Hi Edward,
I'm lucky, I have a seperate supply from our substation that is probably less than 50 metres away. Houses that were built much later than ours have a seperate supply.
My vinyl has wall mount power supplies so the improvement was only noted by amp.
I put in a seperate supply from our distribution point to the lounge for the sound equipment.
No distribution strip.
I was using the std cables that came with the equipment. Recently bought (used) Russ Andrews Yello. Hearing the improvement I made a lead myself from 2 lengths of low loss aerial cable using centre conductor for feed and screen for earth.
The difference I heard was when I changed the leads sequentially, starting with the integrated amp. More dynamics, detail, bass depth and definition. Next my CD transport, then my DAC. These added a little more to the party in terms of detail.
The amp showed the most improvement.