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
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