Pete B. wrote:... Do these units need to have the power cord updated to 3-prong?... or is the 2-pronger on there good to go?
No problem with the magnetic field. Some would argue that it's better to isolate an amp from the physical vibrations of the speakers, but that too is no big deal.
No need to update to 3-prong. No seriously high voltages in there like a tube amp. The 2 pronger also eliminates ground loop hum.
I never needed to worry about ground loops with my FYD because it includes a ground lift switch.