Cable box to outboard DAC


I would like to connect my cable box , a Scientific Atlanta Explorer 2200 , to a DAC . The cable company says that the digital audio out connection is AC-3 . It looks like a single RCA connection . Is this correct ?
Does an aftermarket DAC manufacturer make a component that will read this type of signal ? I would like a better sound than I am getting from the analog RCA outputs which uses the cable box DAC . This is for the cable company's CD quality music only channels not the regular TV channels .
saki70
Thank you Edesilva , I will check the site .
Thanks to all who have tried to help me .
Why not just a cable box that will output PCM? They're not that expensive. Mine does. I'm not at home and so don't have the make and model handy, but if you're interested, send me an email and I'll get it for you. In fact, I will be getting a different cable box soon, and my old one would be available for cheap.
Until cableCARD compatibility is truly here--and it isn't--there is no guarantee that a 3rd party cable box will work with your cable provider's system. Before plunking down money on a cable box, I would ask your cable company techs for compatibility information first. Esp. w/digital cable.