Home-made Midi Triggers
 

Hi,
i just started this project,
i bought 6 10V piezo discs and foam for making my own midi drum triggers. What i find out now is that all the CV->Midi converters only support like up to 5 volts! I doubt anyone can help me with this, though i can still complain and feel bad that i wasted 5 $ away on the piezo discs when they dont work with the converters/drum brains :lol:

May I ask...

What are piezo discs?
How do they output a voltage?
How does this voltage correnspond to a note?

An url about CV would also be acceptable ;)

A piezo element. It's a thing that resonates when supplied with AC (thus can be used as a simple speaker) or it creates a small voltage spike when hit.

See above.

It's a trigger and the voltage can be used as a velocity curve.

Re: Home-made Midi Triggers
 

Well, first of all, transforming 10 volts to 5 volts is not a problem. It can be done for example this way:

Input >-----[====]---->Out<-----[====]-----| Gnd
10MOhm 10MOhm

The resistors here can be other sizes too, but I prefer big values as voltage dividing resistors. As I haven't done anything with piezos and not even quite sure how they work, I have no idea how that dividing would affect the voltage spike. You could always drive it with an opamp or transistor if it runs out of juice - And I think it's preferrable anyways, or even must-to-do.

Could you give me some details on how you've planned to make the triggers?

Yeah, sure.



As you can see on the pic, i am going to "sandwich" the piezo disc between some foam to make it less sensitive(so the velocity arent full values all the time) and to give it a nice feel.

Then the 2 wires coming out of the piezo are connected to a 1/4 inch (jack i guess, im not sure actually) cable, that goes into a voltage transformer and then in a CV>MIDI converter/drum brain.

doepfer has released alot of their prebuilt components that allow you to build your own box. also check out www.ucapps.de (midibox project)

What does that have to do with drum triggers?

My bad. I though you were refering to drum triggers like the trigger finger. Didnt think you acually meant a kit. :oops:

Oh but i was. Sorry if i misunderstood you.