I wanted the best of both worlds: patch presets, and real-time controls. I wanted to be able to call up a patch, and have all the controls fully live, already reflecting the settings dictated by the recalled patch parameters. Basically, like having motorized faders, but no moving parts. With all the parameter information to & from the instrument to be midi, of course.
A logical choice was to use capacitive-type sensors to read finger positions on the control panel, only those types of sensors are prone to being a bit fiddly and have lag when being in an electrically noisy environment, and for music use I needed speed and responsiveness.
So I designed a vesion that basically ignores external electrical noise. Even noise at frequencies at or near the sensor's operating frequency just goes away, leaving a clean sensing signal. The resulting responsiveness lets it feel natural to use. I usually disllike touchscreens & such, but was pleasantly surprised at how this thing handles.
The control panel itself contains the touch sensors and the midi interface circuitry. It's plugged into a laptop computer, which is the brains of it, analyzing the sensor signals to derive where they are touched, and handling display control, patch storage, and real-time parameter data transfer to the instrument. All done in a few kilobytes of assembly language code.
So does using something like this make a difference? I put it on a DX7IID for the test, as that beast has a strong reputation for driving one to drink when trying to program the sounds. This made it very easy to understand and use. I was able to help a drummer understand the basics of FM synthesis in about 15 minutes. The real kicker came after I'd gotten a couple of hours of use on it, and found myself getting dynamics in the sound that I had always dreamed of doing, but never thought that I could, let alone on a DX7!
After pondering this a bit, I came to the conclusion that when you have to switch from a music-oriented state of mind, to an analytical mode of thinking (like using a menu), and back again, it throws a person off-track. In a nutshell, having to mentally task-switch while creating music can take you out of the "zone". Also, there are many things a musician simply can't do with just menus. Picture what it'd be like to drive a car using only menus. Same thing.
So I'm sitting on a way to make synths much easier & fun to understand & use, where to go from here...
I don't have the resources to go much further on this. I'd love to build something more advanced than this crude proof-of-concept prototype.
Incredible Real-Time Touch Controller for the Yamaha DX7 Synthesizer