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> Carla 2.3.1 has been released
On 2021-07-16 by falkTX

This is a bugfix for Carla version v2.3 series, fixing many bug reports and stuff I found along the way.

Carla is an audio plugin host, with support for many audio drivers and plugin formats.
It has some nice features like automation of parameters via MIDI CC (and send output back as MIDI too) and full OSC control.


  • Add NSLocalNetworkUsageDescription and NSMicrophoneUsageDescription in macOS builds
  • Allow canvas eyecandy for Qt >= 5.12
  • Alternative approach to deal with JACK postponed events (improves PipeWire usage)
  • Implement parameter groups for VST2 plugins
  • Ignore hosts calling Carla-VST effOpen twice (don't print errors)
  • Listen to Windows and X11 plugin UI resize events (without extensions)
  • Make some macOS dialogs modal
  • Remove favorite plugins from list when they fail to load
  • Update JUCE plugin code to new APIs, hook into VST2 for feature parity with native implementation
  • Use new tick_double for JACK transport
  • Use posix_spawn to launch macOS bridges
  • Fix available decimal points on a few dialogs being incorrect
  • Fix bridged plugin UIs appearing behind main carla window on macOS
  • Fix canvas auto-refreshing on exit, potentially leading to crash
  • Fix canvas split/join action
  • Fix carla-vst-wine symbol visibility
  • Fix default rack "skin" for a few plugins
  • Fix initial size for LV2 UIs with no UI resize extension (all OSes)
  • Fix loading state of Windows/macOS VST2 plugins without chunk
  • Fix macOS binaries not being debug/symbol stripped
  • Fix midi-pattern plugin having double notes on transport reposition
  • Fix race condition (and potential crash) around postponed RT events
  • Fix Qt >= 5.10 version checks
  • Fix unused JACK latency callbacks (removed)
  • Fix X11 UIs not having keyboard focus


To download Carla binaries or source code, jump on over to the KXStudio downloads section.
If you're using the KXStudio repositories, you can simply install "carla".
Bug reports and feature requests are welcome! Jump on over to the Carla's Github project page for those.

Notes for users

This was already the case for v2.2 and v2.3 but it is worth reiterating:
When using JACK2, the canvas - plugin integrations requires at least JACK2 v1.9.13.
This is because Carla relies on JACK meta-data in order to store information about each plugin/client, and meta-data was only added to JACK2 in version 1.9.13.
Alternatively, you can use JACK1 instead of JACK2, which has meta-data support since a long time.
Note that the "extras" KXStudio repository (which provides an updated JACK2) supports both Ubuntu 18.04 and 20.04.
The UbuntuStudio backports PPA also provides updated JACK2 packages.

There are no official Linux binary builds for v2.3.1 at this point.
Carla v2.3.1 is provided in the KXStudio repositories and in many official Linux distribution repositories too anyway.