Was:audio opamp, LM4562 plots

[Martin Griffith]

Doug Self has done some AP plots of this nice little beasty

http://www.dself.dsl.pipex.com/ampins/webbop/LM4562.htm

and the test circuits (and waffle) are here
http://www.dself.dsl.pipex.com/ampins/webbop/opamp.htm#basic




Martin

 

[Eeyore]

Doug Self has done some AP plots of this nice little beasty

http://www.dself.dsl.pipex.com/ampins/webbop/LM4562.htm

Approx -100dB THD but he still reckons it's a 'problem'.

Doug Self is truly a Self-aggrandising POS.

Graham

 

[[email protected]]

Approx -100dB THD but he still reckons it's a 'problem'.

For some audio freaks, it is. Some of the golden-eared boys do seem to
be hear these levels of distortion and identify it as a problem. Back
around 1990, J. Robert Stuart of Meridian managed to persuade Brian
Moore - one of the U.K.'s better psychoacousticians - that such levels
of distortion can be audible

Doug Self is truly a Self-aggrandising POS.

That may be your opinion. It doesn't seem to be widely shared.

 

[Phil Allison]

" Graham Stevenson = Lying, Autistic Pile of Pommy SHIT"

Doug Self is truly a Self-aggrandising POS.

** Hypocrite - moi ???????


ROTFLMFAO !!!!!!!!!!!!!!!!







....... Phil

 

[Martin Griffith]

Approx -100dB THD but he still reckons it's a 'problem'.

Doug Self is truly a Self-aggrandising POS.

Graham

Just been looking at some Cirrus ADC/DACs, CS4351,CS5341 ( great part
numbers for dyslexics, not)

They don't even plot the THD performance anymore


Martin

 

[Eeyore]

For some audio freaks, it is. Some of the golden-eared boys do seem to
be hear these levels of distortion and identify it as a problem. Back
around 1990, J. Robert Stuart of Meridian managed to persuade Brian
Moore - one of the U.K.'s better psychoacousticians - that such levels
of distortion can be audible

Considering that it's rare to obtain background noise levels of even say 20dB
SPL in purpose designed studios, a signal would have to be of amplitude 120dB
SPL for a -100dB component to be audible above the wideband 20dB SPL noise
floor.

Quite frankly, the ear's performance is so massively degraded at such SPLs that
I find such a postulation frankly quite ridiculous.

That may be your opinion. It doesn't seem to be widely shared.

I have my reasons.

Graham

 

[Eeyore]

Just been looking at some Cirrus ADC/DACs, CS4351,CS5341 ( great part
numbers for dyslexics, not)

They don't even plot the THD performance anymore

Maybe it's below the noise (measurement) floor ? Just a thought. Wouldn't
entirely surprise me.

Graham

 

[Winfield]

Considering that it's rare to obtain background noise levels of even
say 20dB SPL in purpose designed studios, a signal would have to be
of amplitude 120dB SPL for a -100dB component to be audible above
the wideband 20dB SPL noise floor.

Quite frankly, the ear's performance is so massively degraded at
such SPLs that I find such a postulation frankly quite ridiculous.

I can't judge on the golden-ear argument, but I do know that
we all posses an excellent ability to hear sounds far below
the noise floor. This is because we easily hear specific
weak sounds distinct from say broadband white or pink noise
or other much louder background sounds at other frequencies.
A hair cell's responding ability is independent from the rest.

 

[Eeyore]

I can't judge on the golden-ear argument, but I do know that
we all posses an excellent ability to hear sounds far below
the noise floor.

Certainly 'pure tones' 10dB below the *wideband* noise floor figure. Maybe even
15 - 20 dB below for an experienced listener but ONLY under conditions of near
'silence'.

This is because we easily hear specific
weak sounds distinct from say broadband white or pink noise
or other much louder background sounds at other frequencies.
A hair cell's responding ability is independent from the rest.

It goes to hell once a large signal is present because of masking.

Graham

 

[Phil Allison]

"Winfield"

I can't judge on the golden-ear argument, but I do know that
we all posses an excellent ability to hear sounds far below
the noise floor.

** Got SFA to do with THD figures, though, since the original signal is
still there - massively masking low level harmonic or IM residual from
human perception.

At -100 dB, such residuals would be totally inaudible, even if reproduced
on their own, in a normal listening room acoustic ambient ( compared to
normal program level).

BTW:

To appreciate Doug Self's technical point re THD in his " Elements of
Op-Amp Design " page - you must follow the context - all of it.

Discover what his " blameless amplifier " concept is all about.

Apply that to IC op-amps, and it may just dawn on you.

Shame about the genetically dim donkey brains that infests this NG.

Like Graham Stevenson.




........ Phil

 

[Eeyore]

To appreciate Doug Self's technical point re THD in his " Elements of
Op-Amp Design " page - you must follow the context - all of it.

Discover what his " blameless amplifier " concept is all about.

His " blameless amplifier " is a POS. He simply ignores its obvious design
failings because he's a charlatan.

Graham

 

[Phil Allison]

" Graham Stevenson = Lying, Autistic Pile of Pommy SHIT "

Doug Self is truly a Self-aggrandising POS.

** Hypocrite - moi ???????

ROTFLMFAO !!!!!!!!!!!!!!!!


This LUNATIC needs a slug in the head.




...... . Phil

 

[Phil Allison]

"Eeysore the Posting Pommy Nutter "

His " blameless amplifier " is a POS.

** Utter nonsense.

You missed the crucial word " concept"

- cos you are totally manic & quite insane.

He simply ignores its obvious design
failings because he's a charlatan.

** No *YOU* are a classic example of a charlatan - Graham.

A constant pretender to expert knowledge and insights you simply do not
have.

While in reality a truly pathetic case, someone seriously mentally ill and a
useless pimple on the bum of society.


Because Doug Self won a position ( many years ago ) that you naively
imagined YOU deserved - you are now insanely JEALOUS of him.

How pathetic.

Hell hath no fury like a manic narcissist scorned.

Mr Self would be highly amused at your peeved teenage schoolgirl mentality.

Cos he regularly pisses on poseurs like you from a very great height.





....... Phil

 

[Eeyore]

" Graham Stevenson = Lying, Autistic Pile of Pommy SHIT "


** Hypocrite - moi ???????

ROTFLMFAO !!!!!!!!!!!!!!!!

This LUNATIC needs a slug in the head.

Yes darling !

Now roll over and go to sleep will you ?

Graham

 

[Phil Allison]

"Eeysore the Posturing Pommy Nutter "

His " blameless amplifier " is a POS.

** Utter nonsense.

You missed the crucial word " concept"

- cos you are totally manic & quite insane.

He simply ignores its obvious design
failings because he's a charlatan.

** No *YOU* are a classic example of a charlatan - Graham.

A constant pretender to expert knowledge and insights you simply do not
have.

While in reality a truly pathetic case, someone seriously mentally ill and a
useless pimple on the bum of society.


Because Doug Self won a position ( many years ago ) that you naively
imagined YOU deserved - you are now insanely JEALOUS of him.

How pathetic.

Hell hath no fury like a manic narcissist scorned.

Mr Self would be highly amused at your peeved teenage schoolgirl mentality.

Cos he regularly pisses on poseurs like you from a very great height.


ROTFL !!!!!!



....... Phil

 

[Eeyore]

"Eeysore the Posting Pommy Nutter "

** Utter nonsense.

You missed the crucial word " concept"

Whereas you missed the meaning of 'blameless' it seems. His design is anything
BUT blameless. Indeed it embodies some inherent horrible flaws (like crossover
distortion) that he chooses to 'sweep under the carpet'.

Graham

 

[Eeyore]

"Eeysore the Posturing Pommy Nutter "

** Utter nonsense.

I see the record's stuck again.

You really are quite pathetic Phil.

Graham

 

[Phil Allison]

"Eeysore the Posturing Pommy Nutter "

His " blameless amplifier " is a POS.

** Utter nonsense.

You missed the crucial word " concept"

- cos you are totally manic & quite insane.

He simply ignores its obvious design
failings because he's a charlatan.

** No *YOU* are a classic example of a charlatan - Graham.

A constant pretender to expert knowledge and insights you simply do not
have.

While in reality a truly pathetic case, someone seriously mentally ill and a
useless pimple on the bum of society.


Because Doug Self won a position ( many years ago ) that you naively
imagined YOU deserved - you are now insanely JEALOUS of him.

How pathetic.

Hell hath no fury like a manic narcissist scorned.

Mr Self would be highly amused at your peeved teenage schoolgirl mentality.

Cos he regularly pisses on poseurs like you from a very great height.

LOL





....... Phil

 

[Phil Allison]

"Eeysore the Posturing Pommy Nutter "

His " blameless amplifier " is a POS.

** Utter nonsense.

You missed the crucial word " concept" - cos you are totally

MANIC & quite INSANE.

He simply ignores its obvious design
failings because he's a charlatan.

** No *YOU* are a classic example of a charlatan - Graham.

A constant pretender to expert knowledge and insights you simply do not
have.

While in reality a truly pathetic case, someone seriously mentally ill and a
useless pimple on the bum of society.


Because Doug Self won a position ( many years ago ) that you naively
imagined YOU deserved - you are now insanely JEALOUS of him.

How pathetic !!!!

Hell hath no fury like a * manic narcissist scorned * .

Mr Self would be most highly amused at your peeved teenage schoolgirl
mentality.

Cos he regularly pisses on deluded poseurs like you from a very great
height.

ROTFL




....... Phil

 

[John Larkin]

Doug Self has done some AP plots of this nice little beasty

http://www.dself.dsl.pipex.com/ampins/webbop/LM4562.htm

and the test circuits (and waffle) are here
http://www.dself.dsl.pipex.com/ampins/webbop/opamp.htm#basic




Martin

I wish people wouldn't post audio junk to SED. It just brings out the
usual vermin, for the usual abusive rants. Makes me yawn.

John