Music Box Circuit From

About: Evil Mad Scientist, Atari Punk Console Maker, Avante Garde Contemporary Artist, Air Metal Musician

This is how I built the Musc Box Circuit from

Step 1: Prototype and Test

First thing to do is plug in all the parts into a bread board and test it. Just follow the schematic to hook it up.

Step 2: Plan the Controls Placement

Figure out where you are going to place the controls for this. If you plan on being able to change the song it plays you might want to use some potentiometers instead of plain ole resistors.

If you don't know how to read schematics look it up. Or try to understand my explanations.
The resistors are the rectangles with the numbers and K on them. For Mine I used 1 500k potentiometer and 9 100k potentiometers.

The way I planned where to drill the holes for the controls was taped a piece of paper to the lid. Then I put the potentiometers where I wanted them. Then I used a marker to place a mark where the hole should be.

Then I drilled all the holes and put the potentiometers in.

Step 3: Prepare the Potentiometers

Some potentiometers have a little tab that makes it harder to place them. You can just break that tab right off with a pair of pliers.
After their broke off put them in the holes and screw on the nuts.

Step 4: Add Knobs

Put the knobs on your potentiometers.

Step 5: Solder in the IC's

I used a prototype board from Radio Shack that has the same layout as the breadboard to make it easy to transfer your prototype.

Step 6: Figure Our Wire Placement

Now to help remember where the pins of the IC's connect to the potentiometers I taped the pin numbers to the bottom of the potentiometers.

Step 7: Solder in the Diods and Capacitors

Now I added the Diods and Capacitors to the board. The Diodes are the symbol with the triangle and a line on it. The line is the negative and the triangle is the positive. On the diode itself the negative side should have a line too. On the capacitor the side with the line is the negative.

Step 8: Solder Wires to the Potentiometers

Now solder the wires to the potentiometers in the correct order. Or for fun do it in a random order. I used a little round circuit board to connected all the potentiometers to pin 5 of the other 555 that need to be connected to it. Also after doing the whole thing and playing with it alot I think next one I build I will use 50k potentiometers for the tone instead.

Step 9: Add and Output

For the output I used a Mono headphone jack. You can use whatever you want. I built an Atari Punk Console with alligator clips as the outputs once. The output is connected to the negative of the 10uf capacitor on the right side and negative. I also drilled a hole in the side of the box for it.

Step 10: Add Power and a Power Indicator

The schematic does not include for an LED or power switch. I added those. To add a switch I put the positive through the top right pot which has a switch on it. I think its a SPST or Single Pole Single Throw. From the positive coming out of the switch I put a 470 ohm resistor before the positive of the green LED. Then the negative of the LED to the negative rail on the prototype board. I also used two sided tape to hold the battery in place.

Step 11: Now Test It.

plug in you speaker and play with it.



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    11 Discussions

    Dream Dragon

    6 years ago on Introduction

    Looks good, and it even sounds less like a strangled cow than most such devices. I suspect it might even be almost musical at times.

    Isn't there a version of the 555 chip with TWO timers built in? Is it a 556? Would that be applicable in this project?

    I'm guessing you are using one 555 for "pitch" and the other as a kind of LFO/Clock?

    Other than that, it's a really nice looking project and a nicely finished one at that. One tip for getting better pictures, set everything up on the table, and then take a step back and use the ZOOM to get the frame right. I think your camera, like many others doesn't take pictures well if the subject is close enough to reach out and touch. Step back and it will be better.

    1 reply

    There is a dual 555, it is the 556. I bet it would work, but I used two 555s just like in the schematic.

    You may be right about my camera. It's not a very expensive one.

    It is very hard for me to read the pin numbers. Any way you could let me know what they are from top to bottom, left to right?


    5 years ago on Step 11

    Great job, I've built this circuit as well for a game I'm building and it's quite cool. I'm almost there but I've run into a problem maybe someone can help me with. What I need to do is for the tones to cycle once and then shut off. I got close by tying the highest output (pin 11)on the 4017, the reset (pin 15), and count enable (pin 13), and ground (pin 8) together which stop the 4017 from cycling until I reset via a positive pulse via a switch to the reset. However, the way this circuit is built, there is always a tone even when nothing is coming in to pin 5. Any ideas on how to easily turn off the contstant tone on the 4017 or the 555 tone generator until a reset? Thanks in advance.

    2 replies

    Hmm, now the captcha works???
    Thanks for the reply! Tried that with no luck and even tried a NPN transistor used as a switch for power to the 555 tone generator. But I may not have been doing it correctly anyway and I'll retry when I get home. I guess I'll never be an EE after all. I think it all has to do with varying the current on pin 5 instead of a normal 555 piano layout where 5 is not used. Maybe I'll try putting a really, really super low tone on that last pin (inaudible) and pause there. Hmmm. Still open for suggestions though and If I find a solution I'll let you all know.

    Yes, during the testing phase of this circuit I did notice the constant sound. I f I were to try and stop it I would try the following. On a breadboard have it all hooked up and try a resistor that is not to high a value to drown out the sound on pin 16 or 18 of the 4017, or try it on pin 8 or 3 of the second 555.


    6 years ago on Introduction

    How do we exactly give a varying control voltage at pin 5?
    And can someone please explain the working in brief.
    Thank you :)


    6 years ago on Step 6

    It is very hard for me to read the pin numbers. Any way you could let me know what they are from top to bottom, left to right?


    6 years ago on Introduction

    Is there a way to make the LED turn on and off with one of the pulse signals? Think the LED on the Korg Monotron.

    1 reply

    6 years ago on Introduction

    this looks really cool. I have been wanting to make a synth noise thingy for a while. this looks pretty good for my first circuit