Since I first saw your post, I've been on a mission to find out if there's a replacement for the venerable Griffin iMic (which isn't supported past Sierra), and I fiiinally found
Behringer UCA202/
BEHRINGER 2 in/2 Out USB Audio Interface with Digital Output, 2 x RCA Phono
which LOOKS TO ME like it's what you're looking for.

There may be other solutions, but I've spent so much time finding this one that I'm beat from searching.

The new Great Equalizer is the SEND button.

In Memory of Harv: Those who can make you believe absurdities can make you commit atrocities. ~Voltaire