Intelligence and RIAA
 

In article ,
(Don Pearce) wrote:

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.


Don, yes I am still insisting that RIAA playback requires high frequency
boost. Why are you suggesting that I might want to back away from this
position?

Let me attempt to explain, I'm going to assume that you have some
knowledge of math and know what differentiation is. Let's consider an
LP recording which has had a music signal cut into it. Now in our
playback system we need to read the amplitude of the signal cut into the
disc and convert it into an electrical signal of varying amplitude to
drive our speaker system, while along the way undoing any amplitude
equalization that was incorporated when the music signal was originally
cut into the disc using the RIAA record equalization. Now you are
insisting that RIAA playback equalization involves a large high
frequency cut approximating some 38 dB, while I claim that RIAA playback
equalization involves the boosting of the amplitude of the high
frequency signals cut into the disc by approximately 12 dB. What
accounts for the difference in our perspectives? The difference is
simply explained by the fact that you are lumping two separate
equalization curves together while I am talking about only the
equalization necessary to counter the RIAA amplitude equalization
applied when the music was cut into the grooves of the record.

You are assuming that the LP is being played with a "magnetic" pickup.
It is a characteristic of "magnetic" pickups that they differentiate the
amplitude of the music signal cut into the record groove to produce the
electrical output. The differentiation of the recorded amplitude causes
the signal output of the "magnetic" pickup to be tilted upwards towards
the high frequencies at a rate of 6 dB per octave, which results in a
very tinny sound unless this effect is compensated for. To restore the
output of the "magnetic" pickup back to a flat representation of the
recorded amplitude on the disc, we must pass its output through an
integrator circuit. An integrator produces a response which falls
towards the high frequencies at a rate of 6 dB per octave, falling
approximately 50 dB at 15 kHz vs. 50 Hz, this is the first part of your
equalizer. The second part of your equalizer is the same as my RIAA
amplitude equalizer and consists of shelving the high frequencies up by
approximately 12 dB using the time constants of 318.3 usec. and 75
usec.. When you combine the "magnetic" pickup equalizer and the RIAA
amplitude equalizer into a single composite circuit you have what you
call "RIAA equalization". This equalization is the sum of a 50 dB high
frequency cut for "magnetic" pickup compensation and a high frequency
boost of 12 dB for RIAA amplitude equalization, giving a net high
frequency cut of 38 dB for the combined network.

Using a pickup that is directly responsive to the recorded groove
amplitude, like say an FM pickup, or a strain gauge pickup, eliminates
the need for the pickup compensation integrator required with a
"magnetic" pickup, and leaves us with the need to provide only the 12 dB
high frequency boost required by the RIAA cutting curve.

Get it, it's simple once you understand it, the "RIAA phono preamp" you
are describing is really doing two equalization jobs, pickup
compensation and compensation for the RIAA amplitude response.


Regards,

John Byrns

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

Intelligence and RIAA
 

In article .com,
Peter Wieck wrote:

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.


Peter, this article assumes that a "magnetic" pickup is being used to
reproduce the LP. "Magnetic" pickups do not respond directly to the
amplitude of the signal recorded in the LP's grooves and requires
compensation.

Let me attempt to explain, I'm going to assume that you have some
knowledge of math and know what differentiation is. Let's consider an
LP recording which has had a music signal cut into it. Now in our
playback system we need to read the amplitude of the signal cut into the
disc and convert it into an electrical signal of varying amplitude to
drive our speaker system, while along the way undoing any amplitude
equalization that was incorporated when the music signal was originally
cut into the disc using the RIAA record equalization. Now you are
insisting that RIAA playback equalization involves a large high
frequency cut approximating some 38 dB, while I claim that RIAA playback
equalization involves the boosting of the amplitude of the high
frequency signals cut into the disc by approximately 12 dB. What
accounts for the difference in our perspectives? The difference is
simply explained by the fact that you are lumping two separate
equalization curves together while I am talking about only the
equalization necessary to counter the RIAA amplitude equalization
applied when the music was cut into the grooves of the record.

Then article you cite assumes that the LP is being played with a
"magnetic" pickup. It is a characteristic of "magnetic" pickups that
they differentiate the amplitude of the music signal cut into the record
groove to produce the electrical output. The differentiation of the
recorded amplitude causes the signal output of the "magnetic" pickup to
be tilted upwards towards the high frequencies at a rate of 6 dB per
octave, which results in a very tinny sound unless this effect is
compensated for. To restore the output of the "magnetic" pickup back to
a flat representation of the recorded amplitude on the disc, we must
pass its output through an integrator circuit. An integrator produces a
response which falls towards the high frequencies at a rate of 6 dB per
octave, falling approximately 50 dB at 15 kHz vs. 50 Hz, this is the
first part of your equalizer. The second part of your equalizer is the
same as my RIAA amplitude equalizer and consists of shelving the high
frequencies up by approximately 12 dB using the time constants of 318.3
usec. and 75 usec.. When you combine the "magnetic" pickup equalizer
and the RIAA amplitude equalizer into a single composite circuit you
have what you call "RIAA equalization". This equalization is the sum of
a 50 dB high frequency cut for "magnetic" pickup compensation and a high
frequency boost of 12 dB for RIAA amplitude equalization, giving a net
high frequency cut of 38 dB for the combined network.

Using a pickup that is directly responsive to the recorded groove
amplitude, like say an FM pickup, or a strain gauge pickup, eliminates
the need for the pickup compensation integrator required with a
"magnetic" pickup, and leaves us with the need to provide only the 12 dB
high frequency boost required by the RIAA cutting curve.


Regards,

John Byrns

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

Intelligence and RIAA
 

John Byrns wrote:

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,

?

Yep, you're a tube guy all right...

Intelligence and RIAA
 

On May 15, 5:33 pm, John Byrns wrote:
In article .com,
Peter Wieck wrote:





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.

Peter, this article assumes that a "magnetic" pickup is being used to
reproduce the LP. "Magnetic" pickups do not respond directly to the
amplitude of the signal recorded in the LP's grooves and requires
compensation.

Let me attempt to explain, I'm going to assume that you have some
knowledge of math and know what differentiation is. Let's consider an
LP recording which has had a music signal cut into it. Now in our
playback system we need to read the amplitude of the signal cut into the
disc and convert it into an electrical signal of varying amplitude to
drive our speaker system, while along the way undoing any amplitude
equalization that was incorporated when the music signal was originally
cut into the disc using the RIAA record equalization. Now you are
insisting that RIAA playback equalization involves a large high
frequency cut approximating some 38 dB, while I claim that RIAA playback
equalization involves the boosting of the amplitude of the high
frequency signals cut into the disc by approximately 12 dB. What
accounts for the difference in our perspectives? The difference is
simply explained by the fact that you are lumping two separate
equalization curves together while I am talking about only the
equalization necessary to counter the RIAA amplitude equalization
applied when the music was cut into the grooves of the record.

Then article you cite assumes that the LP is being played with a
"magnetic" pickup. It is a characteristic of "magnetic" pickups that
they differentiate the amplitude of the music signal cut into the record
groove to produce the electrical output. The differentiation of the
recorded amplitude causes the signal output of the "magnetic" pickup to
be tilted upwards towards the high frequencies at a rate of 6 dB per
octave, which results in a very tinny sound unless this effect is
compensated for. To restore the output of the "magnetic" pickup back to
a flat representation of the recorded amplitude on the disc, we must
pass its output through an integrator circuit. An integrator produces a
response which falls towards the high frequencies at a rate of 6 dB per
octave, falling approximately 50 dB at 15 kHz vs. 50 Hz, this is the
first part of your equalizer. The second part of your equalizer is the
same as my RIAA amplitude equalizer and consists of shelving the high
frequencies up by approximately 12 dB using the time constants of 318.3
usec. and 75 usec.. When you combine the "magnetic" pickup equalizer
and the RIAA amplitude equalizer into a single composite circuit you
have what you call "RIAA equalization". This equalization is the sum of
a 50 dB high frequency cut for "magnetic" pickup compensation and a high
frequency boost of 12 dB for RIAA amplitude equalization, giving a net
high frequency cut of 38 dB for the combined network.

Using a pickup that is directly responsive to the recorded groove
amplitude, like say an FM pickup, or a strain gauge pickup, eliminates
the need for the pickup compensation integrator required with a
"magnetic" pickup, and leaves us with the need to provide only the 12 dB
high frequency boost required by the RIAA cutting curve.

Regards,

John Byrns

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

- Show quoted text -

Fly **** on the left, pepper on the right.

John, you cannot _EVER_ admit that you have it wrong, and you search
for the exception every time.

Every damned pick-up I have from the Ortophon MC-20 & MC-30 through
various Shures and Grados is "magnetic".

The order-of-discussion is not strain-gauge pick-ups, crystal pick-ups
(which do not get RIAA equalization). What is the order-of-discussion
is those pick-ups that I have as part of the "great unwashed" and use
every damned day. Either on my Revox, or my Rabcos or whatever else I
choose to use. So, for those beasts as-used by the bulk of the
individuals here, Bass is boosted, Treble is cut. On Playback. And
Bass is cut and Treble is boosted. On recording.

However much smoke and mirrors you might throw to the contrary, that
just happens to be .... the .... way .... it .... is.

Peter Wieck
Wyncote, PA

Any other suggestions?

Intelligence and RIAA
 

John Byrns wrote:

Peter Wieck wrote:
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.

Peter, this article assumes that a "magnetic" pickup is being used to
reproduce the LP. "Magnetic" pickups do not respond directly to the
amplitude of the signal recorded in the LP's grooves and requires
compensation.

Let me attempt to explain, I'm going to assume that you have some
knowledge of math and know what differentiation is.

Why makes it so complicated ?

The magnetic pickup responds not just to the amplitude of the signal in the
groove but it's rate of change too.

So a signal of the same amplitude on the disc at say 2kHz will produce a voltage
at the pickup that's twice what it would be at 1kHz.

Graham

Intelligence and RIAA/cycling and fitness.
 

John Byrns wrote:

In article ,
Patrick Turner wrote:

When you get lean and fit, the natural heart rate at rest will fall from
a common 64BPM down to
say 52BPM even if you are 60 like me. A young bloke of 25 who did the
exercize I take would
benefit even more greatly, and have a HR maybe 45.
When I was fit when 40, my HR was 47BPM.

But how do you tell time properly if your resting heart rate isn't a
nice 60 BPM? Also notice that 60 neatly factors into 2*2*3*5.

I have business that runs to TA time, and to extend the days to make
more time
than other ppl have, i lowered heartrate to 52 which isn't bad for an
old codger like me.
When I have expired totally, the heart won't have to keep time, and days
will stretch
infinitely, and I will not have to worry how long anything takes, and
can luxuriate
my mind by considering all there is to consider that is mathematically
beautiful
about gain/phase shift/NFB/stability equations.

They say the Band Up There needs some better PA gear......

52 is unlucky, with factors of 2 x 2 x 13.

I should watch my step.

Patrick Turner.




Regards,

John Byrns

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

Intelligence and RIAA/cycling and fitness.
 

Keith G wrote:
snip,

60 eh? - I'm 60 *tomorrow*!! :-)

Look, I lied a bit.

I have 2 months to go before 60 arrives.
I feel 30 most days

Patrick Turner.

Intelligence and RIAA
 

In article .com,
Peter Wieck wrote:

Fly **** on the left, pepper on the right.

John, you cannot _EVER_ admit that you have it wrong, and you search
for the exception every time.

Peter, you are one sick puppy and a liar to boot. If you truly believe
that I cannot _EVER_ admit that I have it wrong, I suggest you check the
exchange I had with Henry Pasternack last Friday and Saturday in the
thread titled "Stability in Feedback Amplifiers, Part Deux-A" where I
opened a posting Saturday afternoon with these words "Hi Henry, You are
absolutely correct, I was wrong, the "KAB" network does provide an exact
solution for the for the RIAA playback curve as you have demonstrated."
What do you make of that? There is no exception here, I am explaining
how it works without any exceptions, there is no other way for it to
work.

Your problem is that you get a distorted view of me because when we
disagree you are invariably wrong, as now.

Every damned pick-up I have from the Ortophon MC-20 & MC-30 through
various Shures and Grados is "magnetic".

I have no doubt of that, however there are plenty of pickups in the
world that aren't "magnetic". But that is really beside the point as my
mention of "magnetic" pickups was simply an attempt to try explaining to
you something you apparently don't know about "magnetic" pickups and
their equalization requirements.

The point I have been making is the relationship between the amplitude
of the electric signal coming from the microphone and the amplitude of
the modulations etched in the grooves of an LP cut according to the RIAA
recording curve. This has nothing to do with the type of pickup that is
ultimately used to reproduce the LP, although obviously different types
of pickups will have different equalization requirements when playing
the same record.

Now here is the relevant experiment for you to try. First take an audio
frequency sweep generator and feed its output into the cutting system
through the RIAA record equalizer and on to the cutting head. Set the
generator to sweep from 50 Hz up through 15 kHz with a constant output
level at all frequencies, set the level low enough so that it doesn't
smoke the cutting head at the high frequency end of the sweep. Next
record the frequency sweep onto a disc. Finally by whatever method you
prefer, measure the amplitude of the modulations cut into the grooves of
the LP at a sufficient number of frequency points so that you can draw a
graph of the recorded groove amplitude vs. frequency. Now look at the
shape of the groove amplitude graph you have just drawn, which
represents the total equalization applied to the constant amplitude
frequency sweep signal that you have recorded. What you will see is
that the amplitude of the high frequencies cut into the LP's grooves are
shelved down by approximately 12 dB, not boosted as you claim.

You have provided no evidence to show that what I have said is wrong,
you are simply using vigorous assertion to press your position without
even bothering to advance a single argument in support your position.


Regards,

John Byrns

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

Intelligence and RIAA
 

On Tue, 15 May 2007 17:31:24 -0500, John Byrns
wrote:

In article ,
(Don Pearce) wrote:

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.


Don, yes I am still insisting that RIAA playback requires high frequency
boost. Why are you suggesting that I might want to back away from this
position?

Let me attempt to explain, I'm going to assume that you have some
knowledge of math and know what differentiation is. Let's consider an
LP recording which has had a music signal cut into it. Now in our
playback system we need to read the amplitude of the signal cut into the
disc and convert it into an electrical signal of varying amplitude to
drive our speaker system, while along the way undoing any amplitude
equalization that was incorporated when the music signal was originally
cut into the disc using the RIAA record equalization. Now you are
insisting that RIAA playback equalization involves a large high
frequency cut approximating some 38 dB, while I claim that RIAA playback
equalization involves the boosting of the amplitude of the high
frequency signals cut into the disc by approximately 12 dB. What
accounts for the difference in our perspectives? The difference is
simply explained by the fact that you are lumping two separate
equalization curves together while I am talking about only the
equalization necessary to counter the RIAA amplitude equalization
applied when the music was cut into the grooves of the record.

You are assuming that the LP is being played with a "magnetic" pickup.
It is a characteristic of "magnetic" pickups that they differentiate the
amplitude of the music signal cut into the record groove to produce the
electrical output. The differentiation of the recorded amplitude causes
the signal output of the "magnetic" pickup to be tilted upwards towards
the high frequencies at a rate of 6 dB per octave, which results in a
very tinny sound unless this effect is compensated for. To restore the
output of the "magnetic" pickup back to a flat representation of the
recorded amplitude on the disc, we must pass its output through an
integrator circuit. An integrator produces a response which falls
towards the high frequencies at a rate of 6 dB per octave, falling
approximately 50 dB at 15 kHz vs. 50 Hz, this is the first part of your
equalizer. The second part of your equalizer is the same as my RIAA
amplitude equalizer and consists of shelving the high frequencies up by
approximately 12 dB using the time constants of 318.3 usec. and 75
usec.. When you combine the "magnetic" pickup equalizer and the RIAA
amplitude equalizer into a single composite circuit you have what you
call "RIAA equalization". This equalization is the sum of a 50 dB high
frequency cut for "magnetic" pickup compensation and a high frequency
boost of 12 dB for RIAA amplitude equalization, giving a net high
frequency cut of 38 dB for the combined network.

Using a pickup that is directly responsive to the recorded groove
amplitude, like say an FM pickup, or a strain gauge pickup, eliminates
the need for the pickup compensation integrator required with a
"magnetic" pickup, and leaves us with the need to provide only the 12 dB
high frequency boost required by the RIAA cutting curve.

Get it, it's simple once you understand it, the "RIAA phono preamp" you
are describing is really doing two equalization jobs, pickup
compensation and compensation for the RIAA amplitude response.


Regards,

John Byrns

John, I stopped reading "let me explain", I'm afraid. Don't take this
badly, please. I did that because I knew that whatever followed was
going to be a catalogue of misunderstanding and error. It isn't too
important really what those errors are. What is important is that they
are errors, which thirty seconds of research (google for phono preamp
sche,matic - that should do it) will show you. You will then be in the
enviable position of knowing something that you have been getting
completely wrong for years, and being able to learn something new.

Please make this small effort before you post again. I promise you
won't find it wasted. And do listen and understand when I tell you
that those of us who have designed audio gear have never, ever
designed an RIAA preamp that boosts rather than reduces high
frequencies, Do some web research and see if you can find one.

d

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

Intelligence and RIAA
 

Don Pearce wrote:
On Tue, 15 May 2007 17:31:24 -0500, John Byrns
wrote:

In article ,
(Don Pearce) wrote:

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.


Don, yes I am still insisting that RIAA playback requires high frequency
boost. Why are you suggesting that I might want to back away from this
position?

Let me attempt to explain, I'm going to assume that you have some
knowledge of math and know what differentiation is. Let's consider an
LP recording which has had a music signal cut into it. Now in our
playback system we need to read the amplitude of the signal cut into the
disc and convert it into an electrical signal of varying amplitude to
drive our speaker system, while along the way undoing any amplitude
equalization that was incorporated when the music signal was originally
cut into the disc using the RIAA record equalization. Now you are
insisting that RIAA playback equalization involves a large high
frequency cut approximating some 38 dB, while I claim that RIAA playback
equalization involves the boosting of the amplitude of the high
frequency signals cut into the disc by approximately 12 dB. What
accounts for the difference in our perspectives? The difference is
simply explained by the fact that you are lumping two separate
equalization curves together while I am talking about only the
equalization necessary to counter the RIAA amplitude equalization
applied when the music was cut into the grooves of the record.

You are assuming that the LP is being played with a "magnetic" pickup.
It is a characteristic of "magnetic" pickups that they differentiate the
amplitude of the music signal cut into the record groove to produce the
electrical output. The differentiation of the recorded amplitude causes
the signal output of the "magnetic" pickup to be tilted upwards towards
the high frequencies at a rate of 6 dB per octave, which results in a
very tinny sound unless this effect is compensated for. To restore the
output of the "magnetic" pickup back to a flat representation of the
recorded amplitude on the disc, we must pass its output through an
integrator circuit. An integrator produces a response which falls
towards the high frequencies at a rate of 6 dB per octave, falling
approximately 50 dB at 15 kHz vs. 50 Hz, this is the first part of your
equalizer. The second part of your equalizer is the same as my RIAA
amplitude equalizer and consists of shelving the high frequencies up by
approximately 12 dB using the time constants of 318.3 usec. and 75
usec.. When you combine the "magnetic" pickup equalizer and the RIAA
amplitude equalizer into a single composite circuit you have what you
call "RIAA equalization". This equalization is the sum of a 50 dB high
frequency cut for "magnetic" pickup compensation and a high frequency
boost of 12 dB for RIAA amplitude equalization, giving a net high
frequency cut of 38 dB for the combined network.

Using a pickup that is directly responsive to the recorded groove
amplitude, like say an FM pickup, or a strain gauge pickup, eliminates
the need for the pickup compensation integrator required with a
"magnetic" pickup, and leaves us with the need to provide only the 12 dB
high frequency boost required by the RIAA cutting curve.

Get it, it's simple once you understand it, the "RIAA phono preamp" you
are describing is really doing two equalization jobs, pickup
compensation and compensation for the RIAA amplitude response.


Regards,

John Byrns

John, I stopped reading "let me explain", I'm afraid. Don't take this
badly, please. I did that because I knew that whatever followed was
going to be a catalogue of misunderstanding and error. It isn't too
important really what those errors are. What is important is that they
are errors, which thirty seconds of research (google for phono preamp
sche,matic - that should do it) will show you. You will then be in the
enviable position of knowing something that you have been getting
completely wrong for years, and being able to learn something new.

Please make this small effort before you post again. I promise you
won't find it wasted. And do listen and understand when I tell you
that those of us who have designed audio gear have never, ever
designed an RIAA preamp that boosts rather than reduces high
frequencies, Do some web research and see if you can find one.

d

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

Don, baby:

You amused me with your barns and rods (should they be roods?) in this
thread where Sander fed his slug Amstel, made me wonder if I shouldn't
give you another chance, if I hadn't misjudged you as just another
humourless purveyor of excessive negative feedback who should be
kicked on sight. So, just in case you really aren't an enemy of
fidelity, I'm going to give you a tip and hope St Peter is watching
and inscribing my incredible generosity in the Big Book Before the
Pearly Gates.

Save yourself a lot of grinding frustration and anger and either:
a) do not argue with John Byrns on this, meaning drop out now, don't
even tell him to look it up
or
b) accept that what you think you know has some pinholes in it to
which John has already taken a reamer and, before this is over, will
take a bloody great big angle grinder, and therefore go look it up
yourself with your prejudices (what you might prefer to call your
education and knowledge) put firmly aside in a locked box

I've seen John grind down the graduate engineers before, politely,
persistently. He never hesitates to apologize when he is wrong, and he
will always give your argument full consideration and your goodwill
the benefit of the doubt, but I have never seen him fail to understand
the warp and weft of something thoroughly before he starts. You might
note that Chris Hornbeck, a guy who sees through bull**** and
encrustations of hallowed practice to the true fundmentals beneath,
has decided that John is right, giving you the key to why John is
right: "differences between amplitude and velocity, and *why* they're
historically treated differently in cutter-head amplifiers". (Thanks,
Chris. I was struggling with whether that is it or whether it is more
complicated.). Or, in pure self-protection, Don me old gabbas, you
might look up some old RAT threads in which John (ever so politely!)
wiped the floor with that toe-rag Pasternack, admittedly a dullard,
but a dullard who claims to have a Stanford MSEE and observably has a
glib way with the math that often borders on deceit about professional
matters, and sometimes deliberately steps over that limit, after which
Pasternack usually claims that John drove him to betraying his
profession or, even more laughably, "I did it in my zeal to flame
Andre". See above for either of two simple acts you may perform to
save yourself from landing up in the same position as Plodnick vis a
vis John.

There, my duty is done. My money is on Mr Byrns to find all the tees
that aren't crossed and all the eyes that aren't dotted, and to slot
them into a Teflon-covered, Kevlar-armoured argument.

Thanks again for the chuckle.

Andre Jute
The trouble with most people is not what they don't know, but what
they know for certain that isn't true. --- Mark Twain

There are more things in Heaven and Earth, Horatio, than in thy
fondest dreams. --- Will the Shake