I've quoted both of those before just recently. "perfect" may be a word I chose for its shock value, but is it in fact very different from "truly transparent" or "not sure there is a lot of work to be done"?
In my opinion it is very different. Transparent is used in the context of systems, and existing technology. Can a good ADC/DAC can digitize an analog signal, then convert it back to analog "transparently" enough that sophisticated listeners, in blind tests, listening to high-end systems, can not distinguish between the the original signal and the converted one more often than they could guess? Yes. This has been demonstrated a few times.
So DACs can be transparent within the limitations of
those systems and, arguably, the current audio reproduction technology. We could get into the usual second-guessing of every wire in the system being used, down to dismissing the whole test because there is an A/B switch in the signal chain. Let's sidestep that; I'll just agree that there might be some system out there somewhere that would reveal a differece more consitently than the flip of a coin. But given that such tests are never, to my knowledge, conducted on cheap, unrevealing equipment with iPod addled teens fresh from a ear-battering rock concert, I conclude, having looked at lots of similar studies, that well-designed audio electronics can be, and often are, so close to transparent, the differences are so exceedingly small, that they are truly insignificant.
Now we can question "insignificant."
But personally, comparing the studies I've read to the enthusaist message board posts I've also read, I've further concluded that it must be much easier for someone
expecting to hear some of these "differences" to perceive them as dramatic in a sighted test, than it is for
anyone to hear them
at all in a blind test. YMMV.
None of that has anything to do with "perfect." All of that has to do with context. None of this stuff is perfect. But good DACs, and many other things have shown themselves to be transparent in the context of the audio reproduction technology we have. That could, of course, change. If a transducer or room correction breakthrough comes along that allows a much more revealing playback of the best recordings, differences between the small stuff in between the two ends may get a lot more obvious. And "perfect" will still be evasive.
Tim