Homemade 5U Modular Synthesiser
This has been an ongoing project since 2008.
Eurorack modules now available.
Details of the MIDI to CV converter.
20 VCOs finally finished, some build notes here.
Old photos uploaded to the archive page.
Clouds and Elements by Mutable Instruments build details here.
Simple 24 channel mixer, based on Ken Stone's CGS04
24 mono inputs, or switch to 12 inputs on the left channel and 12 on the right. This gives 12 stereo channels, with panning possible by adjusting the levels.
Input signal levels are indicated by the brightness of the LEDs in the latching mute buttons.
Schematic here.
Look Mum No Computer Splashback Delay. Buy the PCB here, modification schematic here.
Acid knob twiddling
Charlie called round to continue some tests on an audio project we're working on, and we also had some fun plugging theremin CV outputs into the synth...
5U Geiger counter module complete. Produces random voltages by comparing the time between clicks. Initially counts three clicks, then takes the time between 1 and 3 as the overall range mapped to 5V, and click 2 as the voltage level. It then waits for the next click to replace click 3, and re-assigns the previous 2 and 3 to the new 1 and 2, if that makes sense.
The 5V is converted into a control voltage signal, with adjustable range and offset, adapted from Ken Stone's joystick schematic. Glide has also been borrowed from a CGS module. Also produces a trigger output every time the geiger counter is activated.
Now available in eurorack.
Dedicated to the memory of Ray Wilson, whose amazing designs and friendly advice were so crucial to this project.
Useful links
As of 2024 it appears some of these links are broken - when I have a moment I need to re link to their respective Wayback archive pages.
Nonlinear Circuits: An excellent source of very unique and imaginative PCBs
Jurgen Haible: JH PCBs now sold by Random Source, including the fantastic Schulte phaser
Thonk: PCBs &c.
PAiA: Good source of classic synth PCBs, also a very good vocoder and theremin
CGS: Ken Stone's site, now archived. PCBs still available via Elby Designs
Music From Outer Space: MFOS PCBs are now sold by others, e.g. SynthCube or SoundTronics
Synthcube: Huge range of great PCBs, although they have messed up literally my last 4 or so orders.
Soundtronics: UK supplier of MFOS and YuSynth PCBs, expensive
Amazing Synth: Source of surface mount PCBs originally designed by Mutable Instruments
YuSynth: Some great clones of classic filters, plus other modules, from Yves Usson. Minimoog clone essential!
Look Mum No Computer: Expanding range of good practical modules, including a VCO with built in tuner
Synthesizers.com: Very high quality pre-assembled modules. Good source of technical information and +/- 15V power supplies.
Project 9090: PCB clone of the legendary Roland TR-909
Jasper: EDP Wasp clone
TTSH: Arp 2600 clone
Derek Revell's Phutney: VCS3 clone
Eric Archer: Inspirational site with schematics and perfboard layouts, including some of the TR-808 drums
Music PCB: High quality PCBs, including Throbbing Gristle's Gristleizer
Papareille Synth Labs: Some interesting stuff, including Coron DS8 drum clones, although PCB quality not amazing
I have only listed sites that I have dealt with directly - there are plenty more. MFOS and CGS are the ones I got started with.
Components: I am based in the UK, and so use RS, Rapid, Farnell / CPC, & eBay of course. Rapid used to be better, but now run out of stock for months at a time. Buying components from Ali Express is also good, and their shipping times seem to be getting faster and faster.
Chia Shin Knobs Co Ltd: Fantastic source of knobs, direct from the factory in Taiwan. Minimum order tends to be 500 or 1000, but with vast savings.
SL Hardwoods Ltd: Timber for cabinets. I don't know if they're necessarily the cheapest.
A look at Daphne Oram's Oramics machine...
A look at Oskar Sala's trautonium...