Pittsburgh Modular Synthesizers: Dissecting the Voltage Lab 2 Laboratory Oscillator 2

A standout feature of Oscillator 2 is pulse symmetry, which enables the creation of step-like pulse waves that go far beyond traditional pulse width modulation. By manipulating the symmetry, users can sculpt unique waveforms that add a distinct rhythmic or harmonic character to their patches. The video demonstrates how pulse symmetry can be dialed in to taste, resulting in a variety of timbres and textures.

What’s especially intriguing is the ability to apply pulse width modulation not just to the square wave, but across multiple wave shapes. The seed button allows users to select between sawtooth, sine, or a blend, influencing the resulting pulse symmetry behaviour. This opens up a playground for modulation enthusiasts, offering a palette of evolving, animated tones that respond dynamically to both manual and CV control.

Oscillator 2 doesn’t stop at traditional wave shaping—it also features a soft clipping mode, which can be engaged to add harmonic richness and subtle saturation to any waveform. This is demonstrated with various wave shapes, showing how soft clipping interacts with both the standard and modulated outputs. The module also includes a randomization mode, echoing the functionality found in Oscillator 1, for injecting unpredictable movement and variation into your sound. Together, these features make the oscillator a flexible source for everything from classic analog warmth to more chaotic, experimental textures.

One of the most compelling aspects of Laboratory Oscillator 2 is its ability to process external signals via the reflect input. This isn’t just an oscillator—it’s a signal mangler, capable of folding, reflecting, and reshaping incoming audio from Oscillator 1 or any other source. The reflection knob folds negative voltages up into the positive domain, creating complex, harmonically rich waveforms that can be further modulated or clipped.

The walkthrough demonstrates how patching Oscillator 1 through the reflect input of Oscillator 2 opens up a world of sonic possibilities, especially when combined with wave folding and modulation. All major parameters—pulse symmetry, reflection, and the big red knob—are CV-controllable, making the module highly interactive in a larger Eurorack setup. Dedicated outputs for sine and seed waveforms, along with standard FM and pitch inputs, round out the integration options, ensuring this oscillator can serve as both a sound source and a creative processor in any modular environment.