AES/EBU converter/adapter
 

Is there any type of cable adapter or converter to connect a 25-pin AES/EBU D-Sub input to a S/PDIF input? How else might I connect my Blackmagic to a surround sound system? I noticed that using my computer's built-in digital out the video and audio are out of sync (at least for monitoring purposes) and it's just no fun to watch. Thanks for any help.