Too many tubes?

Friends, I am putting togther a new system. So far have Halcro MC20 and Atma Sphere MP3. Looking seriously at a pair of Zen Adagios. Is there anything to be gained (or lost) by mating a CD player with tubes (like the BAT, Audio Aero, Jolida) with this tube preamp? My amp and pre are fully balanced. I assume the BAT is as well. Any others? Again, advantage/disadvantage/no advantage for fully balanced CD given other componants are fully balanced? Much obliged.