I've made a substantial improvement in black background, all aspects of sound stage and mid- hi- registers when I dumped isolation transformers and installed a regenerator. I was amazed at the improvement of the system. The single best addition to my system for the money. The addition of an anticable power cord removed doubt about current needs. I have a lot of electronics on in the house frequently, dimmers, wireless equipment and with all xlr connectors and good shielding the regenerator cleaned the AC noise up while giving the constant 121 v I needed. This is not an ad, just my experience.