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Official effect

Asymmetric Overdrive

Offset soft clipping that biases the signal before tanh saturation for a less even breakup shape.

The active path uses the familiar high-pass, low shelf, and 930 Hz pre-shape, but instead of a straight tanh stage it adds gain and positive offset before the nonlinear block. That asymmetry makes the clipping less even between waveform halves, so the harmonic profile is rougher than the otherwise similar soft-clip overdrives.

  • Drive, Boost & Saturation
  • Library #14
  • Preview 8s

Waveform preview

Static peaks come from the compiled FAUST preview render. The live scope is drawn from the browser playback output in real time.

Timeline
0:00 / 0:08
Source
Compiled browser preview
Live oscilloscope from the browser playback output.AnalyserNode keeps the signal path unchanged while exposing the waveform.

How It Works

Technical view

The active path uses the familiar high-pass, low shelf, and 930 Hz pre-shape, but instead of a straight tanh stage it adds gain and positive offset before the nonlinear block. That asymmetry makes the clipping less even between waveform halves, so the harmonic profile is rougher than the otherwise similar soft-clip overdrives.

  • Drive, Boost & Saturation
  • waveshaping / saturation
  • delay processing
  • oscillator / LFO modulation
  • DC blocking

Signal Path

Compiled preview chain

Preview source: An internally generated picked-string phrase is widened to stereo with a 19-sample right-channel delay and slight left/right shelf-EQ offsets before it reaches the active drive path.

  1. 1internal picked-string demo phrase
  2. 2stereo spread with a short right-channel delay
  3. 3high-pass cleanup
  4. 4low-shelf and 930 Hz contour shaping
  5. 5gain plus positive bias before tanh clipping
  6. 6post-drive high-shelf tone shaping
  7. 7dry / wet mix
  8. 8DC blocker
  9. 9output gain trim
  10. 10final tanh limiter

Preview source

An internally generated picked-string phrase is widened to stereo with a 19-sample right-channel delay and slight left/right shelf-EQ offsets before it reaches the active drive path.

Effect core

Single-stage biased tanh overdrive with asymmetric pre-offset before clipping.

Signal path

The static waveform and the live player both reflect this compiled signal chain.

  • internal picked-string demo phrase
  • stereo spread with a short right-channel delay
  • high-pass cleanup
  • low-shelf and 930 Hz contour shaping
  • gain plus positive bias before tanh clipping
  • post-drive high-shelf tone shaping
  • dry / wet mix
  • DC blocker
  • output gain trim
  • final tanh limiter

Controls that matter

These are the currently active controls detected in the FAUST source for this effect.

  • mix: Blends the clean stereo preview source with the soft-clipped overdrive path.
  • output_gain_db: Applies final post-effect level trim after the DC blocker.
  • drive: Raises the level feeding the single tanh saturation stage.
  • tone: Controls the post-drive high shelf after saturation.
  • contour: Changes the low shelf and 930 Hz emphasis ahead of clipping.

Code-backed analysis

The generated description is tied to the active helper blocks and routing found in the current DSP.

  • demo
  • fx
  • outputStage
  • leftDemo
  • rightDemo
  • driveTone
  • phraseMono
  • previewShiftSamples

Controls

Audible controls in this DSP

  • mix

    Active

    Blends the clean stereo preview source with the soft-clipped overdrive path.

    Lower values keep more dry articulation; higher values favor the overdrive voice.

  • output_gain_db

    Active

    Applies final post-effect level trim after the DC blocker.

    Balances loudness without changing how the clipping stage behaves.

  • drive

    Active

    Raises the level feeding the single tanh saturation stage.

    Moves the patch from light breakup toward thicker, more compressed overdrive.

  • tone

    Active

    Controls the post-drive high shelf after saturation.

    Brightens the clipped signal for more edge or smooths it for a darker voice.

  • contour

    Active

    Changes the low shelf and 930 Hz emphasis ahead of clipping.

    Pushes more body or midrange into saturation, changing how focused the overdrive feels.

Analysis

Code-derived notes

Reviewed against the current DSP. This file is one of the few overdrives in the current set that actually changes the clipping behavior instead of only moving EQ coefficients.

Active blocks

  • demo
  • fx
  • outputStage
  • leftDemo
  • rightDemo
  • driveTone
  • phraseMono
  • previewShiftSamples
  • softsat
  • pickedVoice
  • fund
  • pickEnv
  • ampEnv
  • triggerAt
  • maxDelaySamples

Inactive helpers

  • synthVoice
  • organVoice
  • bellVoice
  • quantize
  • combLP
  • echoOnly
  • diffuser

Warnings

No current warnings are attached to this effect.

Source

  • library/drive-boost-saturation/asymmetric-overdrive.dsp
  • Output stage: DC blocker -> output gain trim -> final tanh limiter
  • Library position: 14

More In Drive, Boost & Saturation

Continue through the library

Each effect page uses the same generated description pipeline and compiled waveform preview assets.

Transparent Overdrive

Keeps the dry attack intact while adding a broad low-mid lift and light tanh saturation for edge-of-breakup push.

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Amp-Like Overdrive

Mid-forward soft clipping tuned to feel more like a pushed amp stage than a flat clean boost.

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Hard-Clip Distortion

Cascaded clipping with reinforced lows and upper mids for tighter attack and more modern bite.

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