Musicbox not working with HiFiBerry Amp+

I’m trying to install Pi-MusicBox on a Raspberry B+ with a HiFiBerry Amp+ with no luck.
I found an article on github’s bug tracker and followed the instructions (https://, but still get

root@MusicBox:~# aplay -l
aplay: device_list:252: no soundcards found…

I was wondering if someone succeeded with this configuration, 'cause I’m loosing any hope about being able to make it work.

Thanks in advance,