I'll look into doing away with the USB soundcard. What goes to your input and output jacks on your Behringer? I put the USB soundcard output to the Behringer input and the Behringer output to the speakers.
For the cassettes: connected tape deck directly to the Behringer and the Behringer was connected directly to PC. There was no connection at all to my home stereo receiver.
For the vinyl LPs: I can't recall if I connected my turntable directly to the Behringer or if I left it connected to my home stereo.
At any rate, both were successful. All I had to go on was the Behringer manual that I uploaded and the willingness to do some trial and error fiddling with the various settings in Audacity "preferences" menu.
Also I can tell you this: I just got my UFO-202 out of the closet. As I found it, it has a 2 foot long RCA cable (2 male connectors at each end) that connects the Behringer outputs to the Behringer inputs. I'm not sure what that accomplishes, but I must have found that configuration useful for some purpose. Possibly just for playback over PC?
That was for loopback. It was rather an unsatisfactory fudge to use with a soundcard/drivers which didn't support Stereo Mix.
You shouldn't have to use ANY other sound card.
I've just found that out.
Download the manual for your Behringer. It might possibly differ from mine, but I think the only difference is that the UFO-202 has a turntable connector.
I have the manual. It tells you very little about how to do things.
I have now taken the USB soundcard out of the picture with the mic/line in to the Behringer input and the Behringer output to the speakers amplifier. It seems to work although the levels into Audacity from Internet radio are a bit low.