A cassette recorder is far below the quality of the lowliest digital connection. You can't improve a signal once it is adulterated.
I have a TEAC Z2000, one if not the finest cassette deck ever produced.
I don't go pretending it is comparable to today's digital wizardry. For one thing you can only get a reasonable FR curve at -20db below full modulation. It takes a reel to reel machine, well set up running at 15 ips to get a flat FR at 0db modulation.
You can not upgrade signals, equalize to a degree yes. Once a digital signal is compressed you can up the bit rate or do what ever you want with it, but it will always be the same as the stream it was "upgraded" from. You can not improve it at all.
That picture is part of the '"museum" end of my system. I have that to enjoy my legacy software, and show people what we used to be able to achieve at its best, not claim audio nirvana.
When you really comes down to it, the quality of the rig, is speakers, speakers and speakers, which is why I put so much effort into really getting them right. It is upgrading speakers that gives you better sound, not foolery round the edge, like arguing over absurdly high bit rates, that make not one wit of difference because you have reached a point not only above the limits of human hearing, but beyond the dynamic rage of any conceivable program.
If you get the idea I'm saying there is huge waste of time money, resources and effort on absurdly high bandwidth digital streams you would be correct.