Oh lawwwwd no, no no.
Have you tried a cheater plug?
=/ That's a terrible way to lose some great equipment.
Excuse my ignorance but is that safe with electrostatic amps?
I don't know that it's any less safe than anything else. Cheater plugs are unsafe by definition, even a traditional amp can really hurt or even kill you if the chassis goes live. I would not suggest using one as a permanent ground loop fix, but it might help you nail down your problem.