I've seen first hand gains from going other than USB into the DAC3. Each step up by way of interconnect seems to gain a darker backdrop, and more ease and detail. Depth as well. the best connection thus far that I've used is via the BNC input jack on the BC DAC3 through a Stereovox xv2 IC.
Via coax things get better over TOS by way of jitter reduction and sound stage acquisition. The DAC3 seems to catch the info and reproduce it with a stronger grasp.
With even the use of an adapter, things are better using coax into BNC... especially by way of ambient recall or retreval of the orig recording venue.
these are incremental increases, yet descernable without too much care in listening. Most noticeable is the jump from USB to coax. IMO.
If of course your ripped info was encoded at more than 16/44.1, then even TOS WILL BE A DECENT LEVEL OF improved refinement over it's USB imput.
These items I've noted too might also be, in part, the result of the jitter or dejittering characteristics of the cable interface being used.
I found it impossible to find a maker of all 3 sorts of cabling, USB COAX, & BNC of the same level of quality to experiment with, so keep that in mind too.
Given all the cables I used are quite modestly priced, I'd submit my findings seem valid enough. No uberexpensive wires have yet to remain here, though several were tried.... some upwards of $750 MSRP per 1M.
Perhaps, having another sound card installed with your choice of interface (coax or BNC) would be an option, and possibly save you on many accounts.
Good luck
