What's an Audio Alchemy Extended Digital Processor

I recently had an AA "XDP" Extended Digital Processor tossed in my lap, and I am searching for some information on this unit. I am familar with AA's DTI's, DAC's, CD-transports, etc., but I am having difficulty locating any pertinent info. on this unit. What is it/How is it used? ANY information would be helpful.
It's a dac, but it only has one specialized input. It will only accept a digital input thru an "I2S" (may not be spelling this correctly) input. It was designed to operate with one of AA's DTI jitter reducers, most of which have an I2S output. Thus, it has no jitter reduction capacity and limited input filtering. If you have a DTI and an I2S cable, you're all set. These items should be available on the used market, if you need them. I used an XDP for awhile in a 2nd system and for a budget or entry level piece, it sounded ok. Not the last word in clarity or resolution but not as brite or sterile as some other budget pieces I have heard. It did emit some rfi, so you may want to be careful where you place it.