Friday, April 24, 2009

moog VCF in vintage enclosure

Over the course of the past few years I've owned two Moog Prodigies. I got the first (keyboard-less) one about six years ago and modified it extensively. Eventually I sold it to buy the second one, which is covered in an previous post.

Of all the Prodigy's features, I've really just missed the warmth of the transistor ladder filter. But I've been so completely satisfied with the EML101's sound and versatility in every other regard that I decided it would be best to build a VCF module based on the Moog design.

I've never had much discipline for prototyping or PCB layouts so I arranged and soldered the parts on perf board and let the schematics guide me as I went. It's a challenging aspect of my electronics work.. but it's a good exercise in creative problem-solving.

While checking local thrift shops for an enclosure, I found this old electric shoe-shiner. The 'Regina'-brand "Electric Shoeboy." It originally had an industrial-type motor inside and rotating brushes protruding from each side.

After removing the motor and the shaft, dremmeling the case, and cutting, super-gluing and epoxying aluminum to cover the side holes, I had this finished enclosure! (The last image in this post was found on google to show what this unit looked like before modification.)

I based my circuit on yusynth's plans, but changed a few component values for a greater range of control. I also scaled the keyboard CV input for the EML101, with a SPDT switch to select between 1.2V/octave and 1V/octave.

Here are a few sound samples:

- moogvcf1.mp3
- moogvcf2.mp3
- moogvcf3.mp3
- moogvcf4.mp3
- moogvcf3.mp3
E-mail me if you'd like me to build a synth module in an enclosure of your choice!