... multiple pressings of CDs can have variable audio quality from the same pressing plant, in other words, they don’t sound necessarily alike. There is no electrical or physical reason that I’ve found or my friend Robert has found, but the proof in the pudding, listening to one after another. One CD can sound brighter/duller/tonally richer/thinner, etc. than another or they may sound alike.I don’t find that surprising. Assuming (as appears to be the case) that the data on the CDs being compared is identical, a possible explanation relates to minor physical differences that may exist between the pits or other physical characteristics of the two discs. Differences that might have resulted from aging and use of the pressing equipment that may have occurred between creation of the pressings being compared, or perhaps from the use of different equipment, or perhaps just from normal +/- tolerances in the pressing process. Those physical differences could conceivably result in one disc being "easier" than the other for the tracking servos in the player to track, resulting in less electrical noise being generated by the transport mechanism, resulting in less noise finding its way into the D/A circuitry (even if that circuitry is in a different component), resulting in less timing jitter at the point of D/A conversion.
Undoubtedly there are other conceivable explanations involving comparably subtle technical effects.
As an experienced EE I for one don’t doubt any of the claims or statements in your post just above. I do, however, doubt that fuses are inherently directional :-)
Regards,
-- Al