On Tue, 15 May 2007 17:02:56 GMT, (Don Pearce)
wrote:

On Tue, 15 May 2007 16:52:53 GMT, John Byrns
wrote:

In article . com,
Peter Wieck wrote:

On May 14, 10:21 am, John Byrns wrote:

No, you have that exactly backwards, the RIAA recording curve reduces
the groove amplitude at high frequencies, requiring a complimentary high
frequency boost in playback, which increases the effects of surface
noise.

From: RIAA Equalization Curve for Phonograph Records
By: Don Hoglund

http://www.graniteaudio.com/page5.html

Peter, that URL is dead, it doesn't work! That aside, it isn't clear
what the point of your post is? Are you trying to say that my statement
which you have quote above is wrong? If that is so just spit it out and
tell me exactly what I said that is factually wrong?

However, because the cutter head's movements translate the amplitude
swings of the original signal into velocity -

This is not true, at least historically. IIRC in the early days of
electrical recording the cutters were constant amplitude below the
"turnover" frequency and constant amplitude above the "turnover"
frequency. This response was a result of carefully damped resonances
which were inherent in the design of the cutter head. Early stereo disc
cutters had a response which looked like a mountain peak with a
resonance in the middle of the audio band. Aassuming these curves were
velocity referenced, this would again imply constant amplitude operation
in the area to the left of the mountain peak. I have no knowledge of
the response of contemporary disc cutters, perhaps Iain could chime in
here, but I would be very surprised if their response was anything near
the perfect velocity response you assume. As a result of all this the
electrical equalizers used in disc cutting produce a curve that looks
nothing like the RIAA recording curve commonly presented on web sites,
as they must compensate for the mechanical effects of the cutter head.

You have also failed to consider the old crystal cutter heads that were
used in home disc cutting setups, as well as in some semipro equipment.
Even an ideal cutter head of this type would not produce a constant
velocity recording from a constant amplitude input signal.

the rate at which the
stylus moves during its swings - low-frequency signals would be
recorded with a much larger swing than high-frequency signals of the
same original amplitude. So, the low frequency grooves would be much
wider than the grooves on an equalized disk.


This is only because you have chosen to take a velocity centric
perspective, if you took the more natural groove amplitude view, you
would see that the low frequency grooves would be no wider than high
frequency grooves, and that in fact the amplitude of the high frequency
grooves would have to be reduced, as they are in discs cut to the RIAA
curve by some 12 dB, in order to prevent excessive groove velocity from
occurring at high frequencies. Grooves cut with excessive velocity are
difficult for playback pickups to track without creating excessive
distortion.

The high frequency amplitude cut incorporated into the RIAA recording
curve necessitates that a complimentary high frequency boost be
incorporated into the playback curve. This high frequency boost during
playback decreases the signal to noise ratio of the LP by emphasizing
the high frequency surface noise by some 12 dB.

Peter, don't be one of the sheep, take a moment and think for yourself
for once. If you can't do that at least make it clear what the point of
your post was and tell me specifically what part of my previous post it
is that you take issue with?


Regards,

John Byrns

John, are you still insisting that RIAA playback requires high
frequency boost? It doesn't. An RIAA phono preamp has a feedback
mechanism that provides high frequency cut. I have designed several
myself, and studied the circuits and operation of many. Had I (and
every other designer on the planet) been getting it wrong all the
time, our systems would be muffled and entirely without top. They are
not; they play back just fine, and certainly for my own, when I play a
white noise track on a test disc (recorded with standard pre-emphasis
before you say anything), I recover noise which is flat within about
1dB from 30Hz to 20kHz.

*Please* go and do some reading so you can back away gracefully from
this ridiculous position you are placing yourself in.

d

John, my apologies. I have only just noticed that you are posting from
rec.audio.tubes as your prime group. Ignore everything I wrote above -
you are right and I am wrong. Just as Alice found when she stepped
through the mirror into looking glass land, everything there works
backwards from the real world.

d

--
Pearce Consulting
http://www.pearce.uk.com

On May 15, 12:52 pm, John Byrns wrote:
In article . com,
Peter Wieck wrote:

On May 14, 10:21 am, John Byrns wrote:

No, you have that exactly backwards, the RIAA recording curve reduces
the groove amplitude at high frequencies, requiring a complimentary high
frequency boost in playback, which increases the effects of surface
noise.

From: RIAA Equalization Curve for Phonograph Records
By: Don Hoglund

http://www.graniteaudio.com/page5.html

Peter, that URL is dead, it doesn't work! That aside, it isn't clear
what the point of your post is? Are you trying to say that my statement
which you have quote above is wrong? If that is so just spit it out and
tell me exactly what I said that is factually wrong?

However, because the cutter head's movements translate the amplitude
swings of the original signal into velocity -

This is not true, at least historically. IIRC in the early days of
electrical recording the cutters were constant amplitude below the
"turnover" frequency and constant amplitude above the "turnover"
frequency. This response was a result of carefully damped resonances
which were inherent in the design of the cutter head. Early stereo disc
cutters had a response which looked like a mountain peak with a
resonance in the middle of the audio band. Aassuming these curves were
velocity referenced, this would again imply constant amplitude operation
in the area to the left of the mountain peak. I have no knowledge of
the response of contemporary disc cutters, perhaps Iain could chime in
here, but I would be very surprised if their response was anything near
the perfect velocity response you assume. As a result of all this the
electrical equalizers used in disc cutting produce a curve that looks
nothing like the RIAA recording curve commonly presented on web sites,
as they must compensate for the mechanical effects of the cutter head.

You have also failed to consider the old crystal cutter heads that were
used in home disc cutting setups, as well as in some semipro equipment.
Even an ideal cutter head of this type would not produce a constant
velocity recording from a constant amplitude input signal.

the rate at which the
stylus moves during its swings - low-frequency signals would be
recorded with a much larger swing than high-frequency signals of the
same original amplitude. So, the low frequency grooves would be much
wider than the grooves on an equalized disk.

This is only because you have chosen to take a velocity centric
perspective, if you took the more natural groove amplitude view, you
would see that the low frequency grooves would be no wider than high
frequency grooves, and that in fact the amplitude of the high frequency
grooves would have to be reduced, as they are in discs cut to the RIAA
curve by some 12 dB, in order to prevent excessive groove velocity from
occurring at high frequencies. Grooves cut with excessive velocity are
difficult for playback pickups to track without creating excessive
distortion.

The high frequency amplitude cut incorporated into the RIAA recording
curve necessitates that a complimentary high frequency boost be
incorporated into the playback curve. This high frequency boost during
playback decreases the signal to noise ratio of the LP by emphasizing
the high frequency surface noise by some 12 dB.

Peter, don't be one of the sheep, take a moment and think for yourself
for once. If you can't do that at least make it clear what the point of
your post was and tell me specifically what part of my previous post it
is that you take issue with?

Regards,

John Byrns

--
Surf my web pages at, http://fmamradios.com/

John:

Whoops: http://www.graniteaudio.com/phono/page5.html

should get you there.

For the record: Whatever positions and suppositions you may take, and
from whatever point of view, whichever cutting head and system, the
actual subject-at-hand is the *present* RIAA Curve as practiced each
day. This is presumably a fixed value both on recording and playback.

That curve is at the bottom of the article. The Bass Boost and the
Treble Cut on playback cross the Bass Cut and Treble Boost on
recording at ~1.2Khz.... not quite what you are writing.

References are at the bottom of the article.

Some interesting stuff also on cartridge loading (impedance and
capacitance), something that I have kept in mind for now over 30
years, and something that few of the more recent converts to vinyl do
not understand. Back in the day, better components would list input
capacitance at a given impedance. Some even had adjustments, and ways
to vary both to a fixed value as needed. Most good TTs listed the
capacitance of their cables as well. So it is not just the phono-stage
but what feeds it as well that has effects on the overall results.

John, sometimes your experience and history vastly overcomplicate what
is a pretty simple issue. What 'should be' in the best of all possible
worlds simply ain't necessarily so.

Peter Wieck
Wyncote, PA

On May 15, 1:08 pm, (Don Pearce) wrote:

John, my apologies. I have only just noticed that you are posting from
rec.audio.tubes as your prime group. Ignore everything I wrote above -
you are right and I am wrong. Just as Alice found when she stepped
through the mirror into looking glass land, everything there works
backwards from the real world.


Don:

Be careful. John is a literalist.

Peter Wieck
Wyncote, PA

In article ,
(Don Pearce) wrote:

On Tue, 15 May 2007 17:02:56 GMT, (Don Pearce)
wrote:

On Tue, 15 May 2007 16:52:53 GMT, John Byrns
wrote:

In article . com,
Peter Wieck wrote:

On May 14, 10:21 am, John Byrns wrote:

No, you have that exactly backwards, the RIAA recording curve reduces
the groove amplitude at high frequencies, requiring a complimentary high
frequency boost in playback, which increases the effects of surface
noise.

From: RIAA Equalization Curve for Phonograph Records
By: Don Hoglund

http://www.graniteaudio.com/page5.html

Peter, that URL is dead, it doesn't work! That aside, it isn't clear
what the point of your post is? Are you trying to say that my statement
which you have quote above is wrong? If that is so just spit it out and
tell me exactly what I said that is factually wrong?

However, because the cutter head's movements translate the amplitude
swings of the original signal into velocity -

This is not true, at least historically. IIRC in the early days of
electrical recording the cutters were constant amplitude below the
"turnover" frequency and constant amplitude above the "turnover"
frequency. This response was a result of carefully damped resonances
which were inherent in the design of the cutter head. Early stereo disc
cutters had a response which looked like a mountain peak with a
resonance in the middle of the audio band. Aassuming these curves were
velocity referenced, this would again imply constant amplitude operation
in the area to the left of the mountain peak. I have no knowledge of
the response of contemporary disc cutters, perhaps Iain could chime in
here, but I would be very surprised if their response was anything near
the perfect velocity response you assume. As a result of all this the
electrical equalizers used in disc cutting produce a curve that looks
nothing like the RIAA recording curve commonly presented on web sites,
as they must compensate for the mechanical effects of the cutter head.

You have also failed to consider the old crystal cutter heads that were
used in home disc cutting setups, as well as in some semipro equipment.
Even an ideal cutter head of this type would not produce a constant
velocity recording from a constant amplitude input signal.

the rate at which the
stylus moves during its swings - low-frequency signals would be
recorded with a much larger swing than high-frequency signals of the
same original amplitude. So, the low frequency grooves would be much
wider than the grooves on an equalized disk.

This is only because you have chosen to take a velocity centric
perspective, if you took the more natural groove amplitude view, you
would see that the low frequency grooves would be no wider than high
frequency grooves, and that in fact the amplitude of the high frequency
grooves would have to be reduced, as they are in discs cut to the RIAA
curve by some 12 dB, in order to prevent excessive groove velocity from
occurring at high frequencies. Grooves cut with excessive velocity are
difficult for playback pickups to track without creating excessive
distortion.

The high frequency amplitude cut incorporated into the RIAA recording
curve necessitates that a complimentary high frequency boost be
incorporated into the playback curve. This high frequency boost during
playback decreases the signal to noise ratio of the LP by emphasizing
the high frequency surface noise by some 12 dB.

Peter, don't be one of the sheep, take a moment and think for yourself
for once. If you can't do that at least make it clear what the point of
your post was and tell me specifically what part of my previous post it
is that you take issue with?

John, are you still insisting that RIAA playback requires high
frequency boost? It doesn't. An RIAA phono preamp has a feedback
mechanism that provides high frequency cut. I have designed several
myself, and studied the circuits and operation of many. Had I (and
every other designer on the planet) been getting it wrong all the
time, our systems would be muffled and entirely without top. They are
not; they play back just fine, and certainly for my own, when I play a
white noise track on a test disc (recorded with standard pre-emphasis
before you say anything), I recover noise which is flat within about
1dB from 30Hz to 20kHz.

*Please* go and do some reading so you can back away gracefully from
this ridiculous position you are placing yourself in.

John, my apologies. I have only just noticed that you are posting from
rec.audio.tubes as your prime group. Ignore everything I wrote above -
you are right and I am wrong. Just as Alice found when she stepped
through the mirror into looking glass land, everything there works
backwards from the real world.

Don, I don't understand what the prime group I am posting from has to do
with this issue and your sudden understanding? Could you please explain?


Regards,

John Byrns

--
Surf my web pages at, http://fmamradios.com/

On May 15, 9:08 am, Andre Jute wrote:

Yo, Gerry, I'm a professional communicator. I say exactly what I mean,
no more, no less. If you do not follow, it is because either a) I
intended for you not to understand or b) you are a thicko below my
horizon. You might consider that everyone else understood what I
meant. The only acceptable excuse for not understanding me when I
speak that plainly is that you are unfamiliar with the technicalities
underlying RIAA emphasis and de-emphasis, in which case you should,
rather than attack my language, say you don't understand, and you will
receive a courteous explanation from the few remaining on RAT who
still honour the open-door principles of the ARRL.

Andre Jute

Oh, I see. You would rather show off how edjumicated you are rather
than be kind enough to share information and write in laymen's terms
so EVERYone can understand. You are a Professional elitist snob,
apparently. Rude son-of-a-bitch, too.

On Tue, 15 May 2007 17:56:32 GMT, John Byrns
wrote:

In article ,
(Don Pearce) wrote:

On Tue, 15 May 2007 17:02:56 GMT, (Don Pearce)
wrote:

On Tue, 15 May 2007 16:52:53 GMT, John Byrns
wrote:

In article . com,
Peter Wieck wrote:

On May 14, 10:21 am, John Byrns wrote:

No, you have that exactly backwards, the RIAA recording curve reduces
the groove amplitude at high frequencies, requiring a complimentary high
frequency boost in playback, which increases the effects of surface
noise.

From: RIAA Equalization Curve for Phonograph Records
By: Don Hoglund

http://www.graniteaudio.com/page5.html

Peter, that URL is dead, it doesn't work! That aside, it isn't clear
what the point of your post is? Are you trying to say that my statement
which you have quote above is wrong? If that is so just spit it out and
tell me exactly what I said that is factually wrong?

However, because the cutter head's movements translate the amplitude
swings of the original signal into velocity -

This is not true, at least historically. IIRC in the early days of
electrical recording the cutters were constant amplitude below the
"turnover" frequency and constant amplitude above the "turnover"
frequency. This response was a result of carefully damped resonances
which were inherent in the design of the cutter head. Early stereo disc
cutters had a response which looked like a mountain peak with a
resonance in the middle of the audio band. Aassuming these curves were
velocity referenced, this would again imply constant amplitude operation
in the area to the left of the mountain peak. I have no knowledge of
the response of contemporary disc cutters, perhaps Iain could chime in
here, but I would be very surprised if their response was anything near
the perfect velocity response you assume. As a result of all this the
electrical equalizers used in disc cutting produce a curve that looks
nothing like the RIAA recording curve commonly presented on web sites,
as they must compensate for the mechanical effects of the cutter head.

You have also failed to consider the old crystal cutter heads that were
used in home disc cutting setups, as well as in some semipro equipment.
Even an ideal cutter head of this type would not produce a constant
velocity recording from a constant amplitude input signal.

the rate at which the
stylus moves during its swings - low-frequency signals would be
recorded with a much larger swing than high-frequency signals of the
same original amplitude. So, the low frequency grooves would be much
wider than the grooves on an equalized disk.

This is only because you have chosen to take a velocity centric
perspective, if you took the more natural groove amplitude view, you
would see that the low frequency grooves would be no wider than high
frequency grooves, and that in fact the amplitude of the high frequency
grooves would have to be reduced, as they are in discs cut to the RIAA
curve by some 12 dB, in order to prevent excessive groove velocity from
occurring at high frequencies. Grooves cut with excessive velocity are
difficult for playback pickups to track without creating excessive
distortion.

The high frequency amplitude cut incorporated into the RIAA recording
curve necessitates that a complimentary high frequency boost be
incorporated into the playback curve. This high frequency boost during
playback decreases the signal to noise ratio of the LP by emphasizing
the high frequency surface noise by some 12 dB.

Peter, don't be one of the sheep, take a moment and think for yourself
for once. If you can't do that at least make it clear what the point of
your post was and tell me specifically what part of my previous post it
is that you take issue with?

John, are you still insisting that RIAA playback requires high
frequency boost? It doesn't. An RIAA phono preamp has a feedback
mechanism that provides high frequency cut. I have designed several
myself, and studied the circuits and operation of many. Had I (and
every other designer on the planet) been getting it wrong all the
time, our systems would be muffled and entirely without top. They are
not; they play back just fine, and certainly for my own, when I play a
white noise track on a test disc (recorded with standard pre-emphasis
before you say anything), I recover noise which is flat within about
1dB from 30Hz to 20kHz.

*Please* go and do some reading so you can back away gracefully from
this ridiculous position you are placing yourself in.

John, my apologies. I have only just noticed that you are posting from
rec.audio.tubes as your prime group. Ignore everything I wrote above -
you are right and I am wrong. Just as Alice found when she stepped
through the mirror into looking glass land, everything there works
backwards from the real world.

Don, I don't understand what the prime group I am posting from has to do
with this issue and your sudden understanding? Could you please explain?


Regards,

John Byrns

Don't worry, John. Peter just put me straight.

d

--
Pearce Consulting
http://www.pearce.uk.com

On May 15, 9:20 am, Eeyore
wrote:
Andre Jute wrote:
Yo, Gerry, I'm a professional communicator.

You mean windbag.

Graham

Precisely!

John Byrns said:

John, my apologies. I have only just noticed that you are posting from
rec.audio.tubes as your prime group. Ignore everything I wrote above -
you are right and I am wrong. Just as Alice found when she stepped
through the mirror into looking glass land, everything there works
backwards from the real world.

Don, I don't understand what the prime group I am posting from has to do
with this issue and your sudden understanding? Could you please explain?

He say you toobies live in Bizarro world. Him stay, you go home! Har!




--

Krooscience: The antidote to education, experience, and excellence.

In article ,
Sander deWaal wrote:

(Don Pearce) said:


Did you know there are 2.5 * 10^29 Barns in a square Rod, though?


Hah! Did you know the average snail travels 3 furlongs per fortnight?

Bet you didn't! ;-)


Well, I just looked it up, and they do 0.03mph - which is about 80
furlongs per fortnight. You have slow snails!


We feed 'em beer, so they're mostly running around in circles.

Lucky Lager was especially good for that.

Stephen

Gerry wrote:
On May 15, 9:08 am, Andre Jute wrote:


Yo, Gerry, I'm a professional communicator. I say exactly what I mean,
no more, no less.

I see, said Alice.

--
Nick