The traditional tube preamp/ss power amp set-up allows you to have more driving power for your speakers, as well as adding tube warmth to the overall sound. But, there is no reason why you can not do it the other way around. That is the set-up that I have with a ss Musical Fidelity CD PRE 24 preamp/cd player and a tube Prima Luna Prologue 5 power amp. I prefer the control that I get from a solid state preamp. My speakers are easy enough to drive and I don't need tons of power, as I prefer the way that tubes sound.
regards,
Rich