Andy West's Alembic that was on all those Dixie Dregs album was for sale at Cambridge Music back in the late 80s or early 90s. I thought about getting it, but I didn't really like the way it played. I did love the way Andy played it, though!
 
Edwin

Bob (bsee):
 
I don't think that is the full story-- I seem to remember reading that it was something more superfilter-y.  If so, I'd love to hear about it.
 
I'm thinking about getting individual bass & treble on my new custom, so I'd be really interested if that was the case.  I'm thinking that a sweepable band-pass or sweepable high-pass might be part of Bob's rig.
 
Just speculating (maybe just wishful thinking)...
 
Brad