SPDIF capturing and generation

[FlyingObject]

Hello,

I was wondering if it is possible to capture a spdif signal using a 4472 and generate the same signal using a 6713?  I dont care about reading any data, I just want to be able to reproduce the signal using the 6713 card.

Message Edited by FlyingObject on 04-12-2006 03:49 PM

[Ryan_V[DE]]

FlyingObject,

As S/PDIF is a digital protocol, you would be much better off using a digital card to capture / reproduce the data. There is no defined rate in S/PDIF, but most often it is 20bits at 44.1kHz by 2 channels. This gives a digital bitrate of around 1.7Mbps. Even if your 4472 had this much analog bandwidth, since this is a digital signal, all the sharp edge transitions would be filtered out. Furthermore, since this is a BMC-encoded signal, you really need a PLL to accurately decode it. If you simply periodically sampled the signal then reproduced it at the same rate, all of the edge transitions would be off and whatever device receives the S/PDIF would have a very hard time locking to its frequency, and thus terrible jitter in the derived sample clock. Please let me know if you have any additional questions.

Hope this helps,