Tom186;647636 Wrote: > Sure, both interesting, yours will depend a lot on the DAC though. What > I am after is info on whether the Linn DS SPDIF output is that much > better (or at all better) than that of a modded SBT ... > > Anyone?
The problem here is that such a test is only valid for one particular DAC. There is such large variability in S/PDIF input circuits that if you determine which sounds better with one DAC, there is guaranteed to be other DACs where the reverse is true. The input impedance of receiver circuits varies all over the place (not very many are even close to the official 75 ohm spec). The impedance match between the source and receiver is one of the important aspects of sound quality. A particular source does have a particular jitter and noise signature on its output, AND a particular output impedance. Both the jitter/noise AND the impedance match are important contributors to sound quality for many DACS. The jitter/noise are going to be constant with different DACs, but the impedance match is going to be a crapshoot. The result of this is that say you have a DAC with a 90ohm input impedance and you fed it from a source which has close to 90ohms output impedance, its going to sound better than another source which has lower jitter but has 75ohms output impedance. This makes the whole concept of determining the absolute "quality" of a source to be almost ludicrous. If you take several sources and rank them with different DACs from different manufacturers the ranking order is going to be different, guaranteed. An interesting aspect of this is that because the final result is primarily a combination of the two factors, if you take some sources and significantly improve jitter/noise performance on all of them, the impedance matching is now going to be the predominant factor, so the variability in ranking between them is only going to get worse. So as engineers and tweakers figure out how to improve the jitter/noise performance of the sources, figuring out which one to choose for your system is going to be even more of a crapshoot. That does not mean that things like TT2.0 are worthless, far from it. For a given DAC (say the one YOU have) making these tweaks can improve the final results, because they are improving one of the two main components. If your particular situation has a good impedance match between the source and receiver then such tweaks may make a big improvement. If your situation has a lousy impedance match then the tweaks my be less effective. Again its hard to tell in advance. So I guess what I'm trying to say is that trying to make a determination as to which source is better only makes sense if you specify a particular DAC. John S. -- JohnSwenson ------------------------------------------------------------------------ JohnSwenson's Profile: http://forums.slimdevices.com/member.php?userid=5974 View this thread: http://forums.slimdevices.com/showthread.php?t=89017 _______________________________________________ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
