VST® 3 plug-ins
Heron discovers VST 3 instruments and effects from standard system and user locations. Plug-ins run through an isolated audio-host process so a failed module can be reported and quarantined without loading native code directly into the interface.
Audio Unit, CLAP, VST 2, and AAX plug-ins are not currently scanned. See Supported backends and plug-in formats for the full platform matrix and planned formats.
Scan the catalog
Heron scans on startup. To look again after installing a plug-in:
- open Library;
- choose the plug-in catalog;
- select Rescan VST3.
The startup and scan views report discovered bundles, available plug-ins, and modules that could not be loaded.
Add an instrument
Add an instrument channel, then select its Instrument input slot. Search by name or vendor and choose the plug-in.
If the instrument supports more than one layout, choose its audio mode before loading it. Instrument modes include mono and stereo output.
Add an effect
On any compatible mixer channel:
- select an empty slot under Audio FX;
- search the VST 3 effect catalog;
- choose a supported mode;
- select the loaded insert to open its editor.
Effects may support mono, stereo, mono-to-stereo, or dual-mono layouts. An unsupported mode remains unavailable in the picker.
Manage inserts
An insert can be:
- opened in its native editor;
- bypassed and enabled again;
- moved to another slot;
- removed;
- switched to another supported audio mode.
Changing or removing a plug-in is part of project history where the operation supports undo.
Route a side-chain input
When a VST3 instrument or effect exposes a mono or stereo auxiliary audio input, its native editor toolbar shows Side-chain. Open it, choose the auxiliary input bus, then select Audio, Instrument, or Aux and a source channel. Choose None to disconnect that bus. Each auxiliary input is routed independently.
The source is the channel's post-pan signal: its plug-in chain, fader, mute, solo, and pan all affect the side-chain. Hardware inputs and internal BUS slots cannot be selected directly. Master, Output, the plug-in's own channel, and any source that would create feedback are excluded.
The old selection remains active while the project change is pending. A failed change leaves it untouched and displays a warning. If the project was saved but the audio graph could not be deployed completely, the new selection remains the project value and the editor reports the degraded audio state.
Missing or failed plug-ins
The project keeps a legal signal path when a stored plug-in is missing, quarantined, or fails to start. Check the slot state and catalog status, then:
- confirm that the correct plug-in and architecture are installed;
- rescan the catalog;
- restart Heron if the plug-in was installed while the host was active;
- bypass or remove a plug-in that repeatedly fails.
Never assume two plug-ins with similar names or vendors are interchangeable; their identifiers and saved state may differ.