This is an an interesting test and in the REAL world it may show that the Emperor indeed has no clothes.
HOWEVER hard-core subjectivists can come up with an "out" - "Well of course no one could hear the difference all we could hear was the A-to-D artifacts of the E-Mu 0204, which masked the undoubtedly huge differences in the DACs!"
I don't think that argument is valid, but "they" will think it is.
I'm building an A/B/X box which will compare 2 level-matched DACs in a blind, computer-controlled random test; I hope to (someday!) have this rig at a Can Jam set up for anyone to come over and take the test controlled by the laptop with results to be collected by the computer and announced on Head-Fi. Of course, the subjectivists could claim that passing the line-level audio through the rhodium-plated relay contacts negates the test, or that the interconnects I will be using are masking the sound or...... on and on and on.
PUTTING THEIR MONEY WHERE THEIR MOUTH IS: Here on Head-Fi I once challenged ANYONE to be able to correctly identify the difference of a Beta 22 amplifier going through 1 meter of silver wire and 1 meter of copper wire in an A/B test; If they are correct in six or more trials out of ten, I give them $500 of my money and $500 of their money going to me if not. WHAT A SHOCK no one replied.
All that said, I have my own plans to do an A/B listening test with a couple of DACs that I have, one of my "non scientific" tests - so-called because for reasons of ease and speed I am not going to do a blind A/B comparison at this time. Blind testing will wait until I master the code writing needed to control my relay A/B box from a PC. (Too many projects, too little time)
I have a few DACs because I have a few different rooms with systems, each one needs a DAC.... but so far my impression is that the Musical Fidelity Vdac mk 1 that I have is a little "softer" sounding, maybe even a little "tubey" compared to other DACs I have- I don't know if this judgement will hold up under A/B or blind A/B testing; it may just be a prejudice that comes from reading reviews and so on.
I suspect that one actual difference that might be heard between DACs is a little roll-off in the treble on some DACs. 44.1k DACs do differ a bit in flatness of their high frequency response, and that may be fairly easy to hear if you're young enough to have good hearing above 15 kHz. (Which leaves me out! hahahah!)