I would try and find a tube preamp if you can. I had the 1.6's, and they greatly favored tubes to solid state - at least with an amp. I know the ref 2 has a processor loop. I've heard the vk30SE and thought it was awesome.
If you had to make this decision....
I'm looking for some advice on preamps for my system. Aside from sounding great, a remote and HT loop/direct would be useful. I've heard the BAT50SE, CJ16LS, Melos 333 and Levinson 38S. None of these jumped out as clearly better. My system is Levinson 31 -> Audio Logic DAC -> Meridian 568 -> VTL MB750 -> Magnepan 3.6R. Any suggestions on what else to try?