Agree on the Herron VTSP-3a. I've owned two Modwright pres--the LS36.5 is much more neutral sounding than the LS100 which has more tube bloom and warmth. I had several ARC pres as well, of those the LS26 was the least tubey of the bunch. All said and done if you want a pre that really gets at the best of what tubes and good solid state have to offer take a look at the Herron.
What are the more subtle sounding tube preamps?
I mean "subtle" as in relatively less tube saturation or color than your average tube-pre. Common sense tells me less tubes as in a single dual-triode, but in reality that may not be the case. I currently have my eye on a CJ Classic. Not sure if that will fit the bill. Any suggestions welcome.