Tvad, nice explanation.
Eandylee, it absolutely will help but there's always the qualifiers.
I don't know where anybody might get the notion that dirty AC coming from the street is somehow magically cleaned up if one splits the AC off into dedicated circuits/lines.
Everybody has dirty AC (some worse than others) and depending on the quality of components, everybody can benefit sonically from 'proper' line conditioning. In other words, the more resolving a system is, the more it will benefit from 'proper' line conditioning.
Dirty AC split off into dedicated circuits/lines simply means that the AC noise is now dedicated to that circuit/line.
Perhaps some people confuse dedicated lines with clean AC with the fact that in-house generated AC noise from dimmers, microwaves, appliances, etc. can be minimized by installing dedicated circuits/lines preferably on the opposing phase/leg in the service panel of where the majority of dimmers and appliances reside.
But again, dedicated circuits/lines does absolutely nothing to clean up the dirty AC coming in from the street and it certainly does nothing to clean up the bi-directional digital noise generated from a cdp/dac which will contaminate the AC all the way back to the service panel and out again into all circuits/lines.
Hence, one more qualifier for 'proper' line conditioning is that the line conditioner should be capable of bi-directional noise filtering.
-IMO