Polyphonic Four Voice Control for Eurorack


Basic Version - No CV Control 

FVC-1         Four Voice Controller with Keyboard Logic and Vibrato
 
 

All functions are controlled with CC numbers so you need a controller keyboard  

  • Polyphonic control of 4 MIDI channels.
  • Keyboard modes based on the original Oberheim FVS.
  • 2,3 or 4 voice operation.
  • MIDI IN and 2 unbuffered MIDI Outs  (TYPE A MIDI Jacks).
  • Continuous (Round Robin) or Reset.
  • Split.
  • Split Mode = Mono-L Poly-R or Poly-L  Mono-R.
  • Unison.
  • Freeze.
  • -1 /+2 Octave transpose in semitone steps per Voice - great for stacked chord 
  • Faux Vibrato LFO (uses an offset via Pitch Bend message)
  • Adjustable Pitch Bend and Split Point. 
  • 32 Memories to store settings - recalled with MIDI Program Change.
  • Split, Pitch Bend range, LFO settings and transpose are saved

Please note this is not a commercial venture. Contact me if you want more information

FVC-1 CONTROLLER MAP 

The FVC-1 also receives Pitch and Mod Wheel messages on Channel 1.
The 2-XM does not recognise CC64 Sustain so this is used as pseudo FUNCTION key
 
 
  

Eurorack version designed for Behringer 2-XM

(Works with any MIDI equipped synth with 0-10V CV inputs)


Latest version with Step Sequencer, Utility module and Quantizer



Added a Behringer 1027 sequencer and a DIY CV Quantizer/Clock Divider

CTRLR Editor 


FVC mounted in Eurorack GO case
 
 

 

 



Detailed information about the Polyphonic Four Voice  Controller for 2-XM in a Eurorack 

 Envelope - ADSR plots

There are no Digital to Analogue Converters -DACs  used in this design. The only additional components on the FVCs are op-amps to boost the 5v output to 10V. The ProMicro supports analogue output using PWM. If this happens at a very high frequency the output is very smooth. The output is filtered with a simple RC filter and there is no digital noise picked up by the synth. The Attack is 0-10s with Decay and Release up to 15s. The envelope is exponential. Here are some plots from various ADSR settings:
 

  
 
 



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Enhanced - CV Control 
 
FVC-EG1   VCA ADSR/voice + LFO  +10V  output
FVC-EG2   VCF ADSR/voice + LFO   +10V output
  
 

FVC-EG1 (VCA)

 All the features of the FVC-1
ADSR envelope per voice for VCA CV inputs
ADSR settings can be recalled from memory

 

FVC-EG2 (VCF)

All the features of the FVC-1 
ADSR envelope per voice for VCF CV Inputs
VCF LFO with 4 waveforms
VCF Tracking
ADSR + LFO settings can be recalled from memory
 
 

FVC-EG1/2 with black cover plates


MIDI CC List Enhanced Version

Roland A300 Pro Parameters
B = Button  S=Slider R= Rotary L = Button