Allow me to offer a different opinion on this isolation matter. I worked on a 7D13 with an isolated(floating) section this weeikend. I used my isolation gear so that I could tie my scope ground(common) to the floating common. In such cases isolation is desirable. In the 7603, the power supply transformer provides all the isolation you need. Using another level of isolation allows the 7603's chassis to float and that is not good. It is an unneeded safety hazard.
