In reply to:
Now if you want to measure the output of a violin, you could say, "2x6 the strings of these violins each vibrate at the same frequency when you play a middle C, so how can you say they sound different? If you think there's a difference between a Strad and a Taiwanese violin, you've been brainwashed. Middle C is about 262 Hz, no matter which violin is producing it. We, who know it all, can accurately measure this frequency to a few parts per billion accuracy and can tell you with confidence, middle C is middle C whether you sawing on a Strad or on a knock off."
But one who believes in scientific tests could just as easily say, "2x6, although the strings of these violins each vibrate at the same frequency when you play a middle C, they sound different due to the measurable resonances caused by the differences in wood shape and design. These differences are real and are not a placebo effect because they can be seen in this sonogram. Additionally, due to the differences in cabinet shape, they exhibit different dispersion patterns which can be seen in this plot."
The fact is that while the fundamental note may be the same, the resonant frequencies will not have the same characteristics between different violins. It is like trying to compare the piano to an accordian each playing the same note.
About the differences between solid state amps, the measurable differences (while the amps are not strained) are extremely subtle at best and only tend to show up at the extremes of high and low frequencies. These deviations are never going to be close to 1 dB in any well designed SS amp when asked to produce a signal in the audible spectrum.
