Capturing vs. Ripping

is a matter of semantics. Hope I'm not being pedantic.

You could capture the signal, as hairy_hen described, from the left/right red/white RCA jacks.

Or you could rip it from D504's S/PDIF port, which also uses an RCA-style socket.

More expensive players like CLD-D704, which offer both the RCA-style S/PDIF port
as well as the optical fiber style (Toshiba's TosLink), are expected to give identical data from either port.

So yes, theoretically you could rip PCM or DTS (but not AC3) from your S/PDIF port as long as you've got computer hardware & software which supports doing it.
Typically you'd have to jump through some hoops to prevent Windows sabotaging your efforts.