OK, here are my findings - unless the USB port is powered off, the D10S does not power off - regardless of what software is driving the DAC.
Even the option in OSMC to deactivate the output device after some time of inactivity proved not enough to power it off.
However - there are ways to power off USB ports:
- cutting power off of USB bus by doing
echo 0 > /sys/devices/platform/soc/3f980000.usb/buspower
this however - is a bit overkill as network interface is attached to USB bus and by powering off USB bus you cut networking, too, thus loosing connectivity to Volumio, which leaves you with only option to reboot the device to bring back USB bus to life. - using uhubctl package, which fortunately is available in regular raspbian (Volumio) repositories
So I did:
sudo apt-get update
sudo apt-get install uhubctl
and then D10S can be powered off by doing:
sudo uhubctl -p 2 -a off
to turn it back on do
uhubctl -p 2 -a on
Please note that on Raspberry Pi B+,2B,3B ports 2-5 have ganged power control (can not be controlled individually), all are controlled by port 2, trying to control ports 3,4,5 will not do anything.
Fortunately Port 1 controls power for Ethernet+WiFi, so when you power off the other ports you do not loose connectivity to Volumio.
For further simplifying of power control (permissions etc) please check uhubctl’s author GitHub page at
So now I’m able to power off D10S dac without powering off Raspberry Pi 3B+!
Hope this helps someone else, too.