what a goofy ass read. lotta snake oil out there, sure, but goodness, the erection for objectivity here is a bit 'tarded.
consider the following scenario:
two DACs are tested: A and B. in a lab, in a properly controlled environment (dB matched, bias-controlled, etc, all other components equal), DAC A is shown to be objectively the superior DAC by far (DAC A is say a modern, well-respected, commonly used DAC, DAC B is some piece of crap 1980s budget-component).
Now youre given these two DACs to take home and test yourself, as youre interested in buying one. you (1) have no knowledge of the previously mentioned lab test, and (2) have no knowledge of their manufactured dates, assuming both to be new, and both to be comparable (both are priced within say, $5 of each other).
you listen, and to your ears, DAC A is far superior to DAC B. this is your conclusion.
now, according to the strict objectivity gang bang of this forum, you are not to be trust yourself. your environment was not properly accounted for. that french cheese from 3 nights ago is still giving you gas, making you irritable and therefore perhaps biased. even though, to your ears, DAC A sounded worlds better... best not believe it, right?
but heres the thing: were all biased. im biased. youre biased. and your everyday listening environment likely isnt bias-controlled. objectivity can prove a component provides a more accurate sound over another component; but uh oh - turns out you actually dont prefer that objectively more accurate component. maybe you like certain frequencies muddled based on the type of music you frequent. maybe you prefer highs that explode at the cost others. maybe you like a little distortion.
just like playing video games isnt always subjectively-best at properly calibrated settings that say a graphic designer would use (going to yell at a guy for preferring say, a very cool color temp?), different people hear differently, have different biases, listen to music which emphasizes different frequencies, etc.
want strictly accurate sound? thats your, dare i say, bias.
hell, placebos can be mighty powerful. does the new component produce a perceived difference you enjoy? do you hear the difference often? is this difference worth to you the cost of the component? then go for it. you may learn with time the difference was in fact a placebo. but even the first-hand learning process is fun and worth the price of admission to some.
so take everything with a grain of salt: your experience, the lessons and conclusions of others, it all. certainly a lot of good info in this forum, but ultimately find the components within your budget that give you the best experience. isnt that what sound is supposed to convey?