Trevor,
As a beginning, I would recommend that you read the “Midification” thread on the current forum, end to end. That would give you a very base line knowledge of what it will take.
To answer your question, there are midibox modules to provide all you will need to midify your organ console, and provide the necessary magnet drivers for the pipes. You don’t really have to know alot about electronics, but you will have to develop some skill in following schematics and soldering.
My home project over the last couple of years has been midification of a Moller 2 manual console and assembly, construction, fabrication, etc., etc., of regulators, wind trunks, windchests, blowers, in order to have a hybrid organ of 5 ranks of pipes playing with multiple ranks of electronics sounds either from soundfonts or wave samples. So far I have completed the base organ, i.e. console, wind supply, pipe chests for three ranks with the remaining two under construction. My system is based on the midibox midio128 modules for encoding the keyboards and the midi decoders and magnet drivers. Jim Henry stated it very well above, when he said that you will need a relay to run your organ. This became very obvious for me very soon after beginning my project, until I discovered jOrgan and miditzer. Both can be considered to be relays since they can provide most of the functions of a conventional, commecial relay. What attracted me to them was that they are “free”, with lots of support through the forums for each one. The VTO software was developed to allow anyone with midi keyboards to use their home computer and stereo system and set up an organ. It just so happens that we can benefit from the same software as an actual computer based relay.
In my case, At this point, I lean toward jOrgan and it can provide the relay functions for a theatre organ or a more classical organ. You did not say which type of instrument you desire, although your console is classical. Jim Henry’s recommendation of Artisan products as a relay is well taken. You can put together a very fine relay with Artisan modules and limit your organ to the 20 ranks of pipes you already have, and if you so desire, couple it with other voices with jOrgan, miditzer or someother VTO software. Artisan is pre-built and bears a price tag considerably above midibox kit prices. It is possible to merge the two systems together using parts of each, but that will take some planning. If cost is not an issue, go for it. Otherwise read on.
The other issue you need to understand is that with the VTO software( jOrgan, Mditzer, Haupwerk) the system is PC based and you will need a computer of sufficient computing power to run the system, not necessariy dedicated, but with ample speed, storage and memory. In my case, I am not interestedn having a computer monitor residing on top of the console, so all organ functions are sent and/or received through midi messages. The computer resides in the pipe chamber 30 feet from the console. My console is fully functional with stops, pistons, couplers, two manuals, pedal, swell and combination action. I have not implemented the cresendo pedal but could. Only one other feature is not fully developed and that involves powering the on and off magnets on the stop switches (SAMS). The combination action built in to jOrgan operates the stops, but they don’t change position on the console. To my knowledge, of the VTO software available, only Haupwerk will do the complete organ, although the software is expensive. Upgrades to jOrgan are hopefully forthcoming, same for Miditzer.
In a nutshell, thats what I am doing. It has been an in depth learning experience for me which has provided many hours of pleasure. You can email me if you have specific questions.
Johnc