Doepfer A-111-2 VCO

Module A-111-2 is the successor of the obsolete High End VCO I A-111-1.
Here are the most important features of the module:

triangle core (i.e. all other waveforms are derived from the triangle by waveshapers)

fully analog design

min. 15 octaves pitch range (typ. 0.5Hz - 20kHz in VCO mode / 0.001Hz - 40Hz in LFO mode)

perfect 1V/octave tracking over min. 10 octaves, typ. 20Hz - 20kHz (control LF has to be fully CW for perfect 1V/octave tracking)

exponential frequency controls and inputs:

Tune: range can be selected by means of a jumper, about +/- 1 octave (jumper JP6 not installed) or about +/- 3 octaves (jumper JP6 installed)

Fine: about +/- 1 semitone range

Octave: range switch with 6 positions for 6 octaves

1V/octave CV input

XFM input with attenuator

access to internal 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)

linear frequency controls and inputs:

LF (manual linear frequency control: fully CW = standard setting for usual VCO applications, fully CCW: close to 0Hz frequency)
works also as a kind of range control for the exponential section but for standard VCO applications with 1V/octave control voltage the LF control should be fully CW !

LFM input with attenuator, DC coupled

Pulsewidth controls and inputs (for rectangle output):

PW (manual pulsewidth control from 0%/output = fixed at "low" state up to 100% / output fixed at "high" state)

PWM input with attenuator

Hard Sync input (CEM3340 hard sync type)

Soft Sync input

Waveform outputs:

Sawtooth, output level ~ 10Vpp (voltage range ~ 0 ... +10V)

Rectangle (controlled from pulsewidth section), output level ~ 10Vpp (voltage range ~ 0 ... +10V)

Triangle (output level ~ 10Vpp, voltage range ~  -5V ... +5V)

Sine (output level ~ 10Vpp, voltage range ~  -5V ... +5V)

Range switch to select VCO/VCLFO mode, frequency relation between VCO mode and LFO mode about 500 : 1

dual color LED display (to display low frequencies below ~ 25 Hz)

Nearly "perfect" waveforms

high end triangle to sine converter with excellent sine waveshape (thank's to Tim Stinchcombe who recommended this circuit)

the micro precision VCO A-111-3 uses the same VCO core as the A-111-2, but has less inputs, outputs and controls
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Manufacturer Doepfer
Status Pre-order
Functionality Oscillator VCO
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