That sounds exactly like how I have my setup - except I have an R&D ‘mule’ Vivaldi One rather than Upsampler but I also have a Rossini Clock set up just like you … no changes to cabling are required, just change the audio sync setting from ‘A’ to ‘M’ for the TOSLink input and see if that improves or resolves your audio dropouts.
Phil, I’ve managed to do that now - using Mosaic, I must admit I had tried to do it via the front panel button menu and could only cycle through ‘A, W1 and W2’. Mosaic allows the ‘M’ use I see. However doing this didn’t seem to work. There is no clock sign next to the filter icon any more and the dac now says ‘no input’ reverting immediately to 24/352.8 when I switch Mosaic back to ‘A’ for the upsampler.
You should be able to select between “Audio” (“A”), “Master” (“M”), “Auto Wordclock” (“W”), “Wordclock 1” (“W1”), Wordclock 2 (“W2”) on the TOSLink input on the Upsampler.
If you take the TOSLink output from the TV into the Scarlatti DAC directly rather than through the Upsampler then do you get the same dropouts?
Using the front panel control - input toslink, it cycles through A, W, W1, W2 - it does not show M. If I use the mosaic app and select Master, the upsampler display shown no clock icon at all.
If I select a different input - say usb or network, using the panel it cycles M, W, W1 W2.not A.
I have some ‘plumbing’ to do to try the Toslink feed to the dac. I will get back to you on that.