Not sure of the connections on your device, but maybe you could run your input into a
laptop/desktop running inexpensive recording software (TotalRecorder, and others) and capture it there as a MP3, flac or other file type as selected in the software. As for legality, don't know.
Recording Streaming Audio?
I use a Bluesound Node 2 for streaming. Can I run the Node's digital output to a cd recorder or other recording device? Would the scenario change any if I ran the Node's digital input to a dac that has a digital output, like pro audio gear and some consumer products offer? Would this be considered pirating? (I realize this isn't exactly a pc audio topic but I thought this would be the best place) Thanks for any input