Doepfer A-111-1

The A-111-1 VCO module has a range of about 12 octaves, and produces four waveforms simultaneously: pulse to rectangle, sawtooth, triangle and sine waves. The frequency is determined by the control voltage at the two CV inputs, a range switch, tune and fine tune controls. For FM (frequency modulation) the A-111 can be modulated both exponentially and linearly. For pulse width modulation (PWM) the pulse width of the square wave can be controlled either by hand, or by voltage control. The A-111 also has inputs for Hard and Soft Sync.

The sine derived from the triangle by a simple diode-based converter does not have perfect shape. A self oscillating VCF would give a perfect sine wave.

Manufacture of the module has been discontinued as the CEM 3340 IC used is no longer available.

Specifications

 * Width: 14TE/14HP/70.8 mm
 * Depth: 65 mm measured from the rear of the front panel
 * Current draw: 40 mA