We recently revealed that Circle2 will contain a new oscillator based on state-of-the-art research in digital synthesis. This week, we’d like to share more information regarding this exciting new module and describe how it creates its rich, complex, characteristic sound.
Our new oscillator utilizes a cutting-edge technique called Vector Phaseshaping Synthesis (VPS). Jari Kleimola, Victor Lazzarini, Joseph Timoney and Vesa Välimäki from the Aalto University School of Electrical Engineering and National University of Ireland introduced this style of synthesis in their 2011 paper. Our team at Future Audio Workshop collaborated with Victor Lazzarini and Joseph Timoney on bringing this new technology to a software synthesiser for the very first time.
The core idea behind VPS is simple: the oscillator takes a pair of sine waves with specified frequencies and glues them together at a specified time. Via its two parameters - which control the frequencies of the sine waves and the location at which they are glued together - a VPS oscillator provides direct control of the waveform’s intricate harmonics. By varying these parameters, a VPS oscillator can create a wide variety of rich sonic textures that range from clean, crisp tones (perfect for sub-bass) to distorted leads (perfect for melodies) and thick rumbles (perfect for heavy basslines).
If you take another look at the teaser image from our previous blog post, you’ll see this process in action: In this example, each cycle of the VPS waveform consists of a higher frequency sine wave glued to a lower frequency sine wave. In contrast to many existing synthesis techniques (which create new sounds by adding several sine waves on top of each other), a VPS oscillator joins different sine waves end-to-end. What’s more, by assigning control of the oscillator’s parameters to one or more of Circle’s modulation units, our new VPS oscillator can create dynamic timbres that morph and evolve through time.
A key difficulty with implementing a VPS oscillator in a digital synthesizer is an unwanted auditory effect known as aliasing, which is a form of audio distortion that can lead to incorrect pitch replication. In recent months, the research and development team here at Future Audio Workshop have collaborated with the original inventors of the VPS oscillator to help find a solution to this problem and to ensure that our new oscillator produces pitch-perfect output for a wide range of parameter choices. As well as implementing this new methodology in Circle2, we will also be publishing our work in an academic paper (with the catchy title “Spectral Properties of VPS Waveforms with Applications to the Implementation of Bandlimited Oscillators”) to help drive future innovations on the VPS technique.
In the coming weeks, we’ll be revealing more details about the VPS oscillator, including hosting an interview with the authors of the upcoming academic paper to discuss their inspiration for designing the VPS oscillator, the difficulties that they faced along the way and how they went about finding a solution to the difficult problem of aliasing.
Circle is currently available for a reduced price of only €49/$69. If you purchase Circle from our download store today, you’ll also receive a free upgrade to Circle² on release day, so there’s never been a better time to join the ever-growing community of Circle users worldwide.