M-Audio USB MIDI devices are divided into two categories based on differences in their hardware and firmware architecture: “Series I MIDI” and “Series II MIDI”.

Note: The latest Series II MIDI Drivers now include support for Series I devices.

Series I MIDI

All Series I MIDI devices utilize the same driver and support Mac OS 9 and OS X, as well as Windows 98SE, ME, 2000, XP Home, XP Professional, and all 32-bit versions of Windows Vista. Series I MIDI devices are NOT compatible with M-Audio’s Enigma Librarian/Editor software.

Series II MIDI

All Series II MIDI devices are class compliant for Windows XP, Windows Vista, Windows 7, and Mac OS X. This means that no driver is required for basic operation.  For qualified versions of Windows, users can download and install an M-Audio driver if they wish to (1) use a Series II MIDI device with more than one application at the same time, (2) use long SysEx (system exclusive) commands, (3) use advanced MIDI data (such as MTC quarter frame, song select, or song pointer messages), or (4) simultaneously use other class-compliant USB devices with audio capabilities.  No drivers are needed to utilize all Series II MIDI features under Mac OS X. Some, but not all, Series II MIDI devices offer support for Mac OS 9, as well as Windows 98SE, ME, and/or 2000; please check the download page for driver availability. 

For certain Series II MIDI devices that feature assignable knobs and/or faders**, M-Audio offers the Enigma Librarian/Editor software as a free download.

* Some devices may require Service Pack 2.

** The following Series II MIDI devices feature knobs and/or sliders, but are not compatible with Enigma: Axiom Pro, Axiom (2nd gen), Oxygen 25, Oxygen 49 (blue), Oxygen 61 (blue), MidAir 25, MidAir 37, MK-225C, MK-249C, MK-361C, UC-16, and UC-33 (not “e”).