08-08-13: Mapman
The D/A process (which requires very accurate and precise timing to be done properly) is where pretty much all of the variability comes into play regarding resulting sound quality.
I second Mapman's comment.
Pretty much everything I have read on the subject that I consider to be credible suggests that a CD that is in good physical condition, when played back in real time by a CD player or transport, will have very few if any read errors that are not corrected bit perfectly by the player. My belief, although based on technical understanding rather than experimentation, is that the main reason some CD treatments will improve the sound quality of a CD that is in good physical condition is that the treatments can make it easier for the transport mechanism and its servos to track and read the disc, which in turn will reduce the amount of electrical noise generated by the transport mechanism that may ultimately couple into the D/A converter circuit, where it can affect jitter, and/or that may couple into analog circuitry.
That effect may occur even in the situation where the transport and DAC are in separate components, as many and perhaps nearly all DACs will be sensitive to some degree to jitter that is present in the S/PDIF or AES/EBU datastream they receive.
That specific effect is of course inapplicable to the situation where what is being played back is a computer file that has been created by ripping a CD. So provided that you rip with software that assures bit perfect accuracy, I can't envision any means by which treating the CD prior to ripping would make any difference.
Regards,
-- Al
