Oh I can hear differences when I'm doing it not blind: the Bel Canto one sounds better, mostly because I know it has a lower noise floor and better measured response. I did a test with the BelCanto, a Weiss DAC2 and the DEQ2496: I volume matched with a voltmeter everything let it sit on for a couple days and got my wife to switch all the inputs to my source switching box (with identical cables) and therefore single blind. I couldn't hear one farts of a difference between the two as much as I tried with Qualias, HD800s etc through a GS-X when listening to music. If no music was on I could crank the volume enough to tell the noise floor differences.
I am not saying all DACs sound the same but I think that if the DAC is well designed to be transparent with a plain brick wall fliter and the correct phase response etc then it appears to end up at the same place, which it should. That said, non-brick wall filters maybe superior for some things such as old recordings that were downsampled to 16/44.1 through a good old fashioned brick wall. I can just build one of those filters into foobar if I want using the convolver.
Back on the thread topic. Glad the Perfect Waves are sounding good