Next step: tube preamp or analog?

Suggestions please - building a system and not sure which siren to follow next - tube preamp or analog?  I have convinced myself a decent step in either direction will cost $2000 or more, am I wrong?  Current system, all used gear, is Thiel CS 2.3 or Magnepan 0.7; Krell KAV 350il (integrated amp w/o phono stage), PS Audio Digital Link 3; Oppo BDP-105;  PS Audio UPC-200; all with decent cables.