Q,
I'm not sure if this will help, but you can try:
What I've learned from Wadia was that they recommend putting the Wadia volume to MAXIMUM and let the preamp do the control.
With my Oracle DAC/PRE now, it is set to maximum output when operated as purely DAC, and it sounds much, much better thorough a preamp (at least in my system).
So I follow this same concept in my digital playback: Maximum volume for the dbPoweramp, Maximum volume for the PC, the USB-SPDIF, then the DAC is at 'fixed' mode, and the preamp does the control. I use the same when I was using my MacBook.
This seems logical because I think the variables (no pun intended) are lessened
And I enjoy the playback more.
in fact, i seem to be enjoying it equally - if not more - like my standard digital playbacks. maybe the convenience kicks in; but SQ is "there" so i think one day my CDs/SACDs will take 2nd place or perhaps rest...
.e.