01
Transparent
Minimal drive, +3 dB mode, Mix at 25%. Adds subtle harmonic density without audible saturation character. For mastering and bus processing.
Audubon · Plugins
HRN-001
·
Released v1.3
Soft Saturator
Heron.
Saturation with soul.
The Lavry Gold algorithm. Eight-times oversampled. A live transfer curve that shows you exactly what you're doing to your signal. Nine factory presets and a continuously smooth C¹ transfer function that never clips — it bends.
Coming soon · v1.3.0
$19
01 — Overview
Soft saturation built on a proven algorithm.
Heron is a soft saturator built around the Lavry Gold transfer function — a memoryless waveshaper with a C¹-continuous curve that transitions smoothly from linear behavior into saturation without a hard clip point anywhere in its range.
The Lavry Gold algorithm was originally documented by Dan Lavry as a reference for smooth, musical saturation behavior. Heron implements it faithfully with 8× oversampling to keep the harmonics clean, and a live display so you can see the curve while you work.
Two operating modes shift the saturation's gain structure by +3 dB or +6 dB, changing how aggressively the signal enters the saturation region for the same input level. Nine factory presets cover the most common use cases so you have a starting point for any material.
02 — The Engine
The Lavry Gold curve. No hard ceiling.
The transfer function is a smooth, continuously differentiable curve: linear at low levels, gradually compressing toward a soft asymptote at high levels. There is no threshold — the curve begins bending immediately, logarithmically, with no discontinuity.
C¹-Continuous Transfer Function
C¹ continuity means both the curve and its first derivative are continuous everywhere — there are no kinks, inflection points, or corners in the transfer function. The result is saturation that sounds smooth even at high drive levels, because the harmonic content builds gradually rather than switching on abruptly.
Memoryless Waveshaper
Heron is a static, memoryless waveshaper — the output at any moment depends only on the input at that moment, not on previous samples. This means no inter-sample dependency, no phase rotation from the saturation itself, and predictable, consistent behavior across all frequencies.
8× Oversampling
Waveshapers generate harmonics that alias at native sample rate. Heron runs at 8× the host rate, pushing all alias products well above 20 kHz before a steep low-pass filter brings it back down. The result is clean, musical harmonic content without artifacts.
Live Transfer Curve Display
The transfer curve is drawn in real time as you adjust Drive, Mode, and Input. A moving dot tracks the current operating point on the curve, showing exactly where your signal is on the saturation function at any given moment — input on the X axis, output on the Y axis.
03 — Two Modes
+3 dB or +6 dB. Same curve, different depth.
A — Mode 1
+3 dB — Subtle Warmth
The +3 dB mode shifts the gain structure so the curve starts bending 3 dB earlier. At moderate drive levels, this is a gentle saturation — harmonic enhancement, body, and warmth without obvious saturation character. Use it on vocals, pianos, and acoustic instruments.
B — Mode 2
+6 dB — Driven Character
The +6 dB mode pushes the signal 6 dB deeper into the saturation region for the same input level. The harmonic content is denser and more present. Use it on drums, synth basses, and electric guitars where you want saturation that's audible and characterful.
C — Blend
Mix Control for Both Modes
The Mix control works independently of the mode selection — blend either mode in at any level. This means +6 dB mode at 30% Mix can produce the same perceived saturation as +3 dB mode at 60% Mix, but with a different harmonic spectrum.
04 — 8× Oversampling
Eight times the rate. Zero the artifacts.
A — Aliasing
Why 8× Is Necessary
The Lavry Gold algorithm generates harmonics proportional to the input frequency. At 44.1 kHz, harmonics above 22.05 kHz fold back into the audible spectrum as inharmonic aliasing. At 8× (352.8 kHz), the fold-back products are far beyond what any filter affects in the audible range.
B — PDC
Latency Compensation Reporting
The oversampling filter introduces a small, fixed amount of latency. Heron reports this value accurately to the host for plugin delay compensation. On parallel processing buses, Heron stays in phase with the dry signal and other plugins on the same track.
C — Always On
No Bypass Option
8× oversampling is always active — there's no option to disable it. The extra CPU cost is modest on modern hardware, and keeping it always on ensures the output is always clean. The Mix control is the correct way to reduce the effect, not by disabling oversampling.
05 — Live Transfer Curve
See the saturation as you shape it.
The transfer curve display shows input level on the X axis and output level on the Y axis. A perfectly linear signal would be a 45° line. Heron's curve bows below that line — the further below, the more gain reduction at that level.
Curve Shape
Driven by Drive + Mode
As you increase Drive, the curve bends further from the linear reference. As you switch Mode, the inflection point shifts left (more compression at lower input levels) or right (more headroom before saturation begins).
Operating Point
Live dot indicator
A dot moves along the curve in real time, showing the current input/output pair. When your signal peaks, the dot travels right and upward along the curve. When it's quiet, it sits near the center of the display.
Reference Line
45° linear reference
The 45° diagonal is the linear reference — if the curve lay on this line, the plugin would be transparent. The gap between the curve and the reference is the saturation. More gap equals more harmonic content being added.
06 — Factory Presets
Nine starting points. Infinite variations.
Nine factory presets cover the primary use cases for soft saturation — from almost-transparent enhancement through to clearly colored, driven character. Each preset sets Drive, Mode, Mix, and Input to a musically sensible starting point.
02
Vocal Warmth
Low drive, +3 dB mode, Mix at 40%. Gently enhances vocal presence and fullness. Works on acoustic instruments too.
03
Synth Glue
Medium drive, +3 dB mode, Mix at 60%. Thickens and coheres synthesizer sounds. Useful on pad layers and stacked synths.
04
Drum Bus
Medium drive, +6 dB mode, Mix at 50%. Adds presence and energy to drum buses without triggering transient artifacts.
05
Bass Colour
Higher drive, +6 dB mode, Mix at 70%. Adds midrange harmonics to bass that translate on smaller speakers.
06
Guitar Body
Medium drive, +6 dB mode, Mix at 55%. Enhances body and sustain on DI guitar signals or reamped tones.
07
Mix Bus
Low drive, +3 dB mode, Mix at 30%. Gentle saturation on the stereo bus — adds cohesion and perceived loudness without coloring the mix.
08
Parallel Crush
High drive, +6 dB mode, Mix at 20%. Extreme saturation blended low for parallel processing texture on drums and percussion.
09
Full Drive
Maximum drive, +6 dB mode, Mix at 80%. Intentionally heavy saturation for aggressive sound design and lo-fi character.
07 — Workflow
Start with a preset. Trust the curve.
01
Insert Heron on the channel, bus, or master where you want saturation. It works on mono and stereo tracks equally.
02
Choose the nearest factory preset as a starting point. "Vocal Warmth" for vocals; "Drum Bus" for percussion; "Mix Bus" for the stereo master.
03
Watch the transfer curve as you increase Drive. The curve bends — more bend equals more harmonics. The dot shows where your signal currently sits on the curve.
04
Switch Mode if you need a different saturation depth at the same Drive setting. +3 dB is subtler; +6 dB is more characterful.
05
Use Input to match the incoming signal level to the operating point you want on the curve, then use Output to compensate for any loudness change.
06
Pull Mix back from 100% for parallel saturation. A/B the effect by toggling Mix between 0% and your working level — the Output trim keeps the levels matched.
08 — Specifications
Everything, on one page.
Format
VST3
Platform
Windows 10 / 11 · macOS 10.13+ (Universal — Apple Silicon & Intel) · 64-bit
Version
1.3.0
Algorithm
Lavry Gold — C¹-continuous soft saturation transfer function
Waveshaper type
Memoryless static waveshaper — no inter-sample dependency
Oversampling
8× — always active
Modes
2 — +3 dB (subtle) and +6 dB (driven)
Factory presets
9 — covering transparent through full drive
Drive range
0 – 100% (maps to algorithm gain parameter)
Input gain
−24 to +24 dB
Output gain
−24 to +24 dB
Mix range
0 – 100% dry/wet
Transfer curve display
Real-time · live operating point dot · 45° linear reference
Parameter smoothing
Ramp filter on all parameters — click-free automation
State save
Full settings saved with DAW project as XML
09 — Fine Print
Documentation.
DAW
Any VST3-compatible host — Ableton Live 11+, FL Studio 20+, Reaper, Cubase, Studio One, Bitwig. Insert on any mono or stereo track. 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 only. Works on mono and stereo channels — mix bus, instrument channels, vocal buses, drum buses, or any track needing saturation.
CPU
8× oversampling uses more CPU than a 4× plugin. On a modern processor, Heron uses a small fraction of one core per instance. Multiple instances are practical for most sessions.
Updates
Current release 1.3.0. Free updates for all future 1.x releases.
v1.3.0 — Update check, from the logo
The Audubon Audio wordmark in Heron’s header is now a button. Click it and Heron 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 Heron 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. Soft saturation with adjustable drive, tone, and mix. Up to 9 harmonics, even/odd balance control, 4× oversampling, and a real-time spectrum display showing pre/post harmonic content.
Full User Guide
Step-by-step walkthrough covering the transfer curve display, how to read the live activity indicator, all controls and toggles, oversampling, presets, and best use cases for mastering, bus saturation, and parallel processing.
Open User Guide →
Personal & Commercial Use
Use Heron in any project — music production, mixing, mastering, sound design, post-production, broadcast. 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.