Why do tubed preamps image better than SS?


I realize this may not be true in every case, but can anyone explain why tubes offer more tangible imaging? Are there any SS pre's that can compete with a good tubed unit in this regard?
sjh32
Tube pre's image better because of the dimension and presence they can offer that solid state has not been able to duplicate except for a handfull like Lamm (yes it is solid state-there is no tubes in the linestage) and Ayre k1x. These two image as well if not better than any tube preamp made at any price. But in general tubes do image better than solid state.
Having tube equipment improves your image in audiophile circles. But about the sound...the loudspeaker is far and away the most important contributor to imaging, good and bad.
generally speaking,tube amps seem to offer more 'front to back depth',while ss throws a larger soundstage... but in all honesty, speakers will make a bigger difference in 'realism' than your pre or power amp, provided the components are more than capable of driving them to their potential.