DOEPFER / A-111-4 Quad VCO

Variations

This module is made by Doepfer, a German synthesizer manufacturer. It features four high-precision VCOs.

The A-111-4 is a module equipped with four high-precision VCOs. It's a modified version of the compact, high-precision VCO module A-111-3 Micro Precision VCO/VC LFO, with the LFO mode removed and a master unit adding a mixer with three waveform outputs.

Main Use Cases
• As a monophonic VCO with a fat sound
• As a VCO in a paraphonic patch using a polyphonic CV interface (four VCOs processed by one VCF/VCA)
• As a VCO in a polyphonic patch using a polyphonic CV interface (each of the four VCOs processed by its own VCF/VCA)
• Complex VCO patches utilizing FM and sync with up to four VCOs
Four VCO Sections
• 1V/Oct CV Input
• Octave Switch (-1 / 0 / +1)
• Tune Control (Range can be changed via internal jumper: 2 semitones / 1 octave / 4 octaves)
• Modulation CV Input
• Modulation Destination Switch
Top: Exponential Frequency Modulation
Bottom: Linear Frequency Modulation or Pulse Width Modulation (Select one or the other via internal jumper)
• Modulation Intensity
• Triangle Wave Output
• Sawtooth Wave Output
• Square Wave Output (Approximately 50% when not using external PWM)
• Sync Input (Soft sync or hard sync (CEM3340 type hard sync), select one or the other via internal jumper)
• Minimum 10-octave range (when using appropriate external CV)
• CEM3340-based VCO (Triangle Wave Core)
• Each VCO has its own internal +/- power supply for optimal stability and to prevent unwanted syncing
Master Section
• 1V/Oct CV Input
• Octave Switch (-1 / 0 / +1)
• Tune Control (Range can be changed via internal jumper: 2 semitones / 1 octave / 4 octaves)
• Frequency Modulation CV Input (FM)
• FM Intensity
• Triangle Wave Thumb Output
• Sawtooth Wave Thumb Output
• Square Wave Thumb Output
• VCO When a single waveform output of a section is patched, it is disconnected from the thumb output (this function can be turned off by solder bridging each output socket on the printed circuit board).
• CV Output (Outputs the total CV used to control all four VCOs)
• Bus CV (Selectable via internal jumper)

■ Width: 18HP
■ Depth: 40mm
■ Current Consumption:
+12V: 120mA
-12V: 100mA