Re: Kraig Grady's CD burner Q

To: internet:tuning@onelist.com
Date: 03-26-99

In Digest 122, Kraig Grady writes:

> Does any one know if the new Phillips CD burners are any better?

I found an excellent source of info on CD burners at

http://www.fadden.com/cdrfaq/

Among other things there are specific hardware recommendations based
upon postings of a Usenet group; see:

http://www.fadden.com/cdrfaq/faq05.html#[5-1]

The Philips CDD 3600 (and CDD 3610, different only in interface) are
both on the list of recommended units. My office bought a Philips
CDD 3610 a while back and it seems to work well.

JdL

John deLaubenfels wrote:

> I found an excellent source of info on CD burners at
>
> http://www.fadden.com/cdrfaq/
>
> Among other things there are specific hardware recommendations based
> upon postings of a Usenet group; see:
>
> http://www.fadden.com/cdrfaq/faq05.html#[5-1]
>
> The Philips CDD 3600 (and CDD 3610, different only in interface) are
> both on the list of recommended units. My office bought a Philips
> CDD 3610 a while back and it seems to work well.
>
> JdL

What I want to know if it has the same compression problems as the Minidisc
and /or can you tell the differance between the copy and the original. In
other words is there any generation loss!
-- Kraig Grady
North American Embassy of Anaphoria Island
www.anaphoria.com

> What I want to know if it has the same compression problems as the Minidisc
> and /or can you tell the differance between the copy and the original.

CDs don't involve any form of compression, if that was the question.

To: internet:tuning@onelist.com
Date: 03-27-99

Kraig Grady writes:
> What I want to know if it has the same compression problems as the
> Minidisc and /or can you tell the differance between the copy and the
> original. In other words is there any generation loss!

Carl Lumma writes:
> Unlike MDs, CDs can be copied forever without generation loss. Sony
> deserves the boot in the ass for purposely engineering loss into an
> otherwise digital medium.

I have found that pulling a .wav file from an audio CD does not always
give perfectly consistent results (using Adaptec Easy CD Creator and
a Philips CDD 3610). The error correction used on an audio CD is geared
for audio use, and gives a reasonable approximation when a portion of
data is missing. I have gotten .wav files with clearly audible glitches
yet no error reported in extraction.

In contrast, once you have a good .wav file, if you save it to CD in
data format, there is additional, robust error correction, and your bits
should be secure for generation after generation.

I'd save the audio CD for the final generation to be safe.

JdL

John deLaubenfels wrote...

>I have found that pulling a .wav file from an audio CD does not always
>give perfectly consistent results (using Adaptec Easy CD Creator and
>a Philips CDD 3610).

I assume that your CD reader is capable of digital extraction, and you're
not playing the thing into your sound card and using its DACs to get a wav...

The error correction on the CD shouldn't have anything to do with wav
extraction (unless the CD has so many errors that data has been lost, in
which case you'd hear the artifacts on a CD-Audio player), as it is handled
by hardware, and perfect wav extraction should be possible. I suspect the
artifacts you describe are caused by burps in the data from your CD reader.
Is it IDE?

I have owned Panasonic and Yamaha SCSI CD-R burners, and used both Easy CD
Creator and Sonic Foundry's CD Architect, and have never had any problems.

C.

To: internet:tuning@onelist.com
Date: 03-27-99

[I wrote:]
>>I have found that pulling a .wav file from an audio CD does not always
>>give perfectly consistent results (using Adaptec Easy CD Creator and
>>a Philips CDD 3610).

[Carl Lumma wrote:]
> I assume that your CD reader is capable of digital extraction, and
> you're not playing the thing into your sound card and using its DACs
> to get a wav...

> The error correction on the CD shouldn't have anything to do with wav
> extraction (unless the CD has so many errors that data has been lost,
> in which case you'd hear the artifacts on a CD-Audio player), as it is
> handled by hardware, and perfect wav extraction should be possible. I
> suspect the artifacts you describe are caused by burps in the data
> from your CD reader. Is it IDE?

> I have owned Panasonic and Yamaha SCSI CD-R burners, and used both
> Easy CD Creator and Sonic Foundry's CD Architect, and have never had
> any problems.

It was digital extraction, and, for the most part, these were CD's
maintained to my fanatical level of cleanliness! I've used several
CD-ROM drives capable of digital extraction, and at least one worked
almost flawlessly as far as the ear could tell. But I did find that
successive extractions still don't always give bit-for-bit the same set
of values - have you tried such a test on several .wav files extracted
from audio CD's?

It may be that I have hardware problems, but I'm not convinced that
audio CD format is a safe way to preserve data for successive
generations. CD-ROM (i.e. data) format entails a slight reduction in
capacity in exchange for truly robust error correction.

For more info about unreliability of audio CD .wav extraction, see
http://www.fadden.com/cdrfaq/faq04.html#[4-18-1], "Why doesn't the audio
data on the copy match the original?"

JdL

To: internet:tuning@onelist.com
Date: 03-31-99

[Carl Lumma wrote:]
> Well, I've never checked successive extractions, but any wrong bits
> ought to be clearly audible.

Not true!! The FAQ I reference states flatly that most CD readers will
NOT give successive results the same, bit for bit (from audio CD's, in
constrast to CD-ROM format). My experience, even when both extractions
sound just fine, is that they're usually not identical.

The correction algorithm used for audio CD's does not claim to
regenerate exactly any missing bits, but only to fill in a reasonable
interpolation, close enough for the ear not to notice a difference.

If you are content to live with successive generations that are slowly
changing on the bit level, but "probably" sound the same, go for it! I
prefer to know that my bits are completely secure. Isn't that the point
of using a digital medium?

JdL