A-111-2

High End VCO/LFO

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 planned module:

triangle core
min. 15 octaves pitch range (typ. 0.5Hz - 20kHz)
perfect 1V/octave tracking over min. 10 octaves (typ. 20Hz - 20kHz)
exponential frequency controls and inputs:
Tune (~ 1 octave range)
Fine (~ 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)

Modification final version: additional range switch (between Octave and Tune) to select VCO/LFO mode

http://www.doepfer.de/A1112.htm