It turns out the samplerate for MVS is 384:
But 320 / 0.75 = 426.6 so how best to get from there to 384? Would I need to test everything between 426 and 384 to find it? As I’ve fiddled with samplerate I’ve noticed that there seem to be a predictable number of steps between “good looking” values. How can I determine that number of steps so I can test fewer values?