What preamp creates the largest soundstage?

I have always loved a large soundstage.  I have a small listening room (10x10) and have mini-monitors, driven by a tube amp.  I have played a lot with speaker placement, room acoustics, listening position to create a large soundstage.  I have rolled tubes on the amp and made dramatic improvements. (I have purposely left details on the brands of tubes, amp and speakers out, because I don’t want side comments to distract from my question)

i have a digital source into a solid state naim preamp.  I home demo’ed a well reviewed preamp, and was surprised at how much the soundstage shrunk, both side to side and top downward.  It was deeper, and did have much of the tube magic, but I could not live without the big soundstage.  

so my question is, does anyone have experience with a preamp that produces a big soundstage?  I am looking for recommendations on what to demo next. While I lean toward tubes, I am open to solid state.  I am okay either new or used, and could spend in the 5k range, but would be happy to spend less.  Also comments on specific brands (i.e. xyz is known to have great soundstage in all their preamps) as opposed to models, are welcome.

and I will be the first to admit that perhaps the very large soundstage is not “accurate”to real music, but boy is it seductive and I love it and can’t live without it.