Linux ALSA Focusrite Control/Mixer Drivers

Overview

Focusrite USB audio interfaces are class compliant, meaning they work “out of the box” on Linux as audio and MIDI interfaces*.

However, to access device-specific features (like direct monitoring, hardware mixing, custom routing, and level meters), most models need additional driver support.

This repository provides two drivers that extend the Linux kernel’s audio subsystem (ALSA), adding controls to make those features available:

• Scarlett2: A mature kernel driver supporting nearly every Focusrite USB device from the 2nd Gen Scarlett range onwards.

• FCP: A new hybrid kernel/user-space driver with support for the new big 4th Gen Scarlett models (16i16, 18i16, and 18i20).

Note:

• Scarlett 1st Gen devices are supported by the Scarlett driver which has been in the Linux kernel since 2014.

• Scarlett 2nd Gen Solo, 2i2, and 2i4 have no software-accessible controls, so no need for any special driver. All device-specific functionality is accessible from the front panel.

* Scarlett 3rd and 4th Gen and Vocaster interfaces need MSD (Mass Storage Device/“Easy Start”) mode disabled for full functionality. This will be done automatically when you do a firmware update.

Supported Interfaces

Scarlett2 Driver

Scarlett Series:

• 2nd Gen: 6i6, 18i8, 18i20
• 3rd Gen: Solo, 2i2, 4i4, 8i6, 18i8, 18i20
• 4th Gen: Solo, 2i2, 4i4

Clarett USB and Clarett+ Series:

• 2Pre, 4Pre, 8Pre

Vocaster Series:

• One, Two

FCP Driver

Scarlett 4th Gen:

• 16i16, 18i16, 18i20

Kernel Version Requirements

If your device is supported by the Scarlett2 driver and your Linux kernel meets the minimum version listed below, you don’t need to install this driver as you already have it; jump ahead to the Setup Instructions.

The scarlett2 driver is already included in the Linux kernel, supporting these models:

• Scarlett 2nd Gen: Since Linux 5.4 (bug fixes in 5.14 and 6.7)
• Scarlett 3rd Gen: Since Linux 5.14 (bug fixes in 6.7)
• Scarlett 4th Gen (Solo/2i2/4i4): Since Linux 6.8
• Clarett+ 8Pre: Since Linux 6.1 (bug fixes in 6.7)
• Clarett USB and Clarett+ (2Pre/4Pre/8Pre): Since Linux 6.7
• Vocaster: Since Linux 6.10

The fcp driver is included in Linux 6.14 and later.

Repository Purpose

This repository is a fork of the Linux kernel, used for:

1. Sharing development code before it arrives in the mainstream kernel

2. Sharing backports of the scarlett2 and fcp drivers so you don’t have to wait for your distribution to update to the kernel version you need.

Installation Options

If your kernel already meets the minimum version requirements listed above, you don't need to install anything; jump ahead to the Setup Instructions.

Otherwise, you can either:

1. Module Installation (recommended):

   • Download from Releases
   • Build and install the snd_usb_audio module following the instructions in the enclosed README.md.

2. Full Kernel Build:

   • Check out the fcp branch
   • Build the kernel normally

Setup Instructions

Scarlett2 Driver

• Install the firmware.

• Install and run ALSA Scarlett GUI to update your firmware and configure your device.

FCP Driver

• Install the firmware.

• Install the fcp-server user-space driver and the fcp-firmware firmware update utility from the fcp-support repo.

• Update your firmware with fcp-tool.

• Install and run ALSA Scarlett GUI to configure your device.

Support

Please report any issues with the kernel driver to:

• https://github.com/geoffreybennett/linux-fcp/issues

If using the FCP driver, please report any issues with the user-space driver or tools to:

• https://github.com/geoffreybennett/fcp-support/issues

Contact

• Author: Geoffrey D. Bennett
• Email: g@b4.vu
• GitHub: https://github.com/geoffreybennett

Donations

This software, including the driver, tools, and GUI is Free Software that I’ve independently developed using my own resources. It represents hundreds of hours of development work.

If you find this software valuable, please consider making a donation. Your show of appreciation, more than the amount itself, motivates me to continue improving these tools.

You can donate via:

• LiberaPay: https://liberapay.com/gdb
• PayPal: https://paypal.me/gdbau
• Zelle: g@b4.vu

Disclaimer Third Parties

Focusrite, Scarlett, Clarett, and Vocaster are trademarks or registered trademarks of Focusrite Audio Engineering Limited in England, USA, and/or other countries. Use of these trademarks does not imply any affiliation or endorsement of this software.