Elektor Formant

The Elektor Formant analog modular synthesizer designed by C. Chapman was published in 1977/78 as a series of articles in the European magazine Elektor. The articles were later compiled into a book and a year later there was another book, (not in English) with additions and extensions by M. Aigner.

Description
The Formant uses the 1V/octave control voltage standard.

Front panels
The front panels are 6U to match up with the size of the double Eurocard (200 mm x 160 mm) VCO PCB, the other PCBs are single Eurocard (100 mm x 160 mm). This was already a standard PCB format for Elektor projects.

Part 1 - Formant description and construction

 * Chapter 1 - Introduction
 * Chapter 2 - Keyboard and keyboard interface
 * Chapter 3 - Keyboard construction and power supply
 * Chapter 4 - VCO
 * Chapter 5 - Construction of the VCO
 * Chapter 6 - 12 dB VCF
 * Chapter 7 - 24 dB VCF
 * Chapter 8 - Resonance Filter Module
 * Chapter 9 - ADSR
 * Chapter 10 - VCA
 * Chapter 11 - LFOs and Noise module
 * Chapter 12 - COM

Part 2 - Playing the Formant

 * Introduction
 * Chapter 1 - Extending the Formant
 * Chapter 2 - Control settings of individual modules
 * VCOs
 * VCFs and RFM
 * VCA
 * ADSR envlope shapers
 * LFOs
 * Noise module
 * COM
 * Chapter 3 - Control settings for the simulation of different instruments

Chapter 1 - Additions for the keyboard

 * Touch controller
 * Рortamento on/off switch
 * Pitch detector
 * Digital keyboard controller

Chapter 2 - Extensions to existing Formant modules

 * VCF extension
 * Triangle/sine converter for Formant LFOs
 * Digital Noise Generator (DNG)
 * Coloured Noise Circuit (CNC)
 * Stand-by-switch and headphone output for the Formant-COM

Chapter 3 - Adaptation of various Elektor circuits to the Formant

 * Resonant filter module
 * Ring modulator
 * Phase shifter
 * Elektor Kriminizer - European/American police siren
 * Digital reverb - Totally obsolete

Chapter 4 - Power supply and distribution panels

 * Power supply
 * Front panel proposals with mains power switch
 * Panel for keyboard output voltage and keyboard gate signal
 * Multiple-jacks modules

Chapter 5 - New Formant modules

 * ADSR-controller
 * VC-LFOs
 * LF-VCO
 * Digital Noise (DNG)
 * Envelope Follower (ENV.-F.)
 * Sample and Hold (S & H)
 * Waveform-Processor (WР)
 * Mixer
 * A440 standard (440 Hz tuning)

Apendices

 * A - Patch diagram templates
 * B - The natural tone series
 * C - 256 step sequencer
 * D - Stabilized +9V power supply
 * E - FET op-amps for the Formant
 * F - IC and transistor pinouts