HØJT Audio
HØJT is Danish for loud, and for high. Two things are made here:
- HØJT DSP: free audio plugins for guitar, drums, bass and keys, each drawn as a
stompbox. VST3 and CLAP, for Windows, macOS and Linux. The rest of this page is about them.
- Piano MIDI Visualization: a free Windows app for practising piano with a MIDI
keyboard, which names the chords under your hands as you play
(its page).
The page, with sound examples and downloads ·
Latest release
The HØJT DSP plugins
Guitar Amp (plugins/amp). A whole rig: four amps of our own design, each with its own
cabinet (Klar: clean, Brøl: crunch, Torden: high gain, Glød: warm, at the edge of breakup), and
ten pedals that can be dragged into another order: gate, compressor, overdrive, phaser, chorus,
flanger, tremolo, cabinet, delay and reverb. The cabinet is heard through a dynamic, ribbon or
condenser microphone, or is your own impulse response. It has presets, a tuner and level
meters, and adds 0.1 to 0.3 ms of latency.
Drum Synth (plugins/drums). A full drum kit with no samples: every sound is made in the
plugin. Four kits (Rock, Jazz, Metal, Groove), General MIDI drum map, a hi-hat that follows an
electronic kit's pedal, and velocity that changes the sound and not only the level. Besides the
stereo mix it has six stereo outputs, one per group, for a host with multi-out.
Pitch Shifter (plugins/pitch_shifter). Shifts a guitar by -12 to +12 semitones for live
playing. The delay follows the note being played: about 12 ms on the low E string, under 3 ms
high up the neck.
Bass Synth (plugins/bass). A plucked string bass, one note at a time, with two voices:
Metal is picked, Groove is played with a finger and slides between notes that overlap.
Shimmer Pad (plugins/pad). A slow ambient pad of detuned saws and breath, with a chorus
and a large hall whose tail comes back an octave up.
Glass Bells (plugins/bells). Soft glassy bells with a ping-pong delay and a hall.
Install
Download the zip for your system from the page
or the latest release, and copy
the .vst3 or the .clap to its folder:
| System | VST3 | CLAP |
|---|
| Windows | C:\Program Files\Common Files\VST3 | C:\Program Files\Common Files\CLAP |
| macOS | ~/Library/Audio/Plug-Ins/VST3 | ~/Library/Audio/Plug-Ins/CLAP |
| Linux | ~/.vst3 | ~/.clap |
On macOS, run xattr -dr com.apple.quarantine <the file you copied> once afterwards. The macOS
and Linux builds come from the build server and have not been tried in a DAW yet.
Build from source
Requires Rust. On Linux also the packages listed in
.github/workflows/ci.yml.
# VST3 and CLAP bundles in target/bundled
cargo xtask bundle pitch_shifter --release
cargo xtask bundle drums --release
cargo xtask bundle amp --release
cargo xtask bundle bass --release
cargo xtask bundle pad --release
cargo xtask bundle bells --release
# Every bundle carries its plugin's artwork: a bundle without it was built from other sources
cargo xtask check-art
# Tests
cargo test --workspace
# A plugin's window as a program, without a DAW and without sound
cargo run -p amp --features standalone -- --backend dummy
On Windows, scripts/install.ps1 builds the VST3 bundles from your checkout and installs them
(all six, or name some: scripts/install.ps1 amp drums). Close the DAW first.
The plugins are written in Rust on NIH-plug.
AGENTS.md describes the suite, and plugins/<name>/AGENTS.md how each plugin works,
its parameters and the tools for working on its sound. CHANGELOG.md says what
changed in each release.
Licence
Copyright (c) 2026 Rasmus Højte. Free software under the
GNU General Public License, version 3 or later. The name HØJT and its logo are not
part of that licence, and third-party components keep their own: see NOTICE.md.
The piano viz in piano/ is under the MIT licence, with its own
third-party notices.
