evdplancke;686215 Wrote: > I think you are right. If I remember well the theory, given a signal to > noise ratio and a type of modulation, we can calculate the probability > of error (bit error rate). When we add noise to a signal, this > probability is very close but not equal to 0. The question is: at what > level the bit error rate becomes audible? can we hear a bit error rate > of 1E-10 for instance? > > There have been tests done to show bit perfect transmission to the dac.
Weiss dacs can do this. I belive that it has been confirmed on other dacs and in other ways that transmission is bit perfect. SPDIF contatins AFAIK error detection bits (buit not error correction). I am not convinced that there is any reason why there shopul dnot be perfect recovery of all data provided that the trasnitions are not mixed up (which requires serval ns of jitter). This old paper concludes that amplitude errors through noise are unlikely http://www.scalatech.co.uk/papers/aes93.pdf . It refers to other papers on errors in transmission. But let's suppose that there was an error of one in 10,000,000,000? if there are 705k music information bits per second for one channel of 16/44, that suggest that one sample every 4 hours might be somewhat wrong (depending on whether it was the least or most significant bit). I can't see that this would account for any audible effect because any effect on the output would only last an instant and would probably be filtered out by the Anti imaging filter- if one sample value was significantly changed it would presumably have the effect once decoded of creating a very very high frequency sound which would eb filtered out. I had a look for an estimate of the bit error rate on spdif. I noted one forum where someone asserted the figure 10^-12 or 100 times lower than your figure. -- adamdea ------------------------------------------------------------------------ adamdea's Profile: http://forums.slimdevices.com/member.php?userid=37603 View this thread: http://forums.slimdevices.com/showthread.php?t=91322 _______________________________________________ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
