There are times though (especially in dense musical passages) that the sound is stage is a blur - as if of all the instruments are coming from the same place.
Coming into this a bit late, and forgive me if I missed any comments to this effect, but I can’t get past this comment by the OP. Yes, it could be a lot of things, the recording included, but I doubt that a power cord is going to resolve this issue. Not sure if you favor vinyl or digital, but experimenting with cartridges and phono amps, or putting a good DAC between your CD player and amp might make all the difference in the world.
As for power, lots of good recommendations, I have had good luck with The PS Audio regenerators. It was not jaw dropping, but I achieved my goal of having “late night” sound any time of the day. This after using Furman and Puritan products. Amp still goes straight to the wall, it sounds better.
The recommendation for a direct line is a big one as well, if at all possible run a couple lines for your system. And take @soix’s advice, get a set of AZ Satori’s. I took his recommendation a few years ago, it changed everything for the better.