Surge XT's waveshaper applies a nonlinear per-sample transfer function to add harmonic distortion

The Waveshaper module in Surge XT transforms each audio sample through a shaping function — a transfer curve that maps input values to output values. A Saturator, for example, pushes values away from zero toward ±1, soft-clipping the waveform and adding odd harmonics. The waveshaper sits between Filter 1 and Filter 2 in Serial 1 mode, and at different positions in other configurations (after both filters in Dual 1). The Drive slider controls pre-waveshaper gain, effectively setting how hard the signal hits the curve. A Waveshaper Analysis window shows the transfer curve applied to a sine wave. The full waveshaper is also available as a standalone FX unit that can appear anywhere in the effects chain, with additional pre/post EQ controls.

Examples

Route a sawtooth through a Hard Clip waveshaper with Drive at +6 dB to add aggressive upper harmonics before the final filter sweep. View the analysis window to see how the sine folds.

Assessment

What is the difference between adding Drive to the Waveshaper and raising oscillator volume? Explain how the placement of the waveshaper in Serial 1 vs. Dual 1 configuration affects its relationship to the filters.