[Ardour-Users] Experience? Rework an external 44.1 KHz 16 bit recording

[Paul Davis]

On Thu, Aug 19, 2010 at 11:21 AM, Paul Winkler <slinkp at gmail.com> wrote:
> On Thu, Aug 19, 2010 at 08:28:30AM -0400, Joe Hartley wrote:
>> On Thu, 19 Aug 2010 13:13:37 +0200
>> Ralf Mardorf <ralf.mardorf at alice-dsl.net> wrote:
>> > 1. Did somebody note serious differences for a ripped WAV compared to
>> > S/PDIF FOC?
>>
>> A "ripped" WAV is simply a copy of the binary digits on the CD.  Unless there's
>> a change in format (to MP3, for example), your file will be identical.  Any
>> other method will introduce extra digital->analog and analog->digital
>> conversions, which can only degrade the signal.
>
> S/PDIF transfer is digital, no analog involved.

to follow up from your final point ....

there are two ways to read the data from a CD disc. one involves using
the audio subsystem built into the drive, which eventually pumps out
the bits as S/PDIF with no analog conversion involved BUT ... this
mechanism will use heuristic error correction to handle bad sector
reads. although the error rate is probably small, its likely to be
non-zero, and the chances that the bits delivered over S/PDIF exactly
match the cd are small.

the other involves a "pure" data read which will retry bad sector
reads until they succeed or fail outright. this avoids the error
correction heuristic built into the player and ensures that the bits
you get on disk match the ones on the CD. this is what is used by a CD
ripping program.