Steve: Other than Da Hong, whose modifications in my view change the character of the Jadis and may no longer be available (and may not be that well-executed, judging from at least two separate sources), I don't know of any modifiers of Jadis equipment. Andy's mods were expensive and probably voided any warranty I had left on the preamp, but it was well out of the warranty period anyway. The downside to them is that now, other than Andy, there are very few techs willing to work on the unit, because space inside is limited and Andy had to use a lot of it--it is certainly not neat and tidy. In theory this could also make it more susceptible to noise, although I haven't noticed that. The upside is better frequency extension at the extremes (this may be due to some Audio Note bypass caps he put in), a bit more transparency and a virtual elimination of the last bit of "electronic" sound that the unit had (which wasn't that much to begin with). The improvements on an objective scale were not cost-effective and certainly were no more than subtle (except perhaps in the additional bass extension), but I consider them worth it subjectively because, as a bit of an obsessive compulsive, I'm somewhat nuts I guess.
When you look inside the unit, you'll see that a lot of the capacitors and parts appear to be nothing special and could be replaced with better ones, but the danger there is that (in my view) the Jadis equipment in large part was designed by ear and when you change the parts you can change the character of the unit. I only agreed to let Andy do his mods because he assured me the character would not change and because he did them at my home (stayed over a few nights), we listened as he did them at various stages to be sure I was happy with the sound and he agreed to undo them if they were not to my liking. Without those conditions, I'd be hesitant to have your unit modified, and even then you'd have to weigh against that the loss of any remaining warranty you might have and the possibility that no one will want to service your unit if something goes wrong. I'd therefor advise you against modifying the unit--you might want to consider a JP200 instead, the one unit I'd consider to replace mine.
Unfortunately, I have no long running experience with the CAT Ultimate except on short demo at a dealer. Prior CATs impressed me, but more from the intellectual rather than emotional standpoint. If the design goal was as you noted above, it should be a great piece, and definitely worth an extended listen. But heed Greg's advice, make sure you don't lose what you like about the Jadis in exchange for improved resolution. Hope this all makes some sense.
When you look inside the unit, you'll see that a lot of the capacitors and parts appear to be nothing special and could be replaced with better ones, but the danger there is that (in my view) the Jadis equipment in large part was designed by ear and when you change the parts you can change the character of the unit. I only agreed to let Andy do his mods because he assured me the character would not change and because he did them at my home (stayed over a few nights), we listened as he did them at various stages to be sure I was happy with the sound and he agreed to undo them if they were not to my liking. Without those conditions, I'd be hesitant to have your unit modified, and even then you'd have to weigh against that the loss of any remaining warranty you might have and the possibility that no one will want to service your unit if something goes wrong. I'd therefor advise you against modifying the unit--you might want to consider a JP200 instead, the one unit I'd consider to replace mine.
Unfortunately, I have no long running experience with the CAT Ultimate except on short demo at a dealer. Prior CATs impressed me, but more from the intellectual rather than emotional standpoint. If the design goal was as you noted above, it should be a great piece, and definitely worth an extended listen. But heed Greg's advice, make sure you don't lose what you like about the Jadis in exchange for improved resolution. Hope this all makes some sense.