yes, I think the HX3 can support four sets of drawbars.BUT
not via midi.
Have a look on the MAG-Organs website: http://www.magorgans.com/?page_id=691
I think this baby has a HX3 engine build in and has four sets of drawbars.
At the Keyboardpartner Github respository you will find the schematic for the drawbar sets:https://github.com/keyboardpartner/HX3/ ... ematic.pdf
I think (I think means = I do not know) the technology behind it is working this way: There are two sets of drawbars and an A/B switch where you can choose which set of drawbar is active. This A/B switch sends also an information to the HX3 sound engine to cancel the percussion depending on the selected drawbar set. There are three CD4053 ICs. They switch between the two sets of drawbars. These two sets of drawbars control the volume of the different footages by a control voltage on the slider. This control voltage is switched by the CD4053. When you switch from A to B the HX3 Sound Engine is told "Enable the percussion and adjust the footage to the new volume levels!"
Midi controlling works a little bit different: When you start the HX3 Remote application and choose the "Midi Custom CC" tab, you can see the controllers and the assigned controller numbers. There is only one set of drawbars
for each manual. Each footage has one controller number
assigned. Midi controllers do not send permanent information. The Information is only sent, when you activate the controller by pressing a button or sliding a slider. The informtion flows only in one direction; from the controller to the HX3 expander. You can not manage two sets of drawbars with one controller. The problem is: When you set drawbar set A to 888888888 and set B to 111111111 the silders on your midi controller keep in the "111111111" position when you switch back to set A. If you move a slider from "1" to "2" position the will send the information of position "2". The setting aof drawbar set A was "888888888", so the value of this slider will jump from 8 to 2 and not to 7...
There are two ways to solve this problem: Keyboardpartner updates his software / firmware and implements a second sets of drawbars in the CC map where you can assign different CC numbers. Two switches with different CC controller numbers to switch between the drawbar sets A and B for UM and LM are also needed. The second way is to build a midi controller that will do the same job the Kexboardpartner hardware does: To send all values of all necessary controllers when you switch between the two drawbar sets.
I started building a controller which is working that way, but it will take some time for me to finish this project.
Yeah, HX3 is a great sounding Hammond clone and the idea behind it is brilliant, the developer a genius! But VIA MIDI is is not playable like a Hammond at all (at the moment). I'm also a little bit disappointed about that. A Midi Implementation Chart in the User Manual is missing, so I did not know that fact before buying the Expander.
Perhaps this feature will be integrated during the next updates... Hope so. Or I will sell it and keep my VB3.