JCKeeys,
it was just my guess: Solton being aimed to the pro market, they have almost always had and expander version of their keyboards, since the days of SK4 (4 octave keyboard, almost like a toy, but with a very interesting expander, for people who already owned a keyboard or -I quote their advertisement- for midi-accordion players: this means minding for professionals). So I am pretty sure that in maybe six months they will come out with an SD1 expander. Anyway, next week there will be a public demo of the SD1 here in Rome. I hope I'll be there; if you are interested, I'll keep you informed.

Another term for "expander" is "module", basically a key-less version of a keyboard (if that makes sense). Thus, the X4 is an expander version of the X1. Early midi keyboards had such limited polyphony that an expander version was often added to double polyphony without requiring a second keyboard. Nowadays, polyphony is less of a problem, so modules are used less for expanding a similar keyboard as to provide a new capabilities to a setup that has a different keyboard.

HTH

[This message has been edited by Clif Anderson (edited 03-18-2001).]

Dreamer!.. I'm very interested to hear your comments on the SD1! "When in Rome do as the Romans" and listen to the SD1 demo!!(A pathetic attempt at humor)Thanks for the explanation of "Expander". I'm more famaliar with the term module. Thanks

JCKeeys,
if you want to wet your appetite for the SD1 you can try the following link: http://digilander.iol.it/ketron/ita_main.htm;
there are a couple of rather close-up pictures which really give the idea and some nice MP3 demos to download (a couple of them don't seem to be working, though -namely the Blues and the Soul ones).
If you want to get a "kick" (in every sense), click on "Drums".