[PROBLEM] Dolby Digital/DTS/PCM to SPDIF?

[JetFn1]

I have been trying to extract the Dolby Digital and DTS signal to play 5.1 channels on my home audio receiver. My receiver is capable of both Dolby and DTS but I am unable to extract the Dobly Digital or DTS signal to send over SPDIF optical. I bought this on Amazon, HDMI to SPDIF I get the audio to play Dolby Pro Logic but I cannot get true Dolby Digital or DTS To play in 5.1! The box is just a pass through and does not change the audio format from the HDMI source. I have Dolby Digital and DTS checked in XBMC settings. Any ideas on why I cannot get the 5.1 channels to send through?

Thank you for your time,
Best Regards