I love lights, and I love music… Naturally a color organ is something that I always wanted to make. However the circuits are often pretty complicated, using many op amps, etc. I'm sure that many people feel the same way.
Now the wait is over. If you are a bit familiar with electronics, you can build a 3 way color organ with only 29 components. I've streamlined the circuit to the absolute minimum, using easy to obtain, inexpensive parts. In fact, if you are electronic hobbyist, you probably have all the parts sitting around already!
In case you've never heard of a color organ, it's a device that emits different colors of light based on sound. LED Color Organ Triple Deluxe divides sound into three frequency bands, and emits red, green and blue lights accordingly.
Watch the video and you'll see what it does.
Step 1: Overview
Three groups of LEDs each responds to high, mid, and low frequencies of sound.
In order to simplify the circuit, I design the Organ to connect to a headphone output of audio equipment. The power source can be a 9V battery, or a regulated AC adapter that outputs 9 V. (Most wall wort type adapters output much higher voltage than they are rated, therefore not suited.)
I'd like to thank Collin Cunningham of MAKE: Magazine for publishing his LED Color Organ. His version is a lot more sophisticated and complex (read: expensive), which led me to design a super simple version.