synchronizing sound cards in a cluster
Michael Stein
mas at ucla.edu
Thu Mar 13 15:18:37 PST 2003
two ideas:
a. injection lock the crystal oscillator on the soundcard (assuming
it has a separate crystal for sampling/ADC processing). If all sound
cards in the cluster are the same model/version then they could all be
run/locked from one source. This might be as simple as an external
clock signal feed via a series resistor/capacitor to one pin of the
existing crystal on the sound card.
b. Use multichannel sound cards and put a timing signal on one
channel. Assuming the sampling on each card is driven by the same
clock (likely if all one chip) then I'd think it would then be
possible to align the data from multiple sound cards in software
using the timing channel from each card.
This does not assume that the cards sample each channel at the same
time, just that there is a consistant pattern in the how a card
samples it's multiple channels. It does "waste" some channels.
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