chung wrote:
S888Wheel wrote:
From: chung
Date: 6/17/2004 3:29 PM Pacific Standard Time
Message-id:

S888Wheel wrote:


And, too, a measurable difference is not necessarily audible.


Never said it was. However if there is no measurable differences between
two
signals then there is nothing to discuss. They will make the same sound
with
the same associated equipment.


The problem, of course, is that usually there is a measureable
difference between two components, since our measuring instruments are
so sensitive.

It is not a problem for the instances in which there is no measurable
differrence.

My point is that there are very few instances where there is no
measureable difference, because of the sensitivity of our test instruments.

Care to provide examples where differences are not measureable?

I would offer as an example bit-identity of two .wav files....which
has not prevented listeners from claiming that they still sound different.

In fact, what has happened in that case is lots of time spent trying
to find a *differnt* measurement to validate the supposed difference (with
'jitter' usually named, but AFAIK never proved to be, the culprit).


--

-S.
Why don't you just admit that you hate music and leave people alone. --
spiffy

Steven Sullivan wrote:
chung wrote:
S888Wheel wrote:
From: chung
Date: 6/17/2004 3:29 PM Pacific Standard Time
Message-id:

S888Wheel wrote:


And, too, a measurable difference is not necessarily audible.


Never said it was. However if there is no measurable differences between
two
signals then there is nothing to discuss. They will make the same sound
with
the same associated equipment.


The problem, of course, is that usually there is a measureable
difference between two components, since our measuring instruments are
so sensitive.

It is not a problem for the instances in which there is no measurable
differrence.

My point is that there are very few instances where there is no
measureable difference, because of the sensitivity of our test instruments.

Care to provide examples where differences are not measureable?

I would offer as an example bit-identity of two .wav files....which
has not prevented listeners from claiming that they still sound different.

In fact, what has happened in that case is lots of time spent trying
to find a *differnt* measurement to validate the supposed difference (with
'jitter' usually named, but AFAIK never proved to be, the culprit).



Yes, this is one of the few cases where you can measure no difference,
but that's between 2 CD's and probably not what audiophiles were
thinking of measuring. And there is speculation that bit-identical CD's
may still sound different due to jitter.

On 6/18/04 9:42 PM, in article , "chung"
wrote:

I would offer as an example bit-identity of two .wav files....which
has not prevented listeners from claiming that they still sound different.

In fact, what has happened in that case is lots of time spent trying
to find a *differnt* measurement to validate the supposed difference (with
'jitter' usually named, but AFAIK never proved to be, the culprit).



Yes, this is one of the few cases where you can measure no difference,
but that's between 2 CD's and probably not what audiophiles were
thinking of measuring. And there is speculation that bit-identical CD's
may still sound different due to jitter.

If there is one transport that produces high jitter and one that produces
low jitter - they will sound different. But it is measurable.

Bromo wrote:
On 6/18/04 9:42 PM, in article , "chung"
wrote:

I would offer as an example bit-identity of two .wav files....which
has not prevented listeners from claiming that they still sound different.

In fact, what has happened in that case is lots of time spent trying
to find a *differnt* measurement to validate the supposed difference (with
'jitter' usually named, but AFAIK never proved to be, the culprit).



Yes, this is one of the few cases where you can measure no difference,
but that's between 2 CD's and probably not what audiophiles were
thinking of measuring. And there is speculation that bit-identical CD's
may still sound different due to jitter.

If there is one transport that produces high jitter and one that produces
low jitter - they will sound different. But it is measurable.


No, I was talking about the same CD player/transport/DAC.

chung wrote:
Bromo wrote:
On 6/18/04 9:42 PM, in article , "chung"
wrote:

I would offer as an example bit-identity of two .wav files....which
has not prevented listeners from claiming that they still sound different.

In fact, what has happened in that case is lots of time spent trying
to find a *differnt* measurement to validate the supposed difference (with
'jitter' usually named, but AFAIK never proved to be, the culprit).



Yes, this is one of the few cases where you can measure no difference,
but that's between 2 CD's and probably not what audiophiles were
thinking of measuring. And there is speculation that bit-identical CD's
may still sound different due to jitter.

If there is one transport that produces high jitter and one that produces
low jitter - they will sound different. But it is measurable.


No, I was talking about the same CD player/transport/DAC.

If I understand correclty, the hypothesis inherent CD jitter (versus
playback path jitter), is that two bit-identical CDs can be different
because one was manufactured with more jitter than the other.

If so, one thing I'm not clear on is, why doesn't such jitter show up in
comparison of the 'bits'?

--

-S.
Why don't you just admit that you hate music and leave people alone. --
spiffy

Steven Sullivan wrote:

chung wrote:
Bromo wrote:
On 6/18/04 9:42 PM, in article , "chung"
wrote:

I would offer as an example bit-identity of two .wav files....which
has not prevented listeners from claiming that they still sound different.

In fact, what has happened in that case is lots of time spent trying
to find a *differnt* measurement to validate the supposed difference (with
'jitter' usually named, but AFAIK never proved to be, the culprit).



Yes, this is one of the few cases where you can measure no difference,
but that's between 2 CD's and probably not what audiophiles were
thinking of measuring. And there is speculation that bit-identical CD's
may still sound different due to jitter.

If there is one transport that produces high jitter and one that produces
low jitter - they will sound different. But it is measurable.


No, I was talking about the same CD player/transport/DAC.

If I understand correclty, the hypothesis inherent CD jitter (versus
playback path jitter), is that two bit-identical CDs can be different
because one was manufactured with more jitter than the other.

If so, one thing I'm not clear on is, why doesn't such jitter show up in
comparison of the 'bits'?


I have read that the same music CD made from masters cut from different
machines can sound different, according to tests done at Sony Music. The
data is the same, and the error rate is low. My guess is that a given CD
player's output jitter may be a function of the physical "wobbliness" or
concentricities of the tracks. And a good CD player/DAC should be able
to reject this jitter, but perhaps some players/DAC's do not do a very
good job of this.

The data is still bit perfect. So if you use a good digital audio
extraction program, you will still have bit-perfect data. However, when
the CD is being played in real time, jitter, which is basically noise in
the frequency of the DAC clock, can be affected if the servo circuitry
has a tougher time tracking the lands and pits.

In article , chung
wrote:

The data is still bit perfect. So if you use a good digital audio
extraction program, you will still have bit-perfect data. However, when
the CD is being played in real time, jitter, which is basically noise in
the frequency of the DAC clock, can be affected if the servo circuitry
has a tougher time tracking the lands and pits.

Can theoretically be affected. I don't think I've ever seen anything
establishing a concrete link, just speculation about extra servo
"circuit" noise being coupled into something else. ("Circuit" in quotes
because the servo system here is likely to be a bit of extra DSP
software.)

If there is a real effect along those lines, jitter in the playback
clock does not seem likely -- plain old noise coupling into the DAC
output is a far more realistic scenario. Any change in the digital
portion of the system is unlikely since digital circuits are highly
resistant to noise.

Not that I think noise coupling into the analog section is a likely
scenario either. Servo corrections happen all the time even when there
aren't problems with the disc -- otherwise it wouldn't be necessary to
have servos.

By far the most likely scenario in which nominally bit identical discs
play back different is when they don't actually read back bit identical,
i.e. one or both of the "identical" discs has recording problems serious
enough to sometimes result in uncorrectable errors during playback.

--
Tim

chung wrote:
Steven Sullivan wrote:
chung wrote:
S888Wheel wrote:
From: chung
Date: 6/17/2004 3:29 PM Pacific Standard Time
Message-id:

S888Wheel wrote:


And, too, a measurable difference is not necessarily audible.


Never said it was. However if there is no measurable differences between
two
signals then there is nothing to discuss. They will make the same sound
with
the same associated equipment.


The problem, of course, is that usually there is a measureable
difference between two components, since our measuring instruments are
so sensitive.

It is not a problem for the instances in which there is no measurable
differrence.

My point is that there are very few instances where there is no
measureable difference, because of the sensitivity of our test instruments.

Care to provide examples where differences are not measureable?

I would offer as an example bit-identity of two .wav files....which
has not prevented listeners from claiming that they still sound different.

In fact, what has happened in that case is lots of time spent trying
to find a *differnt* measurement to validate the supposed difference (with
'jitter' usually named, but AFAIK never proved to be, the culprit).



Yes, this is one of the few cases where you can measure no difference,
but that's between 2 CD's and probably not what audiophiles were
thinking of measuring.

Audiophiles have played a significant part in driving the whole 'bit identical
CDs sound different' goose chase.

As a result we have pseudoscientific websites such as:

http://www.altmann.haan.de/jitter/en...ngc_navfr.html

where, after pages of technical discussion of jitter, interlaced with
qyestionable claims of audibility, we are presented with evidence....
from sighted comparison.


--

-S.
Why don't you just admit that you hate music and leave people alone. --
spiffy

Wow, they got total satisfaction policy, so I might give it a try. Not many
guys do that.

"Steven Sullivan" wrote in message
...
chung wrote:

Audiophiles have played a significant part in driving the whole 'bit
identical
CDs sound different' goose chase.

As a result we have pseudoscientific websites such as:

http://www.altmann.haan.de/jitter/en...ngc_navfr.html

where, after pages of technical discussion of jitter, interlaced with
qyestionable claims of audibility, we are presented with evidence....
from sighted comparison.


--

-S.
Why don't you just admit that you hate music and leave people alone. --
spiffy

"Chelvam" wrote in
news:rI_Ac.76602$0y.9306@attbi_s03:

Wow, they got total satisfaction policy, so I might give it a try. Not
many guys do that.


Satisfaction guarantees are not proof of anything. Here is a quote from
that particular website.

"There are several jitter attenuation or reclocking products on the
market. All of these products suffer from the fact, that you need a cable,
in order to connect to the digital receiver (f.e. DA converter). This will
introduce new jitter, the cleaned signal will be contaminated again,
before it reaches the receiving device."

How is jitter reintroduced with a short cable yet digitized telephone
signals travel over miles of copper without impact?

IOW, that site could be deconstructed quite easily, but isn't worth the
time, bandwidth, nor the effort.

r

--
Nothing beats the bandwidth of a station wagon filled with DLT tapes.

IF you got through other posts here, especailly the one on Vintage DAC-
jitter is a higher in separate DAC.

___
"Rich.Andrews" wrote in message
newsa7Bc.72457$eu.43358@attbi_s02...


How is jitter reintroduced with a short cable yet digitized telephone
signals travel over miles of copper without impact?

IOW, that site could be deconstructed quite easily, but isn't worth the
time, bandwidth, nor the effort.

r

--
Nothing beats the bandwidth of a station wagon filled with DLT tapes.

It is all in the digital receiver - and the amount of allowable timing
errors before it turns into audible errors. The higher the "oversampling"
or "sampling" rate, the better the clock recovery has to be - and the less
room for error.

In a digitized telephone network the allowable timing errors and dispersion
allowed is helped with the limited bandwidth, and the recovery circuits are
quite good.

On 6/20/04 10:30 AM, in article , "Chelvam"
wrote:

IF you got through other posts here, especailly the one on Vintage DAC-
jitter is a higher in separate DAC.

___
"Rich.Andrews" wrote in message
newsa7Bc.72457$eu.43358@attbi_s02...


How is jitter reintroduced with a short cable yet digitized telephone
signals travel over miles of copper without impact?

IOW, that site could be deconstructed quite easily, but isn't worth the
time, bandwidth, nor the effort.

r

--
Nothing beats the bandwidth of a station wagon filled with DLT tapes.

On 6/19/04 11:05 PM, in article oa7Bc.72457$eu.43358@attbi_s02,
"Rich.Andrews" wrote:

"Chelvam" wrote in
news:rI_Ac.76602$0y.9306@attbi_s03:

Wow, they got total satisfaction policy, so I might give it a try. Not
many guys do that.


Satisfaction guarantees are not proof of anything. Here is a quote from
that particular website.

"There are several jitter attenuation or reclocking products on the
market. All of these products suffer from the fact, that you need a cable,
in order to connect to the digital receiver (f.e. DA converter). This will
introduce new jitter, the cleaned signal will be contaminated again,
before it reaches the receiving device."

How is jitter reintroduced with a short cable yet digitized telephone
signals travel over miles of copper without impact?

IOW, that site could be deconstructed quite easily, but isn't worth the
time, bandwidth, nor the effort.

If you don't - the other guys will win.

Bromo wrote in news:VbjBc.148836$Ly.4255@attbi_s01:



IOW, that site could be deconstructed quite easily, but isn't worth the
time, bandwidth, nor the effort.

If you don't - the other guys will win.



I did not realize it was about "winning". It is quite obvious that the
information given on the web pages in question, is false. There is no
point in discussing that web site any further.

Magic pixie dust may sound like a great way to fix problems, but truth be
told, magic pixie dust does not exist.

r


--
Nothing beats the bandwidth of a station wagon filled with DLT tapes.