I read a lot of advertisements where manufacturers say you must have clean, noiseless AC going through your system for the best sound possible. Their Power Conditioners, Power Plants, etc will do just that for a cleaner sound you will be able to actually hear. (It sounds like those power cord claims ). Has anyone stumbled onto something that REALLY works? Is there products out there that you can actually hear a difference that do not cost $$$$? Or do we wish we could hear the difference?