Although the 851N can receive MQA encoded content, it is not possible for the 851N to playback full MQA files via TIDAL Connect because the 851N does not have an MQA decoder built in to unfold the MQA files.
There are currently no plans to integrate MQA support into the 851N as this would require a hardware modification to install a Full MQA Decoder.
The TIDAL Music desktop app can play MQA files at their highest quality from your PC or Mac through a USB Audio connection to your Cambridge Audio network player even though a Full MQA Decoder is not built into the unit.
To enable playback, connect a USB A to B cable between your PC or Mac and the Cambridge Audio network player and select “USB Audio” as the desired digital input through the network players interface.
If you wish to stream MQA files from TIDAL directly without the use of a Mac or PC, as the Decoder is not built-in, these files will not be at their original quality of 24 Bit/96 kHz as the files are compressed to approximately 16 Bit/44.1 kHz. This can still be up-scaled to a superior 24 Bit/384 kHz within the CXN (V2) however.
At present, a full MQA decoder is only available in the Evo range of all-in-one Hi-Fi and in the new DacMagic 200M.
To setup the 851N with a DacMagic 200M for MQA Passthrough, please see here.