I have not looked at this decoder's data sheet, but I have worked with several other decoders from the same family. The output is 16 bit stereo, right justified. It will go into most digital filter ICs or integrated filter DACs, provided you set them to 16 bit "standard", "Japanese" or "Sony" format. The rest of the 48 or 64 bit frames are just stuffed with zeroes. As Sony is a right-justified format, you need to know how many relevant bits there are. In a CD-player, it has to be 16.
Note that some of the more modern DACs such as the AD1853 have I2S as the default format and no longer provide mode pins, so you will need a controller to set the correct format or install some glue logic.
On most CXD decoders, the SPDIF can be inactivated by software but in the players without a digital output that I have checked so far, this was never the case. But then you'd have to include a receiver chip which might only make sense if you want to avoid the glue logic. Also, it would degrade the timing unless you insert a master clock that sits on the DAC board and clocks the DAC directly.
Eric
