I can see the cosmetic differences, but are there functional differences between this and the original? Reference: https://www.modulargrid.net/e/intellijel-quadra-expander

Yes.

First the cv inputs are normalized so that a cv into attack can be sent to both attack and decay.

Next the eoc outputs have been greatly improved and now trigger anything.

And I think the quadrature mode has been simplified.

Some really useful refinements. Thanks for sharing the details.

This new version makes more sense. More like the Buchla or Sputnik ones.

Realise this is now a long time ago, but does anyone know if the MK2 expander will work with a MK1 Quadra? I'm guessing/hoping yes...

is this compatible with the new quadrax?? thks