Stereo audio input to MBP 16 in.
As others have asked, I'm also trying to transfer old cassette tapes to my MBP. Since the 16 in. does not have an audio input port (just a headphone port which I understand is for output only), I have to use a USB-c port, which requires an audio jack-to-USB adapter. I purchased one of these (Dukabel) and changed the sound preference input to "USB audio device" for the tape deck. My setup is using an auxiliary cable (male to male) from the tape deck to the audio jack-to-USB adapter and then a USB-A to USB-C adapter to the MBP.
However, the audio software (Quicktime Player and Audacity) is only sensing a monaural audio input signal. Is it the nature of these audio jack-to-USB (A or C) adapters to only pass through a mono signal?
How do I input a stereo audio signal via USB or other method?
MacBook Pro 16″, macOS 10.15