Home-made Midi Triggers

[techno_7]

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:

[pDc]

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 ;)

[Juho L]

What are piezo discs?

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.

How do they output a voltage?

See above.

How does this voltage correnspond to a note?

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

[Juho L]

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!

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?

[techno_7]

Yeah, sure.

http://www.electronicpeasant.com/projects/ssdrums/paddgram.gif

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.

[Merlot]

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

[techno_7]

What does that have to do with drum triggers?

[Merlot]

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:

[techno_7]

Oh but i was. Sorry if i misunderstood you.