I'm interested in this topic, too. Of course one variable we cannot control for is what your power is compared to anyone else's. Your "plugging into your wall" could be very different from my "plugging into my wall." Comparing within your own environment seems the only possible avenue of experimentation.
Power Conditioner Changes Sound?
A recent thread concerns finding the cause of variable sound presentation in a new-ish DAC. I've got the same question regarding a new power conditioner. Recently moved almost everything -- two streamers, DAC, phono preamp, linestage preamp, and powered sub -- to an AQ Niagara 1200. The sound now resembles an adolescent male voice in its unpredictability. AQ says the conditioner should need no burn-in. I'm assuming this is so, and looking instead at the THREE new power cords, including a new one for the amp running straight into the wall (chosen only for its firm grip).
Needless to say, I will be switching and swapping power cables after allowing sufficient burn-in time. But could installing a new conditioner itself account for this crazy variability in sound presentation?