Interphase Cartograph

Interactive phase distortion — iPD — is the technique behind Casio’s VZ-series synthesizers of the late 1980s. Rather than mixing raw oscillator waveforms, it pairs two sound-generating modules into a line and lets one shape the other: bending its phase, or multiplying into it as a ring modulator. The character sits between subtractive and FM — glassy, bell-like, vocal or metallic, and equally capable of plain tones when the interaction stays subtle.

Classic reproduces the original four-line, eight-module architecture with eight iPD waveforms and eight-stage envelopes. Extended adds two more lines, twelve modules, a sixteen-waveform bank, and two interactions the hardware never had: amplitude modulation and through-zero FM. The two are switchable from the header at any time.

Around the engine sit a sixteen-route modulation matrix, a bipolar pitch envelope, patch vibrato and tremolo, an arpeggiator, microtonal tuning with historical temperaments, six performance macros, unison, two LFOs and a randomiser that can roll a whole patch or mutate the one you have. The display is drawn in an OLED style with cyan and amber themes.