Quick question for any of the more electrically minded amongst you all:

Looking at Irving2008's diagram showing an earth loop, when I had the earth wire from the transformer's bolt to my star point. Do I not also have an earth loop with the CY cable shielding going to my star point and that shielding also being grounded where the XLR sockets come into the chassis as the outside of the sockets is the earth conductor?

If that's the case, should I isolate the XLR sockets (or the plate they are mounted into) from the chassis? - I could do this with rubber O-Rings.

Apologies for all the electronics questions, as whilst I have some electronics experience (555 timer circuits and various PC input/simulation projects), those are generally a two wire solution i.e. +ve and 0 or -ve and little risk of zapping myself with dangerous currents ;-)