Surge XT's Modern oscillator blends aliasing-suppressed saw, pulse, and triangle via DPW algorithm

The Modern oscillator is based on the Differentiated Polynomial Waveform (DPW) algorithm for alias-suppressed oscillators, producing very clean saw, pulse, and triangle waveforms with minimal aliasing artifacts. Three mix parameters (Sawtooth, Pulse, Triangle) control independent amplitudes of each waveform; a third waveform parameter can be switched to Sine or Square, and can be run as a sub-oscillator at half frequency — uniquely, this sub-oscillator does NOT participate in unison, contrasting with Classic’s sub. Width controls pulse duty cycle. Sync achieves hard sync effects against an internal reference oscillator. Unison works as in Classic. The DPW-based waveforms are cleaner at high pitches than Classic but the sine mode introduces additional harmonics beyond a pure sine.

Examples

Mix Sawtooth at +80% and Pulse at +30% for a classic supersaw-and-pulse blend. Set Triangle/Sine/Square to Square sub-oscillator mode for a non-unison bass layer beneath a unison lead.

Assessment

What advantage does the DPW algorithm provide over a naive sawtooth oscillator? Explain why the Modern oscillator’s sub-oscillator behaves differently in unison compared to the Classic oscillator’s sub.