This unit has all six channels modified rather than the standard four (level 1 mods) by Cullen Circuits that added $700 or so to their speaker packages that normally shipped with a standard, unmodified unit. This unit was custom modified for audiophile use. The modifications included op amps and capacitors plus 6db gain reduction for improved resolution and signal to noise ratio. It has been used for tri-amping, room equalization and time alignment of a high end system. I will include a copy of downloaded software that allows communication with the unit via 9-pin serial cable. The on-screen software is very well designed and versatile. There has been much written about the DCX2496. Modifications for audiophile use range in cost from $1000 to $2500. The original box and a serial cable is included.