In the West Coast philosophy of synthesis, one oscillator modulating another is a classic way of creating rich timbres. Voltage control of the modulation and of the waveshape is essential for evolving the sounds from whatever CV sources.

The Verbos Electronics Complex Oscillator is configured as a master oscillator with an voltage controlled waveshaper and a modulation oscillator that can be used for FM or AM.

The waveshape of the modulation can be set to triangle, square or saw, each with a dedicated output. Modulation amount can be voltage controlled with a reversing attenuator on the CV input.

The master oscillator has dedicated outputs for triangle, square and sine waves. The master output can blend from sine to square to saw to folded sine all from voltage control with reversing attenuators on all of the CV inputs.

The oscillators are analog triangle cores with discrete transistor exponential converters. Each has inputs for linear and exponential FM. Both have 1 volt/octave trimmed CV inputs as well.

The Modulation Oscillator
The left oscillator ranges from 1 cycle per minute to 500 Hz from the Frequency control. It has outputs for triangle, square and saw waves. The f.m. input goes through an attenuator on the way to linear modulation of the frequency. The c.v. input goes through a reversing attenuator on its way to exponential modulation of pitch. A calibrated volt/octave input is also provided

The Master Oscillator
The right oscillator ranges from 3 Hz to 20 kHz from the panel Frequency control. It has outputs for triangle, square and sine waves and a master output, fed from a complex waveshaping circuit. The f.m. input goes through an attenuator on the way to linear modulation of the frequency. The c.v. input goes through a reversing attenuator on its way to exponential modulation of pitch. A calibrated volt/octave input is also provided. The HARMONICS section allows timbre, symmetry and order parameters on the master output signal to be voltage controlled, each through a reversing attenuator. At the minimum timbre setting, the main output will be a sine wave. At the maximum timbre setting, with high order, the wave can sweep from square to saw to double frequency saw. At low order settings the sine wave is folded over 13 times as the timbre control rises.

Voltage Controlled Oscillation
A toggle switch in the MODULATION section selects a.m. or f.m. (or off in the middle position). With this toggle switch in the f.m. position, turning up the mod. amount will add frequency modulation of the right side oscillator by the left side oscillator in whichever waveshape is selected with the toggle switch in this section. With this toggle switch in the a.m. position, turning up the mod. amount will add amplitude modulation of the signal on the right side oscillators master output by the left side oscillator in whichever waveshape is selected with the toggle switch in this section. At the maximum mod. amount setting the effect is like a ring modulator and varying amounts of amplitude modulation on the way up. The sync toggle switch when flipped left, toward the arrow, causes the modulation oscillator to soft sync to the master oscillator. This creates useful variation in frequency and amplitude modulated tones.