Not there yet, but it’s in reach: An Aftertouch, e.g. channel pressure control, retrofit for the Korg R3 synth.
I really like the Korg R3. No, there’s more: I bought it second-hand out of very rational considerations, and ‘ve come to love it deeply. There are people who don’t like it for its plastic housing, for the limitations in comparison with its more expensive sibling, the Korg Radias, others hate it simply for not being a first-generation Microkorg. In my experience, it’s an excellent virtual analog synth capable of doing massive bass as well as very unusual pads. It’s versatile, it’s compact, it’s cheap, and it sounds great. And unlike the Microkorg, it’s got a proper keyboard, albeit without aftertouch.
For some reason, the MIDI Thru jack in my R3 stopped working today, which is bothersome, but also a welcome excuse to open the R3’s housing and take a look inside. I had this idea of equipping it with an aftertouch sensor for even more variation and liveliness in playing. And now I’m confident it would work, although I won’t be able to do the mod for some time.
The basic idea was to take a couple of standard pressure sensors like the FSR-400 (have a look at the lovely Adafruit tutorial for this kind of sensors), and connect it using the R3’s pedal input. This input is supposed to be used for standard expression pedals, but of course you can use it as a generic analog input – the R3’s firmware allows you to route the control to almost any MIDI CC. There’s also some limited calibration to adapt the synth to different kinds of input.
The expression pedal jack has these signals on a standard 6.3mm plug:
- Tip: +3.3V
- Ring: CV In (in an expression pedal, this would be the connection to the output of the potentiometer
- Base: GND
My first idea was to put the sensors under the synth’s rubber feet – any pressure applied to the keyboard can be measured here, after all – but this wouldn’t work if the synth rest on a keyboard stand rather than on a table. And it would be much more elegant to put the circuitry into the housing.
Anyway: here is a couple of photos from the with notes how it might be done.
- Midifying Jenny, Step 1: Replacing the old keyboard chip with a Teensy (Sunday, 6. January 2019; Schlagworte: Arduino, Jen SX-1000, Löten, Midi, Modding, Retro, Synthesizer, Teensy)
- The Humble Art of iPad Music: A Rant (Wednesday, 21. March 2012; Schlagworte: Animoog, App, iPad, Korg iMS-20, music, Musik, Softsynth, Sunrizer, Synthesizer, SynthX)
- Tech Hack: Alesis IO Dock with USB Hub (Wednesday, 2. January 2013; Schlagworte: Alesis IO Dock, Hacking, iPad, Midi, modification, soldering, USB, USB Hub)