Hardware Secrets posted a guide: How to Use The SPDIF Connector Available on GeForce Video Cards
>> How to Use The SPDIF Connector Available on GeForce Video Cards Review
Some video cards based on graphics chips from nVidia have an SPDIF input connector. In this tutorial we will teach you when this connector should be used and how to use it.
>> How to Use The SPDIF Connector Available on GeForce Video Cards Review