I am kind of wondering is MQA is in fact vaporware, particularly with the "second unfold". We never heard much about this second unfold that supposedly can only be done in hardware (DACs) early on with MQA - it is only recently that we are hearing about it (I could be wrong, but it does seem the narrative has changed quite a bit since I last kept up with MQA). I'm betting the second unfold is in essence a minimum phase filter at a sufficiently high sampling rate to apply appropriate parameters to minimize post impulse ringing. Here's the kicker: Meridian (Bob Stuart) had been one of the earliest proponents of minimum phase filters. -- With respect to John Stuart MQA calling PCM linear phase filters blurry hence lossy (I don't remember the exact words), minimum phase isn't any better. It's just a tradeoff when all things are equal: https://www.superbestaudiofriends.o...d-post-effin-ringing-and-shit-like-that.2627/ Note only that, @ultrabike shows us how minimum phase filters wreck the original waveform: https://www.superbestaudiofriends.o...n-ringing-and-shit-like-that.2627/#post-70767 MQA smells so much of bullshit.