Analog Ring Modulation Circuit

[youtube=http://www.youtube.com/watch?v=kc5JLWrVEQg&hl=en_US&fs=1]

Above is a video and below are some pictures of a simple ring mod circuit I whipped up last night. The circuit is the classic circuit, and I’m simply running two oscillators from a hex schmidt 6-oscillator IC through the circuit as the carrier and modulator. The frequencies of the hex schmidt are being controlled by a PSR (photosensitive resistor) and an FSR (force sensing resistor) respectively. The video shows fairly well how the PSR reacts to the light. The function of the FSR is a little less clear visually, but you can hear it pretty plainly. I can throw up (!) a schematic of the circuit if anyone is interested, but you should be able to find one by doing a google search.

The project requires a 5V power source (batteries only!) a bread board or project board, some wire (i prefer solid-core) two diodes, two capacitors (0.1uf), 1 133k (or thereabouts) resistor, one PSR, one FSR, one hex schmitt oscillator (mm74c14n) and an audio cable or female 1/8 audio jack to run into a) an amplifier, b) a mixer, or c) your computer.  In this case I have two alligator clips attached to the cut-off and split end of a 1/8 audio cable, the other end of which is running into a mixer and then out to small speakers.

Next on the agenda I think I’m going to build me an ADSR for it. This site has a really great page on ADSRs with diagrams, circuit board patterns, etc.