Worlds Smallest Color Organ

Introduction: Worlds Smallest Color Organ

About: Currently a student at Carnegie Mellon University in Electrical Engineering. Classwork and clubs take up most of my time, so I probably won't post any projects soon, though I do plan to come back to posting...

This instructable diagrams a build of what is likely the worlds smallest color organ.  At just over the size of a postage stamp, it is very impressive for its size.  It uses an LM339 quad comparator chip to flash 3 colored LEDs in time with three separate frequency channels of a music input. 

Teacher Notes

Teachers! Did you use this instructable in your classroom?
Add a Teacher Note to share how you incorporated it into your lesson.

Step 1: Parts

To build it, you will need a few things.  All of them are avaliable from, but I suggest that you buy one part from elsewhere. 
LM339 quad comparator
3 x 1k smd resistor (no bigger than 1206)
3 x 470 ohm smd resistor (no bigger than 1206)
2 x 1uf capacitor (no bigger than 1206).  I suggest yo buy this somewhere other than Jameco, since the minimum order quantity is huge for this component.  I just used through-hole capacitors for this one instead
2 x 0.22uf capacitor (no bigger than 1206)
2 x 0.1uf capacitor (no bigger than 1206)
1 x smd prototyping board for SMD 16-pin ICs
1 x audio connector, your choice
1 x 9V battery connector
3 x 500K potentiometers, or fixed resistors of many different values (CANNOT just use 470K resistors and get a "balanced" output)
3 x wires
3 x LEDs  size and power are your choice.  The maximum current from the LM339 is just about 16mA, so you cant use high power LEDs.  I suggest 3mm LEDs, blue for low, red for mid, and yellow for high, but that is yor decision.  The one in the pictures used one red 3mm led, and SMD blue and yellow LEDs.  The SMD LEDs were 5050, so I couldn't fit the red one in.
*optional*  you can add headers for an external display.  The output of the LM339 will drive PNP type transistors if connected directly to the base. 

Step 2: The Schematic

The following is half schematic, half where-to-place-the-parts-diagram. 
The potentiometers can either be soldered in a "bridge" over other components, or you can drill through the board and mount them on the other side. 

If using resistors, you will attach them in step 5. 

Step 3: Soldering Tips

1) When working with SMD components, make sure to have a sharp tip, and small gauge solder.  You only need a tiny bit of solder for each component. 
2) Use an iron below 30W.  Anything higher can destroy the components.
3) After soldering each pin, touch the LM339 chip.  If it is too hot to touch, stop soldering for a few miniutes, then continue.  You may have to stop multiple times. 
4) Use play-doh, adhesive poster putty, silly putty, or even glue to hold the components that you're soldering.  DO NOT attempt to hold them with your fingers while soldering, you WILL be burned by even the lowest powered of irons. 
5) Solder the SMD stuff first, and the pots/resistors, LEDs, and wires next. 

Step 4: Audio and Power

The audio connection is unusual in that it connect audio + to power -.  Just follow the wire diagram for a 3.5mm adapter.  If you use another connector, it should be similar, but you should experiment and make sure that it works for you.  Solder each connection to the proper pad or wire on the circuit proper.   

You can add a switch for the 9v battery, though it is not included in the schematic.   The red, blue, and yellow wires are labeled for their connection to the protoboard circuit. 

"signal", "audio -", and "audio grd" are the same.   

DO NOT attach signal to power ground.  This will short out your input source. 

Step 5: Test It

If using potentiometers, check to make sure they are NOT below 500 ohms.  Now, connect your 9V battery.  The LEDs may blink when connected, and the low, if not all, will turn on steady after a few seconds.  Connect your input (ipod, mp3 player, computer, stereo, etc) and play some music at normal volume.  If you are using potentiometer, adjust them for the desired sensitivity.  If you are using resistors, start by connecting (but not soldering) a 470K resistor between + and input + of one channel (where a pot is shown in the schematic.  Gradually use lower and lower resistors, but not below 470 ohm, until you have the desired result.  Do this for all 3 channels. 

The LEDs should blink on a loud note, but not be almost constantly on.  The bass LED will usually be much more sensitive than the high and mid LEDs, and the mid more sensitive than the high.  This is because a low note is usually more powerful, and the capacitors allow more power to pass through. 

Step 6: Rock Out!

Put on some mad beats and watch the fruits of your labor confound your sight with compliance with sound. 

By soldering 2 component leads to the top pads of the board and bending them over the back, you can make the worlds coolest lapel pin. 

-project Inspired by Colin Cunninghams color organ and SMD circuit videos, though no content from them was used.  The circuit was compleatley designed by me.   

Pocket-Sized Contest

Participated in the
Pocket-Sized Contest

Hurricane Lasers Contest

Participated in the
Hurricane Lasers Contest

Be the First to Share


    • Trash to Treasure Contest

      Trash to Treasure Contest
    • Raspberry Pi Contest 2020

      Raspberry Pi Contest 2020
    • Wearables Contest

      Wearables Contest

    9 Discussions


    3 years ago

    There are on-line schematic designers available that do not require and installaion on your PC (and as you are 5 years older now I'm sure parental controls are not an issue!?)

    Look at

    Interesting article


    Reply 3 years ago

    Thank you, but as you guessed, that's not really a problem anymore (not even living at home now). I have actually moved through several design tools at this point, starting with eaglecad, then gEDA, KiCad, and now altium Designer/Circuitmaker (basically the same software, Designer for commercial projects, Circuitmaker for personal).


    Can this be done using any op-amp? Do you have a full schematic so I can do this on breadboard first?


    Reply 6 years ago on Introduction

    1) the 339 is NOT an op-amp, that's the main distinction between this and most other designs. There's no actual amplification, just switching once the audio reaches a certain power level.
    2) there's a "schematic" on step 2. The pinout for the smd and regular packages are identical. I'll try to make up a real schematic and put that in soon. Right now, the el wire color organ has an identical circuit, if you replace the transistor connected to the 339 with the LED.

    Great job,but next time you might want to add a video of it working and write the schematics in cadsoft eagle. The free version should do what you need and jeremy blum has a great tutorial series if you get lost!

    Here are the links:

    I suggest you go through the tutorials before you download eagle as it will make it a lot simpler!


    Reply 7 years ago on Introduction

    Yeah, I know and I tried to get eagle, but parental controls (meh) blocked me from opening it, and my parents don't like allowing ANYTHING (and they're ticked off 90% of the time) so I cant get it. I'm also not allowed a Youtube account, so I can't post videos.


    Reply 6 years ago on Introduction

    hack the parental controls. Look up how to do it for the specific control in google.


    Reply 6 years ago on Introduction

    In a word: no. For one, those programs (command prompt ones don't work for vista, or for what I'm doing) and programs can't run without permission.