tweaks and proof

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On 6/19/04 10:40 AM, in article cb1j9d027nu@news2.newsguy.com, "Ban"
<bansuri@web.de> wrote:

> Another problem with measuring in general and
>> it really does not matter where, is having the appropriate gear and
>> settings as well as knowing what to measure.
>
> I encourage every audio enthusiast to start going this way,

I would rather get a system together that I like - and spend the extra money
I save by NOT buying thousands of dollars on complex test equipment on
music.
 
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> Care to provide examples where differences are not measureable?

When you don't know what to measure - or are measuring the wrong things.
 

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Bromo wrote:
> On 6/18/04 9:42 PM, in article cb05lj04ne@news3.newsguy.com, "chung"
> <chunglau@covad.net> 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.
 
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Wow, they got total satisfaction policy, so I might give it a try. Not many
guys do that.

"Steven Sullivan" <ssully@panix.com> wrote in message
news:cb1j3n027fq@news2.newsguy.com...
> chung <chunglau@covad.net> 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/english/engc_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 <thatsright@excite.co>
>
>
 
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Bromo <bromo@ix.netcom.com> wrote:
> > Care to provide examples where differences are not measureable?

> When you don't know what to measure - or are measuring the wrong things.

And I predicted someone would retort in this fashion, several days ago.
Thanks for proving me right.


--

-S.
Why don't you just admit that you hate music and leave people alone. --
spiffy <thatsright@excite.co>
 
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>From: Bromo bromo@ix.netcom.com
>Date: 6/19/2004 9:25 AM Pacific Standard Time
>Message-id: <ZNZAc.141241$Ly.3292@attbi_s01>
>
>> Care to provide examples where differences are not measureable?
>
>When you don't know what to measure - or are measuring the wrong things.
>
>
>
>
>
>
>
>

Ah... but that does not make them unmeasurable, that just makes them
unmeasured.
 

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S888Wheel wrote:

> From: chung chunglau@covad.net
>>Date: 6/18/2004 10:48 AM Pacific Standard Time
>>Message-id: <cav9t8020or@news3.newsguy.com>
>>
>>S888Wheel wrote:
>>> From: chung chunglau@covad.net
>>>>Date: 6/17/2004 3:29 PM Pacific Standard Time
>>>>Message-id: <cat60g0dm7@news2.newsguy.com>
>>>>
>>>>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?
>
> Do you think green pens create a measurable difference in the output of a CD
> player?

Fine, I agree that green pen effects are not mesaureable.

> Do you think anything Peter Belt ever invented created a measurable
> difference in any audio signal?

Don't know about his tweaks. Have not heard of them until now.

>
>>
>>> One saves themselves the rigor of doing any further testing. So it
>>> still makes sense to start there.
>>
>>Only in principle. Not in practice.
>
> Fine. If you want to do elaborate DBTs for audible differences with and without
> green pen and Peter Belt tweaks knock yourself out. I still think a simpler
> solution is to measure the effect those products have on the signal to see if
> there is any reason to go forward with any further investigation. Your time
> your dime.

Now try to measure the difference between the output of a CD player,
playing two CD's that are otherwise equal except for the green pen
markings. You think that is easy to do? It seems like you under-estimate
the difficulty in making accurate technical measurements.

>
>>
>>>
>>> Take two cables of the same make, one 3 ft long and one
>>>>3.1 ft long. There is a measureable difference. Heck, the lengths are
>>>>clearly different. And we can certainly resolve the 0.1 nanosecond or so
>>>>in delay.
>>>
>>> A delay is not inherently a difference in the signal.
>>
>>Why not?
>
> Explained further down in my post.
>
> What about a difference in phase shift?
>
> That's different.

Uh, a delay results in a phase shift. There is a difference in phase
shift between those cables.

>
> What about the 0.001dB
>>in level due to the difference in resistance?
>
> That is different as well.

That could easily be due to the one inch difference in cable.
>
> How about the differences
>>in resistance, capacitance and inductance?
>
> All different than a simple time delay.

But all caused by a one inch difference in cable. You see my point?

>
>>
>>> Heck you can measure
>>> differnt components days apart and there is a substantial delay but the
>>signal
>>> is what it is each time.
>>
>>No, the analogy is incorrect.
>
> No it's not.
>
> One could measure those two cables at any
>>time, at any place, with any set of accurate instruments and get the
>>same difference in measurements. These differences are repeatable, and
>>objective.
>
> That's fine, but if the only difference is the time delay than it is not a
> difference in signal content.

Difference in time delay = difference in phase shift= measureable
difference.

>
>>
>>>
>>> It would take an extreme subjectivist, however, to claim that
>>>>there is a sonic difference between those two.
>>>
>>> It would take a mistake in one's impression to say there is an audible
>>> difference if the only measurable difference is a nano second delay.
>>
>>There, you are beginning to make the point for me. You are providing a
>>juegment call that a nanosec. delay does not cause an *audible*
>>difference. Just like I may say that a difference in level of 0.1 dB is
>>not an audible difference, but would everyone agree?
>
> No. Everyone rarely agrees on anything in audio.
>

Obviously, and that was why I said finding a measureable difference does
not mean much. And many tweaks, like changing resistors, capacitors,
different cables, result in measureable differences.

>>
>>Of course, I agree that that delay is not audible, but nonetheless there
>>is a *measureable* difference.
>>
>>The difficulty is in agreeing what is an inaudible but measureable
>>difference.
>
> As I have said so many times now. I suggested that one *start* with checking
> for measurable differences. If none exist then there is no need to go further.
> I *never* said that any measurable difference is proof of an audible
> difference. It is proof at best of a *possibility* of an audible difference. A
> possibility that may need further investigation.
>
>>
>>Another example. Two preamps of the same make, model and specs. One has
>>an output impedance of 200 ohms. The other 202 ohms. Clearly there is a
>>measureable difference. Is it audible?

Well?

>>
>>
>>> Even if
>>> the comparisons are supposed to be syncronized. If they are not syncronized
>>> there is no measurable difference is there since such delays are irrelevent
>>to
>>> the content of the signal.
>>
>>You are making a judgment call on what constitiutes an audible
>>difference. By the way, that is the kind of calls that a lot of the more
>>scientific-minded have tried to make (like one can't tell differences in
>>level finer than 0.1dB, or one can't hear above 20 KHz), and a lot of
>>so-called golden-ear audiphiles do not agree with.
>>
>>>
>>>>
>>>>The crux of the problem is in the disagreement on what differences are
>>>>detectible via listening only. Past research indicates that level
>>>>differences of less than 0.3 dB over the audio band are not detectible
>>>>by listeners. Let's be generous and tighten that to 0.2 dB. If we would
>>>>agree that this is the threshold of audibility, then we can prove fairly
>>>>easily that 99% of the cables and interconnects do sound the same.
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>> I said never said measurable differences were the end, only the start. If
>>there
>>> is no measurable difference it is the start and end. In some cases some
>>time
>>> and effort can be saved.
>>>
>>
>>Very, very few cases. It's better to go straight to controlled listening
>>tests, IMO.
>>
>>
>>
>>
>>
>>
>
> Fine. Have fun with the Peter Belt tweaks. They'll waste about a week of your
> time though.

Actually I am not interested in personally measuring differences, or
doing DBT's, when it comes to debunk myths, if that has not been obvious
in my posts. I firmly believe that the proponents of those tweaks should
provide proof. But between making measaurements and doing DBT's, I
believe the latter to be much more effective, since there is so much
disagreement on what measureable differences mean.
 
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"Chelvam" <chelvam@myjaring.net> 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

--
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From: Steven Sullivan ssully@panix.com
>Date: 6/19/2004 1:50 PM Pacific Standard Time
>Message-id: <cb28v302gl8@news3.newsguy.com>
>
>Bromo <bromo@ix.netcom.com> wrote:
>> > Care to provide examples where differences are not measureable?
>
>> When you don't know what to measure - or are measuring the wrong things.
>
>And I predicted someone would retort in this fashion, several days ago.
>Thanks for proving me right.
>
>
>--
>
>
>
>
>
Are you suggesting we should not worry about people measuring everything that
matters or failing to measure everything that matters?
 
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Michael McKelvy wrote:
> "Sean Fulop" <sfulop@uchicago.edu> wrote in message
> news:caqhu302fh@news2.newsguy.com...
>

>>
>>And I repeat, we cannot be sure that everything can be measured.
>
>
> Then you can't be sure it can't be either. Everything I've seen on the
> subject says that we have the ability to measure everything hearable.
> Unless youhave some proof that the right things or everything isn't being
> measured, you're just making a blank assertion.
>

Yes, but it's an assertion taken for granted by scientists in every
field. It is very uncommon for any scientist to claim "we know
everything about subject X now, finally," or something unprovable like
"we can ascribe a measurable property to every difference we can hear."
There are numerous effects of audio on the person that may not be
captured by current theories about signals and their nature. Obviously
any two signals that sound different will actually be different to some
degree, but simply showing that two signals are different is not the
same as "measurement" of the difference.

In science it is common to err on the side of caution, to always presume
there may be more to any subject or field of inquiry, stuff that remains
undiscovered.

I agree with you that ABX can be useful, but since it is known that the
results can be affected by methodology, once again one can never be
certain that the "perfect" ABX-style methodology has been developed.
These tests were improved steadily over many decades, which yielded
increasing sensitivity to audible differences that could be detected by
the tests. We cannot be sure we now have the perfect audibility tests
for all domains of sonic difference.

-Sean
 
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chung <chunglau@covad.net> wrote:
> Bromo wrote:
> > On 6/18/04 9:42 PM, in article cb05lj04ne@news3.newsguy.com, "chung"
> > <chunglau@covad.net> 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 re: 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 <thatsright@excite.co>
 
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IF you got through other posts here, especailly the one on Vintage DAC-
jitter is a higher in separate DAC.

___
"Rich.Andrews" <bvzxrpl@swissinfo.org> wrote in message
news:eek:a7Bc.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.
>
 
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On 6/19/04 11:47 PM, in article aN7Bc.143806$Ly.57935@attbi_s01, "S888Wheel"
<s888wheel@aol.com> wrote:

> From: Steven Sullivan ssully@panix.com
>> Date: 6/19/2004 1:50 PM Pacific Standard Time
>> Message-id: <cb28v302gl8@news3.newsguy.com>
>>
>> Bromo <bromo@ix.netcom.com> wrote:
>>>> Care to provide examples where differences are not measureable?
>>
>>> When you don't know what to measure - or are measuring the wrong things.
>>
>> And I predicted someone would retort in this fashion, several days ago.
>> Thanks for proving me right.
>>
> Are you suggesting we should not worry about people measuring everything that
> matters or failing to measure everything that matters?
>

You should be a bit worried that if you set up a test that shows something
that observation shows otherwise - rather than assume that people are
deluding themselves (which may be entertaining and somewhat possible in some
cases) - you should entertain the notion that the test itself may not be
measuring the right things.

For instance - there is a lot of faith (yes FAITH) placed in ABX tests.
What are you measuring in an ABX test, really? It is repeatable, but is it
measuring the right things in the right method? These are the things that
should be bothering a true scientist. It is a bit like measuring the speed
of gravity and saying that the people who observe a feather falling slower
than a bowling ball are deluding themselves. Perhaps you aren't measuring
the right things .....
 
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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 cb4727021pe@news2.newsguy.com, "Chelvam"
<chelvam@myjaring.net> wrote:

> IF you got through other posts here, especailly the one on Vintage DAC-
> jitter is a higher in separate DAC.
>
> ___
> "Rich.Andrews" <bvzxrpl@swissinfo.org> wrote in message
> news:eek:a7Bc.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.
>>
>
 
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On 6/19/04 11:05 PM, in article oa7Bc.72457$eu.43358@attbi_s02,
"Rich.Andrews" <bvzxrpl@swissinfo.org> wrote:

> "Chelvam" <chelvam@myjaring.net> 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.
 
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S888Wheel <s888wheel@aol.com> wrote:
> From: Steven Sullivan ssully@panix.com
> >Date: 6/19/2004 1:50 PM Pacific Standard Time
> >Message-id: <cb28v302gl8@news3.newsguy.com>
> >
> >Bromo <bromo@ix.netcom.com> wrote:
> >> > Care to provide examples where differences are not measureable?
> >
> >> When you don't know what to measure - or are measuring the wrong things.
> >
> >And I predicted someone would retort in this fashion, several days ago.
> >Thanks for proving me right.
> >
> >
> >--
> >
> >
> >
> >
> >
> Are you suggesting we should not worry about people measuring everything that
> matters or failing to measure everything that matters?

Hardly. I am suggesting that a common subjectivist
reaction to measurement-based claims of 'no audible difference' is that
the wrong thing has been measured. Bromo was kind enough to also allude
to the *other* standby, namely, 'there are things science can't measure
(optional: yet)'.

The first could be true, but without some viable suggestion for
what the 'right thing' might be, it's hand-waving. The second is a
truism, but again, where's the independent evidence or argument-from-data
to believe it's true in *this* case?

--

-S.
Why don't you just admit that you hate music and leave people alone. --
spiffy <thatsright@excite.co>
 

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Steven Sullivan wrote:

> chung <chunglau@covad.net> wrote:
>> Bromo wrote:
>> > On 6/18/04 9:42 PM, in article cb05lj04ne@news3.newsguy.com, "chung"
>> > <chunglau@covad.net> 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 re: 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.
 
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>From: Steven Sullivan ssully@panix.com
>Date: 6/20/2004 9:47 AM Pacific Standard Time
>Message-id: <XcjBc.148843$Ly.52420@attbi_s01>
>
>S888Wheel <s888wheel@aol.com> wrote:
>> From: Steven Sullivan ssully@panix.com
>> >Date: 6/19/2004 1:50 PM Pacific Standard Time
>> >Message-id: <cb28v302gl8@news3.newsguy.com>
>> >
>> >Bromo <bromo@ix.netcom.com> wrote:
>> >> > Care to provide examples where differences are not measureable?
>> >
>> >> When you don't know what to measure - or are measuring the wrong things.
>> >
>> >And I predicted someone would retort in this fashion, several days ago.
>> >Thanks for proving me right.
>> >
>> >
>> >--
>> >
>> >
>> >
>> >
>> >
>> Are you suggesting we should not worry about people measuring everything
>that
>> matters or failing to measure everything that matters?
>
>Hardly. I am suggesting that a common subjectivist
>reaction to measurement-based claims of 'no audible difference' is that
>the wrong thing has been measured.

hardly the case here since nothing since no specific measurements are being
discussed.


Bromo was kind enough to also allude
>to the *other* standby, namely, 'there are things science can't measure
>(optional: yet)'.

Actually he didn't. He was clearly speaking about the possibility in the
practical world that some people may simply not be measuring everything that
makes a difference. He made no mention of anything actually being unmeasurable.
Scroll up and see for yourself.


>
>The first could be true, but without some viable suggestion for
>what the 'right thing' might be, it's hand-waving.


It's all hand waving with out any specifics. That would be the case here on
both sides.



The second is a
>truism, but again, where's the independent evidence or argument-from-data
>to believe it's true in *this* case?

There is no "case" here. One can hardly ask for independent evidence in regards
to arguments over hypathetics.
>
>
>
>
 
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In article <cb4jv201gli@news1.newsguy.com>, chung <chunglau@covad.net>
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
 
G

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Archived from groups: rec.audio.high-end (More info?)

s888wheel@aol.com (S888Wheel) wrote:

>From: Steven Sullivan ss wrote
....snips......

>>Hardly. I am suggesting that a common subjectivist
>>reaction to measurement-based claims of 'no audible difference' is that
>>the wrong thing has been measured.
>
>hardly the case here since nothing since no specific measurements are being
>discussed.
>
>
> Bromo was kind enough to also allude
>>to the *other* standby, namely, 'there are things science can't measure
>>(optional: yet)'.
>
>Actually he didn't. He was clearly speaking about the possibility in the
>practical world that some people may simply not be measuring everything that
>makes a difference. He made no mention of anything actually being
>unmeasurable.
>Scroll up and see for yourself.
>
>>The first could be true, but without some viable suggestion for
>>what the 'right thing' might be, it's hand-waving.
>
>
>It's all hand waving with out any specifics. That would be the case here on
>both sides.

Let me ask again. If I'm not mistaken you have said that anything that can be
heard can be measured or perhaps that was more like 'if you can't measure a
difference than there would be nothing to hear' or something similar. I then
asked exactly what measureable differences would explain amp/cable sound .....
and I don't recall a response.

Again what should we be measuring to confirm 'amp/wire' sound that we haven't
already done?