Phonostage, preamp or amp?

Hi folks,

My system is in occasional (once every month or two) rotation with a few different speakers and SS amps I have accumulated.

I have been wanting to try tubes for a while and was wondering where to start.

Which component (Phonostage, preamp or amp) in general, would:

• Sonically produce the most noticeable tube effect/experience?
• Require more maintenance?
• Have greater component matching requirements (gain, impedance, etc.)?
• Be the most logical to begin with? 

I listen to mostly jazz, classical and some rock.

Speakers:  Magnepan LRS, KEF LS50s, B&W Matrix 801 S2s, Ologe 5 and Harbeth SHL5+40s.
Amps: Ampzilla 2000 2nd Edition monos, Michael Yee Audio PA-1 and a Forte 1A (which I can't find an owners manual or specs for anywhere!)

Thanks!