Loud hum in one channel

Puerto, yes the hum is present when the preamp is set to TT but not on CD or AUX. I will disconnect the ground wire as soon as I get home and report back. Thanks for your help!

Here's a follow-up: Disconnected TT and ground wire, and noise like jet engines coming out of both speakers, more so on the left, but only on the TT setting, not the CD. Re-connected the Empire, and very noisy on the left channel, not so much on the right. Finally, I connected my Funk TT and also noisy, although nowhere as much as the Empire, and more so on the left. When I connected the Funk TT to the CD interconnects, I get no noise.
The phono amp in the pre-amp was installed when I bought the Prima Luna pre-amp. Is this the culprit?

sounds like a phone pre is the issue.

Sure sounds like the phono amp in the pre-amp is indeed the culprit. That would need to be checked out by a professional but I would sure start with that. If it was the pre amp itself you would probably be getting hum/noise out of any setting (CD, AUX, etc.). Let us know. Hope it isn't too expensive!!!

Thanks, guys. You know, I was never enamored with that phono preamp that was installed, and I wonder why it took the Empire TT to bring out all the bad in it, when the Funk was playing not too badly. At any rate, I will shop for an external phono pre-amp and try it that way. I hope that is all there is to it.