USB question

[Richard Kimber]

I play music stored on my PC via a USB connection to my DAC.

The player (HQPlayer) does not detect the DAC after a reboot unless I
physically remove the USB cable and re-insert it.

This suggested to me that some module was not automatically loaded at
boot, so I did lsmod before and after re-inserting the cable to see if
there was a new module in the list after re-insertion. However the two
outputs listed the same modules, though they weren't quite identical -
there were differences in the 'Used by' numbers following the Size (the
significance of which I don't understand).

Is there some other way I can track down what I need to do to ensure
the DAC is recognised without having to keep un-plugging and
re-plugging the USB cable?

Ubuntu 18.04.1

- Richard.
-- 
Richard Kimber