Please help me troubleshoot my processor

The sub gets distortion as soon as I plug in the digital coaxial audio cable from the Sat receiver into any of the Krell Showcase coaxial inputs of the processor even the ones that are not assigned in the hardware setup. None of the other channels get distortion.
Even if I chose CD on the processor and am listening to my CD, as soon as I plug in the cable into input 2,3 or 4 horrible distortion gets sent to the sub. I tried the NBS Omega IV digi and some monster digi cables.

Even if my Sat Reciever is inplugged. As soon as I complete the digital coax conection from either end, the sub distortion occurs.
Does the distortion sound like white noise?

Does this occur with all other input sources powered down?

If you answered yes to either of these, then I would probably take it to a dealer or at least contact Krell.

If it sounds like white noise, it may be that the digital signal is being routed through the Processor somehow and out to the Sub without being converted. If you have another digital source powered up it will feed a signal to the Processor whether you are using it or not. The digital inputs may need to be assigned, the processor may be combining the two signals.

These are just theories. Admittedly longshots, I find it especially unusaual that it effects the sub output only. My limited exposure to the Showcase presented no problems like this, as a matter of fact it worked flawlessly.

Good luck
With the help of some people in AVS, I've troubled shooted the problem. I have a ground loop in my sat sytem. Wish me luck isolating it.

Indeed sounds like a GL problem. Usually you'll get this from Cable and/or Sat ground loop differential from the reast of the equipment. Easily solved from some pieces from the "shack". Good luck