Opinions on this "white paper"

This idea prevalent among audiophiles that no two components sounds the same is interesting for its logical conclusion, i.e., that two amplifiers that measure exactly the same will sound the same is fallacy because "measurements" can not measure what is really important. However, what about the exact same amp? Will no two amps ever sound the same? What about the various designers who copy work from other designers? What about wire when two manufactures source from the same supply yet claim their wires sound nothing alike? Surely, there is inconsistency on the part of our community about what sounds good, or even what is "well made". Ben Duncan in a past Stereophile remarked that the specific impedance of a cable and output impedances and input impedances of the source and receiver respectively determines the "sound" of wire, or any frequency anomalies we might describe as "sonic signature". To him the wire itself is not as important as is "impedance matching" the line to the source.
Just a few thoughts,
Keith

The incapability for "measurement" of the sonic differences between items, is not a lack on the part of the equipment, or listener. It is a lack on the part of the measurement personnel. They lack the understanding of how to properly measure certain audible characteristics, so they declare the differences to be psychological. This is extremely unscientific, and foolish.

Well, Twl, I wouldn't indict the measurement-makers so hard when the techniques, or even good ideas about what exactly to measure, may simply not exist yet regarding specific sonic qualities displayed by gear that is reproducing music programs. Rather, I would mostly condemn those among them who brazenly claim without pause that what they *are* able to measure settles the issue. (And I do happen to believe that psychology plays a fairly large role in aural perception.)

To Keith (up two), I would comment that your finding of a contradiction which belies audiophiles who claim to hear amp differences, where you say none can be measured, falls down on that last assertion. Your observation about their argument logically extending to different individual examples of the same model amplifier, as somehow being an analogous situation, is faulty. This is because two different *models* of amplifier will never measure exactly the same as each other, so your conclusion is drawn on a false premise. Two entirely different circuits/implementations will not produce the same output under all conditions given identical inputs. You may consider them to be close, but they won't truly be the same.

Their theory that electrical resonance can be a problem with electrostatics has merit. However, there is no proof that it is a significant problem or if so, is audible. They do not show how this resonance can result in "brightness". In general, the things that they say such as: "So it is vitally important that the cables have low inductance" are true for all speakers, including electrostatics. They also say "Many cable manufacturers deliberately add a lot of capacitance to their cables.". This is simply not true. It is an artifact of designs that make the inductance very low, which is the primary goal.

Twl has it exactly right, although maybe the way he said it confused some people. The lack of a scientific measurement which correlates exactly with some particular "thing" that you can hear, does not mean that the "thing" does not exist. All it means is that science hasn't figured out how to measure it yet. The whole world is this way, not just audio, and so it always surprises me that people expect scientific perfection out of audio when, for example, medicine is still in the dark ages (in relative terms, at least).