(sorry, I’m at work, not right by it). I think it’s a Denon, tape to tape (cassette, I mean) recorder deck.
It has RCA Line In/Line Out.
I might not even be hooking it up correctly to the UM2. I was confused because the RCA jacks on the UM2 say output, and I’m thinking, “no, I want the signal to go IN.”
And I’ve bypassed the receiver/amplifier, so that might be wrong. I.e., the tape deck is connected directly to the UM2, so the signal may be so low that nothing shows up in Audacity.
The headphone jack would also work into line-in but you’d need an adapter to split left & right, and with common cables/adapters you’d probably end-up with RCA connectors and the same adapter as above.
I bought a U-Phoria UM2 USB Audio interface
The guitar input will probably work but what you really want is a pair of line inputs (for left & right).
And, maybe a USB-C adapter depending on what came with the interface.
To go from the UM2 to my Macbook, requires a USB-B to USB-C. Unfortunately what I have is USB-B to USB-A cable, joined to a USB-A to USB-C adapter. The adapter has worked for other purposes, but I know I should probably try to reduce the amount of Frankenstein coupling I have going on.