make drum module out of midi keyboard

[jawharp]

ok, here’s my idea.  i dont have much money.  that’s not going to change.  i’m making triggers from remo practice pads.  rather than dump a bunch of money on a drum module that only has a set sound bank, i want to go into a laptop and use whichever samples i want.  this set will be strictly for practicing.

what i want to do instead is get a used m-audio oxygen keyboard, open it, and wire the triggers directly to the switches on the keys on the keyboard.  basically the set will simulate keystrokes on the keyboard.  i would use a midi program of my choice on the laptop to playback different assigned sounds.

my question is, does anyone know anything about the inner workings of one of those keyboards and their switches?  i’m wondering if i wire to the keyboard’s switches, will lose velocity sensitivity on my pads?

joe

Topic

[PFozz]

Hi,
 
Piezo transducers don’t act as switches.
They are “electrical generators” and they can’t be compared to push buttons.
A velocity sensitive keyboard is usually made of 2 switches per key. One of them is ‘on’ when the key is released and the other one goes ‘on’ when the key is fully pressed.
The velocity depends on the time lapse between the start of a pressure (the first switch ‘goes off’) and the end of it (the second switch ‘goes on’).
 
The only thing you may get from an old MIDI keyboard is a hihat variable controller stuff made from the modwheel/continuous controller circuitry. If you’re extremely lucky, the needed pot value for this (exotic) circuitry will be 25k. Otherwise, you will have to build your own controller from a pot that suits this circuitry.
You may also build a hihat controller from an analog joystick (replace one of the pots by your home made hihat controller) and use it in combination with a Joystick-to-MIDICC freeware.
 
Once you have this standalone hihat unit, an old module will do the job (Roland PM-16 / Alesis D4-DM5 / …).
Some are available for 60-80€ sometimes.
 
Actually, my first edrum set was made of a modified Yamaha DD-12, some basic home made triggers, and a home made hihat controller linked to a modified analog joystick. It was a long time ago, but I remember how fun it was to play with all those things…
 
Good luck!
Best regards.

www.eareckon.com

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