Do tubes matter beyond gain stage on preamp?

Short answer: it's not a yes/no answer, they do vs. they don't, it's a question of percentages.

Long answer: it's impossible to generalize.  Almost every tube preamp is going to have a different design/topology.  Depending on a number of variable factors, you can make a preamp that uses just two tubes + ss that sounds better than one using eight or twelve, and vice versa is also true.

As 3-e-p says, beyond this you're getting into design philosophies that different designers hold up as being the best (or which suits them best).

So better to have a couple tubes vs no tubes.

ie. Harmonic distortion is highly desirable vs flat ss.

ashame they dont insert tubes in an av processor.  I run av sound thru a tube pre and it sounds incredible.  

@dekay 

+1 but don't expect a troll to provide details of a made up comment.

jperry, how r u?  Even if made up it would be good, its not. So add somethin or go away.

It depends on the topology of the preamp, as to how many tubes are used.