Last month I filled out the on-line questionnaire at the Richard Gray web site and got this response.
OUR RECOMMENDATIONS:
Since you have four dedicated AC circuits, then you will want to include all components on the RGPC parallel enhancement by placing one RGPC 400 on each circuit. Were you able to place all of your components then all you would need for your system is just one RGPC 600S. Dedicated lines work well, but their importance in our opinion is over stated by many. Since you share your electricity with your neighbors, all of whom are robbing your home of sufficient current to drive you equipment to their fullest potential. What is of more importance is to in effect move the power of your transformer on your street closer to your equipment, and that is precisely what the RGPC technology does. We suggest you plug your basic power amplifiers (not integrated or receivers) and powered subwoofers directly into your wall outlets, with the RGPC units plugged into the adjacent duplex wall outlets, to take full advantage of our non-current-limiting parallel AC line enhancement and energy savings technology. Yes, this means that all components just by being plugged into the same AC circuit will receive RGPC enhancement. Basic power amps and powered subs do not need surge suppression because we feel they are adequately protected by their own internal transformers, while all remaining components should be plugged into the RGPC units themselves to take full advantage of our awesome state-of-the-art surge suppression system.
We can offer you increase in black level, lower noise floor and much more dynamics in both your audio and video reproduction