Hi Jules,
A customer reported me an issue with his zoom tac-2 soundcard on macos. Whenever it is selected, he gets a "Couldn't change sample rate" error. With some luck I finally figured what is causing the issue:
pa.mSelector = kAudioDevicePropertyNominalSampleRate; pa.mScope = kAudioObjectPropertyScopeWildcard; pa.mElement = kAudioObjectPropertyElementMaster; Float64 sr = newSampleRate; if (! OK (AudioObjectSetPropertyData (deviceID, &pa, 0, 0, sizeof (sr), &sr))) { error = "Couldn't change sample rate to " + String(sr) + " Hz"; }
If I replace kAudioObjectPropertyScopeWildcard by kAudioObjectPropertyScopeGlobal , then the driver accepts the sample rate change. I don't know whether the driver should accept kAudioObjectPropertyScopeWildcard , but maybe you want to consider changing it to kAudioObjectPropertyScopeGlobal if you think that is safe and fine.