Modular Synthesizers


This project evolved from several different FX devices which I had built for my Crumar Performer, back in the 80's. (On the picture, it's on top of a Korg ES-50 Lambda.)
Originally they were stuffed into separate plastic boxes, and then I decided to build a "processor-synthesizer" without its own VCOs.
I had modified my Crumar to put out eternally sustained notes, until the next chord was pressed
(in retrospect, quite similar as the "Sustain II" on Yamaha CS- synths ...) and so here, I had a cheap VCO bank....
The JH-1 Synth contained:
* Ringmodulator (single-3080 type; proud of this design, 'cause I didn't know of the similar EN or Serge design back then!)
* State Variable VCF (as in elektor Formant)
(Three rectangular LEDs give a crude graphical output of LP/BP/HP/NF response)
* Exponential VCA
* AR
* LFO with several waveshapes
* S/H
* Noise, Random
* Stereo Chorus / Flanger with CV control
* Pattern generator (Real time programmable shift register)


There was an attempt to make a "JH-2" Modular as well. It had a Doepfer Midi, two discrete VCOs with heated transistor arrays, and SSM-based VCF, VCA and Envelopes. The unit is still working, but I never built any exotic modules into it, and started the "JH-3" project instead. 

I started to build this Modular System around the time when I discovered the "Analogue Heaven" and the "Synth-DIY" mailing lists.
I tried to combine several interesting parts from commercial synths and a few ideas of my own in one large, Emu-Modular style cabinet.
                                                        Click here for the high res, panel readable version

(1) Dual VCO (CEM3340-based, with thru-zero FM and various types of sync)
(2) Dual VC-ADSR (SSM2056-based)
(3) Variable-Slope 6-pole Phaser/Filter (based on two Electronotes ideas)
(4) SEM-filter with envelope (Oberheim's design + SSM2056)
(5) Vintage SSM VCF & VCA (SSM2040 + SSM2020; VC-Resonance)
(6) Interpolating Scanner (SSM2024-based crossfade over 8 VCAs)
(7) Audio Interface (2 Stereo input channels, 2 Stereo output channels)
(8) Dual VCA/Panner/X-Fader (SSM2024-based. Linear Gain controls, exponential Pan/X-fade controls)
(9) Ramp LFO Bank (5 Triangle LFO's + pseudo random)
(10) 2 x 8-Step Sequencer (very simple, with CD4017)
(11) Octave Filter Bank (EMS-clone)
(12) Quadrature (Sin/Cos) VCO/LFO + Komparator + Manual CV's
(13) Ringmodulator + Sample&Hold + 2 Mixers + VCA + Lag + Noise
(14) Manual Controls (A large joystick with X and Y output voltage as well as a quad VCA switchable from 4->1 mixer to 1->4 signal distributor, plus a manual switch 1p2t with zero position)
(15) Analogue Shift Register + 2-Stage Envelopes (x2) + Multiples (Influenced by similar Serge Modules)
(16) Morphing Programmer
(17) Resonant Envelope + VCA / Overdrive / Inverter + Voltage Controlled Clock Divider + VariLogic (switchable AND/NAND/OR/NOR/XOR/XNOR)
(18) Korg MS-20-Filter (HP+LP; with original Korg-35 IC's) + two mixers with 2 normal and 1 VCA input each
(19) Dual Saw VCO (SEM-design), Portamento

Each module is approx. 12cm x 20cm


For more information, please contact
Juergen Haible
All drawings copyright J. Haible (C)1996