One other thought occurs to me and that is to seek out a preamp based on the 6SN7 tube. The Supratek uses this tube, as does the Don Sachs. these are wonderful tubes and there are many, many options out there for tube rolling.
Potential Warmer Replacement for LS17SE
This pre is tubed with 6H30s. Pretty neutral sounding amp and tubes, and no tube rolling with these as there is nothing else. I do like the sound of the pre but am interested in a bit more warmth. Nothing as warm as say CJ, but just a little more sparkle and good feeling. Would also like to keep the wide open soundstage the AR has. Prefer to stay fairly recent, mid 2000s or later. Balanced cables option preferred but not required. And a remote. Pass amp, ATC speakers, Auralic/Aurender front end. Any suggestion for a pre used or new under ~ $3K that might fit the bill?