Dacmagic 100 hardware volume issue

I’ve installed Volumio 2.041 on my RPI3 board.
I have a Cambridge Audio Dacmagic 100 USB DAC.
Unfortunately, hardware volume control seems broken. Please find my screenshot attached.
If “default startup volume” is set to “0” no sound comes from the device. If any other startup volume is selected the DAC always plays at the same standard volume. Acting on volume knob on playback page is ininfluent.
Can you help me?
Schermata 2017-01-22 alle 21.32.53.png

No ideas?

Same DAC, same problem with Volumio 2.609 ;(

To me it seems that your dac does not support volume xint4ol