This is the simplest test that really works and anyone questioning the value of conditioning should try it, assuming of course they really do want to know even if it might contradict everything they think they know. Which, if they can hear, it will. Also anyone shopping for power cords or power conditioning can use this as a kind of baseline, as what you get better work at least this good else why pay money for it?
Now to the OP the more direct answer to your question is after a whole bunch of trials like this I have upgraded from what was originally an ordinary circuit to a dedicated line. The dedicated line is 4ga, and at 240v. Just below the listening room is a silver wired audiophile step down transformer that brings the 240v to 120v. That goes directly into a Bybee based DIY distribution box with an assortment of audiophile outlets. All the wire from the panel to the box is cryo'd.
Not sure if that is elaborate by OP standards or not but it seems to work pretty good for me.