This seems unusual to me. While the Jadis preamp's soundstage is not as "layered" front to back as some I've heard, particularly the Lamm preamps, it nonetheless usually does an excellent job of giving the impression of palpable three-dimensional images (I owned a JP80, the full featured version of your line stage, for about 10 years and now have a JP200). Assuming that there isn't something wrong with your unit, and that room acoustics aren't at fault here (always a possiblity when you're dealing with soundstaging problems), it may be that the Krell amp is the culprit. While solid state amps are capable of excellent soundstaging, and your Krell was always one of my favorites in their line of amps, it still does not give that "palpable presence" that Sam Tellig is so fond of pointing out that you really can only seem to get from a good tubed unit. The images from solid state units are a little more two-dimensional to my ears--blame it on tube distortion or whatever, but tube amps seem to give more rounded, three-dimensional images in a soundstage than their solid state counterparts. If there's any way you could borrow a tubed amp to use in your setup to see if that's the case, it would be worth trying.
