USB audio interfaces for Linux
There’s a lot of USB audio interfaces available but many of them aren’t fully functional under Linux, or even don’t work at all.
Fortunately the situation is improving. As iOS and Android now support USB Audio Class 1 and 2 (UAC1 and UAC2), manufacturers are producing more standard USB Audio devices for use with iPhone and iPad music production software.
A good sign that an audio interface will work under Linux is if it lists iOS support.
Some devices may only be partially functional with basic UAC drivers - examples of this are Focusrite Scarlett devices with more channels - the 6i6 and above. These have an internal mixer that isn’t currently controllable from within Linux, so you have to boot into Windows to set the mixer.
A good starting list of devices that should work under the Linux USB Audio class driver is this list of devices supported by the Auria iOS app http://auriaapp.com/Support/auria-audio-interfaces
There is also a list of devices supported by eXtream Software Development’s custom Android audio class driver here: http://www.extreamsd.com/index.php/technology/usb-audio-driver
Device criteria
Ideally my audio interface would have:
- 48v microphone phantom power
- Mic preamp
- 4 analogue inputs
- Monitor out volume control
- Fully working under Linux
- 24bit 96kHz/192kHz sampling rate
- USB Audio 2 class compliant
- Still have manufacturer support/ be manufactured
Here is a list of devices that I believe should work well under linux, and meet most of my criteria:
- Focusrite Solo, 2i2, 2i4 Gen 2 (not enough analogue inputs)
- Focusrite 6i6, 18i8, 18i20 Gen 2 have more inputs, but also have an additional hardware mixer built in. The mixer is supported in Linux on Gen 1 devices, but not yet for Gen 2. This means that you must configure the routing within Windows. The routing is persisted to flash.
- Steinberg UR12, UR22, UR44, UR242 (Steinberg’s support seems to be poor. Posts on their forums get no reply and the UR22mkII supposedly has a very weak headphone output)
- Tascam US 4X4 (only 24/ 96)
- Roland Rubix44 (Was announced in Jan 2017, but isn’t yet available)
- Behringer U-Phoria UMC404HD (Looks promising; cheap and reports of success under linux. Out of stock everywhere at the moment though!)
- Native Instruments - Komplete Audio 6 (only 24/ 96)
UPDATE: In the end I purchased a Focusrite 18i8 Gen 2. The mixer is not supported under Linux, but this hasn’t proved too problematic.