Synthetic Sound Labs - Model 1200: VCO 1
The SSL 1200 "VCO 1" is a compact, high quality, precision voltage controlled oscillator for MU-format modular synthesizers, with an impressive number of functions for a single width VCO. Capable of accurate tracking over many octaves, it is also capable of acting as a relatively flexible low-frequency oscillator (LFO). With a time-tested sawtooth core, the 1200 uses highly matched integrated transistor pairs and quality temperature compensating resistors provide excellent stability.
One of three common waveforms - Triangle, variable width Rectangle, and Sawtooth may be switch selected to the Wave output, and a separate Sine output is continuously available.
External frequency modulation is switch selectable between linear and logarithmic. The depth of this external modulation is controlled by the CV AMT knob, and opens the door to many new timbres when modulated from other oscillators.
Sync ("hard sync") input can be used to lock two oscillators together to prevent “beating” effects or to provide dynamic timbral variations. Modulating the 1200 VCO's CV IN jack opens up a whole new range of sonic possibilities. Though not necessary in most cases, the input signal should be a clean rising edge (i.e. from a pulse or sawtooth wave) to achieve best results.
- COARSE: Wide range pitch adjustment covering approximately 12+ octaves - (approx. 2 Hz to 20K Hz). There are 7 very usable octaves.
- FINE: Allows smaller and more precise range than the Coarse control (approx. 10 semitones).
- CV AMT: Amount of control voltage attenuation from the CV Input (see below) that modulates the VCO’s frequency. Fully counter-clockwise is zero modulation; fully clockwise is 100% modulation.
- FM LIN/EXP: Selects between linear and exponential modulation from the CV AMT control.
- PW: Selects initial of duty cycle (pulse width) of the pulse wave - 12%, 25% & 50%. 12% provides a thin, reedy tone not unlike that of an oboe or clavinet/harpicord. 50% provides the classic hollow-sounding full square wave like a clarinet, while the 25% setting is a compromise setting between those two extremes. These percentage values are only the initial duty cycle (defined as the amount of the waveform that is positive voltage); the overall shape can be modulated via the PWM jack (see below) for timbral change over time. Please note that this switch only has effect when the pulse wave is selected (see below).
- WAVE: Selects between triangle, pulse, and sawtooth waveforms. When in the pulse position, the PW % and PWM controls can be altered for a wide variety of tonalities.
- 1V/OCT IN: Allows the VCO to track at 12 equal tempered semitones per octave.
- CV IN: Provides an input for control voltages to modulate the frequency of the VCO.
- PWM: Modulates the Pulse duty cycle when the pulse waveform is selected. This control has no effect on other waveforms.
- SYNC (hard): Allows the frequency of the VCO to be slaved to another frequency, creating interesting harmonic and timbral relationships.
- OUT: Output selected by the WAVE switch. ~10V P-P; +/-5V.
- SINE: Continuously available sine wave. ~10V P-P; +/-5V.
Frequency Range: Approx. 2 Hz to 20K Hz
Power: +15V at 27ma, -15V at 26ma, Synthesizers.com (DOTCOM) 6 pin MTA standard.
Width - One Moog Unit (MU) - 2.125" W x 8.75" H
Depth - 3" behind panel