_____________________________________________________________________ 
 ,/                                                                     \,
 |     .,-:::::/   :::.      ...    :::  .,-:::::   ::   .: .,::::::     |
 |   ,;;-'````'    ;;`;;     ;;     ;;;,;;;'````'  ,;;   ;;,;;;;''''     |
 |   [[[   [[[[[[/,[[ '[[,  [['     [[[[[[        ,[[[,,,[[[ [[cccc      |
 |   "$$c.    "$$c$$$cc$$$c $$      $$$$$$        "$$$"""$$$ $$""""      |
 |    `Y8bo,,,o88o888   888,88    .d888`88bo,__,o, 888   "88o888oo,__    |
 |      `'YMUP"YMMYMM   ""`  "YmmMMMM""  "YUMMMMMP"MMM    YMM""""YUMMM   |
 |                                                                       |
 |           ~ E ~ L ~ E ~ C ~ T ~ R ~ O ~ S ~ O ~ U ~ N ~ D ~           |
 |                                                                       |
 |       ,------------------------------------------------------------.  |
 |      /     .,              ., "H O R S E"  .,              .,      /  |
 |     / ~ ,_./\| ~~~~~~~~ ,_./\| ~~~~~~~~ ,_./\| ~~~~~~~~ ,_./\| ~~ /   |
 |    /  ,/(_,(\-.  /    ,/(_,(\-.   /   ,/(_,(\-.   /   ,/(_,(\-.  /    |
 |   /     ((.  `  /       ((.  `   /      ((.  `   /      ((.  `  /     |
 |  '-------------------------------------------------------------'      |
 |      V C O           V C F           V C S           V C A            |
 |                                                                       |
 '\_____________________________________________________________________/'
 ,/                                                                     \,
 |   G3400 "HORSE" - A MODULAR SYNTHESIZER FOR PEOPLE                    |
 |                                                                       |
 |          "Unfortunately, as you probably already know, people"        |
 |                         - @Horse_ebooks                               |
 |                                                                       |
 |          "or for that matter Marino Marini when he didn't pick the    |
 |                rider as carefully                                     |
 |           as the horse"                                               |
 |                         - Frank O'Hara, "Having a coke with you"      |
 '\_____________________________________________________________________/'
 ,/                                                                     \,
 |   A complete instrument with  ample opportunity for interaction and   |
 |   experimentation.                                                    |
 |                                                                       |
 |   "Horse"  is direct  and  powerful, providing  four essentials  of   |
 |   modular synthesis:  oscillator, filter, envelope,  and amplifier.   |
 |   Each submodule  is independent,  and provides multiple  points of   |
 |   manual and/or voltage control.                                      |
 |                                                                       |
 |   VCO  Sawtooth core  based on  silicon controlled  rectifier, with   |
 |        discrete sync  and pulse  shaping circuits,  and temperature   |
 |        compensated volt per octave input. This core is also used in   |
 |        the Korg  PS3100, Roland  TB-303, and the  Formata Polivoks.   |
 |        Erica Synths  notes the  addition of a  sync circuit  to the   |
 |        Polivoks  VCO in  their  DIY  VCO 3;  this  sync circuit  is   |
 |        employed here.                                                 |
 |                                                                       |
 |   VCF  2nd order  nonlinear state variable circuit,  using unbiased   |
 |        (class  B)   gain  cells  as  voltage   controlled  element.   |
 |        Simultaneous Lowpass, Bandpass, and Highpass outputs, with a   |
 |        unique waveshaping  characteristic. The  lack of  biasing in   |
 |        the gain cells results in crossover distortion at two points   |
 |        in the filter's signal path.  This results in a distinct and   |
 |        aggressive tone not found elsewhere.                           |
 |                                                                       |
 |   VCS  ADSR/LFO/Slew limiter, with voltage control over rise, fall,   |
 |        and both. Full ADSR mode  when using the Gate input. Bipolar   |
 |        LFO. Range  switch expands  range from  minutes long  LFO to   |
 |        high audio  rate. The core  of  the circuit is present  in a   |
 |        wide number  of modules and  synthesizers, but namely in the   |
 |        Korg PS3100  and Serge  Dual Universal Slope  Generator. The   |
 |        ADSR logic is novel, to the best of the designer's knowledge.  |
 |                                                                       |
 |   VCA  Biased   discrete  gain   cell  VCA,   with  novel   2-stage   |
 |        wavefolding  circuit,  giving  up  to  40dB^  of  continuous   |
 |        wavefolding. Mode  switches to change between  fold and step   |
 |        functions expand  waveshaping capabilities further.  The VCA   |
 |        portion  is standard  Blackmer  gain cell,  with biasing  to   |
 |        eliminate distortion (unlike the VCF). The wavefolder uses a   |
 |        novel  "step  cell"  nonlinearity, which  creates  deadzones   |
 |        above  and below  0 volts.  The  step cell  allows for  more   |
 |        complex  behaviors  with   fewer  complex  components  (e.g.   |
 |        op-amps)                                                       |
 |                                                                       |
 |        ^ Most  wavefolders can be  described through the  number of   |
 |        folds  they create  or the  number of  stages used.  The two   |
 |        Gauche  wavefolders discussed  are  not  built like  typical   |
 |        wavefolders, where these terms  carry enough information for   |
 |        a user.  Gain, on the  other hand, clearly  communicates the   |
 |        range of defined  behavior. This is also in  line with other   |
 |        waveshaping  effects,  such  as overdrive  and  fuzz,  which   |
 |        similarly utilize gain as the main control parameter.          |
 |                                                                       |
 |   ~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~   |
 |                                                                       |
 |       > Release .. April 23 2026                                      |
 |       > MSRP ..... 450 USD                                            |
 |       > Format ... Eurorack                                           |
 |       > Width .... ~40hp                                              |
 |       > Depth .... ~20mm                                              |
 |                                                                       |
 |       > Power .... +12V @ ~60mA                                       |
 |                    -12V @ ~40mA                                       |
 |                    +5V  is not used                                   |
 |                                                                       |
 |       > Controls . VCO - Coarse/Fine frequency, Pulse width           |
 |                    VCF - Cutoff, Resonance                            |
 |                    VCS - Full ADSR, Scale, range and mode switches    |
 |                    VCA - Input level, gain, DC offset, modes          |
 |                                                                       |
 |       > Inputs ... VCO - Sync, FM*, V/oct, PWM*                       |
 |                    VCF - Aux*, Signal, CV*, Freq                      |
 |                    VCS - Rise, Both, Fall, Sus*^, Gate^               |
 |                    VCA - Gain*^, Unity, In*                           |
 |                         * has attenuator with matching name           |
 |                         ^ has input normalling                        |
 |                    100K input impedance, except:                      |
 |                         Voct = 110K                                   |
 |                         Freq = 150K                                   |
 |                    +/- 5V  nominal levels, except:                    |
 |                         VCS Gate input reacts to ~ +1V DC             |
 |                         VCA Gain is clipped at +5V DC                 |
 |                                                                       |
 |       > Outputs .. VCO - Pulse, Saw                                   |
 |                    VCF - Lowpass, Bandpass, Highpass                  |
 |                    VCS - Inverted output, Two jacks for main          |
 |                    VCA - Clean, First and second folding stages       |
 |                    1K output impedance everywhere                     |
 |                    +/-5V nominal levels, except:                      |
 |                         VCS in ADSR mode is unipolar                  |
 |                         VCF at high resonance will exceed +/-5V       |
 |                                                                       |
 '\_____________________________________________________________________/'
 par: jw74rh1s4
 vim:ve=all:expandtab