Doepfer A-111-2 High End VCO II

Module A-111-2 is the successor of the obsolete High End VCO I A-111-1.

• triangle core
• 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)
• exponential frequency controls and inputs:
• Tune (about +/- 1 octave range)
• Fine (about +/- 1 semitone range)
• Octave (range switch with 6 positions)
• 1V/octave CV input
• XFM input with attenuator
• access to bus CV (via jumper, optional)
• 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
• 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
• Soft Sync input
• Waveform outputs:
• Sawtooth
• Rectangle (controlled from pulsewidth section)
• Triangle
• Sine
• dual color LED display (to display low frequencies below ~ 25 Hz)
• Nearly "perfect" waveforms (no glitches)
• 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
• additional range switch (between Octave and Tune) to select VCO/LFO mode (see lower picture)
• frequency relation between VCO mode and LFO mode about 1:500