Difference a mains power line makes to streaming

Just thought I would check responses from those who have tested these.
I have been testing one on current naim system of NDX2,NAP300 , and a super cap and xps. It is connected to the XPS box to asses increase in Audi ability from streaming.
A question - does the mains power line make a more significant improvement to lower spec equipment ?
I have played Massive attack albums Protection, and Blue Lines and as yet have not noticed any significant change to the sound.

For me, I found my NAP250 made the biggest (albeit small) difference, then went to XPS with even smaller effect. Not tried a third on the HC yet as I haven’t decided if my next move is second HC, or a SC