If you had even the vaguest understanding of networking, you'd realise what utter nonsense this is.
Firstly, the TCP/IP network stream itself cannot change any audio qualities whatsoever. All that can happen is dropouts due to packet loss (very rare).
Assuming an adequately rated power supply of any type, the router will simply pass any traffic (including TCP/IP streams containing audio which itself is just network data) unhindered.
A router, switch and associated power supplies cannot make music "better, cleaner with better separation" or remove "boxy tones, nasal sound in the vocals".
I repeat, the streamed music you are listening to is just TCP/IP network data as far as any network device is concerned.
Based on your comments, the web pages you view on this website (and any other website) would be different depending on which power supply your router is using - and we both know that's not the case don't we?