Thank you. However, my question is not addressed there or in any of the links there that I looked.
If JRiver always uses the default sound device, as it appears to, should I simply choose that device in JRiver and ignore all the other options? There appears no way to deselect all devices in Windows so JRiver behaves on my system that default is the only real option.
I'll try to attach the windows sound choices showing 'Speaker (Realtek)' I can't capture the JRiver devices as your device window goes away as soon as I shift focus to the screencap tool - but the choices are: Default Audio Device, Realtek Digital Output, Realtek Digital Output (Optical), Realtek High Definition Audio, the 2 Samsung HDMI channels, and Speaker (DVR). So JRiver shows all the Windows devices EXCEPT the one that my external amp and studio monitors are attached to. (However if I select the Speaker (Realtek) for Windows and Default for JRiver, JRiver does play through the speakers.
As I stated before, I can survive this way but do not know what was intended by JRiver by this menu - it does not behave as I expected and your cited thread does not explain the purpose unless my copy is NOT working as intended.