Mac users please note: Apple has apparently killed the core sound support for the Beyerdynamic Headzone under Mac OS Ventura. I had to revert to Monterey to keep it working.
For those unfamiliar with the product: this is an external audio interface cum headphone amp that processes surround audio into a binaural format simulating a 5.1 speaker set, and it is quite good at that. Support by Beyerdynamic has ended years ago but mine still works fine - except under Ventura.
Ralf