Doepfer A-111-1 High-End VCO

Module A-111-1 (VCO 2) is a voltage controlled oscillator. The VCO has a range of about 12 octaves, and produces four waveforms simultaneously: pulse (rectangle), sawtooth, triangle and sine waves. The VCO's frequency is determined by the position of the range switch, tune and fine tune controls, and the voltage at the two pitch CV inputs, CV 1 and CV 2. Footage (the octave of the fundamental) is set by the Range control, which has seven octave steps. The Tune control is used for coarse tuning, and the Fine control for fine tuning of the VCO pitch. The A-111 can be modulated by both exponential and linear FM (frequency modulation). You can control the pulse width of the square wave either by hand, or by voltage control - Pulse Width Modulation, or PWM for short.
The A-111 has inputs for Hard Sync and Soft Sync.

For more detailed information please look at the English user's manual A111_man.pdf. 

Technical remark:
The sine is derived from the triangle by a simple diode-based converter and the sine shape is not perfect (nothing but a rounded triangle). For a perfect sine wave the quadrature LFO/VCO A-143-9 is recommended (or a self oscillating VCF).

The sawtooth output of the A-111-1 has a rising (or positive) slope. The front panel shows erroneously a falling (or negative) slope. This has no influence to the sound but becomes important when the module is used as an LFO or is mixed with the sawtooth output of another VCO.

As the special circuit CEM3340 used in this module is no longer available the module has to be discontinued. No longer available !

Up-to-date information May 1st, 2014: We received the irrevocable last batch CEM3340 from the manufacturer and will start to produce the last series of this module ! After the sale of this series the module is no longer available.

Recommended replacement: A-111-2