CLACKTRONICS

BUILD YOUR OWN MODULAR

Start your modular synth journey with this easy-to-follow and inspiring book. Inside a beautiful handmade binder, you’ll find all the information and PCBs you need to construct your own mini Eurorack system. Ideal for beginners, and experienced builders alike, this book guides you through the world of analog electronics, inviting you to try your hand at soldering while gaining valuable knowledge. This is the webpage for the book that contains an extended range of information to accompany the book, as well as a bit of information useful for those who want to find out more about what the book is about.

THE FINISHED SYSTEM

Below is what the book creates, a mini-modular Eurorack synthesizer that you can build-on and use with other compatible Eurorack modules and systems. Click on any module in the image below to go to the relevant section...

LFO Module
Envelope Module
Attenuverter Module
Mixer Module
Passive Mult Module
Microcontroller Module
PSU Module
VCO Module
VCO Module
VCF Module
VCA Module
Passive Mult Module

WHERE TO BUY

Currently the only source is from Thonk based in Brighton(UK) they can ship anywhere in the world and also provide a complete BOM to make life easier.

THE BILL OF MATERIALS

There is a single bill of materials (BOM) for the whole project, within the book, it is attached here for those that are interested or so you can print further copies. The way it works is for each module there is a sub-BOM that you use to select the parts needed from the main BOM. Here is an example of what one looks like - PSU_BOM. Notice there are check boxes so you can tick off the parts you fit as you go along.

The parts can either be acquired with the purchase of the book or by sourcing yourself. I have intentionally designed the system with very common to find parts, unfortunately it will be impossible to get all the parts from the same place. I will try and keep this section up to date as much as possible, as the availability of parts is ever changing.

THE MODULES

Below is a list of all the modules in the initial system, there are links to various helpers and details that did not make it into the book. Also items that are too dynamic for static pages, such as programming information and iBOMs which are a handy interactive BOM generated by InteractiveHtmlBom plugin for KiCAD.

POWER SUPPLY

Creates a simple +-12V power supply from a single 12V DC input. Suitable for building the system without having to spend lots of money on a DC-DC converter part. Contains short circuit protection in the form of polyfuses and LED indicators to show the rail status.

MICROCONTROLLER

A Raspberry Pi Pico based module that lets you program all sorts of different functions and experiments. Supports simple to use languages such as Circuit Python and Arduino, but can also be programmed with more sophisticated lower level languages. It has CV in, CV out, gate in and gate out connections, as well as two control knobs and two LEDs. All of which are user programmable.
  • Micro ibom - Interactive BOM to help assemble
  • Detailed build guide (coming soon) - More detail than could fit in the book
  • Programming guide - More on programming such as example applications, setting up environment etc.
  • ModularGrid page - external site page for Eurorack system planning with this module
  • Raspberry Pi Pico - Dev board info page inc datasheets.

VOLTAGE CONTROLLED OSCILLATOR

The main sound generating part of the system, there are two of these identical to each other. They generate a sawtooth wave and have a V/oct input, as well as sync in and out.
  • VCO ibom - Interactive BOM to help assemble
  • Detailed build guide (coming soon) - More detail than could fit in the book
  • Calibration of V/oct - More detailed information on calibrating the VCO
  • ModularGrid page - external site page for Eurorack system planning with this module
  • TL074 - Texas Instruments IC info page inc datasheet.

MIXER

This simple module mixes either audio or CV through 3 channels. The third channel called "external" has 100x gain to bring up signals from line level or quieter.

ENVELOPE

Attack and Release envelope generator, simple as that. Puts out 10V envelopes.
  • Envelope ibom - Interactive BOM to help assemble
  • Detailed build guide (coming soon) - More detail than could fit in the book
  • ModularGrid page - external site page for Eurorack system planning with this module
  • TL074 - Texas Instruments IC info page inc datasheet.

LOW FREQUENCY OSCILLATOR

For basic vibrato, tremolo effects, has a variable slope knob which is quite unique. Can output a pulse or a ramp simultaneously.
  • LFO ibom - Interactive BOM to help assemble
  • Detailed build guide (coming soon) - More detail than could fit in the book
  • ModularGrid page - external site page for Eurorack system planning with this module
  • TL074 - Texas Instruments IC info page inc datasheet.

ATTENUVERTER

For bringing the higher CV voltages down, inverting them or both. Is also a knob to CV source if nothing is plugged into the input.
  • Attenuverter ibom - Interactive BOM to help assemble
  • Detailed build guide (coming soon) - More detail than could fit in the book
  • ModularGrid page - external site page for Eurorack system planning with this module
  • TL074 - Texas Instruments IC info page inc datasheet.

PASSIVE MULT

Simple unpowered module that fills a gap in the case providing a simple way to split signals to multiple destinations.
  • Passive mult ibom - Interactive BOM to help assemble
  • Detailed build guide (coming soon) - More detail than could fit in the book
  • ModularGrid page - external site page for Eurorack system planning with this module

VOLTAGE CONTROLLED AMPLIFIER

A dual VCA based upon an OTA.
  • VCA ibom - Interactive BOM to help assemble
  • Detailed build guide (coming soon) - More detail than could fit in the book
  • ModularGrid page - external site page for Eurorack system planning with this module
  • LM13700 - Texas Instruments IC info page inc datasheet.

VOLTAGE CONTROLLED FILTER

The main sound of a subractive synth. 12db/Oct filter with Low pass and Band pass output. Two audio inputs for easy mixing without an extra module. Lots of "character" aka distortion and a very interesting resonance sound.
  • VCF ibom - Interactive BOM to help assemble
  • Detailed build guide (coming soon) - More detail than could fit in the book
  • ModularGrid page - external site page for Eurorack system planning with this module
  • LM13700 - Texas Instruments IC info page inc datasheet.

ENCLOSURE

A low cost way to mount all your modules and test them out, constructed from aluminium PCBs. Can be assembled with just a screw driver, screws, soldering iron and a tapping tool.