Maybe the supplier has an in-house repair service or help system similar to the Apple Genius Bars. They recently reorganized that service and it’s much more professional now than the older “geeks behind a high counter.”
I suspect if there is a bad run of equipment the supplier would want to know about it.
I set up a test bench and tried both of my UCA202s (picture). Both signals match exactly because of the “Y” cable. They both came in matching by a tiny percent, certainly not one channel is 3/4 of the other (3dB).
Read your private messages. User Control Panel > Private Messages.
I exchanged the ART at the store. The new one seems to be working fine.
I only tested it with the TV output. I do get balanced input this time. I will do more test later today with my tape deck. Keeping my fingers and toes crossed.
I will keep you posted.
I tested the ART with a few tapes. So far so good.
I guess I am the lucky one to get 2 defective USB interfaces back to back. May be I should go buy a lottery ticket.
Thanks to all who helped. Much appreciated!