I thought that in the case of audio media the sections of the disk
normally used on data CDs for error checking and correction data were
instaed used to store extra audio info hence no error correction on
audio CDs.

Greg Menke wrote:

"C.A. Decker" writes:

Actually this is a common misconception. The actual reading of the disc
is a totally analogue process. The reflected optical signal from the
pits on the CD is not a strict "one" or "zero". The signal varies within
a lower range which we call a "zero", and a higher range which we call a
"one". There is a "guard" band between these two signal levels. It is
only the digital circuitry that comes after the disc reading process that
causes "binning" of the two signals into either a "one" or a "zero". It
may not happen very often, but it is possible to introduce errors at the
analogue reading stage. How this may or may not affect the sound I'll
leave for others to debate. However, recall that many moons ago jitter
was ridiculed and totally dismissed in the press as being an implausable
cause for any affect on the sound. If I recall, it was one of these so-
called nut case audiophiles that originally discovered and measured this
effect. I do believe that low jitter circuitry is now pretty much
standard in any decent quality digital equipment. Cheers.


Any bits flipping because of analog effects is an error reading the
medium. It happens, which is why there are ecc and checksums. Their
job is to detect and/or recover from the error- the same kind of thing
is done in more expensive computer memory to help recover from cosmic
rays flipping bits here and there, among other things.

However, how the audio nuts go from arbitrary bits flipping between
states to an organized effect like "better bass" instead of a simple
increase in random noise is very curious to say the least. Particularly
when such claims are not backed up by before and after disc images
showing the beneficial effects and organized data tables showing the
effect as a function of time-at-temperature.

Gregm