Jea48, we do have ties to the actual grid. Even our cable company complained about the power from the substation feeding my neighborhood. The transformers don't give total isolation. A slight phase shift at the generators do reflect it at the home. But, getting back to the cable issue, the utility is putting some capacitor banks on the primary somewhere(at least the engineer from the cable told me this), and they (utility engineers) think that there may be welders somewhere that may be fed by one of the static lines and generators. It could be even 40-80 miles away. I saw some strange tape wrapped around the insulators (in two substations) fed from the static lines to see if the arcing on them will decrease, and decrease the customers noise. My system is still sounding great though. Good power supplies I imagine.