Not sure if I'm making anything clear or not. :-) You can design audio circuits with floating ground which fit into a case that is connected to the outlet safety ground. I used to work in theater audio and we did just that and our chief engineer felt strongly that it was why we had such industry leading noise specs. There was no conductive path from the chassis to the audio ground, or any other audio or power path. |
I think it’s important to be clear here. AFAIK, one of the advantages of the diamond circuit was that it was pretty suitable to be used with a floating-ground. A good thing. However, also AFAIK, most of the Ayre gear does use a safety ground for the chassis. Much of the gear out there is somewhere in between. They use a chassis ground AND a resistor to reference the signal ground to earth ground, while attempting to minimize current transfer. See if you can find a schematic for a CJ PV-10 which shows this quite nicely. Appliances used to be allowed to use neutral as the ground. This is no longer allowed AFAIK due to the possibility of neutral being imperfect and having lethal voltages across it. Lastly, this is one place where XLR connections can be absolutely superior. You don't need ground to transmit the signal, meaning equipment from point A to point B which can be 30' long and may have different ground potentials can still communicate and not risk a ground loop. |
