Bad hum using Berning TF-12 with Beveridges?

I just purchased a Berning Tf-12 and hooked it up with my Beveridge 2sw's and there is a loud pervasive hum. To be fair this problem has happened with other preamps such as the Audio Valve eklipse, Precision Fidelity c7a. I bought the speakers with long Goertz ribbon interconnect hard wired from the Beveridge direct drive amps going to the input of the preamp. I wonder if I purchase shielded interconnects whether this problem might disappear. I know another Beveridge owner who happily used the Berning Tf-10 with his Beveridges.

Right now I am frustrated because listening though the hum is a chore but with the elimination of the hum the preamp would be marvelous! Even my wife commented on how good the preamp would sound without the hum. Any suggestions would be appreciated.
Have you tried floating the ground?
Czap would I do this with amps or preamp or both? You are the second person today to give me this suggestion. Bob
I recommend purchasing a par of RCA test adapters from Jensen Transformers and performing the troubleshooting steps per Jensen's instructions.

Doing so will identify where the problem lies. Jensen's troubleshooting guide offers several options to fix the problem.
Cheater plugs didn't work. Thanks Tvad for the tip. Bob
Bob, How bad is the hum? Have you tried this preamp in another system to make sure it is ok?

Grounding is important. I know a guy that bounds a grounding rod into the ground outside of the listening room wherever he lives for a dedicated ground.

You can try star grounding at the preamp while floating the ground on all other components.

Different cables and their arrangement might help.

Regards, Ron
Those are all good points. I inserted an old Motif preamp and it didn't buzz nearly to the extent of the Beveridge. Bob
Perhaps you should just sell the me.