opaqueice;325172 Wrote: > Consider the following scenario: suppose you have a local clock in your > DAC with an adjustable frequency (such clocks exist and are used in some > DACs). For simplicity we'll ignore jitter in that clock (and any other > local jitter source) and worry only about jitter in the incoming S/PDIF > stream. Now you record the incoming data stream in a buffer for (say) 1 > second. Then you start to play out the buffer using your local clock. > The analogue signal coming out is jitter-artifact free given the above > assumption. > > But now we will run into a problem - our buffer will start to either > fill or empty depending on the mismatch in average timing between the > local and source clocks. But since our local clock is adjustable, we > can monitor the buffer state and make a (tiny) adjustment. We'd need > to do that at most every second, but in reality much less often (since > the clock mismatch will be smallish). > > As far as I can see this scheme removes all jitter with a frequency > higher than some very low cutoff (which in this example will be around > 1 Hz times the fractional clock mismatch).
Yes, you're right. But I suspect that making the small frequency adjustments to the read clock in such a way as not to compromise it's overall performance is not all that easy. You might like to try and build one and see how it works! My own take on these things is that life is complicated enough as it is, and using complicated solutions to solve problems that you don't need to have in the first place, is generally a bad idea. As ever, YMMV! -- Patrick Dixon www.at-tunes.co.uk ------------------------------------------------------------------------ Patrick Dixon's Profile: http://forums.slimdevices.com/member.php?userid=90 View this thread: http://forums.slimdevices.com/showthread.php?t=50147 _______________________________________________ audiophiles mailing list [email protected] http://lists.slimdevices.com/lists/listinfo/audiophiles
