A station with two radios has two sets of audio endpoints, and the recorder will happily capture the one nobody is listening to — a Flex DAX channel while the operator works a Yaesu over USB. The file is then full of hiss with no relation to what they hear, unaffected by the rig's AGC, and nothing anywhere said which receiver it came from. The device names are now logged, resolved to their friendly names, once when capture starts.