Here is some frequency analysis of recordings that I did with Vinyl Studio in 24/96 resolution. They look strange, as it comes down to 24kHz and then rises in almost a mirror image. The lineage is: Music Hall PA2.2->USB->MacBookPro->VinylStudio. Other recordings from different sources look similar to this.
What does this indicate about the ADC in the Music Hall PA2.2 and/or my configuration?
Thanks for the help.
Yes, it certainly looks to me like an artefact of the ADC. It shouldn't, in my opinion, be generating a frequency distribution like this.
The sharp dropoff around 20 kHz is normal, since most analog sources tail off around there. The rest makes no sense at all. I would ask Music Hall about it:
https://musichallaudio.com/contact-music-hall-audio/
I assume you haven't applied any filtering in VinylStudio. If you have, I would remove it and check again, just to be sure.