USB Audio

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Audio class issues on Windows

Windows systems save the audio settings for each USB Audio device inside the Windows registry (interfaces, number of channels, sub-frame-size, bit resolution and sample frequency). These values are saved for the USB Vendor ID and the USB Product ID. When a device with the same USB Vendor ID and USB Product ID enumerates a second time the audio settings are checked against the saved values inside the Windows registry. If the settings do not match the device will not function (Windows will not request any audio data from it).

It is not known why Windows behaves this way, other operating systems are not affected.

When developing a USB Audio device and experimenting with different sample rates, bit resolutions, etc. it is advised to remove the device from the registry after each change to the audio settings or to use a different USB product ID after every change.