"RJH" wrote in message


Why do some cds produce more 'clatter' (physical noise) from the
transport than others?

Some CDs require more adjustments by the focusing and tracking mechanisms
than others. Consider a CD is a little warped or off-center.

And some cd players seem better at reading cds than others?

Sure, some are more agile at handling imperfect CDs than others.

Is this to do with the transport or error correction circuitry or what?

The error correction circuitry in all CD players is essentially the same,
per standard. However the mechanics aren't.

Incidentally, my best audio reader is a cheapo all in one Panasonic.

It might have the same transport as a high end player.

In article , Kurt Hamster
wrote:
On Sat, 30 Aug 2003 23:58:17 +0000 (UTC), Jim H used
to say...

Why can I read data cds without error, but not audio ones?

Data CDs are *not* the same as Audio CDs.

Data CDs have error checking bits, audio CDs don't.

Eh? Sorry, but I think you will find that audio CDs certainly *do* have
error checking / correction bits. The details are not the same as the spec
for data recording, but the error detection and correction scheme on Audio
CD is quite extensive.

Slainte,

Jim

--
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Audio Misc http://www.st-and.demon.co.uk/AudioMisc/index.html
Armstrong Audio http://www.st-and.demon.co.uk/Audio/armstrong.html
Barbirolli Soc. http://www.st-and.demon.co.uk/JBSoc/JBSoc.html

more from the 'Kurt Hamster school' of uk.rec.audio-ism

On Sat, 30 Aug 2003 23:58:17 +0000 (UTC), Jim H used
to say...

Why can I read data cds without error, but not audio ones?

Data CDs are *not* the same as Audio CDs.

Data CDs have error checking bits, audio CDs don't.

Thanks for only seeing this one question.

Why can I store slightly more music in PCM format at CD quality on a data
cd than a redbook one, I always guessed this was because data cds have less
error protection bits, which cancels out the overhead of file allocation.

Eitherway, when I read data CDs to a iso image file in cloneCD I am doing
an exact copy, reading the error correction stuff as if it were data, and
doing no processing with it. The data is still perfect, just like it is for
audio cds.

Questions I'd still like answered:

Is it possible to create a CDP that reads without injecting errors into the
bitstream?
Has one yet been created?
Why can I read data cds without error, but not audio ones?
Why can we not read CDs without error 20 years after the standard was
created?
Shouldn't digital errors cause gaps in the music
or nothing, not subtle tonal changes?

--
Jim H
3.1415...4999999 and so on... Richard Feynman

A certain Kurt Hamster, of uk.rec.audio "fame", writes :
On Sat, 30 Aug 2003 23:58:17 +0000 (UTC), Jim H used
to say...

Why can I read data cds without error, but not audio ones?

Data CDs are *not* the same as Audio CDs.

Data CDs have error checking bits, audio CDs don't.

Wrong.

http://www.disctronics.co.uk/technol.../cd_frames.htm

--

"Jokes mentioning ducks were considered particularly funny." - cnn.com

On 30 Aug 2003 12:35:16 GMT, (Derbydrummer)
wrote:

From the comments comming back it would appear that there is agreement that all
cd transports/loader/lasers sound the same and by definition have the same
abilities. This is far from the truth and not just a subjective matter as you
are able to see the differences clearly on test equipment.

While different transports will certainly have different 'eye'
patterns, modern multimedia drives with dual lasers are just as good
as 'dedicated' CD drives. That is a simple fact, which you can indeed
verify with measurements.

The new multimedia designs are inferior at reading standard cds or should I say
not as dedicated and the sound quality is only satisfactory for people who aint
bothered about true high fidelity.

This is utter nonsense, and betrays a profound lack understanding of
digital audio systems.

Obviously this concern is only going to be
raised by enthusiasts and these are the minority of consumers and are no longer
of interest to the majors in manufacturing.

It is not just about 0's and 1s and a CDrom on a computer has a lot of fuzz the
digital filter has to look at as well as the signal.

It *is* just about 0s and 1s so far as the transport mechanism and
associated error-correction and data restructuring electronics are
concerned. The digital filter does not come into play until the
datastream has been completely reclocked and edge-cleaned.

If I am going to be forced into using an inferior transport mech then It will
degrade the sound of my audio system.

Absolute ********! If you really *must* use a separate transport (a
fundamentally inferior process with CD), then what matters is the
quality of the DAC, not the quality of the transport. Please note that
a good DAC is *not* sensitive to different transports, despite what
some ignorant 'high end' dealers will try to tell you.
--

Stewart Pinkerton | Music is Art - Audio is Engineering

On 30 Aug 2003 20:11:23 GMT, (Derbydrummer)
wrote:

I don't need to try reading I already can.

OK, try reading and understanding............

Are you saying that three transport from three different manufactures perform
identically? Affraid not, there are to many variable factors, buffing the
signal using a cmos chip being just one of them. This is all I am interested
in.

Since you are aware of this, why are you not aware that the signal
which comes off the transport is completely reclocked and restructured
before it is fed to the filter and DAC?

As you are obviously into digital audio can you explain why the digital signals
differ when viewed on a scope and how the digital filter reacts to the visable
differences seen and how it effects the performance of the filter.

The digital filter has nothing to do with the transport section. If
you are seeing differences at the output of the error-correction
electronics, then you have a *very* inferior transport on your hands.
--

Stewart Pinkerton | Music is Art - Audio is Engineering

a low pass filter?

"TCS" wrote in message
news:slrnbkvmab.2ka1.The.Central.Scrutinizer@turin g.kaosol.net...
On Fri, 29 Aug 2003 21:34:53 +0000 (UTC), Jim H
wrote:
Why be coy about saying Sony and Philips? Odd :-)

Don't forget the "dedicated" mechanisms used in even the most
overpriced audiophile gear are the same cheap units as used in
everything else.

When the cheap ones can read any (undamaged) cd without error, why not?
I
think a lot of audiophiles forget how trivially easy reading a cd is by
modern technological standards.

You're wrong. It isn't easy designing audio circuits nowadays that are
mediocre enough to muffle high audio frequencies for that "warm sound."
Usually you have to use cables so badly enginered that they have a 3 db
dropoff at only 5-10khz or perhaps insert a badly designed triode tube
stage into the audio path. It also helps to have incorporated a fresh
$5,000-20,000 outlay; it doesn't matter for what the money is spent. Of
course a new fresh $5-20K outlay will always sound better than the old
one.

try adjusting the scope probes, or using decent connecting 1ghz bnc cables

"Derbydrummer" wrote in message
...
I don't need to try reading I already can.

Are you saying that three transport from three different manufactures
perform
identically? Affraid not, there are to many variable factors, buffing the
signal using a cmos chip being just one of them. This is all I am
interested
in.

As you are obviously into digital audio can you explain why the digital
signals
differ when viewed on a scope and how the digital filter reacts to the
visable
differences seen and how it effects the performance of the filter.
Regards

DVD players 49 dollars here in the USA at Walmart and similar,
who needs SACD anyway, morons only from what I have read.


"Keith G" wrote in message
...
"RJH" wrote in message
...

"Chris Isbell" wrote in message
...
On 30 Aug 2003 12:35:16 GMT, (Derbydrummer)
wrote:

From the comments comming back it would appear that there is
agreement
that all
cd transports/loader/lasers sound the same and by definition have the
same
abilities. This is far from the truth and not just a subjective
matter
as
you
are able to see the differences clearly on test equipment.

Have you discovered a new law of physics? Try reading "The Art of
Digital Audio" by John Watkinson. This explains why the transport is
physically unable to affect the sound unless there are uncorrected
errors reading the CD.

If you have evidence to the contrary then perhaps you could present
it.


--
Chris Isbell
Southampton
UK

Why do some cds produce more 'clatter' (physical noise) from the
transport
than others? And some cd players seem better at reading cds than others?
Is
this to do with the transport or error correction circuitry or what?
Incidentally, my best audio reader is a cheapo all in one panasonic.


Cheapo? - Check this out
http://www.whsmith.co.uk/WHS/Go.asp?...HDVD400&DB=622 and

http://www.dvdrhelp.com/dvdplayers.p...rch&#comme nt
s (cut & paste if it wraps - sorry...) and http://www.cyberhome-europe.de/

£49* brand new (FFS!) from none other than W H Smiff !! - Multiregion (by
Remote hack), picture and sound quality well up to par, all the trimmings
including Zoom, plays everything in the book (+ or -) except SACD/DVDA and
LPs.............
A
Downside - no display (other than on-screen of course).

How the hell can you beat that......????



*That's FORTY NINE QUID!!!

bought fromn Bestbuy a Mediastor CRW-5224 CDRW drive 52 write speed,
$49.95 and has a $40 mail in rebate, total price 10
bucks.....................
and works very well.



"Keith G" wrote in message
...
"RJH" wrote in message
...

"Chris Isbell" wrote in message
...
On 30 Aug 2003 12:35:16 GMT, (Derbydrummer)
wrote:

From the comments comming back it would appear that there is
agreement
that all
cd transports/loader/lasers sound the same and by definition have the
same
abilities. This is far from the truth and not just a subjective
matter
as
you
are able to see the differences clearly on test equipment.

Have you discovered a new law of physics? Try reading "The Art of
Digital Audio" by John Watkinson. This explains why the transport is
physically unable to affect the sound unless there are uncorrected
errors reading the CD.

If you have evidence to the contrary then perhaps you could present
it.


--
Chris Isbell
Southampton
UK

Why do some cds produce more 'clatter' (physical noise) from the
transport
than others? And some cd players seem better at reading cds than others?
Is
this to do with the transport or error correction circuitry or what?
Incidentally, my best audio reader is a cheapo all in one panasonic.


Cheapo? - Check this out
http://www.whsmith.co.uk/WHS/Go.asp?...HDVD400&DB=622 and

http://www.dvdrhelp.com/dvdplayers.p...rch&#comme nt
s (cut & paste if it wraps - sorry...) and http://www.cyberhome-europe.de/

£49* brand new (FFS!) from none other than W H Smiff !! - Multiregion (by
Remote hack), picture and sound quality well up to par, all the trimmings
including Zoom, plays everything in the book (+ or -) except SACD/DVDA and
LPs.............

Downside - no display (other than on-screen of course).

How the hell can you beat that......????



*That's FORTY NINE QUID!!!