Correct me if I'm wrong but that PCB looks like its been soldered by hand. There's even a pair of bridged pins on the top left.
The two channels are virtually crammed up against each other, which, if the layout isn't effective, would explain the cross-talk. The digital side of the PCM1704s have power decoupling ceramics bypassed with smaller yet further away ceramics, which is just a waste of parts for a package having the parasitic inductance of a SOIC20. The bottom channel seems to be missing a (useless as mentioned) bypass cap.
That said, there is use of high quality parts around the DACs and analog stage.
Definitely hand soldered for all the through hole components (a bit excessive use of solder, but at least they're nice and shiny and not dull looking cold solder joints), and quite a few of the SMD parts.
b0hi, the shorted pins on the PCM2706 chip are 25 and 26, (ZGND and AGNDL).
Edited by Edwood - 5/30/10 at 5:18pm