A Synthesizer Do-It-Yourself (SDIY) Web Site
Open Source Printed Circuit Board Design(s)
I like the Open Source software culture that has grown exponentially over the years. Thus I am starting another Open Source printed circuit board/synthesizer circuit design web site.
First up: a power distribution module for a modular synthesizer.
My Latest Modular Synthesizer: Progress Report
I recently added the Phaser, rewired the inputs on CV2, CV3 and FM input potentiometers on the leftmost oscillator, and exchanged the log 1M step rate potentiometer on the sequencer for a 1 M linear. The improvement is very good -- much better speed control now.
Current Project: 2007
I'm building a fairly large modular analog synthesizer, mostly based on Ray Wilson's very nice MFOS designs. Ray sells some fine circuit boards. I also have some boards and kits from others including Ian Fritz, Tim (Servo) Parkhurst, Scott Juskiw, Seventh Circle Audio, and Blacet Research. I also build my own designs, often based on the Electronotes designs of the 1970's but updated with modern components. I still need to improve on my front panel work: currently I use a laser printer to print designs onto Avery WeatherProof labels (they are white and come 2 per sheet, about 8.25 inches by 5.25 inches each). They are some sort of plastic. They print nicely, don't smudge, and aren't too hard to apply. They tend to get messed up around the potentiometers when the nuts are tightened but usually the knobs cover that up. It's not ideal, but for a quick solution it meets the requirements, is inexpensive, and I can go from concept to finished panel in a couple of hours. Woodworking is another skill that I've yet to master.
16 Step Sequencer
The triple-width module on the right is a 16-step sequencer based on one of the MFOS circuit boards. The single-width modules on the left are (from left to right) a low-pass filter, a dual envelope generator and a dual VCA. The size of each single-width module is 2U (3.5 inches) by 5U (8.75 inches).
My front panel designs are modeled after the ARP 2500 so I try to keep the connectors at the base of the modules in order to avoid obstructing ready access to the knobs and switches. I plan to complete this first set of modules, then step back and consider an upgrade in my front panel labeling capability for the next 12 module case. I'm considering silk screen printing, heat transfer paper, metalphoto, etching, and other techniques.
VCO (Voltage Controlled Oscillator)
The a VCO is based on one of the MFOS circuit boards, with an addition: a waveform mixer. The mixer concept was borrowed from an ARP 2500 oscillator, the design inspired by an Electronotes article, and the circuit board was wired on a proto board. It works! But I need at least 2 more, so I am in the process of laying out a circuit board for it.