It would require more than just changing out the DAC chip. It would also require writing completely different software for the player, software that was coded directly to the new DAC. And from what I understand, these DAC chips aren't exactly pin-for-pin drop-in replacements for each other. A significant amount of hardware engineering would be needed as well.

In other words... if you're going to go to that much trouble to hack up the main board of your one-of-a-kind, never-to-be-made-again empeg car player, the energy is probably better spent on making your own homebrew digital player with the capabilities you're looking for.

Question: Why do you want to play digital copies of DVD-Audio files on your empeg? Is that really what you want to do? Or do you just want to use a DVD player in your car?

If all you want to do is use a DVD player in your car, just daisy chain the DVD player and the empeg using the line-in and line-out connectors on each unit. The empeg doesn't need to decode the DVD audio.

If all you want to do is play the DVD audio track ripped from a music DVD, just use Total Recorder to do that, and convert it to MP3. Or use any of the DVD ripping tools that are available.