@hondagx35: As shared from HifiBerry, I switched the clock on the DAC+ off by adding the ",slave=on" right after "dtoverlay=hifiberry-dacplus" in the /boot/config.txt so we have like this "dtoverlay=hifiberry-dacplus,slave=on" that the sound is very nice and detailed. Can I do the same for my usb DAC on C2? I ask because we cannot access the /boot/config.txt on C2? My usb dac is Sabre9018 so the advice is to change to "dtoverlay=sabreberry32,slave". Thanks.
P.S: I have just received the USB Audio adapter that it works perfectly on C2 via Rune but its sound is not very nice.