DIY Eurorack

For people with more time than money, developing some DIY skills is a must when putting together a modular synthesizer. Most of my summer then was spent burning solder on different PCBs found on the wiggler forum and elsewhere.

The first module I built was a MOTM e350 Morphing Terrarium. For those that don't know, its a dual wavetable (digital samples of waveforms) oscillator. MOTM ships these kits with the PCBs populated with all the smt components, leaving the builder to solder on the jacks and knobs, mount it to a faceplate, and calibrate the oscillator. These factors make the e350 on of the most expensive DIY kits around, and also one of the quickest to build.

Here is a pic I uploaded to facebook earlier this year:

Most of the work went into the faceplate. There are files circulating the web with the standard MOTM faceplate which you can then have created at places like front panel express, or you can make your own. I created this one out of acrylic. I used the faceplate pdf to determine knob and jack placement, then drilled away with a 7mm drill bit. The graphic is a color photocopy from the book Ultraviolet which was pasted onto the back of the acrylic panel. Quick and dirty results, but without any of the module's functions labeled! This oscillator is so awesome I have them memorized anyway. Later on attenuators and switches for additional functions were added in the extra space on the right.

The next module completed was the Ian Fritz Dual Trigger Gate Threshold Sample & Hold (TGTSH!)

This panel is also acrylic, this time the image is the cover illustration for the novel The Invincible by Stanislaw Lem. Wiggler forum member falafelbiels provided me with a photoshop file containing the text and jack/knob placement. Printed with a crap HP Photosmart printer. Might reprint a higher quality graphic later and paste it over top.

This week I am trying to finish a Thomas Henry Dual X-4046 VCO. The PCBs and panel layout were provided by Fonik from the Wiggler forum. Fonik's documentation for building this circuit is fantastic, and the detail in his PCBs is even better. For a relatively complicated circuit, this was a pleasure to build.

For the Dual X-4046 I pasted the graphic to the front of the acrylic plate and coated it with shellac. This image also came from Ultraviolet, I realize it's not really visible in the photo below. The colors really pop in the book, but my efforts to relate that were again stymied by the HP Photosmart printer. The built in scanner does not cut the mustard and the colors are very dull. On the positive side, this oscillator sounds really nice! I hope to have a demo recording of it soon.

One thing I learned from this circuit: when building a module with a lot of knobs or jacks to connect, order some j connectors if the PCB allows for them. Otherwise you will find yourself navigating a jungle of wires to make the necessary connections from the board to the panel mounted components.

Still there are more circuits on the bench! I am still working on a Toppobrillo Triple Wavefolder, Music From Outer Space Dual VCA, and a CGS chime simulator. Can't wait to start recording once this are all built.