MQA via Vivaldi Upsalmpler to non MQA dac (dCS Scarlatti)

I’ve got a free trial of Tidal (currently using Qobuz) with my (probably rare - but the dCS path is a long and slow one for us) combination of dCS kit - Vivaldi upsampler v2, Rossini clock, and Scarlatti dac, the clock limits my implementation to using a single upsampler mode - everything to DXD (352.8). Experimenting with Tidal MQA files I see any incoming stream - typically 24/96 but also 24 /88.2 or 24/192, being processed by the Upsampler as 24/96, 88.2 or 192, to MQA. The Scarlatti dac processes at either 24/ 88.2 or 96 - notably it appears I’ve lost resolution of any 192 file?

Fortunately even with the old Scarlatti, the switching is relatively seamless with the dac automatically modifying its clock source appropriately to either the word clock (44.1 chosen) or ‘Audio’ if it’s a 48 file - thus negating any effect my Rossini clock is having.

All sounds great - as usual - but, given I can’t yet stretch to the ‘renderer’ (Vivaldi dac) and I’m only planning on either Tidal OR Qobuz - I wondered if anyone could offer an opinion on the setup and streaming choice. Qobuz after all - streams at higher Rez rates in many cases allowing me to continue to use my upsampler choice of a 44.1 multiple and therefore always enjoying the clocked outcome.

The behavior that you are seeing is correct and not an indication of a problem. It’s just how MQA works.

MQA streams are encoded into an envelope that is either 44.1k or 48k and the first processing stage (the decoder) converts this to either an 88.2k or 96k bitstream. This is the so-called “first unfold” and this is the stage that is performed by the Upsampler. The sample rate shown on the Upsampler’s front panel is what MQA refers to as the “Original Sample Rate” and is what you will end up with after a complete decoding and rendering process. MQA requires that the Original Sample Rate be shown on any device with a display capable of showing it.

When the MQA decoder is active the Upsampler passes the bitstream through without any additional processing so it is just outputting the decoded (but not rendered) MQA bitstream which is either going to be 88.2kHz or 96kHz. Since the Scarlatti is not an MQA renderer all it can do is playback the stream that is sent to it and that’s why you’re seeing the sample rates that you’re seeing on its front panel.