Spitting sound locking to DoP file Scarlatti via Network Bridge

I am running Roon on a NUC with a large DSD database in DoP format on a NAS. System is a Network Bridge into a Scarlatti DAC via dual AES with no clocking. When I start a DoP album I get a distinct spitting sound through the speakers as the DAC first locks to the signal - short in duration but offputting nevertheless. Apart from the spitting sound, all tracks play fine and Scarlatti display is as one expect.

The same files play fine through Vivaldi upsampler and Rossini direct through ethernet inputs. Network Bridge is set up correctly for dual AES use, as is Scarlatti, and all are running latest firmware. The DSD albums in DoP format are not new and have been played on various dCS systems without any issues for many years. Changing the re-sync delay in Roon has only minimal effect.

Any help much appreciated.

What sync setting do you have selected on the Scarlatti? Is DSD downsampling switched off in the NB?

Audio. DSD downsampling switched off in NB.

OK. DSD ( meaning DSD64 being the maximum that Scarlatti can process) is available as DoP via RCA SPDIF from Network Bridge and into Scarlatti DAC. It is also available using a single AES cable with the dual AES configuration deselected.To help isolate the cause of the issue can you connect this way? Is the same issue then present?

It may also be worthwhile reading this post from 2019 to see if there are any points raised in it that may be relevant to you:

The issue is the same on SPDIF. There’s nothing in the referenced post that helps I am afraid. As I said in the original post, these files play perfectly on Vivaldi and Rossini via Ethernet input. I will test them via Network Bridge through these devices later this morning and report back. My gut feel is that the issue lies in Roon, which displays these files as 24/176 PCM because of the DoP container used.

It may well be a Roon issue. Here is a link to a Lumin owner also experiencing problems with Roon and DoP. The answer to his problem was that Roon cannot read DoP files and it is ( was?) not a supported format. That thread is not too old ( 11 months) but I do not know if things have changed since.

Anyway the answer then seems to have been to convert the DoP encoded files to .dsf.

That’s not the answer unfortunately as the Scarlatti cannot play native DSF files - it needs the files to be in DoP format. The advice on the Roon forum is not strictly correct in the case of dCS devices - Roon can pass DoP files to Vivaldi, Rossini via ethernet input and they play perfectly as DSD files. They also play perfectly through Network Bridge to Scarlatti as DSD files - the only issue with this combination is when they initially lock to the signal. The locking is not a silent process - what I have described as a “spitting” sound. I have also had them playing perfectly through the USB inputs on the various devices using a MicroRendu - in all cases using Roon. Roon displays the DoP albums as 24/176 PCM rather than DSD but it will play the albums on the dCS devices as I have described above. I will try the same files through Mosaic and see whether the “spitting” issue disappears.

Problem still exists when playing DoP files via Mosaic, so it is unlikely to be a Roon issue.

Is there anybody out there who plays DSD via DoP through a Network Bridge into Scarlatti DAC that has experienced the same problem?

Playing the same files via Roon into Network Bridge into Rossini via Dual AES works fine.

The issue therefore would appear to be between Network Bridge and Scarlatti DAC