The 664 Six-Channel Portable Production Mixer with Integrated Recorder from Sound Devices has an unprecedented amount of functionality from a unit that can be battery operated. It starts with a low-noise, transformerless preamplifier section, continues to an intuitive mixing surface, adds a host of digitally-controlled routing features, allows room for analog inserts and aux busses, and finally terminates with versatile, plentiful output connectivity. By the way, the 664 can be configured to record digital audio to CompactFlash or an SD Card from any point in that signal flow. 

664 Manual: 664 Manual