If the Oppo does down sample blu ray audio through its digital output, then I would not get an external DAC.
I just compared a yamaha player s-677 through its analog output against my MSB DAC Link III through digital, and the yamaha is better on cd (less digititis, more natural stereo separation), and much much better with blu-ray discs (no downsampling/software protection). Plus it plays sacd.
That made me realize that DAC chips/output stages and their implementation are so much better nowadays, especially in an Oppo, even in a yamaha (cheap burr brown 5102), that it must be hard to get "better" with an external dac. You would get a different sound certainly, but then in that case I would compare good players (oppo, marantz and others), pick the one you like and forget about outboard DACs.
I just compared a yamaha player s-677 through its analog output against my MSB DAC Link III through digital, and the yamaha is better on cd (less digititis, more natural stereo separation), and much much better with blu-ray discs (no downsampling/software protection). Plus it plays sacd.
That made me realize that DAC chips/output stages and their implementation are so much better nowadays, especially in an Oppo, even in a yamaha (cheap burr brown 5102), that it must be hard to get "better" with an external dac. You would get a different sound certainly, but then in that case I would compare good players (oppo, marantz and others), pick the one you like and forget about outboard DACs.