Ok, I figured out what’s going on.
There’s two playback scenarios for MQA:
- Playing the original MQA bits from the file
- Playing the output of the software decoder in the TIDAL app (MQB)
When I play the MQA file raw, I get a blue light on the S2. When I play the output of the software decoder I get a purple light and an “MQB” indication.
The Pre Box S2 Digital seems to make clean transitions working with the software decoder output, but not when dealing with the original MQA source file.
Roon doesn’t decode MQA at all, so it always plays the MQA through directly. FooBar too. But TIDAL does the partial decode in software. That’s where the critical difference is.
You can turn on “MQA Passthrough” mode in TIDAL’s settings and get hiccups from their app too.
So it seems like this DAC gets in trouble when it’s syncing to MQA, but does fine with MQB.
One day we will decode MQA->MQB just like the TIDAL app, which will probably hide this problem.
But–because Brooklyn and Explorer2 are able to sync both MQA and MQB without artifacts, I think this DAC should be able to do the same. I think that part is an issue in the DAC.