Leisesturm, did you even think that perhaps Timbres wanted the satisfaction of "doing it himself?" Your comments are a bit harsh. The diversity of the forum members is what makes the organforum enjoyable. All of us can learn something whether we agree or not. Even though my console was MIDI-fyed with Artisan uMIDI components, it took many hours of wiring plus writing the program to define what the hardware is supposed to do. If you prefer a more off the shelf approach, that's great; it will save you time and perhaps your experience will help others.
I love to learn new things by working it out for myself. For example, I could have purchased MIDI hardware, but I learn more by developing my own software. Also working with an existing keyboard, the solutions emerge from the hardware. I was able to re-use existing wiring which not only reduced the amount of soldering but also allowed me to see and respond more directly to the architecture of the organ.
Regarding audio, I think I can answer some of your questions. The Firebox is a product I've used before, and it was under $30 on Ebay, so really good value. My experience is that six channels is markedly better than two plus a subwoofer, so I'm happy with the solution bar the hum. I also considered other strategies for mixing / switching the audio, but I couldn't build anything better for close to the price of the snake plus relay box. Also by doing it this way I have access to eight channels of high quality class AB amplification (part of my home theater setup).
Finally, with two kids in college, and a mortgage to pay, the cost of the project is a major deal. Apart from the cost of Hauptwerk, I believe my total spending to get to a fabulous instrument, better than I originally dreamed, has been less than $150.
Timbres--Love your approach to the end product. I also enjoy doing it myself. Amazing how much you can learn from the experience. Wishing you the best.
Thank you for your kind words. Having the ability to participate in a community like this has been key to both the success and the enjoyment of the project.
At the moment our Arduino-based solution can support up to five bus-wired manuals to a single board, one manual per shield. We designed and ordered our own PCBs for this purpose. The diodes are SMD and are mounted on the PCB, not soldered to the switches/stops, which simplifies the actual wiring. The entire cost of the PCBs and diodes thus far has been roughly equivalent to the cost of one Arduino Mega2560 which is required to run the board. The same shields can be repurposed to also handle, via another Arduino Mega, the pedalboard, up to four expression pedals, and around 600 stops.
Now, it's possible we missed solutions out there, but from what we could find the existing MIDI hardware is orders of magnitude more expensive than the $200 or so we have invested. Also, having the software and hardware expertise to handle all of this lets us have confidence in the ability to support it long-term. We also may move one or more times in the next several years and this allows us to be modular. Finally, we also much prefer to use fully open hardware and software, which to our knowledge would not otherwise have been possible.
So there are certainly reasons/justification for going this route.
I'd love to see more information on your solutions. I used a separate Arduino for each manual, and for the stops and expression pedal (I only have one), because the Leonardo is not very powerful, doesn't have that many pins, but does do direct MIDI over USB, so I just connect all the different micro controllers through a 7 port hub.
Please post some pictures, and your code if you're willing to - it would be great to see another homebrew solution.
I think that the folks currently building MIDI and console solutions are doing so for two basic reasons. First, they do so because they possess the knowledge and skills to do so and enjoy the effort. That's a lot like woodworking I suppose. We do it "because we can". Second, some of us are on a budget and amuse ourselves by demonstrating that we can produce a totally state of the art project at nickels and dimes on the dollar. Literally 5 to 10% of the big builder installations when you add the software and the sound and computer equipment to come up with a 2k to 10k installed solution. If someone can locate a free console and turn out a first rate product by adding $200 to $500 in parts plus perhaps 5k of unreimbursed labor then that's a beautiful thing. Chances are a better sounding product won't be on the market at anything approaching the expenditure.
Great work, timbre and physics major and spouse.