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Official effect

Filter Delay

Filtered stereo repeats split into a resonant low-pass left side and resonant high-pass right side.

The current filter-delay family runs delayed repeats into two different filter branches: a resonant low-pass on the left and a resonant high-pass on the right, then adds those filtered repeats back to the dry source. `feedback` raises both the repeat regeneration and filter resonance, while `tone` brightens the delay loop and moves the filter centers upward.

  • Delay & Echo
  • Library #139
  • 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 current filter-delay family runs delayed repeats into two different filter branches: a resonant low-pass on the left and a resonant high-pass on the right, then adds those filtered repeats back to the dry source. `feedback` raises both the repeat regeneration and filter resonance, while `tone` brightens the delay loop and moves the filter centers upward.

  • Delay & Echo
  • resonant low-pass
  • resonant high-pass
  • 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 hits the delay core.

  1. 1internal picked-string demo phrase
  2. 2stereo spread with a short right-channel delay
  3. 3delayed repeats with regeneration
  4. 4left resonant low-pass and right resonant high-pass filtering
  5. 5repeat branches added over the dry source
  6. 6DC blocker
  7. 7output gain trim
  8. 8final 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 hits the delay core.

Effect core

Stereo filtered delay with resonant low-pass repeats on the left and resonant high-pass repeats on the right.

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
  • delayed repeats with regeneration
  • left resonant low-pass and right resonant high-pass filtering
  • repeat branches added over the dry source
  • 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: Scales the repeat branch above the always-present dry phrase.
  • output_gain_db: Applies final post-effect level trim after DC blocking and before the output limiter.
  • time: Sets the base delay time before the filtered repeat branches.
  • feedback: Raises the delay-loop feedback amount and also increases the resonances of the low-pass and high-pass filter stages.
  • tone: Raises the damping cutoff in the delay loop and moves the left low-pass and right high-pass centers upward.

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
  • leftFx
  • rightFx
  • phraseMono

Controls

Audible controls in this DSP

  • mix

    Active

    Scales the repeat branch above the always-present dry phrase.

    Raises repeat level without fully removing the original attack.

  • output_gain_db

    Active

    Applies final post-effect level trim after DC blocking and before the output limiter.

    Matches loudness without changing the actual delay structure.

  • time

    Active

    Sets the base delay time before the filtered repeat branches.

    Moves the filtered repeats from tighter response toward longer echoes.

  • feedback

    Active

    Raises the delay-loop feedback amount and also increases the resonances of the low-pass and high-pass filter stages.

    Adds more repeat count and makes the filtered resonances ring harder.

  • tone

    Active

    Raises the damping cutoff in the delay loop and moves the left low-pass and right high-pass centers upward.

    Makes the filtered repeats brighter and shifts their spectral focus upward.

Analysis

Code-derived notes

Current implementation shares the same split-filter repeat core across Filter Delay and Filter Pong.

Active blocks

  • demo
  • fx
  • outputStage
  • leftDemo
  • rightDemo
  • leftFx
  • rightFx
  • phraseMono
  • previewShiftSamples
  • echoOnly
  • delayA
  • pickedVoice
  • combLP
  • fund
  • pickEnv
  • ampEnv
  • triggerAt
  • maxDelaySamples

Inactive helpers

  • synthVoice
  • organVoice
  • bellVoice
  • softsat
  • quantize
  • diffuser

Warnings

No current warnings are attached to this effect.

Source

  • library/delay-echo/filter-delay.dsp
  • Output stage: DC blocker -> output gain trim -> final tanh limiter
  • Library position: 139

More In Delay & Echo

Continue through the library

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

Tape Echo

Currently a clean stereo feedback echo rather than a worn tape model with wow, flutter, or saturation.

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Ping-Pong Delay

Currently independent left and right stereo repeats rather than a true alternating ping-pong bounce.

View How It Works

Granular Delay

Currently a stepped short-delay texture with quantized fragments rather than a true grain-cloud engine.

View How It Works