I used an RCA video cable (yellow) to hook up the orange sockets for audio coaxial between DVD and receiver. The sound seems to be the same. But I could not get the receiver to recognize DTS or Dolby Digital signals (the indicator light doesn't come on). I wonder if only the real coaxial cable can do the trick, or it is some other issues. I have Onkyo HT-S650.
It works just fine. I forgot to switch the audio output from my dvd player. Once switched, I got Dolby Digital light turned on.