DIY Drum Machine – Circuit Bending

I have been working on a diy drum machine for a while now. I wanted to post this video to show it’s functionality.

The core of this drum machine is from an electronic drum stick. You swing the stick and it makes drum sounds. The stick made 3 sounds; Snare, bass drum, and high hat.

DIY Drum Machine

When you swing the drum stick, it plays a snare sound. There are two buttons on the stick, that when pressed AND the stick is swung, play two more sounds. So this was easy to hook up to a 3-way switch with up as one button, down as another button, and middle was just like swinging the drum stick without pressing a button.

DIY Drum Machine

I rigged it up to a 555 timer and a 4017 decade counter and some pots and switches, and away it went. There is still some glitching that happens I think because of some switches which aren’t wired to ground to de-bounce them.

DIY drum machine - time signature controlerDIY drum machine - switches to control sound typeDIY drum machine - 555 timerDIY drum machine - 4017 decade counter

The 555 timer triggers the drum sound and advances the 4017. The 4017 sends a pulse through one of 10 3-way switches to hold the particular sound. The sound selection is set with the 3-way switch. I hope that makes sense.

Like I said, it’s a work in progress.

DIY drum machine - control board layout design

The case is from a kids toy (big surprise, I know). It was a light box for tracing. It use to have two lightbulbs inside and a semi-transparent screen. The cool thing about is that it has a battery compartment built in. All I had to do was modify it for the voltage I was using. I just shrunk it down. Easy (yeah right).

I painted it up white first and then spray painted a stencil of a fist on top of it. The body was also painted red. The final step for the paint job was to do some clear coat. All in all, a pretty sweet paint job.

Circuit Bending a DIY Drum Machine

In this video, you can see holes for the LEDs that will indicate which point in the sequence it’s at. I am having a heck of a time with that. It seems like, when connected, the sound plays but the LEDs don’t light up. I don’t know if it’s a lack of current or what. I have tried the LEDs in series and in parallel. Neither work now. The joke is, it all worked at one point when it was on a bread board. Upon soldering everything up, everything started changing. I suppose that is the nature of the beast.

I would love to hear your thoughts.

Happy Bending,


14 thoughts on “DIY Drum Machine – Circuit Bending

  1. NICELY!
    I just finished a CV sequencer with a 555 and 4017. i also have a couple of drumpad stle toys that i have bent and would love to sequence. ive seen caspers trigger setup, but it looks like youre achieving control without the addition of the 4016 and 7408 ics. im not sure i understand what you mean by the 4017 “holding” the drum sound. i would love to see a schematic or details on your build.

    • Sorry it took so long to get back to you.

      How did your project come out? I would love to see what you were able to come up with.

      Let me know if you still have questions.

      Thanks for the comment.


  2. hi, love the project, ingenious πŸ™‚ I am trying to replicate it myself, im quite stuck in how thinf are wired together though, ii have the trigger of the toy soldered I’ve quite to ground one wire to the output on the timer, that seams to work. I also have pin 14 on the decade counter connected to the out put on the timer. i’m struggling on how to conect the switches to the 4017. it just seams to be playing the same switch over and over again. any pointers would be very helpful, im new to electronics. I just can’t understand how to connect all ten switches up to the same toy. thanks again, kit

    • Sorry it took so long to reply.
      Were you able to figure something out?

      It’s been a long time since I have had this project out. I don’t quite remember how I hooked the 4017 decade counter to it. I think I used 3 way switches.

      I didn’t use the decade counter to trigger the drum stick brain though. That was done with the 555 timer output. That triggered the drum stick and advanced the 4017 decade counter. Each of the decade counter outputs was hooked up to the 3 way switches which set which sound to play.

      I remember having to do quite a bit of tinkering to get everything working right.

      Let me know how you are going and maybe I can answer some questions.

      Shoot me a video too, that always helps to see what’s going on.

      Good luck.

  3. Howdy Mike-d. here,
    Cool about the drum machine. A friend gave me one of these drum sticks and we were trying to figure out what functions the buttons served or what they all did. My friend had figured out the
    two buttons that did the crash cymbal and snare drum sounds(my snare sounds more like a phaser shooting), when you hit “something” or stop “mid-swing” quickly while holding one of the buttons or not. If you hold both buttons at same time, (on mine) only snare sound- sounds. But we could not figure out the third button. Until I asked the answer machine.(I looked on the internet(surfed the web)). I found this youtube video.

    In the video, I saw the third button played a pre-recorded tune, which was very short and repeated until you pressed the button and turned it back off. The guy only did it on one stick and never mentioned the other stick. One of his sticks has a music note next to the button. Mine does not. My friend and I debated about if both could play the same short tune, or each maybe a different tune. Or only just one, and why just one ? to save money ? To get you to by another pair if you lost that one ? Since I once worked for a joystick factory on an assembly line, I guessed that “yes, only one is going to work, as is, and that the other is probably disabled somehow, like a wire, a piece of solder, a switch, something different to cause it not to work.” I even told my friend that it probably even has the same music box thingy in it as the other, and I was going to check it out. My friend told me I was wrong, and he thought that theory didn’t make any sense to him.
    My friend left and I investigated. I took it apart and looked at it. I came across a UG-106a.PCB and tried shorting it out with a screw driver, which I don’t really recommend because I probably could of blew something out, if I didn’t. It made a quick sound, like I blew something out and then nothing worked for a couple of seconds, till I figured out the battery was no longer completely in place. So I looked to the answer machine for more info on this Printed Circuit Board(PCB), and did not find anything helpful. So I went back to shorting it out with a screw driver, which did not work, the first time, and then I tried again making sure it properly contacted the middle where the button would of pushed, and the half-circle of solder-pathway, this worked, the drum-stick started playing a very short, repeating tune, over and over again. I think this drumstick is just missing something to short or connect the path when the button is pressed, and this button seems to be a (electrical)on/off switch, when you press it, it is “on”, until you press it again to turn it “off”.
    I decided to try looking for more info on the UG-106a.PCB and that’s when I came across this blog. I also came across this website to buy them. I am not trying to sell them, but I did like the Selling jargon, instructions, and other info provided on the site.
    It refers to a demo video on some site which I have not checked out yet, unless that ends up being the youtube link I posted on here also.
    Thanks, I only posted this because I did not see any talk about the music, and did not know if you were aware of the ability to turn it on so simply.
    Mike-d. out

    • Thanks for the comment. Glad to see you can still buy these. I might need to pick some up. Although, I almost always see them at the thrift stores.

      In terms of the music… I don’t remember if mine had it or not.

      If it did, I surely disabled it. It wouldn’t fit with my project. I really just wanted the basic sound.

      Good luck with your projects! …and let me know how they go.


  4. Mike-d. here again,
    One more thing. On the UG-106A.PCB there is a coil with a plastic looking tube around it, when tapped, or touch briefly, this seems to be the thing to switch the drum sound on and off, I’m not sure if the tip is actually sensitive like advertised, but instead this little “thingy”, when hitting something and converting that into turning on the sound.
    Mike-d. out

    • Yes!

      That is the trigger. The spring wiggles and makes contact with a metal rod that runs up through the spring.

      The tip is not reactive or touch sensitive.

      With my drum machine project, I disconnected the wires leading to this spring and rod and triggered the drum machine through this.

      The great part about these drum sticks is how simple and easy they are to circuit bend.

      Sounds like you are having some fun with these too.

      Thanks for the comments!!!

  5. I read your issue with the lights and a while back I made a sequencer with similar issues…. the only suggestions is that maybe either something is not gounded or the polarity was switched accidentally or the lights were just plain burnt out…. the only way I can think of testing that is to take out one of the lights and seeing if it lights up to a nine volt, or taking a new light and touching it to the working circuit to see if it lights up. Any other ideas I have I feel like are silly since you probably know more about it than me since I don’t know the theory but know basics and following diagrams and that’s it.

      • I would start with the drum machine itself. Get that working first.

        You can ad filters on the output of the drum machine.

        I would love to see links to your work. Do you have any videos or pictures?

    • Not really. I only know what I have read about. I’m not an electrical engineer. Just a hobby for me.

      I think that is the main reason I have issues. I’m sure there is some theory that I’m missing.

      I would love to see what you were able to come up with. Any videos or photos?

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