Alesis iO2 Express is a 2×2 24bits 48khz analog I/O interface with instrument, mic and line inputs. It has 2 preamps and +48V phantom power plus MIDI in/out

All features supported (tested in Ubuntu 11.04 and Debian Wheezy) including MIDI.

• Forum post - (August 2011)
• Forum post - Recommended by wolftune (May 2012)
• Forum post - MIDI working (June 2012)
• /Kretz/blog from 2007. Says that it only works in 24 bit mode (Link is dead)