In Linux, USB Audio Class 2.0 compliance are generally built-in. If not, they need to be added, however, we do not support Linux or provide drivers for it. You may need to acquire this from another source. This is because there are many different devices and lots of variables/variations.
Please see the relevant standard documents at USB.ORG: http://www.usb.org/developers/docs/devclass_docs/
(for 3rd parties like other manufacturers)
A specific vendor or even individual may pick the bits that suit their purpose and formulate their own operating system (generally called a Distro aka ‘Distribution’). What is included in this specific Linux Distro from the available repository of building blocks is down to the company or individual that assembles this.
At the time of writing for this note distrowatch.com was tracking 281 different major active Linux Distro’s:
http://distrowatch.com/dwres.php?resource=popularity
With so many variants (and smaller sub-variants such as audio targeted Distro’s not even listed) it is impossible to provide any support for the use of iFi products under Linux or do effective testing. This best highlights the timeline for many, many versions of Linux.
http://upload.wikimedia.org/wikipedia/commons/1/1b/Linux_Distribution_Timeline.svg
