So I came across my original RPi and AMP v0.9 Beta, and wanted to revive them to use as a Shairport-Sync, Mopidy, etc audio endpoint for unpowered speakers.
The Kernel 3.12 instructions (https://www.hifiberry.com/docs/archive/hifiberry-software-configuration/) linked to 4.x+ instructions, but unfortunately resulted in a 404.
Found on another forum elsewhere the link to the 3.18/4.x+ instructions (https://www.hifiberry.com/docs/software/configuring-linux-3-18-x/).
Got it recognized
aplay -l
**** List of PLAYBACK Hardware Devices ****
card 0: sndrpihifiberry [snd_rpi_hifiberry_dac], device 0: HifiBerry DAC HiFi pcm5102a-hifi-0 [HifiBerry DAC HiFi pcm5102a-hifi-0]
Subdevices: 1/1
Subdevice #0: subdevice #0
However alsamixer does not show any controls. No volume controls of any kind, no left/right channels. Literally says "This sound device does not have any controls."
Any thoughts/help? This is from the lastest Buster Raspian, updated