On 15/11/2017 11:27 AM, Phil Allison wrote:
Trevor Wilson wrote:

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Vir Campestris wrote:



**A CD player, unlike a computer transport, interpolates errors. It
does not re-request information be re-read. An argument can be made
that a higher quality transport (more expensive) may read disks
without issuing as many errors. Are those errors audible? Unlikely,
except under extreme circumstances. Nonetheless, high quality
transports add very significantly to the cost of a CD player.

Yes, Trevor, you are missing something.

**No, I'm not missing anything.


A CD player does not normally interpolate errors. Most don't even try.
What they do is use the multi-level error correction data that comes
with the data to work out what they should have played.

**Yes, they do and if error correction schemes fail, they resort to
interpolation. Computer drives do not use interpolation.



** TW is correct, any CD player built to the Red Book standard *interpolates* large errors on the disc. Missing data up to about 3mm of track length ( or 3mS in time ) is corrected by using redundant data on the disc while longer errors get interpolated which is imperfect and sometimes audible.

IME, large errors are caused by serious damage to the disc surface and often cause the laser to loose lock and either skip or start repeating the same sound rapidly.


**Yep. And this is what I use to test for the capability of the systems
to correct large errors:

https://www.stereophile.com/content/...gital-test-cdi

The test disk has calibrated drop-outs from 0.05mm ~ 4mm! The Red Book
standard limit is 0.2mm. I've found a number of (cheap) players can
easily exceed the limit. No player has made it to the 4mm drop-out.


--
Trevor Wilson
www.rageaudio.com.au