I just received my DAC+ and installed it on a new RPi B+ that has been running Volumio for a week (from the RPi's jack).
Everything seems to work after:
- Enabling the I2S driver (set to Hifiberry +)
- Audio output to sndrpihifiberry
- Mixer type to software
As soon as I try to switch to Audio Output = ALSA / Mixer Type = Hardware, the music stops (as I guess the RCA isn't even used then ?). As this is a newly installed volumio and a new DAC+ (not the light) this should work if I understand correctly.
The /etc/mpd.conf has the config below in it:
mixer_control "Playback Digital"
Also check the following link, without luck currently