User Guide

Kestrel

Spectral Pad Engine — holds and blurs the spectrum per band on a drawable curve, then grows real pads out of it: harmonics in key, granular glitch delay, and a one-knob endless reverb.

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What Kestrel does: Kestrel holds the spectrum, but not all of it at once. You draw a curve on a log-frequency axis that decides how much each part of the spectrum hangs, so the low end can stay tight while the top blooms. From that held material it grows pads: harmonics added in key, a granular glitch delay, and a one-knob endless reverb. It runs a 4096-point FFT so a held chord stays a chord instead of smearing into one tone.
Kestrel full plugin interface
Installation
1
Download and unzip

Download Kestrel-v1.1.0-windows-VST3.zip from your Members Area and unzip it. Inside is Kestrel.vst3 — a folder, which is normal for VST3.

2
Copy to your VST3 folder

Windows: move Kestrel.vst3 into C:\Program Files\Common Files\VST3 — Windows may ask for administrator permission, accept it. macOS: run the .pkg installer instead, which puts the Universal build (Apple Silicon and Intel) in /Library/Audio/Plug-Ins/VST3 for you. Full step-by-step for both: the VST Install Guide.

3
Rescan in your DAW

Rescan plugins in your DAW (in Ableton Live: Options → Preferences → Plug-Ins → Rescan). Kestrel appears under Audubon Audio.

4
Activate

The first time you open Kestrel it asks for your serial — it is in your Members Area, tied to your email. Paste it, activate, done. Without a serial the plugin runs in demo mode: full features, with the audio dipping to silence periodically.

The controls
Start here: load Kestrel on a chord or a pad, draw the hold curve high in the mids and upper mids and low in the bass, then bring up the reverb. The low end stays defined while everything above it blooms.
1
The hold curve

The main display is a drawable curve on a hand-calibrated log-frequency axis — the same editor as Curlew and Loon. It sets how much each part of the spectrum hangs. Draw it low where you want the sound to stay tight and moving, high where you want it to freeze and bloom.

2
BR / SN / FLIP / RESET, and undo

BR is a brown-noise walk, SN a smoother random curve, FLIP inverts, RESET returns to default. Five steps of curve undo.

3
Harmonics, glitch delay, endless reverb

Harmonics are added in key against the global key setting, so what grows stays consonant with the track rather than spraying across the spectrum. The granular glitch delay scatters held material in time. The reverb is one knob, from a room to a tail that never closes.

Why the resolution matters
Kestrel runs a 4096-point FFT with Hann² windowing and 8× overlap (hop 512) — four times the spectral resolution of Curlew and Loon. That is not a spec for its own sake: pads need bins narrow enough to keep the individual notes of a chord apart. At lower resolution a held chord smears into a single tone. At this one it stays a chord.

The cost is latency, which the plugin reports to your DAW for delay compensation.