a preamp may color the sound, creating a "flavor" you may or may not prefer. it may be worth your time to listen to a feww preamps.
Will adding a preamp dramatically change my sound?
You can link to my system below, but basically it is a Cary CD player with internal analog volume control direct to a Spectron Musician II amplifier into Totem Forest Speakers, with quality cables and power cords. Honestly I don't feel anything is lacking, but still find myself getting curious about what effect a preamp would have. Anyone have any experience going from a CD direct to amplifier, and later adding a preamplifier? To what result?