Here is presented a very similar design and it is very easy and cheap to create using a DIY kit get from http://us.hifidiy.net/ at a very low price:
This design use the CS8414 as digital input receivera and 4 pcs of TDA1543 in parallel.
The output stage with 2 x OPA604 is not used and
the resampler rate as been disabled to get the best sound.
The complete schematic for this DAC can be download here and in this is very easy to understand that the output signal quality depend on the 500 ohm resistor on the DAC chip output with the function of I/V (current to voltage) converter.
Follows a measurement set of the signal before of any output stage get by Clio system on output to the DAC chips and driving the input signal with the SPDIF output of the USB audio interface Audiophile USB by M-Audio.
In all these measurement I see a perfect and linear distortion spectrum decay and very low distortion level.
BAD RESULT WITH RESAMPLER INSERTED