A-111-3 Micro Precision VCO

A-111-3 is a high end VCO with a 4HP panel

Module A-111-3 is an extremely space-saving precision VCO/LFO with a 4HP panel only. Essentially it's the same basic circuit as the A-111-2 but with reduced features:
triangle core
min. 15 octaves pitch range (typ. 0.5Hz - 20kHz with appropriate external CV)
perfect 1V/octave tracking over min. 10 octaves (typ. 20Hz - 20kHz)
exponential frequency section:
Tune control (~ 0.5 or ~ 2 or ~ 10 octaves range, selectable via internal jumper)
1V/octave CV input
XM input with attenuator
the XM input socket is normalled to a small positive voltage so that the XM control works as fine tune control when exponential FM is not in use
(thank's to Václav of Bastl Instruments for this tip at Superbooth in Berlin)
access to bus CV (via jumper, optional)
linear frequency section:
LM input (without attenuator), DC coupled
Pulsewidth section for rectangle output:
PW (manual pulsewidth control from 0%/output = fixed at "low" state up to 100% / output fixed at "high" state)
PWM input (without attenuator), about 5Vpp for full PW range
Sync input (selectable hard or soft sync via internal jumper)
Waveform outputs:
Sawtooth, output level ~ 8Vpp
Rectangle (controlled from pulsewidth section), output level ~ 8Vpp
Triangle, output level ~ 8Vpp
Nearly "perfect" waveforms (no glitches)
only 4HP panel
Modifications version (prototype 2):
Range switch so that the module can be used as VCO or LFO (in LFO mode all frequencies about 1/100 compared to VCO mode)
LED (for display in LFO mode)
smaller distance between the knobs and smaller knobs (because of the required space for the additional range switch)
This is a preliminary information about the planned module. The features are still subject to change and all specifications are still preliminary without any obligation !