Linux Utilities for Soundcraft Mixers

Soundcraft Notepad mixers are pretty nice small-sized mixer boards with Harmon USB I/O built-in. While the USB audio works great in alsa without any additional configuration needed, there are some advanced features available to the Windows driver that have no Linux equivalent. Most importantly, the USB routing for the capture channels is software-controlled, and requires an additional utility. For example, by default the Notepad-12FX sends the Master L&R outputs to USB capture channels 3 and 4, but this routing can be changed to input 3&4, input 5&6, or input 7&8. This tool aims to give this same software control of the USB capture channel routing to Linux users.

Supported models:

• Notepad-12FX

Prerequisites

The dbus service relies on PyGObject which is not available via pypi without a lot of dev libraries for it to compile against. It is usually easier to install separately using your distribution's package installation tools. Under Ubuntu, the following should work:

sudo apt install python3-gi

Installation

Installation

sudo pip install soundcraft-utils

It is not recommended to use --user mode and install this system-wide so that the dbus service auto-start can reliably find the right python libs.

Set up the DBUS service so it can access the system bus and be auto-started on demand:

sudo soundcraft_dbus_service --setup

The dbus service will run as root, providing access to the underlying USB device so the soundcraft_ctl user-facing part can be run by an unprivileged account.

Upgrading

Simply update your package from pip, and rerun the 'setup' to ensure the dbus service is upgraded to the latest version:

sudo pip install -U soundcraft-utils
sudo soundcraft_dbus_service --setup

Uninstallation

You can remove the dbus and xdg files first by running the following as root:

sudo soundcraft_dbus_service --uninstall

Then remove the package with pip:

sudo pip uninstall soundcraft-utils

Usage

GUI

soundcraft_gui

• Select the desired input using the up and down arrow keys or using the mouse
• Apply the selection by clicking "Apply" (ALT+A)
• Instead of applying the selection, clicking "Reset" (ALT+R) will set the selection back to the current state of the mixer (if known)

CLI

List possible channel routing choices:

soundcraft_ctl [--no-dbus] -l

Set channel routing:

soundcraft_ctl [--no-dbus] -s <number>

When using the --no-dbus, write access to the underling USB device is required. Normally only root can do this, unless you've added some custom udev rules.

TODO

• Polkit restrictions on the dbus service
• Multiple device support
• Add additional model support
  • Notepad-8FX should be easy, once I know what the USB idProduct field is (plus I'd need help from someone with a Notepad-8FX for testing)
  • Notepad-5 likewise, same constraints
• Auto-duck feature
• Firmware upgrade