modifying MIDI circuit boards/patching into consumer keyboards?

[VvvvvV]

I am looking for a MIDI controller keyboard where I can hack into the faders and keyboard contacts and extend them about one meter out to an outboard circuit.

the trouble is that most of them seem to use really complicated velocity sensitive keyboard circuits that are hard to mod at all.


I just hacked up a "Novation remote 25" keyboard which has about 30 MIDI-cc potentiometers, 30 keys and an XY pad.

when I got inside the keyboard contacts, it turns out that each key is activated by four contacts on each key, that look like the number four on a dice(:, plus a bizarre long ribbon connector that runs the whole length of the keyboard under all the keys but that doesn't look like it can make electrical contact with anything very oddly.

to activate a key, I have to join the top and bottom pairs of contacts for that key. I have hacked into the circuit and extended it into copper wires (from a mouse cable) that are about one meter long.

when I try and join the notes one meter away it is tricky getting the contact and then when it does it often hangs on a gate on.

is it really tough to hack into velocity sensitive keyboards?
is it unwise trying to extend circuit board contact for potentiometers and keys about a meter away from the commercial keyboard? Will the static buildup screw it up?

surely modifying commercial stuff is better because you get so many extras like USB, program/Channel changes, knobs and wheels and buttons etc...?

[VvvvvV]

here are some pictures of the beautiful insides of a MIDI keyboard.

1-confounding velocity sensitive note pitch/gate contacts.

What could the ribbon connector be?

[VvvvvV]

velocity sensitive double contacts, a line of rubber buttons with 2 contacts each is pressed by every key, each button has one contact higher than the other to sense velocity.

I can't seem to turn this into a basic note on/off system system even for only five keys.

[VvvvvV]

backside of the velocity board

[VvvvvV]

the potentiometers, LCD display, etc

The keyboard plastic in the background is chunky, refined and impressive.

[VvvvvV]

underside of the keyboard with the strange ribbon connector

[VvvvvV]

main novation controller for the remote series into which the different controller/key panels are plugged, with USB/power, MIDI, all the keyboard IO.

The pitchbend XY wheel and the cheapo XY pad that you think would be the strength of this board are at the left, still an excellent controller.

[laserbeak]

well those are very interesting pics but i'm sorry i cant help.
i found this searching for midi tutorials :P

[VvvvvV]

thanks for the encouragement, in any case, I figured out what the ribbon is going along the length of the keys, it is a resistor that measures channel aftertouch which is a mono MIDI message

I also found that there is no easy way of turning the contacts from any commercial MIDI controller with velocity sensitivity into basic note on off keys like to get on a DIY MIDI board, unless you are really a mad electronics buff it is literally a type of electronic shafting for anyone that triesbecause all the velocity sensitive contact go into a really fkkkkt bastard microcontroller

however if you really wanted to you could use some of the Midi potentiometers and remap them somehow, if you have some kind of program, into keys and use them as switches.

[Optical]

Haha, you are doing exactly the same thing as I tried to do 2 years ago with my edirol PCR50

those stupid pads are almost impossible to reengineer

i was trying to make the keys into piezo trigger drum pads for an eDrum kit.
Basically to register a key press the switches close a few milliseconds apart, and the micro deciphers the time difference as the key velocity.

I had made a ramping signal that ramped according to the voltage peak of the piezo (peak hold cct into constant current ouput opamp charging a capacitor if i recall), then triggered two comparators as it ramped up. then the ramp reset after the second comparator had triggered. but it required 5 opamps, a few transisitors and a whole lot of mucking around tuning the ramp times etc. in short, it worked terribly. perhaps good in theory though


What are you extending the wires to do? I ended up building this http://www.edrum.info/ to make my edrum set and it was much simpler and worked straight away haha
plus my keyboard stayed intact