Hi there, I hope someone can give me some pointers on my problem.

I have a C-Media 8738 based sound card with SPDIF in & out. I have been running with the official C-Media drivers (v6.39) for quite a while and the AC3 and DTS signals have been fed out of the optical SPDIF to my Yamaha amp which has recognised the DolbyDigital or DTS signal and decoded them fine.

Anyway, recently I decided I wanted to try ASIO to get bit-perfect music output. To achieve this I loaded the M-Audio DIO2448 drivers which allow ASIO output. I was amazed that this worked perfectly (using Winamp with ASIO plugin) and I got bit-perfect output which I confirmed by playing a DTS encoded 44.1 WAV file. However, I have found that I can no longer get AC3 output from my DVD's, the amp only sees it as Pro-Logic. If I go back to the C-Media drivers, AC3 output is working again, but obviously I don't get ASIO anymore.

Can anyone give me any ideas why AC3 is not working with the M-Audio drivers?


Many thanks

Russell