01
Init
All defaults. FAT and COLOR at 0%, Mix 100%, Clip on at 0 dB / SOFT 1. A transparent, zero-latency starting slate.
Audubon · Plugins
GRB-001
·
Released v1.1
Master Clipper
Grosbeak.
Fat, loud, finished.
One window makes a mix bus fat, adds top-end colour, and finishes through a GClip-style ceiling you can see. Zero latency end to end — safe as the last plugin on the master or drop bus of a live session.
Free · v1.1.0
Free
01 — Overview
The Condor master section,
grown into its own bird.
Grosbeak takes the mastering chain from the Condor Multiband — fatten, colour, clip — rebuilds every weak part of it, and puts the whole thing behind one clip monitor you actually watch. FAT morphs clean into loudness-matched warmth. COLOR lifts the air without pushing the upper mids. A variable-knee GClip ceiling finishes it. Nothing here adds latency until you ask it to.
A master-bus glue clipper that makes things thick and loud without turning the fat knob into a hidden volume lever.
The Pine Grosbeak — "gros" for fat — is the plump raspberry-red finch. The plugin is named for what it does: it makes a bus heavy. FAT is a biased-tanh saturator whose makeup gain is loudness-matched (AC-RMS of a −12 dBFS sine, within ±1.3 dB across the whole sweep), so the knob adds harmonic weight, not level. An optional SUB SAFE crossover keeps the low end out of the saturator. And because both nonlinearities are first-order ADAA, the default signal path is bit-transparent and zero-latency — the honest last-in-chain finisher.
02 — The Engine
Four stages, one signal path.
Input trim splits into a phase-matched dry tap and the wet chain. FAT saturates, COLOR shelves and excites, MIX blends against the dry, OUTPUT sets level, and the CLIP section finishes into a variable ceiling. Both nonlinear stages are anti-derivative anti-aliased (ADAA-1) — so at rest, the whole thing is a straight wire.
FAT — Biased-Tanh Saturator
One knob morphs clean into loudness-matched 2nd/3rd-order harmonic warmth (H2 down to −19.7 dB at max). The dry/wet morph is folded into a single biased-tanh ADAA curve, so the blend can never comb. Makeup is derived from the AC-RMS of the static curve over a −12 dBFS sine (±1.3 dB across the sweep), and a DC blocker cleans up the bias term the even harmonics leave behind.
SUB SAFE — LR4 @ 110 Hz
Optional, off by default. When on, a Linkwitz-Riley 4th-order crossover at 110 Hz routes everything below the split around the saturator — the low end stays clean no matter how hard you push FAT. The dry stays phase-matched via the LR4 allpass reconstruction. The 2nd harmonic of a 43 Hz sub drops from −34 dB to −112 dB at full FAT. Off = the original full-band Condor-master sound.
COLOR — Shelf + Air Exciter
An RBJ 2nd-order high shelf (fc 4.8 kHz, S 1, gain 20·log10(1+0.58·color) ≈ +4.6 dB at 15 kHz maxed) adds air without the upper-mid forwardness of a naive one-pole. Above it, an envelope-normalised ADAA exciter on the 8 kHz band adds sheen that stays constant with input level — the same sparkle at −24 dBFS as at −6 dBFS (0 dB swing).
CLIP — Variable-Knee GClip
The finisher. GAIN drives into a ceiling; CLIP sets the ceiling (−18…0 dB); SOFT sets the knee (0…6 dB — 0 is a pure hard clip, 1 dB reproduces the Condor GClip exactly). A C1 cubic Hermite knee keeps slope continuous at both edges. The clip section toggles off for honest A/B null tests. All of it drawn live in the Clip Monitor.
03 — FAT
Weight, not volume.
The original Condor fattener used an asymmetric tanh with a slope kink at zero — a crossover-style fizz on quiet material — and a 1/√ makeup guess that turned the knob into a +7 dB loudness lever. Grosbeak's FAT is a smooth biased curve, ADAA-anti-aliased, with makeup matched to the AC energy of the signal, so you hear thickness appear while the level barely moves.
A — Curve
Smooth Biased Tanh
FAT builds the shaping curve as tanh(u+b)−tanh(b): a bias term b (0.30 × fat) tilts the transfer function to favour even harmonics, and the whole curve is offset so it still passes through zero. No kink at the origin means no crossover fizz on low-level passages. At maximum, the 2nd harmonic sits at −19.7 dB — audible warmth, not obvious distortion.
B — Makeup
Loudness-Matched
Peak-matching isn't enough — saturation changes the crest factor. Grosbeak measures the AC-RMS of the static curve across one cycle of a −12 dBFS sine and sets makeup from that, holding output loudness within ±1.3 dB across the entire 0–100% sweep. Turning FAT up gives you harmonic density, not a level jump that fools you into thinking it sounds "better."
C — Anti-Alias
ADAA, Zero Latency
FAT is a first-order antiderivative anti-aliased (ADAA-1) nonlinearity — it suppresses the worst aliasing without any oversampling, so the default path stays zero-latency. A post-FAT DC blocker removes the DC component the even-harmonic bias produces. Want more headroom against aliasing on extreme slams? The HQ 4× pill oversamples the whole chain.
04 — COLOR & Mix
Air that stays put.
COLOR is two moves in one knob: a proper 2nd-order presence shelf and an air-band exciter that's normalised to the signal envelope. The old Condor colour aliased and its sheen swung 33 dB from −24 to −6 dBFS input. Grosbeak's holds a 0 dB swing — the same air at any level — and MIX blends the whole wet chain against a latency-free, phase-matched dry.
A — Shelf
RBJ Presence Shelf
A true RBJ cookbook 2nd-order high shelf at 4.8 kHz (S 1), gain 20·log10(1+0.58·color) — about +4.6 dB at 15 kHz fully up. Calibrated to the same high-air lift as the old shelf but with 1.6 dB less lift at 2.5 kHz, so you get top-end sheen without the upper-mid forwardness a 6 dB/oct one-pole skirt drags along with it.
B — Air
Level-Independent Exciter
On the band above 8 kHz, an ADAA tanh exciter is fed a signal normalised by a 5 ms / 200 ms envelope follower, then scaled back by that envelope. The result is the same amount of excitement at −24 dBFS as at −6 dBFS — a 0 dB level-dependence swing, and at least 12 dB less aliasing than the original naive tanh.
C — Mix
Phase-Matched Parallel
MIX blends the processed wet against a dry tap taken right after the Input trim — so a parallel blend stays level-balanced, not louder. Because there's no oversampling in the default path, the dry and wet are sample-aligned and phase-coherent: a 45% Mix thickens without any comb filtering. Great for parallel saturation on a drum or synth bus.
05 — The Clip Section
A ceiling you can see.
The GClip-style finisher is generalised into three controls and drawn in real time. The Clip Monitor hero shows the actual measured DSP peaks — clipper output as a frost wave, the slice that got cut as glowing raspberry, the ceiling as a raspberry line, and a dashed line where the SOFT knee starts to bend. No re-simulation in JavaScript: those are the numbers the audio thread measured.
A — Ceiling
GAIN · CLIP · SOFT
GAIN drives the signal into the ceiling (the loudness lever). CLIP sets the ceiling itself, −18 to 0 dB. SOFT sets the knee width, 0 to 6 dB: 0 is a pure hard clip, 1 dB reproduces the Condor master's GClip bit-for-bit. The knee is a C1 cubic Hermite — slope 1 entering, slope 0 at the ceiling — continuous at both edges at every setting.
B — Monitor
Clip Monitor + Knee Inset
The scrolling monitor shows real pre-clip and post-clip peaks at 30 Hz with a live readout ("CUTTING −1.2 dB" / "CLEAN" / "CLIP OFF"). The KNEE inset draws the live transfer curve, auto-scaled to the ceiling, with a knee-start tick and the eased operating point of the programme material. A Type-1 activation glow, driven by the measured FAT activity, breathes when the saturator is working.
C — HQ & Delta
HQ 4× & Delta Listen
HQ 4× (default off) oversamples the entire nonlinear chain — the worst-case alias floor drops from −34 dB to −71 dB with 0.00 dB of H2/H3 character change; off stays the bit-identical zero-latency path, on reports the oversampler's few samples to the host. DELTA listen plays output minus the gain-matched dry — exactly what FAT and COLOR add and what the clipper removes — and nulls bit-exactly when the chain is linear.
06 — Controls
Every parameter, and what it does.
Input
−18 – +18 dB · default 0
Trim into the whole chain. Drives FAT and COLOR harder. The dry tap for Mix is taken after this trim, so parallel blends stay level-balanced.
Fat
0 – 100% · default 0
The fattener. Morphs clean into loudness-matched 2nd/3rd-order harmonic warmth (H2 −19.7 dB at max). Loudness holds within ±1.3 dB across the sweep.
Sub Safe
On / Off · default Off
LR4 @ 110 Hz keeps subs out of the saturator, phase-matched dry. Off = the original Condor-master full-band sound.
Color
0 – 100% · default 0
Presence shelf (RBJ, 4.8 kHz, ≈+4.6 dB @ 15 kHz maxed) plus an envelope-normalised air exciter — the same sheen at any input level.
Mix
0 – 100% · default 100
Parallel blend of the wet chain against the phase-matched, latency-free dry. Lower it for parallel thickening that never combs.
Output
−18 – +18 dB · default 0
Level into the clip section — set how hard the fattened, coloured signal arrives at the ceiling before GAIN.
Clip (on/off)
On / Off · default On
The clip section on/off. On, Grosbeak is a finisher; at CLIP 0 dB / GAIN 0 it only touches actual overs. Off = an honest bypass for null tests.
Gain
−18 – +18 dB · default 0
Drive into the ceiling — the GClip loudness lever. Push it to push more of the programme into the knee and past the ceiling.
Clip (ceiling)
−18 – 0 dB · default 0
The ceiling itself. Everything above it is clipped; the SOFT knee eases the approach. Shown live as the raspberry line in the monitor.
Soft
0 – 6 dB · default 1.0
Knee width below the ceiling. 0 = pure hard clip; 1 dB reproduces the Condor GClip exactly; higher = a rounder, softer approach.
HQ 4×
On / Off · default Off
Oversample the whole nonlinear chain at 4×. Off = zero-latency identity path; On drops the worst-case alias floor ~37 dB and reports latency. Toggle while stopped.
Delta
On / Off · default Off
Listen to output minus the gain-matched dry — exactly the adds and cuts. Accent-lit so it can't be left on unnoticed; nulls bit-exactly when linear.
07 — Factory Presets
Nine starting points.
Applying a preset resets every parameter to default first, then dials in only the values listed — so each is a clean, predictable starting point. HQ and Delta stay at their defaults in every factory preset: HQ is a session choice, Delta is a listen mode.
02
Bus Glue
A touch of FAT and a hint of COLOR. Light harmonic weight and air to glue a stereo bus together without any obvious effect.
03
Fat & Loud
More saturation, more colour, and a few dB of clip GAIN. A confident, forward master-bus thickness that pushes into the ceiling.
04
Drop Slam
Heavy FAT and COLOR into +6 dB of GAIN with a near-hard knee (SOFT 0.5). For the drop — maximum weight and loudness.
05
Warm Master
Gentle FAT with a wide, soft knee (SOFT 3) and Mix pulled to 85% — a warm, rounded master finish that keeps some dry intact.
06
Sub Safe Slam
SUB SAFE engaged, heavy FAT (55%) and +5 dB GAIN. Slam the mids and highs hard while the sub-bass stays clean under 110 Hz.
07
Air Lift
A little FAT and a lot of COLOR (42%). Mostly presence shelf and air exciter — brighten and open a dull mix without adding weight.
08
Just Clip
No FAT or COLOR — +4 dB GAIN into a tight knee (SOFT 0.2). Pure ceiling control for a transparent, loud clip-only finish.
09
Parallel Thick
Big FAT (62%) blended at 45% Mix. Parallel saturation — dense harmonics under the dry signal without losing the transient snap.
08 — Workflow
How to use it.
01
Put it last. Grosbeak is a finisher — insert it as the last plugin on the master, drop, or a group bus. It's zero-latency in the default path, so it's safe on a live session's master. Start from Init: every stage is at rest and the signal passes bit-transparent. Set Input so the meters read healthy before you touch anything else.
02
Fatten. Bring up FAT while listening for density, not level — the makeup is loudness-matched, so a "louder" impression is real harmonic weight, not a volume trick. 15–30% glues a bus; 40–60% is a clear, thick character; past 60% is a deliberate slam. If the low end starts to smear or lose punch, turn on SUB SAFE to route everything below 110 Hz around the saturator.
03
Colour. Add COLOR for air and presence. The shelf lives at 4.8 kHz and the exciter sits above 8 kHz, both level-independent — the sheen holds whether the section is quiet or loud. 5–15% is a subtle sweetening; 30–45% is an obvious lift for a dull source. Because the air is envelope-normalised, it won't pump or over-brighten on transients.
04
Blend (optional). For parallel processing — thick harmonics under an intact dry — pull MIX down. The dry tap is phase-matched and latency-free, so 40–60% Mix thickens without comb filtering. Leave Mix at 100% for a straight in-line master fattener. This is the move for drum and synth buses where you want body but need to keep the attack.
05
Finish at the ceiling. Set OUTPUT to arrive at the clip section at a sensible level, then use the CLIP section: CLIP for the ceiling, GAIN to drive into it, SOFT for the knee. Watch the Clip Monitor — frost is your output, raspberry slices are what's being cut, the raspberry line is the ceiling. Aim for occasional cuts on peaks, not constant heavy clipping, unless a slam is the goal.
06
Check your work. Hit DELTA to hear exactly what FAT and COLOR are adding and what the clipper is removing — if it nulls to silence, the chain is linear and you're bit-transparent. For extreme slam settings where aliasing matters, flip on HQ 4× (toggle while stopped for a clean switch); it reports a few samples of latency and drops the alias floor ~37 dB with no change to the character.
09 — Specifications
Everything, on one page.
Input
−18 … +18 dB · default 0 — trim into the chain; dry tap is post-trim
Fat
0 … 100% · default 0 — loudness-matched biased-tanh saturator (H2 −19.7 dB @ max)
Sub Safe
On / Off · default Off — LR4 @ 110 Hz routes subs around FAT
Color
0 … 100% · default 0 — RBJ shelf (4.8 kHz, ≈+4.6 dB @ 15 kHz) + 8 kHz air exciter
Mix
0 … 100% · default 100 — parallel blend vs. phase-matched dry
Output
−18 … +18 dB · default 0 — level into the clip section
Clip (on/off)
On / Off · default On — clip section enable; off = honest bypass
Gain
−18 … +18 dB · default 0 — drive into the ceiling
Clip (ceiling)
−18 … 0 dB · default 0 — the clip ceiling
Soft
0 … 6 dB · default 1.0 — knee width; 0 = hard clip, 1 = Condor GClip
HQ 4×
On / Off · default Off — 4× oversample of the nonlinear chain
Delta
On / Off · default Off — output minus gain-matched dry (monitoring)
Channels
Mono or stereo (input must match output)
Format
VST3 · Windows 10 / 11 · macOS 10.13+ (Universal — Apple Silicon & Intel) · 64-bit
Latency
Zero in the default path — HQ 4× reports the oversampler's few samples (PDC)
MIDI
None
Presets
9 factory · user presets saved to Documents
Version
1.1.0
10 — Fine Print
Documentation.
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.
DAW
Any VST3-compatible host — Ableton Live, FL Studio, Bitwig, Reaper, Studio One, Cubase. Insert on any mono or stereo track, bus, or master. VST3 only — Logic Pro and GarageBand load Audio Units, not VST3, so they are not supported.
Latency
Zero in the default path — safe as the last plugin on a live master bus. HQ 4× reports the oversampler's few samples, compensated automatically by any host with PDC.
Activation
No iLok, no dongle — download and use. Your download stays accessible in your Members Area.
Personal & Commercial Use
One licence covers all your personal and commercial productions. No royalties, no project restrictions.
Terms & Refunds
See the Terms of Service and Refund Policy for full details.
No Redistribution
You may not resell or redistribute the plugin binary. Source code is not included.
v1.1.0 — Update check, from the logo
The Audubon Audio wordmark in Grosbeak’s header is now a button. Click it and Grosbeak 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 Grosbeak 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 — First Release
The Condor master section grown into its own bird. FAT: loudness-matched biased-tanh saturator with the dry/wet morph folded into one ADAA-1 curve and a post DC blocker. Optional SUB SAFE (LR4 @ 110 Hz). COLOR: RBJ 2nd-order shelf (4.8 kHz) plus an envelope-normalised ADAA air exciter at 8 kHz. Variable-knee GClip finisher (CLIP ceiling, SOFT knee, GAIN drive) with a C1 Hermite knee. HQ 4× oversampling pill (default off). DELTA listen. Real-measured Clip Monitor + knee inset, 9 factory presets, WebView2 UI.
Full User Guide
A step-by-step guide covering every control, the Clip Monitor, and four workflow recipes (master glue, drop slam, parallel thickening, clip-only finish).
Open User Guide →