Recently when playing MQA streams from Tidal that are reported as being 24/44.1 FLAC Audirvana sends them to my DAC as 24/88.2 for some reason. 24/48 gets similarly doubled to 24/96.
That’s exactly what MQA is supposed to do - compress higher resolutions into 24/44 or 48 (depending on whether the source recording is a multiple of 44 or 48?), to then be decompressed by the MQA decoder, in this case A3, albeit not losslessly, and if originally higher than 88 or 96 it would require an MQA DAC to go the whole hog decompressing.
MQA audio files whose original sample rate is 1x (44.1 or 48kHz), are upsampled to 88.2 or 96kHz by the MQA decoder using the tuning metadata in those files.
The benefit is the use of this upsampler filter metadata to upsample with the right digital filter settings.