The Mackie Onyx 400f is a FireWire audio interface with 4 Onyx mic pre-amps, an additional 4 balanced line inputs and 8 line outputs. Paul White, Sound On Sound, January 2006, comments:

When I reviewed the Onyx mixer, I was particularly impressed by the sense of clarity and detail these preamps presented, and they come very close in performance (both subjectively and technically) to some of the extremely expensive and esoteric boutique mic preamps currently available.
This comment was made when the Mackie Onyx 400f was over £700. Upgrade your project studio with some serious mic pre-amps and take advantage of the end of line clearance of the Mackie Onyx 400f Save even more with a Mackie Onyx 400f Cubase 5, Logic 9 or Sonar Producer bundle. Update 30/09/09: The Onyx 400f is now discontinued.