With a small inner resistance I once again went to highresaudio.com. I bought the MQA album from UNAMAS - A.Piazzolla by Strings and Oboe.
Would Mister ? from Highresaudio listen to his MQA albums himself, his report and the "stop of the MQA sale" ;-) would probably not have happened.
It does not matter to me how MQA works - if I got goose bumps when listening to such music (does this term exist in English?) MQA is simply an absolutely great Audiophile development!

M since 1980 - Series 100! Main: 861v8, 818v3, UHD722, 2-DSP8000SE, DSP5500HC, 4-DSP6000 S, DSP6000 R, Oppo 203 4K, MacMini M1 16GB-Roon 4TB SSD, NVIDIA Shield, Sony VPL-VW500-4K, Samsung OLED 77-4K, iPad Pro, Turntable: Acoustic-Solid Royal/Ortofon SPU Royal N, PPA Quad P24
2.: G92DAB, 2-DSP3100,3-DSP33, M1500, MacMini+Explorer2 3TB SSD, MS200-Roon