Beyond that, the 2882 has digital potentiometers for its inputs. These have a gain range of approximately 42dB, and can produce zipper noise while applying gain changes. The ULN-2 preamps have a much higher gain range of approximately 72dB of gain available. The self-noise of the ULN-2's preamps is much quieter than that of the 2882.  The ULN-2 has a send/return path and front panel knobs for analog input, headphone and monitor gains.

Both units share 2 channels of switchable AES or SPDIF I/O, and 8 channels of ADAT, switchable with 2 channels of TOSlink I/O.

Both units can also record to your software host up to 18 channels of firewire returns.  These can be sourced from any direct output or bus output in the MIO mixer. This can include any combination of physical inputs of the box, DAW channels from your host or buses.  All channels in the mixer can be sourced for recording pre and/or post effects.

+DSP relies on communication between the primary and secondary DSPs on the masterboard in the Mobile I/O. At 2x rates on the Legacy 2882+DSP, the primary DSP does not have enough cycles to reliably communicate with the secondary DSP in addition to all the other things it needs to do for basic audio transport and mixing. As a result, +DSP operation on the 2882+DSP is unreliable at 2x rates and has been disabled.