Velocity Sensitive Drum Trigger From Old Headphones




Introduction: Velocity Sensitive Drum Trigger From Old Headphones

With a little software and some stuff you have around the house, you can make a simple drum trigger. A fancier version would use a real drum pad, a piezo transducer, and a cord with a headphone-jack; but this can literally cost you nothing to play around with.
Using a free VST app you can use the mic in to control MIDI events. It can be used to control drum machines or simply trigger samples.

Step 1: Equipment and Tools

What you need:
set of old headphones (only one side needs to work)
mouse pad
empty soda can
cassette tape case (or whatever case you like)


Step 2: Cut a Hole in the Cassette Case

I decided to make a 1.5 inch square pad for the trigger. I added a 1/16 inch gap for the hole, and cut a square 1 and 5/8 inches into the cassette case. I liked the case because the two spindles give the pad more support.
I also cut a notch on the side of the case for the cord to fit out of.

Step 3: Cut the Pads

I cut the a 1.5 inch square piece from the mouse pad and the pop can.
I cut a second section of mouse pad slightly smaller than the lid of the cassette case.

Step 4: Prep Ear-bud

Remove the plastic casing around the ear-bud, then cut a small hole in the larger section of mouse pad for the ear-bud to fit into. Make it smaller than the ear-bud so it can't slip through.
You can use a pair of broken headphones as you only need one speaker. Cut away the broken one.

Step 5: Glue the Assembly Together

Glue the large section of mouse pad to the inside of the case.
Glue the section of pop can to the under-side of the "trigger pad."
Fit the exposed ear-bud into the hole, and glue the "trigger pad" in place.
Make sure the metal of the pop can that is glued to the "trigger pad" is touching the metal of the ear-bud.

After this was all dry I used black tape to finish off the look and disguise the cassette case.
UNOPAD (get it?)

Step 6: Install Software

A plugin that triggers MIDI notes based on the sound level of the incoming audio stream in different frequency bands. It allows you to "detect" occurrences of percussive sounds in an audio stream and send out a MIDI event whenever that happens. Available as VST effect for MacOSX and Windows.

Virtual midi cable program ( MIDI Yoke or Maple Cable)

You can use Ableton, Cubase, Cakewalk, Fruity Loops, etc. to run the VST
a Stand Alone VST Host. I suggest SAVIHost

Set the Midi Out of SAVIHost to Midi Yoke 1. Then in your audio app, set Midi In to Midi Yoke 1.

In the Wave Devices settings of SAVIHost set the Input port to your mic input.

In KTDrum, make sure you set the Threshold and Gain of the Trigger 1 high enough to trigger events, but not to low enough for ambient noise to set off.

Have Fun and make Great Music!



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    33 Discussions

    Got the UNOPAD joke btw..
    hilarious lol

    Can you plug it into a the espression pedal connector of a midi master keyboard and get the velocity response?

    one could use the circuitry of a usb keyboard to give different signals to the pc... with a soft like hydrogen witch is free.. a suggest the puppy studio, a linux distro aiming for sound creation with real time kernel.. it already comes with qwerty to midi in hydrogen, u just have to press the key.. with a lot of well known drum kits, like the tr808 and tr909 and so on.. u can use your own samples and it runs from a cd or flash pen, don't need to install it.. give it a try.. I'll do something like an diy akay mpc out of legos.. hope it will work, it will be my first project..

    should also read:

    god work, hope u enjoy it..

    6 replies

    yes this is exactly what i want to do. it would have to a usb keyboard though? couldn't i just switch a ps2 end for a usb somehow?

    view my instructable:-

    Yes U could, I know ppl do it, but don't know how....

    please see this...

    from my undestanding, with software like drumagog u can use like 1 mic and a pair of small headphones, or maybe two sets of headphones.. plub one in the mic slot and the other one (I suposse) in the signal in, with the vst U can trigger one diferent sample on each chanel.. with velocity sensitivy and all.. the problem is the price of such vst...

    there are free alternatives, like this one:

    only 3 frequencies (Low,Mid,High).. I'll try some day to do an airdrum like that guy..

    try to search the free alternatives in the search for trigger and see whats free and hot..

    Good luck..

    Sorry about 1 thing.. I suggested U the same vst that U used in Ur instructable.. sorry.. It works with bass, midle and high, so I suposse if U wire 3 piezzos with diferent material covering it, producing distintal frequencies, in theory should work....

    view my instructable:-

    is there some way to make more than one and assign midi cc numbers to each one? how does one from the store work with multiple pads and using a midi cable?

    You are turning and old broken pair of ear-buds into a microphone, then using software to translate that into midi with velocity.

    ahh :L thanks and wel i know alot of people have been asking this but is there any way of having both headphones work as 2 pads?

    Can somebody tell me is it possible and if it is how can I connect more than one drum trigger (I want to make a drum kit) with my computer but without using a drum module?Please tell me if you know!

    1 reply

    Use a rock band type game controller then, this will only handle one "drum."

    Only if you could get them to produce different frequency inputs - you might be able to do that by changing the type of foam, making it harder or softer, or thicker or thinner..

    if i have 2 can i hook them up so ill have a trigger machine with 2 or more buttons?!