https://www.youtube.com/watch?v=fkI-F7aqs3cI I enjoy playing the C-system chromatic button accordion, which is different then diatonic-button accordions ("button boxes"), piano accordion, and bayan (B-system) accordion. See my links for a better description of what a C-system accordion is.I wanted to leverage my comfort with that keyboard layout with an instrument more designed for electronic music. There are some MIDI button accordions available (Roland V-accordions have a button model) but I wanted something more compact and abstracted and under $500.The right hand side of this instrument has 65 "Cherry-Mx" style mechanical keyboard switches with round key caps. The left-hand side has a 2-axis analog joystick and some buttons. So far I am using the joystick for pitch modifications and volume modifications and the buttons for switching octaves and waveforms
65×
Gateron Clear Keyswitch - Plate Mount - Linear
This is a cherry MX clone. lightest spring I could find. I also tried some cherry MX silvers that fit my plate better.
65×
round Cherry MX key caps
these were intended for a steam-punk QWERTY keyboard. I sharpied some of them black to make the keyboard layout easier.
65×
1n4148 diodes
One per key to prevent ghost notes
1×
Mounting plate
I had this laser cut at my local metal shop. I used 16 gauge which is too thick for the Gateron switches so I ended up having to thin the tabs. CAD drawings can be found on the github page
Hey folks, here are a couple more pics. For the one of the back plate, this is 1/8 steel scrap that I had. I like the patina. From left to right you have
USB for MIDI / power supply
1/4 MONO line-level audio out
Octave down
Octave up
Joystick. vertical axis makes the controller louder / softer. Horizontal controller bends pitches
Four Red control buttons. (well 3 because the bottom one already broke. No more cheap switches for me!) They are:
cheap-ass broken button
unassigned
Change pitch bend between entire instrument mode or last note played mode
change wave form
Two LEDs that initially showed which of the 5 octaves was selected, from one (bottom blinks twice) , 2 (bottom blinks once), 3 (no lights), 4 (top blinks once) and 5 (top blinks twice). I disconnected them because the blinking was distracting.
There is also a close up of the keys, where you can see the round Cherry MX key caps I am using for the buttons. There is not really a pattern to what letters go to what switches other then the C-G in the middle. The black keys are just white keys with sharpie.
You can see how tight I am for space on the back. Im leaning towards making this model MIDI only and building a second prototype with a little more room.
Hi Jon. This is the best CBA midi controller for practicing that I've seen. The buttons are realistic and spacing is perfect, and 5 rows has more potential than 3. If it's available for under $500 I'd definitely buy one.
Wow, this thing looks (and obviously sounds) great! I'd love to see more build info and pictures. Did you lay out your own PCB for the switches?
You mention you're using MIDI now but adding the audio shield will give you better sound quality, can you explain a little bit? I would think you can get any sound quality you want with MIDI, but the sound shield would make it self contained.
For the cherry MX switches you can get either PCB or plate mount. I did the plate mount. they are hand wired as a matrix with a diode on each switch. I think PCB would have been easier. You can check out the CAD drawings for the mounting plate in the github repo. I will also get some more pictures up. (all though it is pretty messy looking from the back end right now) The sounds in the demo are all self contained (not MIDI). The issue is that the digital/audio converter that comes on the Teensy board 3.6 does not handle multiple notes very well. You can hear them distorting in the video. When I add the audio shield I will be able to get better sound quality and do more complicated things with the sounds I am generating, like combining multiple wave forms together (FM synthesis) to come up with a wider array of sounds. RIght now the audio out is either a sine, sawtooth, square, pulse, triangle, or reverse sawtooth wave. You can hear me cycle through them in the demo video.
Hi Jon. This is the best CBA midi controller for practicing that I've seen. The buttons are realistic and spacing is perfect, and 5 rows has more potential than 3. If it's available for under $500 I'd definitely buy one.