Atari Punk Organ, a Simple 555 Synthesizer





Introduction: Atari Punk Organ, a Simple 555 Synthesizer

This is my Atari punk organ, it is a 555 timer piano run through an Atari punk console monostable generator, the piano is based on another instructable I made:
t has 2 speakers which both play different sound at the same time, which makes an interesting sound and it is tunable using the trimmer potentiometers so you could in theory make an accurate scale, the notes are also layed out like on a piano.
Another feature is a potentiometer that controls pitch bend and a rotary switcjh to change the capacitors on the organ, changing the sound.

Step 1: Video

This is a video showing what it sounds like:

Step 2: What You'll Need

What youll need to make this:
2x 555 timer chips
2 speakers
10k + 100k potentiometers
20 buttons
20 2k trimmer potentiometers
10n, 100n, 47n and 2 10uf capacitors
rotary switch
large perfboard (or you could make a printed circuit board)
assorted wire and battery clip
glue, cable tie and cork

soldering iron
wire cutters/pliers
probably desoldering pump/wick
screwdriver for the trimmers

Step 3: The Piano Circuit

The piano circuit is based of a circuit diagram made by Collin Mitchell, the keyboard is connected through pin 2 and pin 3 goes to both the speaker and the atari punk module, I used jumpers on both sides of the perfboard and attached the battery clip to the 1 and 8 pins, i used  hot glue to stop them breaking from stresses due to movement, the speaker is glued to the bottom of the boardwith bostik and acts as one of the legs. 
The 100n capacitor is replaced by the rotary switch, with three capacitors connected. the wire from 6/2 goes to one of the middle termnals and other capacitors you want to use are connected to the other terminals of the switch and to ground. I used 100n, 47n and 10n capacitors but you could use more different values.

Step 4: The Keyboard

Making the keyboard needed lots of soldering, the trimmers replace the resistors in the origional diagram and the left and middle pin need to be soldered together, you could make a bridge using solder but i found it was quicker to use the leg of a resistor i cut of from anaother project and saved. The switches i used have 2 pins that are allways coneced on either side, i soldered all the connected pins on the bottom together to make a long unbroken line which is connected to pins 6 and 2 on the 555. when a button is pressed it conntects pin 7 to 6/2 and all the resistors before the button was pressed add up their values and that controlls the pitch
The top layer of buttone is set out like a pianos black notes so there are larger gaps between the bases of the buttons, so instead of using solder to birdge the bases i used a piece of wire that went to each button and the pins 2/6. The green wires are where the bottom layer is sonnected to the top, look at the 5th picture to see where they go as it is hard to explain. 

Step 5: The Atari Punk Module

follow the schematic for the second monostable half of the atari punk console, connecting the ground to the ground on the piano ic and the power to pin 8 through a switch so it can be turned of if not wanted in the music. Pin 2 is connected to pin 3 on the piano ic with a jumper wire under the board. I used a 100k instead of a 500k pot. as i think it makes a better sound and i put it on the left side to the board although I would recommend that you put it next to the other potentiometer so it is easier to play with one hand, I glued the second speaker to the top of the board and to make it neater I put the wires from the speaker down into the board and connected them to pin 3 and ground using jumpers under the board

EDIT: the picture is not mine, it is from

Step 6: Finishing Off

I am using the piano speaker as one of the legs so I used a wine cork that i cut at an angle and superglued that to the bottom of the board, im sure there are more elagant solutions but i think it looks quite good.
you could make an enclosure but im not sure how you could mount the buttons unless you made the whole thing completely differently, I like it without an enclosure. I put hot glue on the bases of the potentiometers to make them more stable and easier to use with your little finger while playing the keys with the rest of your hand, it you put both potentiometers next to each other this would not be necessary. i used a cable tie to attach the power cable to one of the holes in the perfboard and glued the switch and speakers on with bostik.
I power it with 4 AA battery which produce about 5v and make it loud, a 9v is ok if your just using the keyboard but it isnt usually powerful enough for both 555s.



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    25 Discussions

    i made something similar for school last year, it was too funny :)

    Made one of these tonight. Great fun. I added a filter and delay to it and it's epic. The tools of the trade for the power electronics and harsh noise wall pioneer...

    Also just fun to play about with. Stick it into a sampler and you've got an endless supply of NIN - year zero / venetian snares type sonics to mess around with.

    Love it :)

    I'm afraid there isn't one its years since I made this, you should be able to make it with the 2 schematics posted, connecting the output of the first to the trigger of the second, if there's anything specific you're having trouble understanding or getting to work I'll try to help you out.


    4 years ago

    wow~ awesome!!! im so interested this organ. can i get a blueprint?

    i wanna make it. my email add is

    Hi, I'm so interested in this project. I want to make one for me but I want to ask you some questions. First if you have more pictures of the circuits, because I don't understand how are conected some parts of the system. Second, how are connected the speakers? Because I want to make maybe, my own array of speakers or let an output to connect a 3.5 jack. And maybe, I will make a pre amp for the organ. Thaks for this great project.

    hey dude? what if i remove the atari punk part of the circuit? what do i change in this circuit? :) this would be a great help for our electronics project! :D

    1 reply

    if you want to remove the atari punk part in the circuit, you can use this simple circuit, the simple toy organ

    555 TIMER TOY ORGAN.gif

    hey dude? what if i remove the atari punk part of the circuit? what do i change in this circuit? :) this would be a great help for our electronics project! :D

    Can you send me the blueprint to this??
    It would help a lot.

    What's the monostable bit for?

    Please can the topic starter or anybody help me out with the circuit diagram for the entire organ ! Please
    Please help me asap I am opting this for my College project.

    Is there any way I could get a schematic of the whole project not just two different? Nice project Btw, i liked your loved your last one.

    Excuse me, but the picture in step 5 is mine. I don't appreciate it's use without my permission. The least you could've done was give me credit.

    5 replies

    im sorry, i got it off a website called synthtopia and it has a link on the picture to that i presume it was on first, i thought that the link on the picture was enough credit but i will give credit to the website in the instructable

    well, the picture isn't entirely mine, but I have made modifications to it (the output terminals and the coloured resistor. Here is the original page from link. You may notice that the resistor is not colored, and there is no ground for the output.

    you didnt give credit to him at all, and what you changed is allmost negligable

    the link in the picture is his/her credit, but you still took the picture directly from my instructable.

    i assumed that you made it, i didnt bother to look that your username was different