Here we have the Micronas MAS 3529H Dolby Digital and Mpeg2 Layer 2 Audio Decoder. Its the heart of the sound card, without it, there would be no 5.1. Dolby labs made a contract with Micronas to manufacture these chips under specifications.
6
The MAS 3529H decoder IC acts as a complete implementation of 5.1 DTS and Dolby Digital/Pro Logic II decoders. On the chip’s 8-channel output an Lt/Rt or Lo/Ro downmix is available simultaneously to the multi-channel audio for recording or headphone usage.
The second chip is the Wolfson Microelectronics WM8766G. This semiconductor is a 24-bit 192kHz 6-channel DAC used in many home theater devices such as receivers and dvd/blu-ray players.
The chip right below it is the Xilinx XC9536XL High Perfonmace CPLD (Complex Programmable Logic Device). It works with the Wolfson chip to calculate delay time of the center and surround speakers.