Phantasmatic

Phantasmatic is another new module for Cherry Audio’s Voltage Modular. Like its older brother Prismatic, it uses phase distortion to shape waveforms by changing the way the phase accumulator moves through a wavetable.

Where Prismatic uses an 8-bit processing path, with small lookup tables and fixed-point arithmetic running at a 16Khz sample rate, Phantasmatic runs at 48Khz and uses double precision floating point arithmetic throughout. This eliminates most of the soft (and occasionally harsh) digital noise that blankets Prismatic’s output, yielding a cleaner but slightly less characterful sound. It also cleans up a lot of aliasing, especially with the 2x oversampling anti-aliasing filter engaged (controlled via a “niceness” switch, where Prismatic had a “nastiness” switch for making the sound worse).

The philosophy is the same: rather than using subtractive synthesis, filtering out unwanted harmonics, we dial in extra harmonics over a base frequency by interpolating between waveforms (or, in fact, interpolating between phase distortion profiles that turn a sine wave into something more sawtooth-like or square-like). It’s quite a distinctive, and intuitive, way of building patches.

As with Prismatic, the module’s code is in the vulpus-labs-vm monorepo. It can be interesting to compare the two, if you’re interested in that sort of thing.