I recently purchased a Signal Power Cord for my Audio Refinement amp and was instantly blown away by the improvement in the soundstage it gave over my stock cord.
"instantly blown away" is significant - so you may indeed have problems with dirty power or gear interaction. I doubt the manufacurer of the amp would sell it with a stock power cord if a tremendous improvement could be had with such a simple change. Have you considered trying the power cord you already have with each component (A/B testing) or an active power conditioning unit that you could use for all you gear?
Another thing to check would be to unplug all gear that you don't need....it is possible that a dirty SMPS power supply somewhere is inducing noise into the rest of your gear through the mains - TV's use quite a bit of power and can dirty the mains.