LTA has a new one out getting good reviews. $3,950.00
Aero - Digital-to-Analog Converter (DAC) by Linear Tube Audio
on another note why do you think chip based R2R's are inferior? to me they are more accurate as the resistors on the chip are better matched, wont drift out of spec as fast and do the same thing as a string of outboard resistors. chip based R2R's are not digital in anyway just a bunch of resistors on a chip apposed to laid out separately. well that's my understanding of them from my research.