synchronizing sound cards in a cluster

Wade Hampton wade.hampton at
Thu Mar 13 17:28:46 EST 2003

Jim Lux wrote:

> The real question is whether one can synchronize the sampling of the 
> sound card.  Synchronizing the processor to better than a microsecond 
> is fairly straightforward (one could always use some interrupt line, 
> for instance), but the interaction with a sound card is fairly complex. 

Depends on the sound card.  If you have a card like the M-Audio Delta 1010
(96K, 24-bit, 8 analog inputs, 8 outputs), it comes with a "world 
clock".  This
should be able to be used to sync. the sample clocks on the cards.  
I believe there are some other studio cards with "world clock" inputs.

You may also be able to use S/PDIF as a sync source.

I have a couple of 1010's and they are excellent.  I'm using the commerical
OSS driver, but it does not support the world clock sync (yet).  

You might want to try contacting the opensound folks and
the alsadriver folks for recommendations.

For sync'ing your data, could you provide a sync signal on another channel
as a rough sync (not nearly as good as if all the sample clocks are in 

Good luck,
Wade Hampton

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