The only information on the details I could find (and this was a while back - at least 6 months and possibly much longer) was that the format was very similar to DSD and most probably a 1 bit format - no idea where I read this.
Korg MR-1 = FutureProof!!!!
Except for that no longer being made and sold thing...
The MR-2 is available for about $500, without support for XLR, or P48