The configuration was done according to the instruction for Linux 4.x in the kb. "aplay -l" results in:
**** List of PLAYBACK Hardware Devices ****
card 0: sndrpihifiberry [snd_rpi_hifiberry_dacplus], device 0: HiFiBerry DAC+ HiFi pcm512x-hifi-0 
Subdevice #0: subdevice #0
Is this ok? What does subdevices mean? Should not the expected output be 1/1? amixer only has "Master" and "Capture", belonging to the default card (which is PulseAudio as I see with alsamixer) I have the expected set of mixer controls when I chose card 0 with a play or change the card in alsamixer. However I do not have any output with aplay or mplayer. Could you please help?