Getting 5.1 analog sound from Macbook

Hello,

I'm trying to get my old 5.1 speaker setup (with 3 analog input cables) to work with my 2015 MBP. I can't seem to find any reasonably priced external sound cards that work with Mac and have analog 5.1 output, and on the other hand I haven't been finding any toslink to analog 5.1 adapters. Any advice?

Thank you,