opaqueice;175776 Wrote: > I don't think your comment clouds the issue - that possibility remains. > But once again, if the problem is EM interference from the switch mode > PSU it should be much *more* audible without music playing or with a > silent track. > > The TacT does some DSP. That's very unlikely to be affected by this > level of EMI (otherwise your computer would crash when you plug in the > PS for the SB). So the only culprit could be jitter induced by the > EMI, or noise added to the analogue stage. Both are possible - Sean's > measurements show that this doesn't happen with the SB, but it could > with the TacT. However both are caused by the same effect - EMI making > circuits noisy - and I see no reason why that would be audible in > increased jitter but not as an increased noise floor. On the contrary > it should be much easier to hear in the noise. But who knows - these > are very complex systems.
Jitter is not influencing the signal as you seem to presume. It is not simply noise added to a signal such that it's presence is detectable in the "noise floor" when nothing is being played (or even silence is being played). It mixes down from HF into the music signal creating harmonics that are only there accompanying the signal we are trying to reconstruct. The exact nature of those harmoics depends on the jitter. Apparently bitstream type DACs are more susceptible to this problem than the older multibit DACs -which could explain the popularity of those old designs in some circles. P.S: This also answers post 587 P.P.S: Measuring jitter via its influence on analogue signals is done by inputing a signal and measuring any resulting sidebands. Not by measuring silence on the analogue out. -- P Floding ------------------------------------------------------------------------ P Floding's Profile: http://forums.slimdevices.com/member.php?userid=2932 View this thread: http://forums.slimdevices.com/showthread.php?t=32231 _______________________________________________ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
