Hello, I've bought and install a miniamp on my RPI zero W.
I've the last version of raspbian, and I've modified the config.txt like your instructions. When I test it with aplay -l it's recognized, but when I run a music (wav, mp3 or mp4), I haven't sound (speaker and multimeter). The only problem I can see is my gpio connections. I soldered the first 6 pins and the last 6; because I use the other.