@jea48 Thanks for your attention. Yes, as you described, there is a green insulated wire included in the run. I will need to open things up to see if there is also a bare copper wire for grounding the box and to confirm that the box is metal... but I know we used an armored cable running on the outside of the wall to get this additional dedicated circuit to my amps, and so the armor on the cable acts as further shielding/ground, but is not the same as the green wire (isolated) ground.
When I bought the house, the home grounding went to a water pipe, but the electrician added a outdoor rod. Unfortunately, I am convinced that the rod is sunk just in loose sandy soils rather than moist clayey soils, and I may look into relocating it to something with better grounding properties.
I appreciate your input - feel free to offer more. If I buy the Furutech and want to maintain the isolated ground, I would need to snap off the metal strap that connects the ground lug to the mounting plate. I assume this is doable???

