Doepfer A-111-4V Quad Precision VCO Eurorack Module (Black)

A-111-4 contains four precision VCOs and has individual controls, inputs and outputs for each VCO available as well as a common control and output unit. After all the A-111-4 is very similar to four A-111-3 without LFO mode but built in output mixers for the three waveforms, and a master unit for all four VCOs.

Controls, inputs and outputs for each of the four VCOs:
1V/Octave CV input
Octave switch (+1 / 0 / -1 octave)
Tune control (range internally adjustable by jumpers: ~ 2 semitones / ~ 1 octave / ~ 4 octaves)
Modulation CV input
Modulation destination:
upper position: exponential frequency modulation (XM)
lower position: linear frequency modulation (LM) or pulsewidth modulation of the rectangle (PM), selectable via internal jumper
Frequency Modulation (FM) or Pulsewidth Modulation of the rectangle (PWM)
Modulation intensity
Triangle output
Sawtooth output
Rectangle output (about 50% without external PWM)
Sync input (hard or soft sync internally selectable via jumper, CEM3340 hard sync type)
min. 10 octaves range (with appropriate external CV)
CEM3340 based VCO (triangle core)
each VCO has it's own separate internal +/- power supply for each for best stability and the prevention of unwanted synchronisation of the VCOs
Controls, inputs and outputs of the master section:
1V/Octave CV input
Octave switch (+1 / 0 / -1 octave)
Tune control (range internally adjustable by jumpers: 2 semitones / 1 octave / 4 octaves)
Frequency Modulation CV input (FM)
FM intensity
Triangle sum output
Sawtooth sum output
Rectangle sum output
as soon as the single waveform output of a VCO is patched this waveform of the VCO in question is removed from the sum (this function can be turned off for each single output socket by means of solder brigdes on the pc board, i.e. the sum contains then all signals independent of the patching of the single output)
CV output (outputs the sum CV that is used to control all four VCOs)
bus CV (via jumper, optional, please remove the bus jumper if this feature is not used to avoid unwanted frequency modulation as then the unused CV line of the bus works as a kind of antenna)
Typical applications:
fat sounding monophonic VCO with the possibility to adjust any intervals
paraphonic patches in combination with the polyphonic CV interface A-190-5 (all four VCOs processed by one VCF/VCA)
full polyphonic patches in combination with the polyphonic CV interface A-190-5 and four complete VCF/VCA sections
complex VCO patches with up to four VCOs by means of the frequency modulation features (exponential an linear) and the sync functions
The following document shows the positions and functions of the jumpers and trimming potentiometers of the module: A111_4_trimming_potentiometers_and_jumpers.pdf
Pay attention that faulty adjustments caused by the user are not covered by warranty. In this case the working time required to re-establish the correct adjustment has to be charged.