Dear MikeM:
Thank you for your post, and I know you are trying to help me, but I respectfully disagree.
Hi-fi equipment in the league of Hovland or Kimber Select is state-of-the-art and cannot be expected to operate perfectly in every single environment. My guess is that the decisions to not shield the Kimber Select interconnects and to not equip the Hovland with a standard degree of RFI shielding were made intentionally because, it most installations, the designers found that those two products sound better that way, all while knowing full well that, in certain installations, these design characteristics will not be practical. Some street Ferraris have only four inches of ground clearance, and, the motors in those cars demand high RPM's -- drive one here, in manhole-rich, broken pavement Manhattan, and the undercarriage will occasionally bottom out and the plugs will foul due to the engine being lugged down at low RPM's. If you want "practical", you get a Buick or a Rotel. But if it's real glory that you seek, my experience has been that things will likely get complicated.
In short, I do not think it is a design flaw to make a preamp that should be used with a shielded interconnect, or, to make an unshielded interconnect that should be used with a preamp featuring RFI shielding. As for your own experience with Hovland, I'm sure it is as you report -- again, a product like this is not going to work perfectly in every environment.
The problem is not a big deal for me and something that I almost expect at this level. I'll see how the RFI retrofit works and go from there.
Thanks again