Rossini w/clock and SPDIF from a CD

Hi, so if I understand correctly… the clock only works when using Network and USB connection … as the clock has no way to sync up with the transport sending something via the SPDIF… right?

So, the question I have is… doesn’t the Rossini Clock phase with the onboard clock continuously anyway? I mean, the way I understood it, the clock replaces the onboard clock (as it’s more accurate)… so why should it matter where the source for the 1’s and 0’s comes from?

It depends upon the transport. All dCS transports have a wordclock input and are therefore connected to the wordclock.

Subject to the synchronisation mode chosen by the user, If the clock is only connected to e.g the DAC then the DAC can still receive the timing reference from the clock. However the idea of a wordclock is not just about accuracy. It is called a system wordclock as it ensures that all of the attached components are running in synch. With a USB connection from a computer then as that connection is asynchronous the timing of the data from it will also run in synch.

Without synchronisation although both transport and DAC are processing, say, a 16/44.1 file the two 44.1s won’t necessarily be the “same” 44.1 i.e. starting from the same point in time and errors (e.g. glitches) may occur.

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right, but when playing something from a CD Transport (that isn’t made by dCS) and using not the analogue output (which uses the CD players internal DAC) but the SPDIF… are’t you just sending 1’s and 0’s at this point and letting the DAC / clock of the Rossini do the digital processing?

There are various sychronisation modes available. By choosing “Audio” the dCS DAC will extract the clock embedded in the S/Pdif datastream i.e. the S/Pdif interface is not just music data. This is potentially the least accurate timing. There are, of course, no 0s or 1s involved in practice :slightly_smiling_face:.

thanks, yeah, I understand the basic principals of PCM and DSD but now I understand it even better… I actually got off the phone with dCS in the UK just earlier, and they explained the reason for example USB and NetWork are different… being the source, essentially. I guess my question was, well then… who provides the clock? And the answer was as you stated in the Audio mode… but apparently some keep the SPDIF in the W mode and it works… others don’t… could be a double edge sword, but I might play with both to see if I can hear a difference for the better or worse.

It will “work” i.e. in the sense that you will hear sound with the DAC in “W” mode and connected to the wordclock when using a CD transport with no wordclock connection. However after it has been running for a while you may hear clicks every so often. These will be due to synchronisation errors which progressively increase, produce the glitch and then start the cycle again until the next one - and so on.

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