John, I have not owned a KCT but used to work at a store that sold them. I do recall they ran quite hot. Since you have a ton of parts shoved into a relatively slim box, the preamp heats up. I am not sure, but would guess that the power supply is located on the left side of the preamp. If you are concerned, talk to your dealer or call Patrick Bresnahan at Krell to discuss the matter.
Krell KCT Preamp
I have had my KCT for several months now. I have it on the top shelf so it can breath. The left side is always hotter then hell. Is this normal? You can hold your hand on it, but it shure seems to be hotter then what you would think a stereo unit should be. Other owners please let me know what yours is like. Thanks, John