USBridge with latest version of Volumio. Question about Volume control

Hi to all.
I have connected with the USB port to a Sonnet Morpheus DAC.
What is the best setting for the Volume Mixer?
Hardware Volume or disable volume control?

please see: Volume Control and audio quality - Volumio Documentation

Hardware should not impact the quality and allows you to control the volume from the web interface.
So if you want that functionality, use Hardware.
However since you DAC already has a physical volume knob, I would put it to None.

Ok. Thanks