ASTRAEL

what it is

Astrael is a granular sampler built around a gravity field. Load a sample, place wells on the 2-D field, and each well fires grains from its position in the waveform. Grains fall through a DSP chain — filter, delay, reverb, shimmer, diffusion, convolution blur — and the field itself is simulated space: black holes capture and bend, white holes repel and radiate, matter orbits.

Astrael also separates every sample into stems (vocals / drums / bass / other) locally on your machine, so wells can play isolated layers of the source.

requirements & install

• macOS 11.0 or later, Apple Silicon or Intel (universal binary).
• Formats: AU, VST3, Standalone.
• The installer places the plugins, the standalone app, and the stem-separation model. Everything runs locally — audio never leaves your machine.
• After installing, rescan plugins in your DAW. For AU in Logic or Live, a full DAW restart is the reliable rescan.

quick start

• Click load (or drag a file anywhere onto the window). WAV, AIFF, MP3, FLAC, OGG.
• Just play — MIDI, the on-screen keys, or your computer keyboard. Notes are pitched voices (C4 = original pitch) reading from the ✷ star marker on the waveform, which parks itself on a good sustained spot when the sample loads. Drag the marker — even mid-chord — to play from a different moment.
• Click the field to place a well — a star that fires grains on its own rhythm from that position. X = position in the sample, Y = grain size (top tight, bottom long). Wells layer under your playing and chord-follow held notes.
• Drag wells to move them. Double-click or press delete to remove one; with the cursor over empty space delete removes the newest well.

the field

wells

Up to 16 wells. Each fires on the rhythm set by the gravity macro (and the quantize grid, if on). A well plays whatever stems its brush allows — see stems.

black holes — shift-click

Hold shift over the field and a shadow-disc ghost previews the placement; click to commit. A black hole:

• sets every plain well orbiting it (GR-style orbits — far wells precess forever, wells that stray too close spiral in and are consumed),
• speaks with an accretion voice: each absorbed particle becomes one deep grain, two octaves down, stretched long,
• time-dilates its neighbourhood: nearby wells sink in pitch and stretch, deepest at the horizon.

white holes — option-click

The time-reverse. It repels wells, fountains particles, and blueshifts its neighbourhood — nearby wells rise in pitch and tighten. Its own voice is a sparse high sparkle, two octaves up, quarter length.

convert in place

shift-click an existing well to collapse it into a black hole — shift-click again to turn it back into matter. option-click toggles white hole the same way. Fully reversible experimentation.

playing

midi

• midi notes (default): every key is a pitched voice — C4 = original pitch — reading from the star marker. Held notes appear as stars on the field and follow the marker as you drag it. Wells chord-follow your held notes at the same time.
• midi scan (header selector): the legacy mode — each note plays a grain from a position in the sample (low notes left, high notes right) at native pitch; with wells placed, notes only transpose them.
• Pitch bend works in both modes (±2 st in notes, ±12 in scan).

computer keyboard

Ableton-style layout, active whenever the Astrael window is focused (exactly when your DAW's own computer-keyboard stops working):

virtual keyboard

The strip along the bottom is mouse-playable and lights up every note source — hardware MIDI, computer keys, and mouse — so you can watch chords land. The computer-key letters are printed on the active octave and follow Z/X. It is always on — the instrument's front door.

header controls

stems

A few seconds after loading a sample (5 s minimum length), Astrael separates it into vocals / drums / bass / other on a background thread — the status bar tracks progress. Results are cached to disk, so re-loading the same file restores stems instantly.

The brush chooses what a well reads; mute chooses what sounds at all. They combine: a drums-brushed well goes silent while drums are muted, and comes back when they are not. Stem volumes scale everything the same way.

macros

Three pages of macros under the trim strip. Hover any knob for its one-line description.

The trim strip above the macros crops the playable region of the sample — drag the flags at either end. The ✷ star marker on the strip is where MIDI voices read from: drag it any time (it glows while notes sound, and its beam is visible on the field, bending around black holes like everything else).

license & trial

• First run starts a 14-day trial — every feature, no key.
• Your license key arrives by email with your purchase. Paste it into the panel, press activate — one activation covers AU, VST3, and Standalone on that machine. The license allows up to 3 of your own machines.
• Activation needs internet once; after that Astrael never requires a connection — offline studio machines are never interrupted.
• Licensing never touches audio: sound keeps running no matter what.

troubleshooting