UR12 soundcard poweroff

I would like to ask a little question about an UR12 soundcard. As it doesnt have a power off position of the power source button i wonder if its ok if i switch the position to 5V DC whenever i want to turn it off. I use it with usb and no external power source.
So when i don`t want to use it do i have to unplug the USB cable in order to turn it of ? or it is ok to just switch it to 5V DC position ? And the output volume should be on 0 when i do this ?
There is no information about powering it off in the manual.
Thank you.