Dewtron

Dewtron was the trademark of Design Engineering (Wokingham) Ltd. or D. E. W. Ltd.. A British company incorporated by Brian H. Baily on 5th February 1964. From 1965 the company advertised a range of DIY electronic music products, in various magazines and newspapers until it ceased trading sometime between 1980 and 1982. The adverts always give an address of Ringwood Road, Ferndown, Dorset, never Wokingham.

Products

 * Apollo - 49 note mono synth with matrix of swiches for patching.
 * Fuzzorama - fuzz box
 * Gipsy - 37 note 2 VCO mono synth
 * Hawaiian glide unit for Farfisa Compact organs.
 * Mister Bassman - 13 note pedal board, with either string or organ tone.
 * Modumatrix - a matrix of switches for patching.
 * Reverb
 * Rythm modules
 * Waa-waa -

Synthesiser modules
"Projext X stands for any design of synthesiser that you, the constructor wishes to build." The kits were a selection of potted lumps of resin concealing the circuitry, with protruding colour coded wires. To make a synthesiser or signal processor the user wired these up to a power supply and controls, in a case of their choice. The circuits are linear Hz/V rather than the now more common exponential V/octave response. In the 1970s up to thirty modules were available, some of which were:
 * 3 and 4 octave keyboard
 * Joystick
 * Patchboard sockets and plugs
 * AF-1 fader
 * ES-1 self-triggered envelope shaper
 * ES-2 externally-triggered envelope shaper
 * OFT-1 offset voltage module for parallel VCVO tracking
 * PG-1 percussion, as in Hammond percussion
 * PH-1 voltage controlled phaser
 * PP-A power supply
 * PV-1 pitch to voltage
 * REV-1 spring reverb
 * RM-2 ring modulator
 * SA-1 selective amplifier, a bandpass filter for auto wah-wah
 * SHE-1 sample and hold, and envelope
 * SLO-OSC
 * VCA-1 amplifier
 * VCF
 * VCO-1 saw and square, bottom note 1 Volt rising 200 mV/octave, not reliably in tune
 * VCO-2 triangle, sine, square available simultaneously, resin encapsulated, available in matched groups for consistent tuning
 * VSLO-OSC
 * WN-1 white noise gnerator

YouTube

 * How to tame a Ring Modulator: the Moog MF-102 by murderousmaths - demonstrates a twin Dewtron ring-mod from about 13:00