MODULE 2220 - TRI/SAW/PULSE VCO

The 2220 Tri/Sawtooth/Pulse VCO is a three waveform exponentially voltage controlled oscillator with many of the features of the 2200 VCO. The oscillator’s frequency is determined by the sum of the settings of the coarse and fine initial frequency controls and any frequency control inputs. Control voltages may be applied from either of 2 keyboards via the keyboard switch, through the precision 1V/octave input, or through the attenuated frequency control input. As with the 2200, switching to low range lowers the frequency ten octaves, but the entire 20 octave range may be continuously swept. The pulse width control and the pulse width modulation input are summed and vary the duty cycle of the pulse waveform from 0% to 100%, with a maximum sensitivity of 10%/volt. The phase relationship between sawtooth and pulse is the same as in the 2200: the pulse rises as the sawtooth falls, and the pulse falling edge location is controlled by pulse width modulation.