Whilst I was committing a bit of a crime, selling some Naim gear, to be precise, I noticed an interesting effect related to cables.
In the very beginning the 5si was producing some subtle noise, not audible at the normal level of volume - by normal I mean at 8-9 o’clock - however, clearly audible at 12-1 o’clock. I know, it is insane - we were just trying to find the solution.
At the normal level the sound felt a bit “broken”.
We made a few fixes:
- connected the nd5 xs2 and 5si with din-din, which drastically reduced the level of noise,
- then, we replaced the mains cable with some thick, handmade one, which reduced the noise even further
- douched both in to the dc breaker socket, which gave almost no impact
- and, finally, connected to the network with the wire.
All tests were done with no music rendered, we were not going to kill our ears 
In the very end we eliminated the rest of noise and the stack started to shine.
So, I made an assumption, that the mains and Ethernet cables do not alter the sound directly, rather impact on the noise floor which rob the texture, details and stage.