Wednesday, October 08, 2014

AJH Synth MiniMod Eurorack Modules

MiniMod vintage
transistor core VCO
Another new modular synth company, AJHSynth is headed up by Allan "J" Hall, who has been involved with synths, electronics and music for more years than he cares to remember.
He started by building a guitar fuzz box at the tender age of 12 and an interest in synthesisers and electronic music soon followed, fuelled by an unhealthy overexposure to early Tangerine Dream, Pink Floyd, Vangelis and Kitaro.

For the last 15 years he has been building and modding synth systems both for himself and other electronic musicians, as well as spending some time as a semi-pro musician playing keyboards in several rock and tribute bands.
Allan spent five years as a service technician repairing and modifying Moog, Arp, Korg, Roland and other analogue synthesisers along with some Pro Audio design work, previous to this he spent two years designing and building "boutique" valve (tube) guitar amplifiers.

MiniMod countour
generators (2 x ADS)
AJHSynth are based near Bournemouth on the South coast of England, where this small but enthusiastic bunch of synth. heads now indulge their passion for all things modular.

The MiniMOD Eurorack system aims to replicate the sound of the vintage Moog Model D as closely as possible, so they used exactly the same internal circuitry and every module runs at the same internal signal and control voltage levels as the original.

Their quest was to bring the unbeatable fatness and legendary sounds of this classic synthesizer to the 3U Modular world and have separated the synth into five modules, comprising:
MiniMod transistor ladder filter
VCOVCFVCADual Contour, and Glide + Noise, which can be easily integrated into an existing Eurorack system or, with the addition of a case and power supply, it becomes a self contained stand alone synthesizer.

Click here for an overview of the MiniMod.

glide + noise
The MiniMod is based on the circuitry of most desirable Model D of all, the very early R A Moog Mk1 model with its unique and sweet sounding VCO design, the core of which uses discrete transistors only, with no integrated circuits.
We have also based the transistor ladder VCF on the early design, which uses fully matched transistors throughout.
Less than 300 Mk1 Model D’s were built with this very early VCO design out of a total of around 17,000 which were produced between 1970 and 1981.

The Minimod has been more than 18 months in development, thousands of hours have been spent analysing the original Model D using both real world measurement and computer based Spice circuit simulation programs, they carefully selected components and built many prototypes before they were happy that we had done justice to the original sound and circuit behavior.
MiniMod discrete
cascaded VCA

MiniMod Eurorack modules comprise separate VCO, VCF, VCA, Dual Contour and Glide/Noise for maximum flexibility so that they can be easily integrated into a larger Eurorack format Modular synthesizer to tap into the endless control and expansion possibilities – they removed all of the control limitations of the “closed system” of the original Model D synthesizer so that the sounds that you can now create are limited only by your imagination and the other modules that you add to your system. All of the modules can be used independently in your existing Eurorack system.

 A full MiniMod system would comprise 3 x VCO, 1 x VCF, 1x VCA, 1 x Dual Contour, 1 x Glide-Noise and this will take up exactly 84hp of Eurorack space, so that it will fit into 3U of rack space with a suitable Eurorack frame and power supply (not supplied)
Just add a Midi/CV converter and keyboard for a fully functional BIG and FAT monophonic synthesizer.

Sound examples:

More videos and sound-examples at


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