First, I work at Broadcom switching products, so I do know what I am talking about.
Home routers & switches work at giga hertz frequencies and speed, which are WAY over ANY audio signals you are listening to especially if they are hard wired (ethernet), rather than using 11ac or 11ax wifi (which, depending on whether you are running at 2.4G band or the 5G band MAY be subject to collisions and may likely be a bit slower as a result).
The basic supply that comes with all boxes are absolutely fine. Since those work great even at frequencies 1000 times higher than your audio and still working perfectly fine, what you are noticing is nothing but the placebo effect.
Do not waste your money on snake oil.