I do not possde the expander, but I saw some time ago for sale on a clbre site (a corner), and re-reading my old journals Keyboard Magazine, I came across a article about the bte. Those who have the No. 25 (September 89, but yes my little lady!), Page 11 to the entry.
In the opinion of complment Sat XR, sound samples are 44.1 kHz.
In 89, the XP was worth 4000 F, and the XR 2000 F.
I also found a site with an article on it: http://www.studio250.fr/docs/dream/dream samxr discdec 89.pdf rdig by a certain David KORN.