I just dug out my old Tascam 112 cassette recorder that's been sitting in the store which I bought in the mid 90s - and I've done a comparison between something recorded in my DAW at 48K, 32 bit floating point, then this file re-imported as a 320 MP3, and then the .wav recorded onto the Tascam, reimported back to the DAW.

OK, there's no way any of you would know this, but I thought I would check before I dive in myself. I have a CD master that needs to be duplicated onto cassettes with Dolby B. Thing is, the duplication system keeps it digital all the way until the signal is put on hub of tape which is then loaded into the plastic shell.