Gcx ground loop problems..

[Captain Chunkulus]

Okay, so I have boiled it down to the lowest common denominator and here is where I stand.. I plug directly into my amp, no hum.. I plug into the guitar in on my gcx and then out of the gcx into my amp and I have hum.. If I put effects in any of the loops and run from the rear guitar output into loop one or any other loop and then into the amp.. I get hum.. I went from george l's solderless cables to soldered cables (I have a cable tester so I know all of my cables are fine)... Still get hum.. So like I said I took everything out of all of the loops to see what the result would be and still I get the hum.. When I move the cable around, I get more or less hum depending on how close the cable is to the amp.. Doesn't matter what cable I use it does the same thing with all of them.. Any Ideas how to fix the problem? I was thinking of getting an ebtec hum eliminator but I don't know..

[JohnClark]

First lets focus on the signal routing needed to test this...
1.Guitar -> Guitar In on the GCX
2.Guitar Out on the GCX -> amplifier

When doing this test, was there anything else connected to the amp or anything else in the rack? If you isolate the GCX from the rack rails, does the buzz stop?

[Captain Chunkulus]

When pluging directly into the gcx using either the buffered or the unbuffered loop with nothing else plugged into the gcx, I get a ground loop.. If I unrack the gcx with the same set up I still get the ground loop.. If I unplug the gcx and use the same cable to plug into the front of my amp direct, the ground loop goes away.. All of my cables are brand new soldered ends.. Not solderless george l's.. Ieven tried fliping the ground switch on my head as well, no difference.. I was thinking of trying the ebtech hum eliminater.. What do you think?