I recently got an Audio Power Power wedge AC line conditioner for my system (Sony XA7ES, Classe CAP-100, Platinum Audio Solo, Kimber PBJ and 4TC), and noticed an immediate improvement in clarity, transparency and general "there-ness." I have always lived in areas of bad AC power quality (apartments or old houses), so this device was a welcome change. Unlike some other AC power conditioners, the power wedge stuff uses a real isolation transformer for the source components (because of current demand the amps do not get isolated sockets). These transformers are used in labs, like the one I work in, but the power wedge gives the same industrial/lab performance for less money. Mine is one of the older models (pre-ultra). This means it does not come in a fancy enclosure, but I got it for 35% off on a closeout. For the money, it has made a great impact in the system.