BR
Brown Walk
A bounded random walk (brown noise) redraws the whole curve — wild, unpredictable, never quite the same twice.
Audubon · Plugins
WRB-001
·
Released v1.1
Drawable Waveshaper
Warbler.
The distortion curve is whatever you draw.
A 512-point transfer curve you shape by hand, with the whole Curlew drawing rig along for the ride — freehand draw, two randomizers, FLIP, RESET, and 5-step undo/redo. A Sub split keeps the low end out of the curve entirely, so you can draw as wild as you want up top.
Coming soon
$29
01 — Overview
The curve is the distortion.
Most waveshapers hide the transfer function behind a "Type" list. Warbler puts it front and centre: a 512-point curve you draw by hand becomes the exact input→output mapping the audio runs through — no interpretation, no approximation. The default identity ramp is a straight diagonal (bit-transparent); every shape you draw into it becomes a distinct flavour of harmonic distortion.
Named for the warbler, a bird that bends and reshapes its own song — Warbler bends yours. It's scaffolded from Curlew, so the whole hand-drawing rig comes for free: freehand draw, brown-noise and smooth-noise randomizers, FLIP, RESET, and a 5-step undo/redo history.
With the identity curve, Drive at 0 dB, Bias and Tone at 0, Mix at 100%, Sub off and Output at 0 dB, the wet path is x → x — Warbler only colours the sound once you draw or drive it. A Sub split keeps everything below your chosen frequency dry and untouched, so the most aggressive scribble never eats your low end.
02 — The Engine
One table. Drawn, stored, and played back exactly.
The curve you see is the curve the audio thread reads. Every driven sample is clamped to ±1, looked up in the 512-point table with linear interpolation, and returned as the bipolar output — the same table the canvas draws from, read and written across the same bridge.
512 Points, Linear Interpolation
The table is fine-grained enough that hand-drawn curves stay smooth in playback — no stair-stepping between points you didn't intend to draw.
Only the Shaper Aliases
Sub split, Drive, Bias, Tone and the DC blocker are all linear or pre/post stages — only the table lookup is nonlinear, so only it needs oversampling.
5-Step Undo, Real History
Draw, randomize, flip or reset — every change is snapshotted so you can step back through the last five generations and forward again.
The Picture Never Lies
The curve on screen is fetched straight from the processor's own state — what you see drawn is exactly what the shaper reads.
03 — Draw, Randomize, Undo
Freehand it, or let the tools surprise you.
Click and drag directly on the curve to draw. When you want a starting point instead, four tool chips reshape the whole table in one click.
SN
Smooth Noise
Interpolated noise slewed and soft-driven toward the rails — a more musical, rounder random shape than the brown walk.
FLIP
Invert
Flips the curve vertically (output → −output) — an instant, exact inversion of whatever you've drawn.
RESET
Identity
Back to the clean identity diagonal in one click — the transparent starting point for a new drawing.
The ‹ › chips step back and forward through your last five curve generations — draw something you like, try BR on top of it, and undo straight back if it wasn't an improvement. Loading a session, project, or preset starts undo/redo fresh; it doesn't inherit history from wherever you were before.
04 — Sub Split
Draw anything up top. The low end stays dry.
A — Linkwitz-Riley Crossover
The Shaper Never Sees the Sub
Everything below the Sub frequency is peeled off before the curve, kept fully dry, and added back afterward — the most violent hand-drawn curve can't touch it.
B — Sub = Off Disables the Split
Full-Band Shaping When You Want It
Turn Sub down to Off and the crossover is bypassed entirely — the whole signal runs through the curve, useful when you want the low end to distort too.
C — 20 – 320 Hz Range
Set It Above Your Fundamental
Dial Sub to sit just above the note you're playing so only the harmonics above it get drawn into the curve.
05 — Bias, Tone & DC Block
Shift it off-centre. Tilt what comes out.
A — Bias
Reads the Curve Asymmetrically
Bias offsets the signal before it hits the curve, so the table gets read off-centre — the same drawn shape suddenly produces even-harmonic, tube-like warmth instead of a symmetric response.
B — Tone
A Gentle Post Tilt
Tone tilts the wet signal dark or bright after the curve, taming or brightening whatever harmonics your drawing generated — without touching the curve itself.
C — DC Block
Always On, Never in the Way
Bias and asymmetric curves inject DC offset; a ~5 Hz one-pole high-pass removes it from the wet path automatically, well below any musical sub content.
06 — Global Controls
Eight controls drive the shape.
Drive and Bias feed the curve; Tone, Auto Gain, Mix and Output finish the blend; Sub and Oversample are there when you need them.
Drive
0 → 36 dB
Input gain into the drawn curve — 0 dB reads the table at unity.
Bias
−100 → 100 %
Pre-shape DC offset — reads the curve asymmetrically for even-harmonic warmth.
Tone
−100 → 100 %
Post tilt EQ, dark ↔ bright — tames or brightens the new harmonics.
Mix
0 → 100 %
Parallel dry/wet blend.
Sub
Off, 20 → 320 Hz
Keep-low crossover. Off turns the split off — full-band shaping.
Output
−24 → 24 dB
Output trim for level-matched comparisons against bypass.
Auto Gain
On / Off
Compensates the wet path for Drive, on by default, so pushing Drive changes character, not just loudness.
Oversample
Off / 2× / 4× / 8×
Off by default (zero latency, zero extra CPU). Reach for it on aggressive curves or high notes; latency is reported honestly when engaged.
07 — Factory Presets
Fourteen starting curves.
Applying a preset resets every parameter to default first, then draws its own curve and dials in its own settings, so recall is always clean. The bass-leaning presets set Sub to keep the low end intact.
Init
The clean identity diagonal — the drawing starting point.
Warm Tanh
A soft tanh curve for gentle, musical warmth.
Hard Clip
Aggressive hard-clip curve with output trimmed to match.
Growl Fold
A wave-folded curve with Sub engaged for a low-end growl.
Metal Screech
A denser fold with bright Tone for a metallic edge.
Tube Asym
Asymmetric tube-style curve with Bias dialed in for even harmonics.
Bit Ladder
A staircase curve for a lo-fi, quantized character.
Sub-Safe Sat
High-drive soft saturation with Sub protecting the fundamental.
Reese Grind
A grinding tanh-plus-ripple curve built for Reese-style bass.
Parallel Heat
High Drive blended back with Mix for parallel-style saturation.
Diode Buzz
A diode-rectifier curve with Bias for extra buzz.
Formant Wobble
A wobbling curve that adds a vowel-like formant character.
Crossover Buzz
A dead-zone curve for a gated, buzzing crossover-distortion character.
Fold Chaos
The densest fold, pushed hot and blended in with Mix for full chaos.
08 — Workflow
From blank curve to a shape you own.
01
Insert Warbler and pick a factory preset, or start from RESET's clean identity diagonal.
02
Draw directly on the curve, or hit BR / SN for a random starting shape — undo (‹) steps back if it isn't working.
03
Set Sub just above your fundamental so only the harmonics above it get drawn into the curve; Sub = Off shapes full-band.
04
Raise Drive to push harder into the curve; add Bias for even-harmonic asymmetry.
05
Tilt Tone to taste, balance with Mix, and trim Output to match bypass level.
06
Reach for Oversampling only on the most aggressive drawn curves at high Drive.
09 — Specifications
Everything, on one page.
Format
VST3
Category
Fx · Distortion
Platform
Windows 10 / 11 · macOS 10.13+ (Universal — Apple Silicon & Intel) · 64-bit
Version
1.1.0
Transfer curve
512-point, hand-drawn, linear interpolation
Curve tools
Freehand draw · BR (brown walk) · SN (smooth noise) · FLIP · RESET · 5-step undo/redo
Drive
0 – 36 dB pre-gain into the curve
Bias
−100 to 100%, pre-shape asymmetry, DC-blocked
Tone
−100 to 100%, post tilt EQ
Sub split
Off, 20 – 320 Hz Linkwitz-Riley crossover, keeps sub dry
Auto Gain
On/off, compensates wet level for Drive, on by default
Oversampling
Off (default) · 2× · 4× · 8×, polyphase IIR, honest latency reporting
Mix / Output
0 – 100% parallel blend · −24 to +24 dB trim
Factory presets
14 — Init, Warm Tanh, Hard Clip, Growl Fold, Metal Screech, Tube Asym, Bit Ladder, Sub-Safe Sat, Reese Grind, Parallel Heat, Diode Buzz, Formant Wobble, Crossover Buzz, Fold Chaos
Latency
0 samples with Oversampling Off; reported honestly when engaged
State save
Full curve, settings and presets saved with DAW project
10 — Fine Print
Documentation.
DAW
Any VST3-compatible host — Ableton Live 11+, FL Studio 20+, Reaper, Cubase, Studio One, Bitwig, and others. VST3 only — Logic Pro and GarageBand load Audio Units, not VST3, so they are not supported.
Operating System
Windows 10 or 11 (64-bit) — the editor uses WebView2, which is built into Windows 11 and most current Windows 10 installs. macOS 10.13 High Sierra or later — one Universal build runs natively on both Apple Silicon and Intel Macs.
Format
VST3 effect. Insert on any mono or stereo channel where you want a hand-drawn transfer curve instead of a fixed distortion type.
Latency
Zero with Oversampling Off (the default). 2×/4×/8× add a reported latency your host compensates for automatically.
Recommended Setup
Start with a factory preset like Warm Tanh, Sub around 100 Hz, and Drive around 8 dB. Then draw over the curve or hit BR / SN to explore.
Updates
Current release 1.1.0. Free updates for all future 1.x releases.
v1.1.0 — Update check, from the logo
The Audubon Audio wordmark in Warbler’s header is now a button. Click it and Warbler asks audubonaudio.com one question — which build is current — then shows that number beside the one you are running, with a link straight to the members area if there is something newer and a plain “you have the current version” if there is not. If it cannot reach us it says so rather than claiming you are up to date. This is the only moment Warbler touches the internet, it happens only on that click, and nothing about you goes with it — no serial, no licence, no machine id, not even your version or operating system. The comparison happens on your own machine.
v1.0.0 — Initial Release
First public release. 512-point drawable transfer curve with freehand draw, brown-noise and smooth-noise randomizers, FLIP, RESET, and 5-step undo/redo. Sub split crossover, Drive, Bias, Tone, Mix, Output, Auto Gain, optional 2×/4×/8× oversampling, and 14 factory presets.
Full User Guide
Step-by-step walkthrough of the curve editor, draw tools, Sub split, Bias/Tone, and workflow recipes for drawing bass-safe distortion.
Open User Guide →
Personal & Commercial Use
Use Warbler in any project — music production, mixing, sound design, post-production, broadcast, and live performance. No royalties, no project restrictions.
Single User
One license per user. Install on the computers you personally own or operate.
Serial Activation
Your license includes a unique serial number tied to your email. Your serial and download are permanently accessible in your Members Area.
Free Updates
All 1.x updates are free. Your serial activates the current version and all future updates in the 1.x line.
No Redistribution
The plugin binaries may not be shared, resold, or redistributed. Each user must obtain their own license.