Hifiberry volume too low

Hi all,

installed Digi+ on Pi 3 and Roon 1.6 to use it as a brigde. Digital out is hooked up to my preamp. Working fine - and here comes the question:
When playing music using the roonbridge the volume is lower than playing music directly from my preamp over it´s network capability (of course volume control of the preamp is unchanged - was set to -35db in both cases).

Can anyone point me into the right direction?

Thanks in advance ,

Which OS are you using on the Pi?

Linux pi3 4.14.94-v7+ #1193 SMP Tue Jan 22 15:34:30 GMT 2019 armv7l GNU/Linux

Distributor ID: Raspbian
Description: Raspbian GNU/Linux 9.4 (stretch)
Release: 9.4
Codename: stretch

Can you run alsamixer and post the result?

lqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq AlsaMixer v1.1.3 qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqk
x Gerät: snd_rpi_hifiberry_digi F1: Hilfe x
x Chip: F2: System-Informationen x
x Ansicht: F3:[Wiedergabe] F4: Aufnahme F5: Alle F6: Soundkarte auswählen x
x Element: Tx Source [AIF] Esc: Beenden x
x x
x x
x x
x x
x x
x x
x x
x x
x AIF x
x x

Have you followed the instructions on the link above to verify if your volume on the Pi is set to max?

this is how the mixer looks like :

Can only choose the device with F6 . maybe the digiberry+ has no option for volume control?

Correct, no volume control for the Digi+ in alsa.
Xref https://support.hifiberry.com/hc/en-us/community/posts/115003307869-Rasbpian-MPD-Hifiberry-Digi?mobile_site=true
From what I can tell, yours is set up the same as mine.