Are Preamps necessary?

I love classical music, and I have a simple system: a pair of Klipsch (RF-5) floorstanders, and Yamaha components (CDP, Tuner, and Amp). What I want from my system is to be able to close my eyes and feel like I'm there at the symphony, live.

I want to know if a preamp will help me achieve my goal. When are they necessary, or beneficial?

David