seanadams;253647 Wrote: > OK good... next thing to test is to try listening to Transporter's > _analog_ outputs while it is being fed by the 48KHz word clock. They > should operate both in 44.1 and in 48KHz mode. Then if you disconnect > the word clock while playing, the analog outputs should either go > silent or speed way up or down.
The Transporter, when using the internal DAC, works just fine. It produces analogue output for 44.1, 48 and 96 (which I have tried) and sounds good. seanadams;253647 Wrote: > Also, try playing both 44.1 and 48 KHz tracks while in 48KHz mode. The > 44.1 tracks should sound sped-up. Yes, when I used a dCS Delius as external clock to Transporter this works as well. Indeed, the 44.1 sounds speed up. I also tried to run 96 like this. And then of course slows down. Notice, I still use the analogue outputs. seanadams;253647 Wrote: > ?!? Why? > > Such a configuration should only be used if you have some requirement > to synchronize multiple _source_ components, perhaps for editing > purposes. > > It is the MCLK (eg 11.2896MHZ) signal that actually drives the internal > operation of a modern DAC chip, and the whole point of word clocking > (for the purpose of reducing jitter) is to put that clock as close as > possible to the DAC chip itself. > > A PLL is absolutely _terrible_ at generating a master clock from a word > clock, compared to generating it directly with a crystal. But that is > not even the only source of jitter - you are also accumulating it in > all the connections between this equipment, and in the clock source > device itself, as it has to divide a crystal-generated clock internally > to produce that low word clock frequency. Well, I use a system where the dCS Paginini clock is used to syncronize the Transporter and a dCS Paganini DAC. The DAC receives S/PDIF data from the Transporter and does not need to decode the clock from the data - as is also the situation in master mode. seanadams;253647 Wrote: > I am not aware of any situation where a word clock would be advisable > for driving a DAC. You will get jitter much worse than anything you'd > get even from traditional s/pdif master->slave clocking.... i.e. this > is not only defeating the jitter eliminating mechanism of the word > clock interface, but is actually making the jitter far worse even than > plain s/pdif. You are probably running your DAC on a few hundred > picoseconds of jitter, as opposed to the 30ps or less that would come > from a good quality internal oscillator. 1) You may use a DAC in master mode to feed clock to the Transporter. I used to do this with a dCS Delius, and have tried the same with the dCS Paganini DAC. 2) Even better is to syncronize both the DAC and the Transporter to an external clock - if this clock is of higher precision than the one in the DAC. seanadams;253647 Wrote: > That's fine... but driving the DAC from a word clock signal is not OK. > The problem could in fact be that the jitter is so high that the system > is on the borderline of being able to operate at all. Sorry, your statement is wrong - at least as I see this issue and as I understand your statement. I use a dCS Paganini clock that syncronizes a dCS Paganini DAC and the Transporter. seanadams;253647 Wrote: > Have you tried hooking things up in the usual word clock configuration > where the DAC (not a separate box) is the clock master? Yes, with a dCS Delius - 44.1 works but 48kHz does not work. The dCS Paganini works well at 44.1 but does not output 48 so this I can not try (that's why I have the Paganini clock - which outputs also 48). seanadams;253647 Wrote: > Also, have you talked to dcs about this issue? I'm not just trying to > point fingers here, but without having the equipment on-hand this is > very hard for me to diagnose. They may be able to provide some > additional insight here. I have the user's manual of my dCS units and they explain the issue in details. Further, I have tried to contact the support at slimdevices - may be I did not succeed to post it properly(?) - and they haven't provided any technical answer yet. Rgds. -- achri-d ------------------------------------------------------------------------ achri-d's Profile: http://forums.slimdevices.com/member.php?userid=10325 View this thread: http://forums.slimdevices.com/showthread.php?t=39770 _______________________________________________ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
