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Are some DACs more forgiving of disc damage?

paulfromcamden

paulfromcamden

Baffled
My understanding is that CDs use CIRC error correction to correct read errors. I wondered if implementations vary between DACs such that some units might cope better with less than perfect discs that generate a lot of errors. And if there were any other factors that might influence how they cope with poor discs?

Purely hyperthetical for my own curiosity..
 
paulfromcamden said:
My understanding is that CDs use CIRC error correction to correct read errors. I wondered if implementations vary between DACs such that some units might cope better with less than perfect discs that generate a lot of errors. And if there were any other factors that might influence how they cope with poor discs?

Purely hyperthetical for my own curiosity..
Click to expand...
CDs have data redundancy built in (ie the same data is recorded more than once) so they can (sometimes) be perfectly read even though chunks of data are corrupted. But a ripped file doesn't. So at that point we are in the realm of interpolation.
 
paulfromcamden said:
My understanding is that CDs use CIRC error correction to correct read errors. I wondered if implementations vary between DACs such that some units might cope better with less than perfect discs that generate a lot of errors. And if there were any other factors that might influence how they cope with poor discs?
Click to expand...
CDDA error correction or for greater damage, error concealment (interpolation), is done by the CD transport. The DAC just plays the final datastream
 
The data on CD is put together (reassembled, as it does not come off the disc in sequential order) long, long before it gets anywhere near the DAC. So the DAC has nothing to do other than play the datastream that is delivered by the electronics from laser to buffer.
 
adamdea said:
CDs have data redundancy built in (ie the same data is recorded more than once) so they can (sometimes) be perfectly read even though chunks of data are corrupted. But a ripped file doesn't. So at that point we are in the realm of interpolation.
Click to expand...

Perhaps worth unpacking that a bit. (pun alert!)

When you rip a CDDA with a 'computer' the reading process will also use the data redundancy on the disc. But the drawback of ripping at high speed can mean the disc is harder to read. One of the ways to tackle that is to have the rip keep re-reading sections of the CDDA as it goes, then comare multiple reads of the same part to give it a chance to correct 'random' read errors.

Utilities like cdparanoia then give you a running commentary on this and how well they are doing with the chosen drive and read speed. This can be useful as a way to know when a rip is OK or not. Sometimes a different drive gives better results... or worse.
 
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