The Duet 2 has a completely redesigned mic preamp and converter compared to the original it has four outputs with independent speaker and headphone outs. The outputs are also balanced. It connects to your Mac via USB 2.0 and it supports 24-bit/192kHz recording.
The device has an OLED color screen and the touchpads are configurable. It comes with Maestro 2 software and has an optional breakout box and a redesigned breakout cable. The new Duet 2 will ship this month at $595.