Isolation Transformer - Use with Cheater Plug

Forgot to say that I do have Directv and audio is connected to the preamp via RCA jacks. So maybe a RCA ground isolation device is what I really need.

Thanks for the responses. I originally had the pair plugged into the same outlet with the cheater plugs. (I did not have this problem until I replaced my previous power amp.) Without the cheater plugs, the hum is very loud.
Sorry to still be confused - I didn't word my original question very well. Since the Tripp-lite did not solve my ground hum problem, is it at least giving me some protection from shock since I have to use the cheater plugs one way or the other? Or should I just go back to plugging the pair straight into the wall outlet and try something else? (I might try isolating the RCA cords next.) Thx again.

Thx again. And the humor went over my head - I have no idea what you are talking about :)
Jea48 - Yes, without the cheater plugs and even inserted into the same outlet I get the hum. I replaced a Parasound with a McCormack power amp and that started my having this problem. Cheater plugs do solve the problem but I had read where an isolation transformer might solve it as well and there would be no possibility of a nasty shock using that method.
It appears from what you guys are telling me, it that I am still better off to have the pair plugged into the Tripp-lite using the cheater plugs than to go back to having the pair plugged directly into the outlet. It reduces the chance of a lethal shock.