VSTHost User Manual

Overview

VSTHost is a standalone DAW and plugin host. It combines arrangement, editing, mixing, automation, and rendering in one workspace and supports:

• Instrument, sample, beats, and bus tracks
• VST3 plugin hosting with full parameter automation
• Piano-roll MIDI editing, sample editing, and beats pattern editing
• Internal mixer and effects workflows
• Computer-keyboard note input ("keyboard piano")

Quick start

1. Create or open a project.
2. Add a track with Ctrl+T.
3. Use the Browser to preview or load instruments, samples, MIDI files, or presets.
4. Record or place clips on the timeline.
5. Edit notes, samples, or beats in the active editor.
6. Mix with track controls and effects.
7. Export the song with Ctrl+R.

Useful first actions

• Open the Browser with Ctrl+Shift+B
• Start or stop playback with Space
• Save with Ctrl+S
• Undo with Ctrl+Z

Main areas

• Tracks panel. Arrange clips, select tracks, manage mute, solo, and record-arm.
• Mixer. Adjust levels, pan, and effect routing.
• Browser. Browse plugins, project items, track presets, and cloud samples.
• Editors. The lower editor area changes to match the selected content — piano roll, sample editor, or beats editor.

Browser basics

• Single-click a sample to preview it.
• Single-click a MIDI file to preview it on armed tracks.
• Double-click a sample or instrument to create a new track from it.
• Tabs: Plugins, Project, Cloud samples.
• Search filters the current Browser view.
• Show starred limits the Browser to favourite items.

Tracks & clips

• Instrument tracks — MIDI driving a synth or sampler.
• Sample tracks — audio clips.
• Beats tracks — pattern-based drum programming.
• Bus tracks — routing and mix organisation.

Clip editing is context-sensitive. Selecting a MIDI clip opens piano-roll editing; selecting an audio clip opens the sample editor.

Clip aliases

Alias clips are linked copies of a clip. They look and play like normal clips, but the musical or audio content is shared across every linked instance. Use aliases when you want the same phrase, beat, or sample edit in several places and want future edits to update all occurrences.

• Copy a clip, then choose Paste clip as alias from the track context menu.
• With the arrangement focused, use Ctrl+Shift+V to paste as alias.
• Alias clips show a small chain marker and a subtle striped top edge.
• Moving, trimming, deleting, selecting, and placing an alias affects only that clip instance.
• Editing the notes, beats pattern, sample processing, clip automation, or clip name updates all aliases sharing the same source.
• Fades and sample gain are per clip instance, so you can mix or fade one alias differently from another.

Piano roll

• Black keys are shaded to match standard keyboard layout for quick orientation.
• The 5th of the current scale is colour-coded on the keyboard guide — useful for spotting strong harmonic targets while sketching melodies, basslines, or chord voicings against the project key.

Looping

• Timeline looping follows the arrangement loop markers in the tracks view.
• Clip-local looping takes over when a loop range is set inside the sample editor or piano roll.
• While arrangement playback is running, open editors still show the playhead for the currently playing content.

Automation

Automation lets you change parameter values over time. VSTHost has three places where automation lives:

• Track automation — lanes under the track in the arrangement view. Use it for volume rides, pan moves, send levels, and effect-knob automation that should follow the track.
• Master automation — same idea, but for the master bus. Volume, pan, and master-effect knobs.
• Clip automation — travels with the clip when you cut, move, or duplicate it. Use it for instrument knob automation (filter sweeps, pitch envelopes) and MIDI lanes (modwheel, pitch bend, aftertouch) that are part of a particular phrase.

Adding track or master automation manually

1. Click the automation icon under the track header to add a lane.
2. Pick the parameter from the menu (volume, pan, an effect knob, an instrument param).
3. Click in the lane to add a point, drag a point to move, right-click a point to delete.
4. Right-click empty area for Copy automation, Paste automation, Clear automation, or Delete automation (removes the whole lane).

Automation editing is undoable. A drag is a single undo step.

Editing clip automation

Open a piano-roll clip and look at the velocity-editor strip below the notes. The dropdown on the left selects what the strip is editing:

• Note velocity, Note panning — per-note attributes (the strip shows bars).
• Aftertouch, Modwheel, Pitch — built-in MIDI lanes (the strip becomes an automation lane).
• Any instrument or track-effect parameter, e.g. Cutoff, Resonance, Filter Mix. Available when the track has an instrument or effect loaded.

When the strip is showing an automation lane, click in empty area to add a point, drag a point to move, right-click a point to delete.

Right-click in the velocity strip

The right-click context menu is mode-aware:

• Velocity mode — Reset velocity to default (100)
• Pan mode — Reset pan to center
• Aftertouch / Modwheel / Pitch / custom param — Delete automation (greyed out when the lane is empty)

The reset items act on every note in the clip. Delete automation removes the lane entirely (undoable, single entry).

Recording automation in real time

The transport bar has a REC AUTO toggle next to the REC button. When it is on, knob and fader movements made during recording are captured as automation points.

1. Click REC AUTO to enable automation recording.
2. Press REC to start recording.
3. Move any control during playback — master fader, track fader / pan / send, instrument knob, internal effect knob — or send a MIDI CC, pitch wheel, or aftertouch from an external controller.
4. Press Stop. The recorded lane appears under the relevant track or master with the points you just laid down.

The whole take is one undo step (Record automation). A take that only contains automation (no notes, no audio) is still kept — you don't need to record notes for the automation to survive.

REC AUTO and per-track REC arm are independent

The per-track REC arm icon R captures notes and audio into that track. It does not affect automation — automation recording is gated only by the global REC AUTO toggle. So:

• You can record automation on any track (or the master / a bus) without arming it.
• Arming a track only matters if you want to capture incoming MIDI notes or audio into a clip on that track.
• During a single take, knob moves on multiple tracks are all captured (as long as REC AUTO is on). If you want only one track's automation, leave REC AUTO off and edit lanes manually instead.

What gets captured

Mixer (volume, pan, sends), internal instrument knobs, internal effect knobs, VST3 plugin parameters (instrument, track effect, master effect), MIDI CC / pitch wheel / aftertouch from external controllers, and master automation. Plugin parameter changes are captured both when you drag a knob in the plugin's own UI window and when the host's mixer surfaces drive the plugin parameter.

Drag-to-merge

Dragging an automation point through another point does not destroy that other point. Points only merge when you release the drag on top of another point — at that moment, the colocated points collapse to one. This lets you sweep a point past existing points without losing them.

Drawing behaviour

• Lane interpolation is linear between points.
• A single-point lane holds that value at every beat (including before the first point and after the last).
• Lane values are normalised to [0, 1] and re-mapped to the parameter's actual range during playback.

Limitations

• Track-level lanes (volume, pan) cannot be set as clip lanes — they aren't applied during clip-local evaluation. The dropdown filters them out.
• Master automation lanes don't appear inside clips — only inside the master strip.
• Automation playback writes directly to engine fields. A small ring on the knob's outer edge shows the automation-driven value when it differs from the knob's manual position.

How knobs move

Every knob in VSTHost has two rings:

• Inner ring — the value. This is what the project saves and what Ctrl+Z undoes. It is the position the knob "is set to".
• Outer ring — the active value. This is what you actually hear. It equals the inner ring plus any live modulation on top.

If no modulator is wired up, the two rings are the same. The outer ring only diverges when a modulator is animating the parameter.

Four ways a knob moves

• Mouse — drag, mouse-wheel, or double-click to reset.
• Controller (MIDI CC) — right-click → Link to controller, learn a CC, then your hardware fader moves the knob exactly like the mouse would. The on-screen knob follows the hardware, and the change is saved with the project.
• Automation lane — a recorded curve on the timeline. During playback, the lane drives the knob.
• Modulator (LFO, Envelope, Envelope Follower, Macro, Steps, Sidechain) — adds movement around the inner ring. A modulator never changes the saved value; it only paints the outer ring.

When more than one is active

• Mouse, controller, and automation are three handles on the same knob. Whoever moved it last wins. Grab the mouse mid-CC sweep — your hand wins. Push the hardware fader during automation playback — the controller wins (in Touch / Write mode it also writes the new value into the lane; in Read mode the next lane point pulls it back).
• Modulators stack on top. Two LFOs and a sidechain on the same knob? Their offsets sum, then clamp to the parameter's range. Modulators never fight — they just add.
• Modulators don't override the value. No matter how many modulators are running, the inner ring (saved value) only changes when you, your controller, or an automation lane moves it.

Undo and gestures

A hardware fader sweep is one undo step, not one per CC message. The same is true for a mouse drag. If you sweep a knob across with your controller and want to take it back, Ctrl+Z once snaps the inner ring back to where it was before the sweep started.

Reset

Right-click → Reset sets the inner ring back to the parameter's default. Modulators keep modulating around the new base.

Internal instruments

VSTHost includes built-in instruments in addition to external VST3 plugins. They appear in the Browser under Instruments.

Internal effects

Built-in audio effects that can be inserted directly on tracks, buses, or the master.

MIDI controllers

VSTHost talks to external MIDI controllers (keyboards, control surfaces) through the MIDI Settings dialog. Each connected MIDI input can be assigned a driver that adds controller-specific behaviour such as button mappings, LCD feedback, and bank navigation.

MIDI Settings dialog

• The MIDI Inputs table lists every detected MIDI input with Enable, Input Device, Driver, and Port columns.
• Tick Enable to start receiving from a device.
• The Driver column selects how VSTHost interprets incoming messages. Generic treats the device as a plain MIDI keyboard.
• The Port column assigns a numeric port slot, used when routing tracks to a specific MIDI input.

FL Studio driver compatibility

VSTHost runs FL Studio controller scripts as drivers, so many existing controllers work without custom code.

• Drivers live in a Controllers/ directory next to the VSTHost executable. On a default Windows install that's C:\Program Files\VSTHost\Controllers.
• Each controller has its own subdirectory inside Controllers/, containing one or more device_*.py scripts with a # name= header.
• The shared FL Studio compatibility runtime must be present at Controllers/fl_compat/_runtime.py. Without it, no drivers are discovered.
• Python must be available on the system. The runtime spawns one Python child process per active driver.
• Driver discovery happens at startup. Restart VSTHost after copying or updating drivers.
• When a device name or USB vendor ID matches a discovered driver, VSTHost auto-suggests it for that input. The suggestion can be overridden manually.

Export & stem extraction

• Ctrl+R opens the export dialog.
• Render the complete song or the current selection.
• Tracks can also be exported as separate audio files.
• Right-click a sample clip and choose Extract stems to split it into separate stem tracks.
• Stem extraction imports the rendered stems back into the project as new sample tracks.

Headless render

VSTHost can also render projects from the command line. Useful for batch exports, CI checks, or repeatable mix renders without opening the main window.

VSTHost.exe render project.sand --output mix.wav
VSTHost.exe render project.sand --output mix.flac --format flac --sample-rate 48000 --bit-depth 24
VSTHost.exe rendertracks project.sand --output-dir stems --format wav
VSTHost.exe inspect project.sand

Commands

• render <project.sand> — render the full project to one audio file.
• rendertracks <project.sand> — render each renderable track as a separate file.
• inspect <project.sand> — print project metadata: BPM, track count, clip count, estimated duration.

Options

• --output <file> — destination file for render.
• --output-dir <dir> — destination folder for rendertracks.
• --format wav|flac|mp3 — audio format. If omitted for render, the output extension is used.
• --sample-rate <hz> — export sample rate, e.g. 44100 or 48000.
• --bit-depth 16|24|32 — output bit depth. FLAC uses integer depths; MP3 is encoded from 16-bit PCM.
• --mp3-bitrate <kbps> — MP3 bitrate, e.g. 192 or 320.
• --start <seconds> and --end <seconds> — render only a time range.
• --quiet — hide progress output.

Keyboard shortcuts

Shortcuts are context-sensitive. Some keys do different things depending on which panel or editor has focus.

Global

Shared editing

Routed to the active editor when applicable.

Arrangement / tracks panel

Mixer

Piano roll

Sample editor

Beats editor

Keyboard piano

When keyboard piano is enabled with Ctrl+K, the computer keyboard can trigger notes. Capture happens in music-editing surfaces only (tracks panel, piano roll, sample editor, content editor). Disabled while typing into text fields.

Knob & slider modifiers

VSTHost · v2.4 · last updated May 2026 · back to home