Zargon- thank you for your detailed response. No hum. no dimming lights, no hiss. It is more of a thing where sometimes you don't know how good it can get until you hear it. When I used Silclear, for example, I was surprised at how much difference it made. This I attribute to more solid connections with less arcing. So rather than eliminating obvious noise, I was interested in achieving blacker backround, better staging, smoother highs etc. if this was possible. I may well just relax and enjoy the music and if money is to be spent, look more into room treatments.