A simple question: will Bartok benefit from an Audio-Re-Clocker like Mutec MC3+ USB?
I learnt from an old post that audio signal from network will be buffered first and then fed to the DAC based on the DAC’s clock. Does that mean Bartok has already applied audio-re-clocking? If that is the case, does anyone know will it apply to USB, and S/PIDF input?
Sorry that I am outdated and just heard about audio-re-clocking products like Mutec. If dCS product already built-in with it, which I would like to know from you, we don’t need to spend extra money and just give the DAC a good external word clock.
The short answer is that if you are just using such a device as a re-clocker for USB or network audio, it won’t make a positive difference. If you are using it for an SPDIF source, it is unlikely to make a difference on the Bartók. If you are using it as a master clock, it will likely be a benefit provided the source device can also accept a clock input.
The long answer is that if we’re talking about network or USB audio here, then no, there is no benefit to using a re-clocker. These devices try to smooth out problems in jittery sources. Network and USB audio are “asynchronous”, meaning there is no timing information embedded in them anyway, so there is nothing to smooth out. Here, the Bartók will run in Master Mode - it does not have to re-clock, as there is no clock information there to begin with anyway. It just runs at it’s own rate.
For an SPDIF input, you’re essentially betting that the clock and Phase Locked Loop circuitry inside the re-clocker is better than the same circuitry inside of the DAC (in this case the Bartók). We have some really damn good bespoke hardware and software for these, so I would be surprised if a re-clocker (just working as a re-clocker, not as a master clock) made a positive difference. Not the case for all DACs, but with the Bartók I wouldn’t expect it to make things better.
Adding an external clock into the mix is a little different, as that isn’t trying to deal with a jittery source as much as it is a jittery internal clock inside the DAC, among other things. There’s a lot more that comes into this but generally they are a good idea provided you can lock both the source device and the DAC to the same master clock (so your S/PDIF source would need a clock input as well).
I found that if I am using a CD player without an external clock in, the Bartok (which I have a 44.1 ext clock in) can select “Audio”, “Master”, and “Word Clock”. The SPIDF output signal from the CD player should have a clock signal inside, and if I don’t select “Audio”, it should run into problems like timing irregularities. But that is the case, I don’t hear any problems no matter whether I am selecting “Audio”, Master", or “Wordclock”. Could you tell us a bit about that as well? And how about the sound quality?
In that case, you definitely want to select “Audio”. Because of how we operate the PLL in the Bartók, there shouldn’t be any noticeable difference in sound quality comparing Audio to Master, and Word Clock would only be relevant if you were using a Master Clock.
If you don’t hear any irregularities when using “Master” like clicks or dropouts in the sound, then it means that your CD player’s clock is running at a very close frequency to the Bartók’s clock, so the sound never has to stop and re-lock. It’s still a good idea to run the Bartók in “Audio” mode, just to be on the safe side to ensure you never get clicks or dropouts if the clock frequency of the CD transport or Bartók happens to vary for some reason.
funny I just PMd James with the exact same question! Thanks for the responses. I’ve set mine to Audio (although it appears to work just fine on any of the settings (audio, master, auto word clock (I have a Rossini clock).
Sine Audio is the correct setting - that is what I’m sticking with!
Per our PM I have a CD-Transport using the AES in set to Audio. For a lark I tried it with Master, and Auto word clock (I have the Rossini Clock). In all cases every thing played back perfectly. No audible digital glitches!
My question is why would this be the case? I’d expect the Master and Auto Word Clock to cause audible glitches. Does it mean the clock output of my Transport is operating close to that of the Bartok and Rossini clock? Curious more than anything
Not necessarily … When you run the clock as “Master” rather than “Auto” and the source audio drifts far enough out of sync then the DAC can repeat (or drop) individual samples as required so yes you are getting “audio” glitches but not “audible” glitches (as each repeated sample when playing from CD is only 1/44,100th of a second in duration).
This is actually what I have to do myself when using the TOSLink audio feed from my LG TV as the LG’s TOSLink out is too unstable for the DAC to reliably lock on to - leaving it on “A” (which you would expect would deal with an unstable source best) resulted in regular mutes while the DAC resync’d to the TV audio whereas setting it to “M” kicks in a different set of “rules” which - technically - aren’t correct but in my particular instance do work.
In terms of optimum performance the MU1 is not wholly compatible with Bartok as there is no wordclock input/output. That does not mean it will not work but there are limitations, see page 38 regarding Synch settings etc.
Thanks. I read a bit more and it looks like the Grimm sends the clock signal via AES as well:
“For the digital audio circuits, GRIMM found the digital signal is very sensitive to tiny changes in the timing of the signal, jitter. So much so that they say it is essential for the clock in the DAC to be locked to the clock in the MU1. They believe that the clock used in the GRIMM MU1 is far more stable than most of the clocks used in a lot of DACs. The easiest way to achieve this was to link the GRIMM MU1 and the DAC via a cable and send the clock signal from the GRIMM MU1 to the DAC. This is not possible with USB so ruled out that very popular connection. I2S could have been used but there is no clear standard so is not used. That leaves the balanced AES/EBU and unbalanced S/PDIF connections. These connections carry a clock signal to the DAC and can lock the two clocks together. GRIMM, therefore, recommends using AES/EBU or S/PDIF as the best connection.”
So I guess I need to get the clocks to lock with eachother. I wonder what Sync setting that is? It looks like the first option “Audio”?
Hi Martijn, Yes, the AES3 signal contains an embedded word clock so the DAC should be left with sync mode set to Audio. This will work fine as the PLL in the DAC will clean up any jitter. However as Pete says it is not the optimum configuration for any of the dCS DACs which perform better when they can act as the master clock and best when both DAC and source component are slaved to the same external master clock. You could say that Grimm and dCS have slightly different ideologies on the subjects of optimum digital interface and clock synchronisation.
Exactly. At this level most components should form a “wonderful combination” since if they don’t one or the other or both must be compromised. The MU1 and the Bartók are not incompatible in any way. AES3 is a very well established digital interface standard and both products support it fully and will talk over it without a hitch. The incompatibility is more on the philosophical level. Both of them think they are the best player on the team and should be the captain. You can choose to believe one or the other or just tell them both to shut up and play!
U fortunately that is not strictly so for the reason I expressed earlier. I am in no way saying that the combination may not be liked subjectively but I try to steer clear of such opinion as anyone can like anything ( that is not to say that the opinion may not be widely held). There is full explanation in the Bartok user manual. The Audio setting " Does not give the best jitter performance or the best sound quality". Other synch settings require a source with wordclock input. That does not mean that using it means it will not work or that the resulting sound will not be enjoyable.
Why are we splitting hairs here Pete? These two products are fully compatible in one of the dCS’s five sync modes. Just because the Bartók offers other alternatives that the Grimm can’t utilise doesn’t make them incompatible IMO. dCS considers embedded word clock sub-optimal from a performance perspective and Grimm doesn’t. To a degree these positions support the companies’ commercial agendas. Surely everyone is free to vote with their ears/wallet without being judged by people who voted differently?