This isn't exactly what you are asking for, but I'll mention it anyway. I have a CJ Premier 18. Goes for about 2k used.
"The ideal preamp will reproduce classical music in an organic and natural way. (Not looking for vintage).
My budget is $2000 to $2500 used."
That's exactly how I would describe how it sounds. But if you must have tubes, I really like the VTL 2.5 and CJ's tube preamps. You can't go wrong with either, but with CJ, the older units like the PV 10 and 12, may be too warm for you.
"The ideal preamp will reproduce classical music in an organic and natural way. (Not looking for vintage).
My budget is $2000 to $2500 used."
That's exactly how I would describe how it sounds. But if you must have tubes, I really like the VTL 2.5 and CJ's tube preamps. You can't go wrong with either, but with CJ, the older units like the PV 10 and 12, may be too warm for you.