switches are on UPS which have several hours of capacity each. Those are mostly in place to take the occasional bump from the electric utility. The entire house is on a backup generator.
It’s geek central around here. It’s helpful that my wife is in total agreement with all of these measures.
