There are two levels of MQA decoding, hardware and software. My Bluesound Node performs MQA software decoding. I will take an MQA encoded files from Tidal and either decode it in software and run it through its own internal DAC, outputting a left and right line level audio signal or is will take the decoded MQA and out put it as a 96/24 digital signal that can be then [processed by any DAC capable of reading a standard 96/24 file.]
The Tidal Desktop App will also perform software MQA decoding with no additional equipment needed.
My limited high level understanding of hardware MQA is that the algorithms in a hardware MQA chip are customized tot he piece of equipment it is installed in and therefore the decoding takes into account the sonic signature of the unit so that the output is as close as possible to the original signal even given the units particular colorations. According to the MQA web site , hardware decoding yields performance similar to what one would see from a 192/24 signal. How the measured or determined that I have no idea, but it is what they claim.