hi Angelo,
First You must regard two different things:
1) HX 3 buildt as stand alone organ - however totally buildt up Yourself or buildt up using older organ equipment
and
2) HX 3 Expander Module driven only by MIDI commands
Things how to do and what´s possible to realize via MIDI You can read in our HOAX wiki :
http://wiki.keyboardpartner.de/index.ph ... ontrollers
( like DOEPFER or NI B4 controller )
Please read this explantions in Hoax Wiki carefully
Nothing else as declared there will be realizable
A combined version of 1) and 2) will occur some problems specially in driving by VST Software in PC
The HX 3 is NO VST INSTRUMENT !! its hardware controlled itself by direct connected drawbars and switches
But there is perhaps another way to realize Your idea.
Every switch can be replaced by relais components.
Its Your turn how to drive those relais from Your PC program.
As I know there it gives several MiDI equipment "MIDI to RELAIS Switch" ( avalable at DOEPFER )
For the rotary vibrato switch You also can use 6 relais for the 6 positions
maybe that´s a way to realize Your problem
Things like motor controlled drawbars may only run when You use stereo pots in each drawbar.
One fader pot ( of the two buildt in a motor fader) used and connected direct to HX3. the other fader pot is free for Your PC System if required for correct positioning The resistance value of HX3 drawbars potis can be between 5 Kohm and 47 kOhm - a good deal will be 10 kOhm LINEAR ) Never use those with LOG curve.
So in fact Your system will only need the normal HX3 board , FATAR scan and the preset 24 board
... and if wanted the LESLIE Interface
The preset 24 board You chose via jumper as defined "with real switch" so You also can drive this via RELAIS ( a relais is a switch )
So finally I think Your System is realizable and there is no need to use the HX 3 Expander Module
The key word of Your system is " MIDI to switch "
happyfreddy