[Audio_Empire[_2_]]

On Tuesday, December 4, 2012 5:33:07 PM UTC-8, Trevor Wilson wrote:
On 12/5/2012 9:36 AM, Arny Krueger wrote:

"Trevor Wilson" wrote in message
...

On 12/4/2012 2:51 PM, Arny Krueger wrote:

"Audio_Empire" wrote in message
...

FWIW the DBTs that were published in Stereo Review agree with me.

**Please point me to the issue in which this test was published. I have a
pretty decent collection of old audio magazines. If I was really bored,
I'd even pick up an issue of Stereo Review. I may still have it. OTOH, I
still have every issue of Audio magazine I purchased. Now THAT was a
proper audio publication. Stereo Review was strictly a fire-starter only.

Given the utter disdain for SR, I can't imagine why you would want to know
more details.

**SR was for children. Audio was for adults. SR was strictly for
emergency boredom only.

However, this is the reference you seek:

Masters, Ian G. and Clark, D. L., "Do All CD Players Sound the Same?",
Stereo Review, pp.50-57 (January 1986)

**Thanks for that. I'll see if I can locate it.

I am fully aware of the typical high end audiophile disdain for SR and in
particular Julian Hirsch. IME both he and the magazine rocked a lot of
cradles by spiking any number of audiophile myths. Compared to the
underground publications of the day it was a paragon of science and
factuality.

**No, it wasn't. That honour was reserved for Audio magazine. SR was for
children. And rather undiscrinimating ones at that.


Not to mention the fact that Mr. Kruger's reference is an article
written in SR more than a quarter of a century ago and therefore is
really rather irrelevant. Whatever that article concluded, it is of no
value today. DISMISSED!

[Arny Krueger[_5_]]

"Trevor Wilson" wrote in message
...

On 12/5/2012 9:36 AM, Arny Krueger wrote:

I am fully aware of the typical high end audiophile disdain for SR and in
particular Julian Hirsch. IME both he and the magazine rocked a lot of
cradles by spiking any number of audiophile myths. Compared to the
underground publications of the day it was a paragon of science and
factuality.

**No, it wasn't. That honour was reserved for Audio magazine. SR was for
children. And rather undiscrinimating ones at that.

Contrary to some beliefs, publishing good science isn't a zero sum game. I
am under the impression that more than one publication can publish good
science at the same time.

I agree that Audio Magazine published articles with good science, including
the results of a number of DBTs.

Audio also published some articles that weren't so relevant such as the ones
referencing the non-existent audible characteristics of certain plastic
capacitor dielectrics, and allegedly audible op amp slew rate limiting in
then modern op amps that was a complete figment of the author's imagination
and sighted evaluations. Despite the fact that they did publish the results
of some DBTs, Audio was far more indiscriminate than Stereo Review.

[Sebastian Kaliszewski]

On 12/05/2012 11:11 PM, Audio_Empire wrote:
On Tuesday, December 4, 2012 5:33:07 PM UTC-8, Trevor Wilson wrote:
On 12/5/2012 9:36 AM, Arny Krueger wrote:

"Trevor Wilson" wrote in message
...

On 12/4/2012 2:51 PM, Arny Krueger wrote:

"Audio_Empire" wrote in message
...

FWIW the DBTs that were published in Stereo Review agree with me.

**Please point me to the issue in which this test was published. I have a
pretty decent collection of old audio magazines. If I was really bored,
I'd even pick up an issue of Stereo Review. I may still have it. OTOH, I
still have every issue of Audio magazine I purchased. Now THAT was a
proper audio publication. Stereo Review was strictly a fire-starter only.

Given the utter disdain for SR, I can't imagine why you would want to know
more details.

**SR was for children. Audio was for adults. SR was strictly for
emergency boredom only.

However, this is the reference you seek:

Masters, Ian G. and Clark, D. L., "Do All CD Players Sound the Same?",
Stereo Review, pp.50-57 (January 1986)

**Thanks for that. I'll see if I can locate it.

I am fully aware of the typical high end audiophile disdain for SR and in
particular Julian Hirsch. IME both he and the magazine rocked a lot of
cradles by spiking any number of audiophile myths. Compared to the
underground publications of the day it was a paragon of science and
factuality.

**No, it wasn't. That honour was reserved for Audio magazine. SR was for
children. And rather undiscrinimating ones at that.


Not to mention the fact that Mr. Kruger's reference is an article
written in SR more than a quarter of a century ago and therefore is
really rather irrelevant. Whatever that article concluded, it is of no
value today. DISMISSED!


I see no base for your self proclaimed dimission. Did human hearing
change during the last quarter of century? If that article compared CDP
101 to other 1986 players in a blind test then that article is fully
relevant to the discussion wether CDP 101 sounded just fine or terribly.

rgds
\SK

[Trevor Wilson]

On 12/6/2012 9:11 AM, Audio_Empire wrote:
On Tuesday, December 4, 2012 5:33:07 PM UTC-8, Trevor Wilson wrote:
On 12/5/2012 9:36 AM, Arny Krueger wrote:

"Trevor Wilson" wrote in message
...

On 12/4/2012 2:51 PM, Arny Krueger wrote:

"Audio_Empire" wrote in message
...

FWIW the DBTs that were published in Stereo Review agree with me.

**Please point me to the issue in which this test was published. I have a
pretty decent collection of old audio magazines. If I was really bored,
I'd even pick up an issue of Stereo Review. I may still have it. OTOH, I
still have every issue of Audio magazine I purchased. Now THAT was a
proper audio publication. Stereo Review was strictly a fire-starter only.

Given the utter disdain for SR, I can't imagine why you would want to know
more details.

**SR was for children. Audio was for adults. SR was strictly for
emergency boredom only.

However, this is the reference you seek:

Masters, Ian G. and Clark, D. L., "Do All CD Players Sound the Same?",
Stereo Review, pp.50-57 (January 1986)

**Thanks for that. I'll see if I can locate it.

I am fully aware of the typical high end audiophile disdain for SR and in
particular Julian Hirsch. IME both he and the magazine rocked a lot of
cradles by spiking any number of audiophile myths. Compared to the
underground publications of the day it was a paragon of science and
factuality.

**No, it wasn't. That honour was reserved for Audio magazine. SR was for
children. And rather undiscrinimating ones at that.


Not to mention the fact that Mr. Kruger's reference is an article
written in SR more than a quarter of a century ago and therefore is
really rather irrelevant. Whatever that article concluded, it is of no
value today. DISMISSED!


**I dissagree. DBTs are an excellent and very useful tool for
determining the performance of anything. That includes audio equipment.
It is, however, possible to mis-manage a DBT. I am not familiar with the
SR test of CD players and the magazine, if I had it at all, is long
gone. If Mr Krueger still has a copy, perhaps he may be prepared to
email a copy to me, so I can comment. Otherwise, I'll keep searching for
a copy.

That said, I would be far more interested if SR had compared the CDP101
and a far higher performance machine, like the Marantz CD80. I am
reasonably certain that, provided SR used appropriately transparent
amplification and speakers (some nice ESLs would be ideal), that the
differences would be obvious to most educated and experienced listeners.

--
Trevor Wilson www.rageaudio.com.au

[Audio_Empire[_2_]]

On Thursday, December 6, 2012 3:33:28 AM UTC-8, Sebastian Kaliszewski wrote=
:
On 12/05/2012 11:11 PM, Audio_Empire wrote:
=20
On Tuesday, December 4, 2012 5:33:07 PM UTC-8, Trevor Wilson wrote:
=20
On 12/5/2012 9:36 AM, Arny Krueger wrote:
=20

=20
"Trevor Wilson" wrote in message
=20
...
=20

=20
On 12/4/2012 2:51 PM, Arny Krueger wrote:
=20

=20
"Audio_Empire" wrote in message
=20
...
=20

=20
FWIW the DBTs that were published in Stereo Review agree with me.
=20

=20
**Please point me to the issue in which this test was published. I h=
ave a
=20
pretty decent collection of old audio magazines. If I was really bor=
ed,
=20
I'd even pick up an issue of Stereo Review. I may still have it. OTO=
H, I
=20
still have every issue of Audio magazine I purchased. Now THAT was a
=20
proper audio publication. Stereo Review was strictly a fire-starter =
only.
=20

=20
Given the utter disdain for SR, I can't imagine why you would want to=
know
=20
more details.
=20

=20
**SR was for children. Audio was for adults. SR was strictly for
=20
emergency boredom only.
=20

=20
However, this is the reference you seek:
=20

=20
Masters, Ian G. and Clark, D. L., "Do All CD Players Sound the Same?"=
,
=20
Stereo Review, pp.50-57 (January 1986)
=20

=20
**Thanks for that. I'll see if I can locate it.
=20

=20
I am fully aware of the typical high end audiophile disdain for SR an=
d in
=20
particular Julian Hirsch. IME both he and the magazine rocked a lot o=
f
=20
cradles by spiking any number of audiophile myths. Compared to the
=20
underground publications of the day it was a paragon of science and
=20
factuality.
=20

=20
**No, it wasn't. That honour was reserved for Audio magazine. SR was f=
or
=20
children. And rather undiscrinimating ones at that.
=20

=20

=20
Not to mention the fact that Mr. Kruger's reference is an article
=20
written in SR more than a quarter of a century ago and therefore is
=20
really rather irrelevant. Whatever that article concluded, it is of no
=20
value today. DISMISSED!
=20

=20
=20
=20
I see no base for your self proclaimed dimission. Did human hearing=20
=20
change during the last quarter of century? If that article compared CDP=
=20
=20
101 to other 1986 players in a blind test then that article is fully=20
=20
relevant to the discussion wether CDP 101 sounded just fine or terribly.
=20
=20
=20
rgds
=20
\SK

I'll make this easy. No 1986 disc player sounded really good,=20
and almost as importantly, early CDs sucked big-time.=20
Most were mastered from analog sources, and worse, they=20
were mastered from tapes that were intended for mastering=20
LPs, not CD and therefore had (vinyl) disk cutting "moves"=20
applied to them. This caused even the more decent players=20
(actually the only ones that were decent in 1986 were the=20
Magnavox (Philips and some Philip's-based) players, and=20
even those sounded awful with some of the early CDs.=20
I haven't read the referenced article so I don't know what=20
they used for listening material in this test. If they used any=20
of the early CDs, then I don't wonder that they all sounded=20
the same. Still, that's pretty much irrelevant. The discussion=20
was about how bad a Sony CDP-101 sounded next to a more=20
modern player (specifically, I believe, some Marantz D-80=20
was mentioned). In passing, it was noted that the Sony=20
sounded bad then and it sounds bad now. Several other=20
posters argued that the Sony sounds fine, and one poster=20
even said that it's still his primary player. Based on all of this,=20
I maintain that a 1986 DBT of player sound is irrelevant,=20
regardless of it's outcome. =A0Now show me a 2012 DBT=20
that contrasts a modern CD player with the Sony CDP-101=20
and then, the outcome might warrant some attention.

[Audio_Empire[_2_]]

On Wednesday, December 5, 2012 2:14:27 PM UTC-8, Arny Krueger wrote:
"Trevor Wilson" wrote in message=20
=20
...
=20
=20
=20
On 12/5/2012 9:36 AM, Arny Krueger wrote:
=20
=20
=20
I am fully aware of the typical high end audiophile disdain for SR and=
in
=20
particular Julian Hirsch. IME both he and the magazine rocked a lot of
=20
cradles by spiking any number of audiophile myths. Compared to the
=20
underground publications of the day it was a paragon of science and
=20
factuality.
=20
=20
=20
**No, it wasn't. That honour was reserved for Audio magazine. SR was fo=
r=20
=20
children. And rather undiscrinimating ones at that.
=20
=20
=20
Contrary to some beliefs, publishing good science isn't a zero sum game. =
I=20
=20
am under the impression that more than one publication can publish good=
=20
=20
science at the same time.
=20
=20
=20
I agree that Audio Magazine published articles with good science, includi=
ng=20
=20
the results of a number of DBTs.
=20
=20
=20
Audio also published some articles that weren't so relevant such as the o=
nes=20
=20
referencing the non-existent audible characteristics of certain plastic=
=20
=20
capacitor dielectrics, and allegedly audible op amp slew rate limiting in=
=20
=20
then modern op amps that was a complete figment of the author's imaginati=
on=20
=20
and sighted evaluations. Despite the fact that they did publish the resul=
ts=20
=20
of some DBTs, Audio was far more indiscriminate than Stereo Review.

I don't know where you got your information, Mr. Kruger, but I have heard, =
in a=20
ABX test, =A0the difference between Polypropylene capacitors and electrolyt=
ics=20
and different types of non-polarized capacitors. The Polypropylenes were=20
demonstrably cleaner.=20

Also, to dismiss Walt Jung's work with operational amplifiers is actually=
=20
laughable. Early Op-amps were very poor (by todays standards) and=20
were not really suited to audio. They had low slew-rates, yes, but more
importantly, they had asymmetrical slew. Since the positive-going=20
signal in a classic seventies/eighties op amp took a much shorter path=20
through the silicon than did the negative-going signal, the result was=20
unequal rise and fall times for a waveform. Using a 10 KHz square-wave=20
as a test signal, it is easy to see that the rise-time on these devices=20
was much faster on the leading edge than it was on the falling edge.=20
Also, getting back to slew rate, the faster the slew, the more vertical=20
both the rise and the fall slopes were. If you put a current=20
high-performance audio op-amp like the =A0LM49710 through the same=20
test, a 10 KHz square wave looks the same coming out of the op-amp=20
(at any audio gain) as it does from the function generator (which
bespeaks not only faster slew, but symmetrical slew as well). Then=20
there's common-mode rejection. the 741 and 301 family of op-amps=20
had terrible CMR compared to today's audio specific op amps. As for=20
noise, the aforementioned LM49710 has 2nV/root Hertz of self noise.
Contrast that with a 741 type which has over 20+ Nv/root Herz. That's=20
an order of magnitude more noise. =A0

I used to own a Crown IC150 preamp. It came with LM301s as the=20
active gain stage. The only thing that it had going for it (other=20
than being constructed like a tank) was that the two op-amps were=20
socketed for mini-DIPs, Every time I upgraded the op-amp with=20
newer ones (the last upgrade was a pair of Burr-Brown OPA27s),=20
it brought measurably improved performance and audibly=20
superior sound.

No wonder high-end audio designers such as Nelson Pass and=20
John Curl (to name but two), until recently, avoided op-amps=20
like the plague .=20

BTW, One of the reason why early CDs sounded so bad is that=20
they were all mastered using a Sony PCM-1600, 1610, 1620,=20
or 1630 digital processor. These things were chock-full of 741=20
op amps and aluminum electrolytic coupling capacitors. The=20
sound wouldn't have had a snowball's chance in hades of being=20
decent, even if the A/D converters in those processors DID have=20
something close to an actual 16-bit resolution (which they didn't.=20
Most early A/D (and DACs) were lucky to get 13-bit resolution
from a 16-bit unit.=20

[Audio_Empire[_2_]]

On Thursday, December 6, 2012 3:18:24 PM UTC-8, Trevor Wilson wrote:
On 12/6/2012 9:11 AM, Audio_Empire wrote:

On Tuesday, December 4, 2012 5:33:07 PM UTC-8, Trevor Wilson wrote:

On 12/5/2012 9:36 AM, Arny Krueger wrote:



"Trevor Wilson" wrote in message

...



On 12/4/2012 2:51 PM, Arny Krueger wrote:



"Audio_Empire" wrote in message

...



FWIW the DBTs that were published in Stereo Review agree with me.



**Please point me to the issue in which this test was published. I have a

pretty decent collection of old audio magazines. If I was really bored,

I'd even pick up an issue of Stereo Review. I may still have it. OTOH, I

still have every issue of Audio magazine I purchased. Now THAT was a

proper audio publication. Stereo Review was strictly a fire-starter only.



Given the utter disdain for SR, I can't imagine why you would want to know

more details.



**SR was for children. Audio was for adults. SR was strictly for

emergency boredom only.



However, this is the reference you seek:



Masters, Ian G. and Clark, D. L., "Do All CD Players Sound the Same?",

Stereo Review, pp.50-57 (January 1986)



**Thanks for that. I'll see if I can locate it.



I am fully aware of the typical high end audiophile disdain for SR and in

particular Julian Hirsch. IME both he and the magazine rocked a lot of

cradles by spiking any number of audiophile myths. Compared to the

underground publications of the day it was a paragon of science and

factuality.



**No, it wasn't. That honour was reserved for Audio magazine. SR was for

children. And rather undiscrinimating ones at that.





Not to mention the fact that Mr. Kruger's reference is an article

written in SR more than a quarter of a century ago and therefore is

really rather irrelevant. Whatever that article concluded, it is of no

value today. DISMISSED!





**I dissagree. DBTs are an excellent and very useful tool for

determining the performance of anything. That includes audio equipment.

It is, however, possible to mis-manage a DBT. I am not familiar with the

SR test of CD players and the magazine, if I had it at all, is long

gone. If Mr Krueger still has a copy, perhaps he may be prepared to

email a copy to me, so I can comment. Otherwise, I'll keep searching for

a copy.



That said, I would be far more interested if SR had compared the CDP101

and a far higher performance machine, like the Marantz CD80. I am

reasonably certain that, provided SR used appropriately transparent

amplification and speakers (some nice ESLs would be ideal), that the

differences would be obvious to most educated and experienced listeners.



--

Trevor Wilson www.rageaudio.com.au

I would love to see that DBT, but since SR is RIP, they don't have an
archive. Unless someone has a copy of the magazine, I'm afraid it's
probably no way to view the test.

[Arny Krueger[_5_]]

"Trevor Wilson" wrote in message
...

That said, I would be far more interested if SR had compared the CDP101
and a far higher performance machine, like the Marantz CD80.

They did.

I am reasonably certain that, provided SR used appropriately transparent
amplification and speakers (some nice ESLs would be ideal), that the
differences would be obvious to most educated and experienced listeners.

The speakers were if memory serves the larger Magnepans and the
amplification was Hafler.

[Audio_Empire[_2_]]

On Friday, December 7, 2012 2:50:42 PM UTC-8, Arny Krueger wrote:
"Trevor Wilson" wrote in message

...



That said, I would be far more interested if SR had compared the CDP101

and a far higher performance machine, like the Marantz CD80.



They did.



I am reasonably certain that, provided SR used appropriately transparent

amplification and speakers (some nice ESLs would be ideal), that the

differences would be obvious to most educated and experienced listeners.



The speakers were if memory serves the larger Magnepans and the

amplification was Hafler.

Nothing wrong there. Magnepans had limitations, but nothing that would affect
the outcome of a DBT. And Hafler amps were very clean mostly transparent, so
no problem there either. Like I said, I would love to see that DBT just for general
interest.

[Arny Krueger[_5_]]

"Audio_Empire" wrote in message
...

I'll make this easy. No 1986 disc player sounded really good,

It is easy to prove that by then the better players were sonically
perfect-their interposition into a high quality audio chain had no audible
consequences.

and almost as importantly, early CDs sucked big-time.

If I go back and listen to the first 100 or CD that I bought then they
showed the normal variations in sound quality. Some were great, some sucked.
No instances of hypercompression, for example.

Most were mastered from analog sources,

So that means I can dismiss every post ever made about the glories of either
LP or analog tape sound? ;-)

and worse, they ere mastered from tapes that were intended for mastering
LPs, not CD and therefore had (vinyl) disk cutting "moves" applied to
them.

The above comment shows a complete and total lack of correct information
about the production procedures of the day.

Yes, high volume recordings had both "cutting masters" and "duping masters"
that included any number of audible tweaks to improve someone's perceptions
of the sounds of LPs and cassettes duplicated from them, respectively. These
were made from "grand masters" that contained no such concessions to the
limitations of analog media.

Digital mastering preceeded the introduction of the CD by 5 years or more.

So, the above comments lack credibility on the grounds that they do not
reflect correct knowlege about the audio production techniques of the times
that they attempt to represent. More like audiophile myth than generally
accepted practice.

[Arny Krueger[_5_]]

"Audio_Empire" wrote in message
...

Nothing wrong there. Magnepans had limitations, but nothing that would
affect
the outcome of a DBT. And Hafler amps were very clean mostly transparent,
so
no problem there either. Like I said, I would love to see that DBT just
for general
interest.

The fact of the matter is that said DBTs happened right in front of my nose.
They reflected the best wisdom of the day related to doing reliable and
sensitive DBTs. They were based over 12 years of practical experience doing
DBTs.

[Arny Krueger[_5_]]

"Audio_Empire" wrote in message
...
On Wednesday, December 5, 2012 2:14:27 PM UTC-8, Arny Krueger wrote:

I don't know where you got your information, Mr. Kruger, but I have heard,
in a
ABX test, the difference between Polypropylene capacitors and
electrolytics
and different types of non-polarized capacitors. The Polypropylenes were
demonstrably cleaner.

It is true that if you do not use correct engineering practices with any
electronic part particularly Hi-K ceramic and electrolytic capacitors, that
audible differences will be found.

It appears to me that you have proven that to be true. Congratulations upon
your rediscovery of the wheel! ;-)

Of far greater value is knowlege and application of correct engineering
practices for using the various kinds of electronic parts that exist. It is
possible to build a wide range of sonically transparent audio components
that incorporate electrolytic capacitors. You just got to do it right, and
many engineers seem to know how to do it.

Also, to dismiss Walt Jung's work with operational amplifiers is actually
laughable.

Some of Walt's worked was spot on, but of course that work related to op amp
properties that were well known in the audio industry in that day. It may
have made good reading for amateurs and poorly-informed professionals (which
abound) but nobody who had done any serious work with op amps and audio in
that day was surprised.

Other of Walt's work relating to the audibility of presumed defects in high
quality op amps of the day are shall we say difficult to confirm no matter
how sensitive the listening test you perform. If you simply look at his
measured results and compare them to what is far more widely known today
about psychoacoustics, serious questions arise. Further investigation of
these questions suggests that science is indeed consistent with itself and
some of his claims were unhhh... controversial.

[Trevor Wilson]

On 12/8/2012 9:50 AM, Arny Krueger wrote:
"Trevor Wilson" wrote in message
...

That said, I would be far more interested if SR had compared the CDP101
and a far higher performance machine, like the Marantz CD80.

They did.

**The difference is, I can assure you, significant. Do you have the
article? Would you be prepared to email a copy?


I am reasonably certain that, provided SR used appropriately transparent
amplification and speakers (some nice ESLs would be ideal), that the
differences would be obvious to most educated and experienced listeners.

The speakers were if memory serves the larger Magnepans and the
amplification was Hafler.

**Maggies using ribbon tweeters are suitably neutral. The Hafler XL280
is average. Hafler preamps are extremely ordinary. Don't even think
about the earlier Hafler power amps. None are overly transparent, IMO.
ALL suffer with the usual issues afflicting early MOSFET amps - poor
micro and macro dynamics, veiling, etc. A Phase Linear would be a MUCH
better choice. Primitive that they were, they still sounded a bunch
better than any Hafler.


--
Trevor Wilson www.rageaudio.com.au

[Trevor Wilson]

On 12/8/2012 9:50 AM, Arny Krueger wrote:
"Trevor Wilson" wrote in message
...

That said, I would be far more interested if SR had compared the CDP101
and a far higher performance machine, like the Marantz CD80.

They did.

**Dunno how I missed this. The CD80 was not available until well past
1986 (the publication date of the article). Around 1989, as I best recall.


--
Trevor Wilson www.rageaudio.com.au

[Scott[_6_]]

On Dec 8, 7:30*am, "Arny Krueger" wrote:
"Audio_Empire" wrote in message

...

Nothing wrong there. Magnepans had limitations, but nothing that would
affect
the outcome of a DBT. And Hafler amps were very clean mostly transparent,
so
no problem there either. Like I said, I would love to see that DBT just
for general
interest.

The fact of the matter is that said DBTs happened right in front of my nose.
They reflected the best wisdom of the day related to doing reliable and
sensitive DBTs. They were based over 12 years of practical experience doing
DBTs.

Given your stated position in this very thread on the lack of need to
control for same sound biases in ABX DBTs and given the well known
biases of some of the folks who were involved in those tests I would
have to put the results of those tests in the highly tainted anecdotal
evidence bin. Unless of course you can cite the controls used in those
tests to prevent the effects of same sound bias from affecting the
results. I really doubt this represented the best wisdom of the day
given the fact that the real pros doing scientific research on human
hearing knew very well back then that there was a need for controls
for *all* known biases for any given DBT test.

[Trevor Wilson]

On 12/9/2012 4:25 AM, ScottW wrote:
On Dec 7, 2:50 pm, Audio_Empire wrote:
On Wednesday, December 5, 2012 2:14:27 PM UTC-8, Arny Krueger wrote:
"Trevor Wilson" wrote in message

...

On 12/5/2012 9:36 AM, Arny Krueger wrote:

I am fully aware of the typical high end audiophile disdain for SR and in

particular Julian Hirsch. IME both he and the magazine rocked a lot of

cradles by spiking any number of audiophile myths. Compared to the

underground publications of the day it was a paragon of science and

factuality.

**No, it wasn't. That honour was reserved for Audio magazine. SR was for

children. And rather undiscrinimating ones at that.

Contrary to some beliefs, publishing good science isn't a zero sum game. I

am under the impression that more than one publication can publish good

science at the same time.

I agree that Audio Magazine published articles with good science, including

the results of a number of DBTs.

Audio also published some articles that weren't so relevant such as the ones

referencing the non-existent audible characteristics of certain plastic

capacitor dielectrics, and allegedly audible op amp slew rate limiting in

then modern op amps that was a complete figment of the author's imagination

and sighted evaluations. Despite the fact that they did publish the results

of some DBTs, Audio was far more indiscriminate than Stereo Review.

I don't know where you got your information, Mr. Kruger, but I have heard, in a
ABX test, the difference between Polypropylene capacitors and electrolytics
and different types of non-polarized capacitors. The Polypropylenes were
demonstrably cleaner.

Also, to dismiss Walt Jung's work with operational amplifiers is actually
laughable. Early Op-amps were very poor (by todays standards) and
were not really suited to audio. They had low slew-rates, yes, but more
importantly, they had asymmetrical slew. Since the positive-going
signal in a classic seventies/eighties op amp took a much shorter path
through the silicon than did the negative-going signal, the result was
unequal rise and fall times for a waveform. Using a 10 KHz square-wave
as a test signal, it is easy to see that the rise-time on these devices
was much faster on the leading edge than it was on the falling edge.
Also, getting back to slew rate, the faster the slew, the more vertical
both the rise and the fall slopes were. If you put a current
high-performance audio op-amp like the LM49710 through the same
test, a 10 KHz square wave looks the same coming out of the op-amp
(at any audio gain) as it does from the function generator (which
bespeaks not only faster slew, but symmetrical slew as well).


What relationship does square wave reproduction have to
audio signal amplification?

**A great deal, as it happens. For a tech, a square wave can us an
enormous amount about an audio system, very rapidly. 16/44 digital
systems cannot accurately reproduce a square wave of more than 7kHz.
Early CD players, like the CDP101, could barely reproduce a 5kHz square
wave with anything approaching reasonable fidelity. If an amplifier
produced performance as mediocre as the average 16/44 machine, it would
be condemned by every reviewer, outside those who review SET amplifiers.


If slew rate limitations had any impact to an audio signal, I think
it would show up in simple FR tests.

**Not quite. Digitally reconstrcuted signals work differently to
analogue systems. In an analogue system where the -3dB point is (say)
22kHz (and a 6dB/octave roll-off), a reasonable facsimile of a (say)
10kHz square wave can be reproduced. In a 16/44 digital system, a 10kHz
square wave is impossible to reproduce. The system will likely reproduce
a sine wave, or something approximating it.

FWIW: A well trained ear can perceive the difference between a 5kHz
square wave and a 5kHz sine wave easily. A 7kHz waveform is more
difficult, but not impossible.

Read up on: 'Power under the curve'. It will all make sense. Square
waves deliver more power than sine waves, for a given frequency and peak
to peak amplitude.



--
Trevor Wilson www.rageaudio.com.au

[Audio_Empire[_2_]]

On Saturday, December 8, 2012 7:30:01 AM UTC-8, Arny Krueger wrote:
"Audio_Empire" wrote in message

...



I'll make this easy. No 1986 disc player sounded really good,



It is easy to prove that by then the better players were sonically

perfect-their interposition into a high quality audio chain had no audible

consequences.



and almost as importantly, early CDs sucked big-time.



If I go back and listen to the first 100 or CD that I bought then they

showed the normal variations in sound quality. Some were great, some sucked.

No instances of hypercompression, for example.



Most were mastered from analog sources,



So that means I can dismiss every post ever made about the glories of either

LP or analog tape sound? ;-)



and worse, they ere mastered from tapes that were intended for mastering

LPs, not CD and therefore had (vinyl) disk cutting "moves" applied to

them.



The above comment shows a complete and total lack of correct information

about the production procedures of the day.



Yes, high volume recordings had both "cutting masters" and "duping masters"

that included any number of audible tweaks to improve someone's perceptions

of the sounds of LPs and cassettes duplicated from them, respectively. These

were made from "grand masters" that contained no such concessions to the

limitations of analog media.



Digital mastering preceeded the introduction of the CD by 5 years or more.



So, the above comments lack credibility on the grounds that they do not

reflect correct knowlege about the audio production techniques of the times

that they attempt to represent. More like audiophile myth than generally

accepted practice.

Methinks Mr. Kruger is out of his depth here and shows little or no knowledge
of how many early classical CDs were produced. Teldec, DGG and EMI have
all admitted that they used record cutting masters in many early classical CD
productions to expedite getting product to market. I'm talking strictly classical
music here. Whether or not pop titles were handled in the same way. I don't
know or care as I have no regard for these types of music.

[Audio_Empire[_2_]]

On Saturday, December 8, 2012 7:31:17 AM UTC-8, Arny Krueger wrote:
"Audio_Empire" wrote in message

...

On Wednesday, December 5, 2012 2:14:27 PM UTC-8, Arny Krueger wrote:



I don't know where you got your information, Mr. Kruger, but I have heard,

in a

ABX test, the difference between Polypropylene capacitors and

electrolytics

and different types of non-polarized capacitors. The Polypropylenes were

demonstrably cleaner.



It is true that if you do not use correct engineering practices with any

electronic part particularly Hi-K ceramic and electrolytic capacitors, that

audible differences will be found.

This is ridiculous. The qualities of capacitors in audio engineering has
been known for decades. But you just said in a previous post that Audio
Magazine's articles about capacitor sound were suspect. If one designs a
piece of gear using aluminum, polarized electrolytic capacitors or Tantalums
as coupling capacitors in a piece of audio gear, then that gear has been
poorly designed. Yet most Japanese gear routinely used electrolytics as
interstage coupling. If you take a piece of such gear and parallel the
electrolytics with small polypropylene capacitors to bypass the high
frequencies, the device will sound better. Lots of times, Mylar capacitors
were used for coupling due to cost considerations. This design decision
is not an engineering decision, its a bean-counter decision carried out by
the design engineer(s). Yet, again, if you replace the Mylar capacitors with
polypropylene "Wonder Caps" or "Sideral Caps" the device sounds better.
I was part of a DBT where two Hafler preamps were built as kits. One was
built totally stock. The other was built (by me) replacing every Mylar
capacitor in the signal chain with "Wonder Caps" and the two were compared.
The assembled listeners unanimously picked the modified preamp as sounding
the best every time.

All the article in audio did was to try to explain the mechanism (Dielectric
Absorption Distortion) that caused some capacitors to cause a lot
of distortion that did not show-up using conventional sine-wave
distortion tests while other caps using different dielectric material
to have less of this, clearly audible distortion.



It appears to me that you have proven that to be true. Congratulations upon

your rediscovery of the wheel! ;-)



Of far greater value is knowlege and application of correct engineering

practices for using the various kinds of electronic parts that exist. It is

possible to build a wide range of sonically transparent audio components

that incorporate electrolytic capacitors. You just got to do it right, and

many engineers seem to know how to do it.

While that's obvious. What should also be obvious is that many times
the choice of components is often an economic choice made to insure
that a design meets its selling price goals. Sure, Wonder Caps were
more expensive than say Mylars of the same value and lots more
expensive than aluminum electrolytics. Some companies like
Audio Research used polypropylenes in their designs because price
wasn't the object for them that it would be for say, Sony, or Technics
or any other "mid-fi" manufacturer.



Also, to dismiss Walt Jung's work with operational amplifiers is actually

laughable.



Some of Walt's worked was spot on, but of course that work related to op amp

properties that were well known in the audio industry in that day. It may

have made good reading for amateurs and poorly-informed professionals (which

abound) but nobody who had done any serious work with op amps and audio in

that day was surprised.

This isn't about what was known and what was unknown. Yes, of course, Jung was
writing for an enthusiast magazine. Yes, to an engineer with experience using
op-amps, his articles in audio were a bit pedantic. So what? The audience the
magazine was aiming at is mostly not design engineers, but were audiophiles
equipment sellers, and other audio professionals who were not designers. That
doesn't mean that Jung's articles should be dismissed, And for your edification
the distortions inherent to slow slew rates and asymmetrical slew characterized
by Jung IS audible.



Other of Walt's work relating to the audibility of presumed defects in high

quality op amps of the day are shall we say difficult to confirm no matter

how sensitive the listening test you perform. If you simply look at his

measured results and compare them to what is far more widely known today

about psychoacoustics, serious questions arise. Further investigation of

these questions suggests that science is indeed consistent with itself and

some of his claims were unhhh... controversial.

They may be controversial to those who haven't been in a position (or lack
the listening skills) to hear these effects. But those of us who have been in
such a position and have heard these effects, as described by Jung, don't
find them controversial at all.

[Audio_Empire[_2_]]

On Saturday, December 8, 2012 9:25:43 AM UTC-8, ScottW wrote:
What relationship does square wave reproduction have to
audio signal amplification?


You're joking, right? Square waves tell a lot about the linearity
and the bandwidth of an amplifier. Looking at square waves
can show if the amplifier is either integrating or differentiating
the signal, it will indicate overshoot, ringing, asymmetrical slew,
whereby the rise and fall times of the op-amp are different
(not good) and the slew-rate itself will show gain-bandwidth
limitations of the op-amp in question. slow rise and fall times
can indicate the presence of slew-induced and transient
intermodulation distortion. These tests are most likely to be
used to test suitability of an op-amp to the task for which it's
being chosen. Ideally, an op-amp will pass a perfectly square
waveform with no other signal riding on the horizontal portions
of the wave, and it will have perfectly vertical rise and fall with
no overshoot and with the tops and bottom of the wave being
perfectly flat and the transitions forming exact 90 degree angles
at all the frequencies in the op-amp's passband. Now this is a
theoretical ideal, and not obtainable, but where and how a real
world op-amp differs from the ideal characteristics shows
the device's limitations and suitability for its application.


If slew rate limitations had any impact to an audio signal, I think
it would show up in simple FR tests.

Did you mean FIR (Finite Impulse Response) tests?

It depends. Slew rate is definitely linked to gain-bandwidth
of a device. This is easily measured using FFT (Fast Fourier
Transform) tests, but slew also determines the device's
ability to correctly reproduce transient sounds, and this
is best determined by tests which directly measure rise and
fall times. So-called "smart" oscilloscopes are best for this,
but really, any oscilloscope with the bandwidth and resolution
to allow one to measure time directly on the 'scope's graticule
is usually sufficient.

[Trevor Wilson]

On 12/10/2012 9:42 AM, ScottW wrote:
On Dec 8, 5:21 pm, Trevor Wilson
wrote:
On 12/9/2012 4:25 AM, ScottW wrote:





On Dec 7, 2:50 pm, Audio_Empire wrote:
On Wednesday, December 5, 2012 2:14:27 PM UTC-8, Arny Krueger wrote:
"Trevor Wilson" wrote in message

...

On 12/5/2012 9:36 AM, Arny Krueger wrote:

I am fully aware of the typical high end audiophile disdain for SR and in

particular Julian Hirsch. IME both he and the magazine rocked a lot of

cradles by spiking any number of audiophile myths. Compared to the

underground publications of the day it was a paragon of science and

factuality.

**No, it wasn't. That honour was reserved for Audio magazine. SR was for

children. And rather undiscrinimating ones at that.

Contrary to some beliefs, publishing good science isn't a zero sum game. I

am under the impression that more than one publication can publish good

science at the same time.

I agree that Audio Magazine published articles with good science, including

the results of a number of DBTs.

Audio also published some articles that weren't so relevant such as the ones

referencing the non-existent audible characteristics of certain plastic

capacitor dielectrics, and allegedly audible op amp slew rate limiting in

then modern op amps that was a complete figment of the author's imagination

and sighted evaluations. Despite the fact that they did publish the results

of some DBTs, Audio was far more indiscriminate than Stereo Review.

I don't know where you got your information, Mr. Kruger, but I have heard, in a
ABX test, the difference between Polypropylene capacitors and electrolytics
and different types of non-polarized capacitors. The Polypropylenes were
demonstrably cleaner.

Also, to dismiss Walt Jung's work with operational amplifiers is actually
laughable. Early Op-amps were very poor (by todays standards) and
were not really suited to audio. They had low slew-rates, yes, but more
importantly, they had asymmetrical slew. Since the positive-going
signal in a classic seventies/eighties op amp took a much shorter path
through the silicon than did the negative-going signal, the result was
unequal rise and fall times for a waveform. Using a 10 KHz square-wave
as a test signal, it is easy to see that the rise-time on these devices
was much faster on the leading edge than it was on the falling edge.
Also, getting back to slew rate, the faster the slew, the more vertical
both the rise and the fall slopes were. If you put a current
high-performance audio op-amp like the LM49710 through the same
test, a 10 KHz square wave looks the same coming out of the op-amp
(at any audio gain) as it does from the function generator (which
bespeaks not only faster slew, but symmetrical slew as well).

What relationship does square wave reproduction have to
audio signal amplification?

**A great deal, as it happens. For a tech, a square wave can us an
enormous amount about an audio system, very rapidly. 16/44 digital
systems cannot accurately reproduce a square wave of more than 7kHz.
Early CD players, like the CDP101, could barely reproduce a 5kHz square
wave with anything approaching reasonable fidelity. If an amplifier
produced performance as mediocre as the average 16/44 machine, it would
be condemned by every reviewer, outside those who review SET amplifiers.

Without real cause as their complaints are fundamentally a lack of BW
beyond 20kHz.

**Not so. There is more to it.


The reason a CD cannot reasonably produce a square wave of more than
7kHz is because the BW to reproduce the 3rd and 5th harmonics is not
present.

**Grandmother, eggs, suck.




If slew rate limitations had any impact to an audio signal, I think
it would show up in simple FR tests.

**Not quite. Digitally reconstrcuted signals work differently to
analogue systems. In an analogue system where the -3dB point is (say)
22kHz (and a 6dB/octave roll-off), a reasonable facsimile of a (say)
10kHz square wave can be reproduced. In a 16/44 digital system, a 10kHz
square wave is impossible to reproduce. The system will likely reproduce
a sine wave, or something approximating it.

Exactly...you're making my point by complaining about a lack of BW
beyond the audible range.

**Let's get back on topic. Specifically: The Sony CDP101 vs. a more
advanced player. The CDP101 cannot manage a 7kHz square wave.
Additionally, you seem to be labouring under the misapprehension that
human hearing has some kind of brickwall filter at 20kHz. It ain't so.
In my younger days (mid-20s) I found that I was unable to walk into one
of the warehouses that was owned by the company I worked for. Some
testing showed that the ultrasonic sensors used by the alarm system were
unbearably loud to me and one or two others in the company. A frequency
counter confirmed that they were operating at close to 25kHz.


FWIW: A well trained ear can perceive the difference between a 5kHz
square wave and a 5kHz sine wave easily. A 7kHz waveform is more
difficult, but not impossible.

5 kHz square waves need 3rd (and with measurement tools better than
the crappy human ear 5th order harmonics) to be reasonably accurately
recreated....or 15 khz.
It's obvious why a 7 kHz square wave sounds like a sine wave...unless
you can detect the lack of a 21 kHz harmonic.


Read up on: 'Power under the curve'. It will all make sense. Square
waves deliver more power than sine waves, for a given frequency and peak
to peak amplitude.

Square waves are useful for identifyling measurable performance
differences in amplifiers. But those differences being audible or
having impact on the output of audio BW signal (20 to 20 Khz) is
completely different matter.

**I suggest you examine the square wave output from a Sony CDP101
sometime. It ain't all that good.


--
Trevor Wilson www.rageaudio.com.au

[Audio_Empire[_2_]]

On Sunday, December 9, 2012 2:42:49 PM UTC-8, ScottW wrote:
On Dec 8, 5:21=A0pm, Trevor Wilson

Square waves are useful for identifyling measurable performance
=20
differences in amplifiers. But those differences being audible or
=20
having impact on the output of audio BW signal (20 to 20 Khz) is
=20
completely different matter.

The main reason, in my humble opinion, why square waves are=20
important is to measure rise and fall times, and to look at amplifier=20
linearity in the frequency domain. A square wave will show=20
if an amp integrates or differentiates an audio signal (either by=20
design or inadvertently) and to check the slew of the op-amp,=20
and to see if the slew is symmetrical or not. These last two might=20
not be important in some applications, but in audio, they certainly are.

[Dick Pierce[_2_]]

Audio_Empire wrote:
The main reason, in my humble opinion, why square waves are
important is to measure rise and fall times, and to look at amplifier
linearity in the frequency domain. A square wave will show
if an amp integrates or differentiates an audio signal (either by
design or inadvertently) and to check the slew of the op-amp,
and to see if the slew is symmetrical or not. These last two might
not be important in some applications, but in audio, they certainly are.

So let's take a specific case, relevant to the problem
at hand: the output of a DAC. How relevantis slew rate,
REALLY, in such a case?

Let's assume the DAC output at digital full scale is 2
volts RMS. That's 2.8 volts peak. Now, we can say with
some certainty that the highest possible frequency of
interest is 20 kHz, but let's go overboard a bit an
say it's really 25 kHz. And let's go one step further and
assume some combination of signals might cause the peak
to go to 4 volts (theoretically possible, but requires
some rather extraordinary conditions EXTREMELY improbable
in actual music). What's the slew rate requirement needed
to go there?

The instantaneous output voltage goes as:

Vt = Vpk sin(w * t)

where w is radian frequency (2 pi F), vPk is the peak
output voltage and t is time. Now, to get the rate of
change with respect to t, we have to differentiate, thus:

dV/dt = w Vpk cos(w * t)

the maximum rate of change will occur when cos(w * t) = 1,
so let's assume that condition. w in our case is 2 pi * 25,000
or 157 radians/sec. Thus:

dV/dT = 157,000r/sec * 4 volts

or 628,000 volts per second.

That seems like a lot, at least until you scale it to the same
units typically used in op amp specifications, e.g., volt/uS.

In which case, it's a measily 0.628 volts per microsecond.

Now, let's see how that compares to real op amps. And, just
for laughs, let's use one of the proponents of the importance
of "slew-induced distortion," Walter Jung, as the source for
our data.

Let's take the measily, over 40 year-old uA741: 0.5 v/uS. Yeah,
I might agree, it's not up to the task. Do any CD players or
DACs you are aware of use 741's in the audio path?

Well, then, how about comething a little more contemporary, like
the boringly common 5532, at 9 v/uS. Plenty of room, I would say.
And that's a design nearly as old as the CD itself.

How about some other, really common things, like the 4558: well,
that's 1.7 v/uS. TL072: 13 v/uS.

Another selection criteria: available at Radio Shack. LF411: 10v/uS,
LM301: 10 v/us, LM387: 6 v/us.

So, now, the question, Mr. Empire, is: do you have ANY data showing
ANY DAC or CD player suffering from slew rate limiting?

--
+--------------------------------+
+ Dick Pierce |
+ Professional Audio Development |
+--------------------------------+

[Dick Pierce[_2_]]

Audio_Empire wrote:
On Saturday, December 8, 2012 9:25:43 AM UTC-8, ScottW wrote:

What relationship does square wave reproduction have to
audio signal amplification?

You're joking, right?

I might suspect he is not.

Square waves tell a lot about the linearity
and the bandwidth of an amplifier.

They tell us nothing about the linearity. Let me illustrate
to proofs of this.

Take an amplifier that requires, say, 0.1 volts to drive
it to it's sull output level of 1 volt. Drive it with
a 10 v pk-pk squat=re wave, and examine its output. What does
the result square wave output tell us about the fact that
we are driving the amplifier FAR into it's non-linear region.
Second, drive the input to a 74HCTF00 gate with a 10 kHz square
wave, assume the output is properly loaded. What does the
resulting square wave tell us about the linearity of a 74HCTF00
gate?

Looking at square waves can show if the amplifier is either
integrating or differentiating the signal,

ALL amplifiers integrate, unless you are suggesting there are
some that have infinite bandwidth. And ALL AC-couple amplifiers
differentiate.

So what?

it will indicate overshoot, ringing, asymmetrical slew,
whereby the rise and fall times of the op-amp are different
(not good) and the slew-rate itself will show gain-bandwidth
limitations of the op-amp in question. slow rise and fall times
can indicate the presence of slew-induced and transient
intermodulation distortion. These tests are most likely to be
used to test suitability of an op-amp to the task for which it's
being chosen. Ideally, an op-amp will pass a perfectly square
waveform with no other signal riding on the horizontal portions
of the wave, and it will have perfectly vertical rise and fall with
no overshoot and with the tops and bottom of the wave being
perfectly flat and the transitions forming exact 90 degree angles
at all the frequencies in the op-amp's passband. Now this is a
theoretical ideal, and not obtainable, but where and how a real
world op-amp differs from the ideal characteristics shows
the device's limitations and suitability for its application.

And it's the last 4 words of your paragraph that are the most
relevant, and ones that seem to be universally ignored by a large
portion of the audio community. Those words are "suitability
for its application."

What is the application here" Audio reproduction, I think, yes?

That sets VERY loose requirements on the "suitability for
application," like it or not.

Let's assume, for the moment, that the required bandwidth is 20 kHz.
In the world of analog design, that's NOTHING. And ANY decent
square wave generator set to 1 kHz FAR, exceeds the requirements
for audo bandwidth.

Back in the days when tube amplifiers had narrow bandwidths and
decidely non-linear phase behavior, they might make it to 20 Hz to
20 kHz but would already exhibit half their ultimate phase shifts
at those frequencies. And the square waves would show it. But
so would a simple frequency response.

So what?

If slew rate limitations had any impact to an audio signal, I think
it would show up in simple FR tests.

Did you mean FIR (Finite Impulse Response) tests?

WHat on earth is a "finite impulse response " test? I
do a lot of DSP work, and I've heard of FIR filters, but I
ain't ever heard of a "finite impulse response test."

I think the gentleman is referring to a very common abbreviation
for a Bode plot, a magnitude vs frequency plot, or, what some
might also call a "frequency response" test.

And if that's what he means, then he's absolutely right, slew-rate
limitations will be apparent in a standard FR plot done at maximum
amplitude.

It depends. Slew rate is definitely linked to gain-bandwidth
of a device. This is easily measured using FFT (Fast Fourier
Transform) tests,

And how is that done, if you will?

but slew also determines the device's
ability to correctly reproduce transient sounds,

IF AND ONLY IF the input signal exceeds the slew rate capability
of the device. What kind of audio signals do that? What kind of
signals from a DAC do that?

and this
is best determined by tests which directly measure rise and
fall times.

Sorry, but rise time and slew rate are different measurements,
related, but different.

So-called "smart" oscilloscopes are best for this,
but really, any oscilloscope with the bandwidth and resolution
to allow one to measure time directly on the 'scope's graticule
is usually sufficient.

So, a little bacjkground, if you will.

In 1976, I worked for Leon Kuby who, at the time, was the
director of technical training for Harmnn Kardan, JBL, etc.
It was just at this time when Harman was touting it's square-wave
criteria for audio electronics, and they were pushing it HARD.
And I was required to push it hard. It was a pure marketing
initiative. No one in engineering at either Harnman or JBL or
the other divisions, which at the time included diverse companies
like Ortofon and Tannoy (remember "Tannoy" without the "T" spells
....), could provide a technical basis for the excessive obsession
with sqaure wave performance.

Most escpecaiily troubling was the fact that at the time, there did
not exist a single consumer music delivery medium which could come
anywhere NEAR the square wave performance of ANY consumer product
of the time. LPs were off by an order of magnitude, as was the
highest-quality FM broadcast, analog tape, cassette, and so on.
Even at the time and since then, the micriphone used for producing
recordings fell orders of magnitude short.

If the assertion is that slew rate performance is critical, show
us products that exxhibit slew-rate limiting. I mean, using your
fancy "smart scope" or FFT of "finite impulse response test,"
show us where this REALLY is a problem.

Please.

Becasue all of my scopes, smart and dumb alike, all of my FFTs
DO NOT EVERY show this to be a problem with audio signals delivered
by music-delivery media. (Now, I don't know how to do "finite
impulse response tests, so it's possible I'm missing something.
But I don't think so.)

The bottom line: how does the square wave response of a system
relate in a RELEVANT fashion to the required performance for
producing audio signals when the bandwidth of a sqaure wave FAR
exceeds that of the audio signals?

In other words how is it "suitable for the application?"

--
+--------------------------------+
+ Dick Pierce |
+ Professional Audio Development |
+--------------------------------+

[Dick Pierce[_2_]]

Trevor Wilson wrote:
FWIW: A well trained ear can perceive the difference between a 5kHz
square wave and a 5kHz sine wave easily. A 7kHz waveform is more
difficult, but not impossible.

This is all based on a common, but seriously flawed, "test."
This claim has been repeated over and over, yet has been debunked
over an over.

The test (and claim) goes something like this: take a function
generator, run the dial up to 7 kHz, and switch between sine
and square wave: the difference is audible.

Now, the conclusion drawn is that the hear can hear the
difference between the fact that one is a 7 kHz sine wave
and the other is a 7 kHz square wave.

But, in fact, that's NOT waht's being heard: what's being
heard is that the 7 kHz sine wave and the 7 kHz sine
component of the 7 kHz square have a substantially different
amplitude (by over 2 dB), and it's fairly easy for the ear
to hear that difference between the two, based SOLELY on the
energy at 7 kHz.

When people who have made this claim (and who are interested
in actually exploring what's going on) have carefully adjusted
the test such that the amplitude of the 7 kHz sine wave and the
1 kHz compont of the square wave are the same, they find it
essentially impossible to tell the difference.

Read up on: 'Power under the curve'. It will all make sense.

Not within the context of reproducing the klinds of signals
we actually end up listening to, it doesn't.

Square waves deliver more power than sine waves, for a given
frequency and peak to peak amplitude.

Not within the audio bandwidth, theyd don't. Therefore, how is
your "power under the curve" relevant for audio (read "music")
signals?

--
+--------------------------------+
+ Dick Pierce |
+ Professional Audio Development |
+--------------------------------+

[Sebastian Kaliszewski]

On 12/09/2012 02:21 AM, Trevor Wilson wrote:
On 12/9/2012 4:25 AM, ScottW wrote:
On Dec 7, 2:50 pm, Audio_Empire wrote:
On Wednesday, December 5, 2012 2:14:27 PM UTC-8, Arny Krueger wrote:
"Trevor Wilson" wrote in message

...

On 12/5/2012 9:36 AM, Arny Krueger wrote:

I am fully aware of the typical high end audiophile disdain for SR
and in

particular Julian Hirsch. IME both he and the magazine rocked a
lot of

cradles by spiking any number of audiophile myths. Compared to the

underground publications of the day it was a paragon of science and

factuality.

**No, it wasn't. That honour was reserved for Audio magazine. SR
was for

children. And rather undiscrinimating ones at that.

Contrary to some beliefs, publishing good science isn't a zero sum
game. I

am under the impression that more than one publication can publish good

science at the same time.

I agree that Audio Magazine published articles with good science,
including

the results of a number of DBTs.

Audio also published some articles that weren't so relevant such as
the ones

referencing the non-existent audible characteristics of certain plastic

capacitor dielectrics, and allegedly audible op amp slew rate
limiting in

then modern op amps that was a complete figment of the author's
imagination

and sighted evaluations. Despite the fact that they did publish the
results

of some DBTs, Audio was far more indiscriminate than Stereo Review.

I don't know where you got your information, Mr. Kruger, but I have
heard, in a
ABX test, the difference between Polypropylene capacitors and
electrolytics
and different types of non-polarized capacitors. The Polypropylenes were
demonstrably cleaner.

Also, to dismiss Walt Jung's work with operational amplifiers is
actually
laughable. Early Op-amps were very poor (by todays standards) and
were not really suited to audio. They had low slew-rates, yes, but more
importantly, they had asymmetrical slew. Since the positive-going
signal in a classic seventies/eighties op amp took a much shorter path
through the silicon than did the negative-going signal, the result was
unequal rise and fall times for a waveform. Using a 10 KHz square-wave
as a test signal, it is easy to see that the rise-time on these devices
was much faster on the leading edge than it was on the falling edge.
Also, getting back to slew rate, the faster the slew, the more vertical
both the rise and the fall slopes were. If you put a current
high-performance audio op-amp like the LM49710 through the same
test, a 10 KHz square wave looks the same coming out of the op-amp
(at any audio gain) as it does from the function generator (which
bespeaks not only faster slew, but symmetrical slew as well).


What relationship does square wave reproduction have to
audio signal amplification?

**A great deal, as it happens. For a tech, a square wave can us an
enormous amount about an audio system, very rapidly. 16/44 digital
systems cannot accurately reproduce a square wave of more than 7kHz.
Early CD players, like the CDP101, could barely reproduce a 5kHz square
wave with anything approaching reasonable fidelity. If an amplifier
produced performance as mediocre as the average 16/44 machine, it would
be condemned by every reviewer, outside those who review SET amplifiers.

Irrelevant.
No analogue audio amplifier has a brickwall filter around 22kHz. So
while looking at sqare wave passed by an (analogue) amplifier tells some
important things about that amplifier (many of those things not directly
audible anyway -- rather more relevant to its stability) it doesn't tell
the same things about DAC.



If slew rate limitations had any impact to an audio signal, I think
it would show up in simple FR tests.

**Not quite. Digitally reconstrcuted signals work differently to
analogue systems. In an analogue system where the -3dB point is (say)
22kHz (and a 6dB/octave roll-off), a reasonable facsimile of a (say)
10kHz square wave can be reproduced. In a 16/44 digital system, a 10kHz
square wave is impossible to reproduce. The system will likely reproduce
a sine wave, or something approximating it.

So? The reality is that, while 10kHz wave will be (possibly audibly)
attenuated in audible band if passed via 6db/oct lowpass with -3dB point
at 22kHz it wont be aubily attenuated by passing bie 60dB/oct one.


FWIW: A well trained ear can perceive the difference between a 5kHz
square wave and a 5kHz sine wave easily. A 7kHz waveform is more
difficult, but not impossible.

Yes, 3rd harmonics will differ between square and sine waves.


Read up on: 'Power under the curve'. It will all make sense.

Nope!

Square
waves deliver more power than sine waves, for a given frequency and peak
to peak amplitude.

You're ignoring the fact that part of that power is beyond the reach of
human ears. Squara wavee will produce more heat than same frequency sine
wave -- but that does automatically mean that additi0nal power would be
audible.


What adds nice squareness for 7kHz wave on an osciloscope is well beyond
human hearing range. Hence that curvy thing at 7Khz which contains only
3rd harmonics (at 21KHz) will sound the same as something squarelike,
containng umpteen harmonics. Those higher harmonics won't be audible to
any human.

rgds
\SK

[Audio_Empire[_2_]]

On Sunday, December 9, 2012 7:58:24 PM UTC-8, ScottW wrote:
On Dec 9, 6:40=A0am, Audio_Empire wrote:
=20
On Saturday, December 8, 2012 9:25:43 AM UTC-8, ScottW wrote:
=20

Go ahead and measure rise and fall times.
=20
When you find an op amp with rise or fall time
=20
less than around 17usec....than you've found a potentially audible
=20
problem.
=20
I don't think you will.
=20
=20
=20
ScottW

SID is audible. But that's not the point. The point is that=20
square waves will show characteristics of an op-amp. That's why=20
most op-amp data sheets have lots of pictures (usually not photos)
depicting square-wave performance.=20

[Audio_Empire[_2_]]

On Monday, December 10, 2012 10:01:36 AM UTC-8, Dick Pierce wrote:
Audio_Empire wrote:

On Saturday, December 8, 2012 9:25:43 AM UTC-8, ScottW wrote:


In other words how is it "suitable for the application?"

It may not be important. I was just answering the question about what square-waves show about op-amps in general.

[Arny Krueger[_5_]]

"Scott" wrote in message
...
On Dec 8, 7:30 am, "Arny Krueger" wrote:

Given your stated position in this very thread on the lack of need to
control for same sound biases in ABX DBTs

Quotes?

and given the well known biases of some of the folks who were involved in
those tests

Quotes?

I'm not answering claims that have nothing but the author's say-so backing
them up.

[Arny Krueger[_5_]]

"Audio_Empire" wrote in message
...
On Saturday, December 8, 2012 7:31:17 AM UTC-8, Arny Krueger wrote:
"Audio_Empire" wrote in message

...

On Wednesday, December 5, 2012 2:14:27 PM UTC-8, Arny Krueger wrote:



I don't know where you got your information, Mr. Kruger, but I have
heard,

in a

ABX test, the difference between Polypropylene capacitors and

electrolytics

and different types of non-polarized capacitors. The Polypropylenes
were

demonstrably cleaner.



It is true that if you do not use correct engineering practices with any
electronic part particularly Hi-K ceramic and electrolytic capacitors,
that
audible differences will be found.

This is ridiculous.
The qualities of capacitors in audio engineering has
been known for decades.

That would appear to be a paraphase of what I just said.

But you just said in a previous post that Audio
Magazine's articles about capacitor sound were suspect.

I didn't say that the entire article was suspect.

If one designs a
piece of gear using aluminum, polarized electrolytic capacitors or
Tantalums
as coupling capacitors in a piece of audio gear, then that gear has been
poorly designed.

I can cite dozens of components designed by widely-respected companies, that
contradict that *rule*.

Yet most Japanese gear routinely used electrolytics as
interstage coupling.

As does much equipment from American and european companies.

If you take a piece of such gear and parallel the
electrolytics with small polypropylene capacitors to bypass the high
frequencies, the device will sound better.

Technical tests showing psychocostically signficiant (audible) issues,
reliable listening tests to support this claim?

Lots of times, Mylar capacitors
were used for coupling due to cost considerations.

There is no doubt that except for size and cost, film capacitors would be
the rule.

This design decision
is not an engineering decision, its a bean-counter decision carried out by
the design engineer(s).

A audiophile-grade film capacitor of sizes commonly used in audio gear for
coupling capacitors can cost as much, and be the physical size of the entire
component.

Yet, again, if you replace the Mylar capacitors with
polypropylene "Wonder Caps" or "Sideral Caps" the device sounds better.

Technical tests showing psychocostically signficiant (audible) issues,
reliable listening tests to support this claim?

I was part of a DBT where two Hafler preamps were built as kits. One was
built totally stock. The other was built (by me) replacing every Mylar
capacitor in the signal chain with "Wonder Caps" and the two were
compared.

Documentation?

[Scott[_6_]]

On Dec 10, 3:14*pm, "Arny Krueger" wrote:
"Scott" wrote in message

...
On Dec 8, 7:30 am, "Arny Krueger" wrote:

Given your stated position in this very thread on the lack of need to
control for same sound biases in ABX DBTs

Quotes?

"The above ignores a well known aspect of human nature which is to
strive for
a positive result from any activity that requires substantial effort.

An ABX test requires substantial effort on the part of listeners so
the
listeners will follow their human nature and strive for a positive
result
simply because they are expending the effort and don't want the
outcome to
be futile."


*and given the well known biases of some of the folks who were involved in
those tests

Quotes?

You need quotes for that? Tell you what, you are the one with all the
back issues of Stereo Review. Cite one review of any amp or CDP where
they do not make the claim that they all sound the same.


I'm not answering claims that have nothing but the author's say-so backing
them up.

I'm not concerned whether or not you answer any claims. But my claims
have a good deal more than just my say so. Heck they have your say so
as quoted above from this very thread.

[Audio_Empire[_2_]]

On Monday, December 10, 2012 3:15:33 PM UTC-8, Arny Krueger wrote:
"Audio_Empire" wrote in message

...

On Saturday, December 8, 2012 7:31:17 AM UTC-8, Arny Krueger wrote:

"Audio_Empire" wrote in message



...



On Wednesday, December 5, 2012 2:14:27 PM UTC-8, Arny Krueger wrote:







I don't know where you got your information, Mr. Kruger, but I have

heard,



in a



ABX test, the difference between Polypropylene capacitors and



electrolytics



and different types of non-polarized capacitors. The Polypropylenes

were



demonstrably cleaner.







It is true that if you do not use correct engineering practices with any

electronic part particularly Hi-K ceramic and electrolytic capacitors,

that

audible differences will be found.



This is ridiculous.

The qualities of capacitors in audio engineering has

been known for decades.



That would appear to be a paraphase of what I just said.



But you just said in a previous post that Audio

Magazine's articles about capacitor sound were suspect.



I didn't say that the entire article was suspect.



If one designs a

piece of gear using aluminum, polarized electrolytic capacitors or

Tantalums

as coupling capacitors in a piece of audio gear, then that gear has been

poorly designed.



I can cite dozens of components designed by widely-respected companies, that

contradict that *rule*.



Yet most Japanese gear routinely used electrolytics as

interstage coupling.



As does much equipment from American and european companies.



If you take a piece of such gear and parallel the

electrolytics with small polypropylene capacitors to bypass the high

frequencies, the device will sound better.



Technical tests showing psychocostically signficiant (audible) issues,

reliable listening tests to support this claim?



Lots of times, Mylar capacitors

were used for coupling due to cost considerations.



There is no doubt that except for size and cost, film capacitors would be

the rule.



This design decision

is not an engineering decision, its a bean-counter decision carried out by

the design engineer(s).



A audiophile-grade film capacitor of sizes commonly used in audio gear for

coupling capacitors can cost as much, and be the physical size of the entire

component.



Yet, again, if you replace the Mylar capacitors with

polypropylene "Wonder Caps" or "Sideral Caps" the device sounds better.



Technical tests showing psychocostically signficiant (audible) issues,

reliable listening tests to support this claim?



I was part of a DBT where two Hafler preamps were built as kits. One was

built totally stock. The other was built (by me) replacing every Mylar

capacitor in the signal chain with "Wonder Caps" and the two were

compared.



Documentation?

Why would there be documentation? This was an informal test between
a bunch of audiophile buddies. A friend of mine and I both bought Hafler
DH-101 preamp kits at the same time. He built his stock, I substituted
the coupling and bypass caps in the kit with Wonder Caps of the same
value. At a meeting of our little informal group of audio nuts, it was
decided that we would do a DBT of the two being fed the same signal
(from a CD player) and then feeding the same power amp (a MOSCode
600, IIRC) through one of those Switchcraft surface-mount switches
with the three pairs of stereo inputs and one output. The speakers
were a pair of Magnaplanar Tympani-3C (all eight panels). Levels were
matched using an audio generator at 400 Hz and a Radio Shack digital SPL
meter and a VTVM. After a dozen of so tries everyone agreed that there
was definitely a difference and that unit #1 sounded significantly less
transparent than #2. No one knew which preamp was which (you could
only tell by taking the covers off the units).

[Audio_Empire[_2_]]

On Monday, December 10, 2012 3:13:23 PM UTC-8, Sebastian Kaliszewski wrote:
On 12/09/2012 02:21 AM, Trevor Wilson wrote:

On 12/9/2012 4:25 AM, ScottW wrote:

On Dec 7, 2:50 pm, Audio_Empire wrote:

On Wednesday, December 5, 2012 2:14:27 PM UTC-8, Arny Krueger wrote:

"Trevor Wilson" wrote in message
snip

Square

waves deliver more power than sine waves, for a given frequency and peak

to peak amplitude.



You're ignoring the fact that part of that power is beyond the reach of

human ears. Squara wavee will produce more heat than same frequency sine

wave -- but that does automatically mean that additi0nal power would be

audible.

Yeah, but that's more due to the duty-cycle of the output devices than it is
power. wouldn't you say?


What adds nice squareness for 7kHz wave on an osciloscope is well beyond

human hearing range. Hence that curvy thing at 7Khz which contains only

3rd harmonics (at 21KHz) will sound the same as something squarelike,

containng umpteen harmonics. Those higher harmonics won't be audible to

any human.

Agreed. I don't know if this is true or not, but I have read that phase-shift at
or near the Nyquist cutoff frequency can have an effect in the audible range,
although no one has ever been able to explain to me WHY this might be so.

[Dick Pierce[_2_]]

Audio_Empire wrote:
On Monday, December 10, 2012 3:13:23 PM UTC-8, Sebastian Kaliszewski wrote:
You're ignoring the fact that part of that power is beyond the reach of
human ears. Squara wavee will produce more heat than same frequency sine
wave -- but that does automatically mean that additi0nal power would be
audible.

Yeah, but that's more due to the duty-cycle of the output devices than it is
power. wouldn't you say?

Two points: the "duty cycle" of a square wave, by any reasonable
definition of duty cycle, is the same for a square wave as a sine
wave.

Second, by definition, a square wave of a given RMS value will
produce EXACTLY the same heat as a sine wave (or ANY waveform of
ANY kind) of the same RMS value.

We're throwing a lot of pseudofacts around without apparently
understanding what we're saying.

What adds nice squareness for 7kHz wave on an osciloscope is well beyond
human hearing range. Hence that curvy thing at 7Khz which contains only
3rd harmonics (at 21KHz) will sound the same as something squarelike,
containng umpteen harmonics. Those higher harmonics won't be audible to
any human.

Agreed. I don't know if this is true or not, but I have read that phase-shift at
or near the Nyquist cutoff frequency can have an effect in the audible range,
although no one has ever been able to explain to me WHY this might be so.

What phase shift? I routinely look at complete A/D and D/A
systems (and by routinely, I mean several times a day) whose
phase shift across the entire audio band is within a VERY small
range. For example, I'm currently measuring one that's within
10 degrees to 20 kHz, and the only reason it's not that good
at low frequencies is because of the relatively small coupling
caps that result in it being 3 dB down at 12 Hz.

Look, people keep claiming this phase shift myth. It's not a
question as to whether large phase shifts near the Nyquist
frequency might be audible: you get to have that discussion
complete apart from reality, because the reality is these phase
shifts you're so worried about simple DO NOT EXIST.

--
+--------------------------------+
+ Dick Pierce |
+ Professional Audio Development |
+--------------------------------+

[Dick Pierce[_2_]]

Audio_Empire wrote:
SID is audible.

IF AND ONLY IF IT ACTUALLY HAPPENS.

But that's not the point.

No, that is PRECISELY the point.

You'e making claims about a test signal which, until you show
data to the contrary, I and many others assert is IRRELEVANT
to the (using YOUR wordfs) "suitability of the application."

The point is that square waves will show characteristics
of an op-amp.

So does the color of of the package. So what? What color
the physical package is is indeniably a characteristic
of the op-amp, and a completely irrelevant one.

That's why most op-amp data sheets have lots of pictures
(usually not photos) depicting square-wave performance.

For several reasons, one of which is that the manufacturers
well know that the specialty audio market makes up a VERY
small part of their market and they make no money by catering
to the very constrained and, to be honest, wierd requirements
of that market.

--
+--------------------------------+
+ Dick Pierce |
+ Professional Audio Development |
+--------------------------------+

[Dick Pierce[_2_]]

Audio_Empire wrote:
On Sunday, December 9, 2012 7:58:24 PM UTC-8, ScottW wrote:
The point is that
square waves will show characteristics of an op-amp. That's why
most op-amp data sheets have lots of pictures (usually not photos)
depicting square-wave performance.

One further point, it should be noted that when I went and
loked up the slew rate performance of the various op amps in
my earlier post, not a single one of these figures was derived
from any pistcure or photos of square waves. Every one of the
slew rate figures was cleverly and carefully derived through
a special, proprietary algorithm I've developed that I call,
"looking at the slew rate specification." The data is
disguised in a very subtle fashion by the manufacturers, and
you have to know exactly where to look. For example, in the
spec sheet that Signetics published for the 5534, you'll see
it hidden in the line that says:

Slew rate: 13 V/us


--
+--------------------------------+
+ Dick Pierce |
+ Professional Audio Development |
+--------------------------------+

[Doug McDonald[_6_]]

On 12/10/2012 5:13 PM, Audio_Empire wrote:
On Sunday, December 9, 2012 7:58:24 PM UTC-8, ScottW wrote:
On Dec 9, 6:40 am, Audio_Empire wrote:

On Saturday, December 8, 2012 9:25:43 AM UTC-8, ScottW wrote:


Go ahead and measure rise and fall times.

When you find an op amp with rise or fall time

less than around 17usec....than you've found a potentially audible

problem.

I don't think you will.



ScottW

SID is audible. But that's not the point. The point is that
square waves will show characteristics of an op-amp. That's why
most op-amp data sheets have lots of pictures (usually not photos)
depicting square-wave performance.


Its also true that opamps are frequently used in applications
where the transient response is directly visible in the time domain.

Television and oscilloscopes come to mind. In these cases the "look"
of a square wave is really really important.

Doug McDonald

[Doug McDonald[_6_]]

On 12/10/2012 9:34 PM, Audio_Empire wrote:


Agreed. I don't know if this is true or not, but I have read that phase-shift at
or near the Nyquist cutoff frequency can have an effect in the audible range,
although no one has ever been able to explain to me WHY this might be so.



Sure they have ... I have, right here, and you agreed!

The answer is intermodulation distortion in tweeters.

Changing ringing characteristics can change this distortion.

I've been able to hear it, without a double blind test, very easily,
using several crappy tweeters at high levels. But in really good tweeters,
no, I didn't. This was many years ago ... I could redo the tests, but
I'd have to run the brick wall down to say 11 or 12 kHz.

Doug McDonald

[Doug McDonald[_6_]]

On 12/11/2012 5:56 AM, Dick Pierce wrote:
Look, people keep claiming this phase shift myth. It's not a
question as to whether large phase shifts near the Nyquist
frequency might be audible: you get to have that discussion
complete apart from reality, because the reality is these phase
shifts you're so worried about simple DO NOT EXIST.


They most certainly DID exist in early CD players, and I
believe even today in some high end ones.

I have been told ... this is hearsay ... that one high end one
has a switch to set the digital brick wall filter to either
"flat phase" (symmetrical ringing on 1 kHz square wave transitions)
or "causal phase" (no ringing before the transition).

Its this difference that I was listening for in the previous posting
I just made. Those tests were made long ago using a scientific-type
16 bit DAC and computer generated (FFT) brick-walled waveforms
(variable frequency brick wall). The Nyquist frequency of the DAC
was 50 kHz and a Bessel filter of good opamps was used on the analog
output. A scope verified the waveforms.

Doug McDonald

[Dick Pierce[_2_]]

Doug McDonald wrote:
On 12/11/2012 5:56 AM, Dick Pierce wrote:

Look, people keep claiming this phase shift myth. It's not a
question as to whether large phase shifts near the Nyquist
frequency might be audible: you get to have that discussion
complete apart from reality, because the reality is these phase
shifts you're so worried about simple DO NOT EXIST.

They most certainly DID exist in early CD players, and I
believe even today in some high end ones.

Indeed that's true and just shows to go you that for every
well-reasoned design principle, there are pathologically
dreadful exceptions, especially in high-end audio.

There is a DAC whose name does not pop to mind that does
away entriely with the anti-imaging filter as some sort of
manifest evil. The effect is that it dumps huge amounts of
ultrsonic and RF garbage out, which I consider to be not only
stupid but almost crominally irresponsible. What's ironically
amusing is that tere are still those in the high-end realm that
assume that it is "common knowledge" that the output of a DAC
consists of a series of stair-steps, and this one"high-end" DAC
is the only one that comes close to that behavior.

It merely proves a correlary of the First Law of Acoustics:
any idiot can designa DAC and, unfortunately, many do.

--
+--------------------------------+
+ Dick Pierce |
+ Professional Audio Development |
+--------------------------------+

[Arny Krueger[_5_]]

"Scott" wrote in message
...
On Dec 10, 3:14 pm, "Arny Krueger" wrote:
"Scott" wrote in message

...
On Dec 8, 7:30 am, "Arny Krueger" wrote:

Given your stated position in this very thread on the lack of need to
control for same sound biases in ABX DBTs

Quotes?

"The above ignores a well known aspect of human nature
which is to strive for
a positive result from any activity that requires substantial effort.

An ABX test requires substantial effort on the part of listeners so the
listeners will follow their human nature and strive for a positive result
simply because they are expending the effort and don't want the
outcome tobe futile."

Your conclusion does not follow from the quote. I simply pointed out The
existence of a bias to strive for positive results that I have observed in
real life. Perhaps you would prefer that I not make an honest and complete
report?


and given the well known biases of some of the folks who were involved
in
those tests

Quotes?

You need quotes for that? Tell you what, you are the one with all the
back issues of Stereo Review.

I have no such thing. I don't believe that I have even one paper copy of SR
in my posession, nor do I know a priori where I might find such a thing.


Cite one review of any amp or CDP where
they do not make the claim that they all sound the same.

Where is the reliable evidence that the CDPs being discussed in SR at that
time actually sound different?