Ardour 6.6 released

Ardour 6.6 is now available. This is primarily a maintenance release, although it does include several new features, including auto-show of touched parameters, tuning possibilities and keeping track of x-runs during recording.

There's a short video for one new feature in this release, "show automation on touch".

This release also sees the first official builds for Apple M1 systems. These are still experimental and are not part of the regular download system. There are more details in this forum post.

Release notes for other older versions are linked in the list below.

New Features

  • Option to automatically show automation-lane when touching a control. (Edit > Show Automation Lane on Touch)
  • Auto-shown automation parameters automatically put into touch mode upon graphically adding a new control point (this and the previous change makes editing automation much simpler/faster than it has been).
  • Verbose cursor audio region peak display - press Alt or use internal edit mode ('e' shortcut) to see audio peak levels in an audio region.
  • Keep track of xruns (overruns/underruns) per file when recording
    • Option to how x-run markers in regions.
    • Show x-run count in source-list by default.
    • By default, don't create timeline x-run markers.
    • Show per-region x-run markers by default.
  • ACE Fluidsynth plugin can now process MIDI sysex messages, in particular MIDI Tuning Standard (MTS) messages.
  • New Lua script to send tuning defined in a Scala file as MTS messages.
  • New Lua script to send arbitrary 12TET tuning (A = XXX Hz) as MTS messages.
  • The density (pixels-between-lines) for the editor grid is now user-configurable.
  • Ruler can now show 1/64th and 1/128th note positions when appropriate.
  • MIDNAM file for the Moog Grandmother.


  • Issues with snapping to grid fixed (or at least, dramatically improved).
  • Improve MIDI note selection behavior to be more consistent with selection rules in general.
  • Now possible to close & save even if the audio/MIDI engine is stopped.
  • Eliminate/reduce fuzzy font rendering on many buttons (for HiDPI displays)
  • Improving sizing of certain GUI elements containing variable text.
  • Improved appearance for the BBT ruler.
  • Prevent additional mouse button presses while dragging from interfering with the drag.
  • Add new user option to control whether or not the default transport speed is reset when stopping (true by default).
  • Clicking an automation track when in object/grab mode now adds a new automation point, making line drawing easier.
  • OSC: commands targeting "strip" or "select" now use the same code for better consistency.
  • OSC: Allow to specify marker name
  • Creating monitor-sends from templates now functional.
  • Bail out if export cannot be started.
  • Do not bother to render waveforms in tracks displayed with extremely small heights.
  • video-export dialog: only show abort/progress when exporting.
  • Safely handle removal of sidechain input.
  • Ignore inline-display unless plugin-meta data explicitly mentions it.
  • Do not allow feedback override on foldback sends.
  • Add input port signal meters, scopes and monitors.
  • Add option to skip MIDI track input auto-connect.
  • Indicate that plugin-window MIDI keyboard is not recorded.
  • Sort input port signal meters by port name.
  • More use of port "pretty names" (user-assignable names for all ports)
  • VKeybd: include port-name in dropdown.
  • VKeybd: show pretty-name in port-connector.
  • Implement dynamic input port meters.
  • Micro-optimization: pre-calculate pan-law.
  • Hide "Midi Through" ports on Linux only.
  • Hide hidden ports in port-matrix.
  • Report failed connections when reconnecting ports.
  • Retain "Virtual Keyboard" pretty name across engine restarts.
  • Update Ctrl-surface MIDI port list when ports change.
  • Disable vertical autoscroll for UI (editor) elements where it doesn't make sense.
  • macOS: fix setting app icon file on recent versions of macOS.
  • macOS: explicitly ask for mic/input permissions.
  • Expose resampler quality (read-only)
  • Consistent naming of mixer strip processors used for disk reading/writing.
  • Updated MIDNAM file for Waldorf Blofeld.
  • Various fixes for the MSVC project files.

Bug Fixes

  • Problems with playhead movement while rewinding fixed.
  • Stop after locate-while-rolling now works (again).
  • Prevent silentfile over-read
  • Fix mix-buffers-with-gain FMA (SIMD) implementation to avoid crackling in some situations
  • Fix implicit Vkeybd MIDI meta-data.
  • Fix Faderport1 port-connection.
  • Fix typo in vst3-scanner --help text.
  • Fix Aux-send copy/paste.
  • Fix mp3 and video-export (ffmpeg/ffprobe detection)
  • Fix send panner when copying sends.
  • Fix fader font-size.
  • Fix bugs where multiple threads tried to read from the same AudioSource (file)
  • Fix invisible multicahannel waveform at rec-stop.
  • Fix default track name patterns, remove additional space.
  • Fix crash when requesting disk/in monitoring of busses.
  • Fix tracking-text offset.
  • Fix typo in OSC gain feedback message.
  • Fix deadlock during export.
  • Fix latency compensation for newly created tracks when using the JACK audio/MIDI backend.
  • Fix automation context-menu state when reordering plugins.
  • Fix crash when detaching Editor or Mixer w/o session.
  • Fix mixer initial group-tab display.
  • Fix race condition when deleting tracks.
  • Fix round-corner backround of insensitive ArdourWidgets.
  • Fix renaming export timespans.

Improvements in the ALSA audio/MIDI Backend

  • Set pretty port names for audio I/O
  • Fix slave device lookup.
  • Fall back to nearest available buffer-size, rather than report an error
  • Explicitly list millisecond buffer-sizes (helps with some newer laptop builtin audio interface that only support millisecond-sized buffers).
  • Allow selection of clock-source when using multiple devices
  • Retain port-connections of slave devices.

Plugin-related Changes & Improvements

  • VST3
    • Improve verbose scanner output.
    • Allow multiple identical timer-handlers
    • Allow multiple file descriptors per plugin UI
    • Announce IPlugFrame interface support.
    • Always pass buffers for all audio busses.
    • Set I/O correctly.
    • Pre-allocate AudioBusBuffers.
    • Fix VST3 path customization.
    • Fix plugin bus configuration.
    • Use a proxy for connecting and passing messages #8481
    • Allow filename mismatch inside the bundle.
    • Backport VST3/musl support
  • LV2
    • LV2 "uri-map" extension no longer supported.
    • Fix LV2 boolean Atom values size #8558
    • Fix ACE.lv2 inline-display meta-data.
    • Tweak fluidsynth performance on ARM CPUs.
    • ACE Fluidsynth: consistent port-names.
  • AudioUnits: Fix variable I/O instruments.
  • VST2: relax MIDI port detection.

Lua Scripting Changes & Improvements

  • LuaDSP use vectorized peak-finding.
  • Add Lua bindings to modify plugin pin bypass/thru-map.
  • Add Lua binding to get a file's basename.
  • Luasession: load default session snapshot.
  • Fix macOS Lua wrapper script env.
  • Allow cast of ControlList to AL (for undo)
  • Extend plugin parameter Lua bindings.
  • Add Playlist::set_name() Lua binding & unique name check.
  • Allow Lua bindings up to 11 args.

ProTools Session Import

  • Race condition (random crashes/issues) fixed while creating audio tracks.
  • Track naming scheme improved.
  • Progress bar now covers entire import process.
  • Import -> Cancel -> Import workflow now possible.
  • Fixed crash while bringing in audio material from PT session.

Translation Updates

  • German.
  • Chinese.
  • Russian.


Robin Gareus, Ayan Shafqat, Ben Loftis, Clara Hobbs, Damien Zammit, David Robillard, John Emmas, Len Ovens, Martin Vlk, Nikolaus Gullotta, Paul Davis, Todd Naugle, Tyler Stank


Edgar Aichinger (German), Yq-Ysy (Chinese), Alexandre Prokoudine (Russian)