Dirt

Two stages, not one drive control

DIRT provides independently configured A and B distortion stages. Each has three clipping modes and controls for drive, saturation/wavefolding, asymmetry and tonal balance. Serial routing lets the first stage reshape what the second receives; reversing their order can therefore produce a different result even without changing either stage's settings.

Saturation through wavefolding

Amount moves from dry behavior toward saturation, then into wavefolding beyond its center. That second region folds waveform peaks rather than merely clipping them, adding a more complex harmonic structure. Parallel routing offers another approach: build contrasting tones in A and B and blend their outputs. DIRT can add controlled edge to a part, emphasize a narrow or dark source, or create a heavily compressed, sustained texture. Establish the routing first, then compare stage modes and compensate the wet level before judging the result.

Source: Manual, “DIRT / Overview of DIRT,” pp. 14–16.

Set the topology first

Routing offers A > B, A < B and A + B. The first two place the stages in opposite serial orders; the third processes them in parallel. Serial ordering matters because the first distortion changes both level and harmonic content entering the next.

Shape each stage

• Drive: Raises input gain into the stage and therefore increases distortion intensity.
• Mode I: The least colored, most restrained clipping option.
• Mode II: A balanced distortion with the brightest tone.
• Mode III: A darker, more crushed response for stronger treatment.
• Amount: Introduces saturation through the first half of its travel and wavefolding through the second. Use Drive and Amount together: they influence different aspects of how the waveform is reshaped.
• Bias: Adds asymmetric behavior and even harmonics. It can give an otherwise hollow distortion more body.
• Tilt: Tilts the processed spectrum. Clockwise reduces lows and increases highs; counterclockwise does the reverse. Use it to keep a heavily driven stage from becoming overly bass-heavy or sharp.

Levels and final balance

Safety switches off the normal gain compensation. Treat it cautiously: removing compensation can drive the next stage harder in serial routing and produce substantial level changes. FX Trim adjusts the wet level from −18 to +6 dB for matching processed sounds.

In serial modes, Mix is an equal-power dry/wet crossfade. In parallel mode it becomes Blend, balancing A against B—not dry against wet. That distinction matters when preserving an unprocessed attack: parallel routing alone does not guarantee a dry path. Compare at matched listening levels before deciding that additional Drive is an improvement.

Source: Manual, “Overview of DIRT,” pp. 14–16.