doepfer/a-110-1

A-110-1 Standard VCO

Doepfer

Voltage-controlled oscillator producing four waveforms simultaneously (square, sawtooth, triangle, sine) with a frequency range of about ten octaves, controlled by Range switch, Tune knob, and CV inputs.205

Capabilities 3

Hard Synchard-sync
Hard sync input resets slave VCO waveform on each master VCO cycle; produces harmonic sidebands when slave frequency is higher than master.205
Pulse Width Modulationpwm
Square wave pulse width controllable manually via PW knob or by voltage via two PWM inputs (PW CV 1 and PW CV 2), with an attenuator on PW CV 2.205
Voltage-Controlled Oscillatorvco
205

Jacks 9 — 5 in / 4 out

NameSignalVoltageDescription
Inputs (5)
CV 1cvPrimary CV input for VCO pitch control, following 1V/octave standard. Normalled to internal bus CV; inserting a patch cable disconnects the bus CV.205
CV 2cvSecondary CV input for VCO pitch/FM; level adjustable via CV 2 attenuator. Summed with CV 1. Typically used for FM (vibrato, auto-bend, etc.).205
PW CV 1cvPulse width modulation CV input 1. Voltages from PW CV 1 and PW CV 2 are summed to modulate the square wave pulse width.205
PW CV 2cvPulse width modulation CV input 2; level adjustable via PW CV 2 attenuator knob. Summed with PW CV 1.205
SYNCaudioHard sync input. Resets the slave VCO's waveform to the beginning of a cycle whenever the master VCO starts a new cycle.205
Outputs (4)
Sawtoothaudio205
Sineaudio205
SquareaudioSquare/rectangle wave output. Pulse width adjustable manually or via CV. At 50% pulse width, only odd harmonics are present.205
Triangleaudio205

Parameters 5

NameTypeRangeBehavior
CV 2knobAttenuates the control voltage at CV 2 input before it is summed with CV 1 to control VCO pitch.205
PWknobManually sets the pulse width of the square wave output. Can also be modulated via PW CV inputs.205
PW CV 2knobSets the gain of the PW CV 2 input signal affecting pulse width modulation of the square wave.205
Rangeswitch-2octave – 2octaveSets footage (octave of the fundamental) in five steps over a wide frequency range.205
Tuneknob-0.5octave – 0.5octaveEnables fine tuning of the oscillator frequency. Useful for detuning one oscillator relative to another when multiple oscillators share the same CV.205

Firmware history 0 versions

No firmware history recorded.

References 2

  1. [205]
    A-110-1 Standard VCO Manualmanual
    verified 2026-05-06
  2. [206]
    Doepfer A-110-1 product pageproduct_page
    verified 2026-05-06