Why would a solid state preamp necessarily be the answer. While some do have somewhat big and mushy bottom ends, that is not always the case. I find that you lose a bit of what one looks for in tube gear by using a solid state linestage (large, open soundstage, natural sounding attack and decay of notes, etc.).
The "problem" with boomy bass can be generated by or exacerbated by the linestage utilized. This is often a matter of synergy and cannot be determined until the unit is tried in a particular system. I generally find tube units to be more unpredictable, in terms of synergy, but, in any event, a home trial is a NECESSITY, particularly if you are spending big bucks.
I use an Emotive Audio Epifania, a tube unit that is very neutral in sound. The company's Sira model, on the other hand, can, in some systems, sound a bit boomy in the bass. Other top tube models I have heard and liked include Kondo, Audionote (uk) and Shindo linestages.
I have heard and owned a few solid state linestages. I personally like the top-of-the-line Ayre (open on top and not as mechanical sounding as most solid state stuff, a touch lean in the bass, so it might be to your liking) and the Connoisseur (dynamic but not edgy). On the less expensive side, I own, and like the Placette Active (big soundstage, dynamic and exciting). I also own the Levinson No. 32 (incredible ergonomics and controllability, but a touch dark and tame sounding).
