The quote above is taken from:
http://diyaudio.com/forums/showthread.php?postid=482068#post482068
....and it really sums up (or should!) the raison d'etre of a discussion forum such as this.
Further thoughts or objections to the above are welcome....
http://diyaudio.com/forums/showthread.php?postid=482068#post482068
....and it really sums up (or should!) the raison d'etre of a discussion forum such as this.
Further thoughts or objections to the above are welcome....
Mike, I'd agree assuming the discussion is intended to be technical in nature in the first place. But there are lots of folks having a lot of fun building stuff (some of it really amazing stuff!) who aren't familiar with the technical issues at all, and for them the hard core technical aspects just aren't of interest. So to say that the nitty gritty technical issues are the core of the forum excludes a large number of people, many of whom are key contributors, and without whom the forum can't succeed. I don't think that's what you meant, but because it could be construed that way, I thought I'd mention it.
But technical discussions can become fruitless when blind faith is invoked as an argument (really a non-argument). That causes the discussion to either stall or just go around in circles. One of the things I like very much about engineering is the abstract nature of the ideas involved. It's not like politics or religion, where the issues can have deep emotional implications. In the ideal case, engineering ideas can (or at least should) be discussed completely dispassionately. Having emotional investment in an idea or collection of ideas only prevents people from considering ideas outside that framework. And that can only hurt.
In the audio realm, I've noticed there are certain people who have brought up certain key ideas that were controversial at the time, and they challenge the ability of people to discuss the ideas in a dispassionate way. Take Otala for instance. He brought up some new, controversial ideas about TIM back in the '70s. It turns out there were some minor errors in what he did, but the things he was theorizing about, the basic concepts were real and measurable. This seemed to bring about a kind of religious war, with people on the objectivist side saying "he was a so-and-so and completely wrong" and people on the subjectivist side embracing everything he said - including the things that were in error. And even if they were in error, so what? He's a human being like anybody else. None of the people who were involved in any of the vicious attacks on him back then are here in this forum now, so there's no need for anyone to become defensive about it. They're just abstract ideas fer cryin' out loud. Nobody kicked anybody's dog.
But technical discussions can become fruitless when blind faith is invoked as an argument (really a non-argument). That causes the discussion to either stall or just go around in circles. One of the things I like very much about engineering is the abstract nature of the ideas involved. It's not like politics or religion, where the issues can have deep emotional implications. In the ideal case, engineering ideas can (or at least should) be discussed completely dispassionately. Having emotional investment in an idea or collection of ideas only prevents people from considering ideas outside that framework. And that can only hurt.
In the audio realm, I've noticed there are certain people who have brought up certain key ideas that were controversial at the time, and they challenge the ability of people to discuss the ideas in a dispassionate way. Take Otala for instance. He brought up some new, controversial ideas about TIM back in the '70s. It turns out there were some minor errors in what he did, but the things he was theorizing about, the basic concepts were real and measurable. This seemed to bring about a kind of religious war, with people on the objectivist side saying "he was a so-and-so and completely wrong" and people on the subjectivist side embracing everything he said - including the things that were in error. And even if they were in error, so what? He's a human being like anybody else. None of the people who were involved in any of the vicious attacks on him back then are here in this forum now, so there's no need for anyone to become defensive about it. They're just abstract ideas fer cryin' out loud. Nobody kicked anybody's dog.
Mikek is extraordinary related the intelligence, not only Maths, he is clever
And i think more than half forum together...this man is gênius...and he use to make some fun sadic funny game with us all the time.
Take a look his signature:
A formely artist called Mikeks...think about that title for on deep knowledge man, top hi calculator living machine.
The art of controversy i could capture, he is clever and he is just pushing the lines and the dolls are jumping alike a dolls theather.
I use to joke this way with my Spanish Beauty...she is brave and furious...and i now how to move her mood the way i want....when she talked too much or start some conversation i do not like ... i order her to shut her mouth.... easy...she start to scream and i runned out from the subjetc....laughing about my "power" to control an manipulate the pretty woman mood....and certain people never perceive the trick...i told her.....will show you who is the dominant here....Me Tarzan , You Jane!......and shut your mouth now!.... and she turns nervous again.....when discovered the week point, just put the finger on it.
The hability with Mathematics, and the "maybe sadic" intention, makes him wonderfull artist of controversy....take a look... he entered and stablish some confusion..... and with class, and with good words, with know how...no one can touch him...this is a technological discussion.... covered under this fantasy he kick our a---- easy and when he want.
More than feel bad with his superiority....much more clever than i am, i respect very much his competence related manipulate people.... he is better Psychologist than Enginneer, but he did not realise that already.
See.... he create the thread to "fish" the "fishes"......this is alike you enter in one gimnastic academy and ask loud an clear.. the ones are gay here shut your mouth...this is so shocking that no one will open the mouth... and will confirm...thats Mike...Genius... sorry for us...he will make with us what he wants.... but i am learning his tricks...i have a deep positive impression related his capacities...his brain is magnificent, despite someone can understand that is beeing used, sometimes, for not so good purposes.
In my country we call that "botar pilha".....this means..."putt batteries" in someone.... alike one toy, when you put new fresh batteries, the toy start to move and make their noise.... he use to put batteries in some guys...i am sure he is falling from the chair laughing with the people giving attention to his tricks.
Long life and healthy to you Mikeks, and my deep and sincere congratulations related your capacities...well directioned will be magnificent job to manking....but unfortunattelly i am sure you are not happy...no one with your intelligence can be happy.... it is impossible seeing clearly the world dirty...be happy, only possible for common people alike me...having bad life, third world politics making dirty all the time, and i laughing because so stupid to perceive they are ------- me all the time... alike that animal that eat only smelling meat...the rest of other dead animals, having one smilling expression in its face.
This way you get Hugh, and i like hugh very much...i dislike that..could not see that good man moving as result you push him to that...this way..... the revenge is tell people your trick...bôooooo! to you.
you damned...hehe...very intelligent....too much Mikeks!
regards,
Carlos
And i think more than half forum together...this man is gênius...and he use to make some fun sadic funny game with us all the time.
Take a look his signature:
A formely artist called Mikeks...think about that title for on deep knowledge man, top hi calculator living machine.
The art of controversy i could capture, he is clever and he is just pushing the lines and the dolls are jumping alike a dolls theather.
I use to joke this way with my Spanish Beauty...she is brave and furious...and i now how to move her mood the way i want....when she talked too much or start some conversation i do not like ... i order her to shut her mouth.... easy...she start to scream and i runned out from the subjetc....laughing about my "power" to control an manipulate the pretty woman mood....and certain people never perceive the trick...i told her.....will show you who is the dominant here....Me Tarzan , You Jane!......and shut your mouth now!.... and she turns nervous again.....when discovered the week point, just put the finger on it.
The hability with Mathematics, and the "maybe sadic" intention, makes him wonderfull artist of controversy....take a look... he entered and stablish some confusion..... and with class, and with good words, with know how...no one can touch him...this is a technological discussion.... covered under this fantasy he kick our a---- easy and when he want.
More than feel bad with his superiority....much more clever than i am, i respect very much his competence related manipulate people.... he is better Psychologist than Enginneer, but he did not realise that already.
See.... he create the thread to "fish" the "fishes"......this is alike you enter in one gimnastic academy and ask loud an clear.. the ones are gay here shut your mouth...this is so shocking that no one will open the mouth... and will confirm...thats Mike...Genius... sorry for us...he will make with us what he wants.... but i am learning his tricks...i have a deep positive impression related his capacities...his brain is magnificent, despite someone can understand that is beeing used, sometimes, for not so good purposes.
In my country we call that "botar pilha".....this means..."putt batteries" in someone.... alike one toy, when you put new fresh batteries, the toy start to move and make their noise.... he use to put batteries in some guys...i am sure he is falling from the chair laughing with the people giving attention to his tricks.
Long life and healthy to you Mikeks, and my deep and sincere congratulations related your capacities...well directioned will be magnificent job to manking....but unfortunattelly i am sure you are not happy...no one with your intelligence can be happy.... it is impossible seeing clearly the world dirty...be happy, only possible for common people alike me...having bad life, third world politics making dirty all the time, and i laughing because so stupid to perceive they are ------- me all the time... alike that animal that eat only smelling meat...the rest of other dead animals, having one smilling expression in its face.
This way you get Hugh, and i like hugh very much...i dislike that..could not see that good man moving as result you push him to that...this way..... the revenge is tell people your trick...bôooooo! to you.
you damned...hehe...very intelligent....too much Mikeks!
regards,
Carlos
Actually Carlos, i suspect i am of average stupidity.....no greater or less than 99.999999999999% of the folk on this forum
...Indeed, it is precisely because i am not particularly intelligent that i have a very strong affinity for material developed from intuitive first principals...
It is only from the later that demonstrably sound advanced ideas may be developed....in my experiance...
I believe passionately that the proponents of a given theory should from the outset be able to expound on it's tenets in lay language to anyone who may care to listen, without invoking advanced mathematics....
In otherwords, the material should be at their fingertips, they should be fluent in their chosen discipline, and almost literally feel the later in their fundament....
This is why i object strongly to 'experts' who give demonstrably incorrect advice to enthusiasts on the grounds that their 'experiance' and reputation is necessary and sufficient to justify blind faith in their panaceas.
...Indeed, it is precisely because i am not particularly intelligent that i have a very strong affinity for material developed from intuitive first principals...
It is only from the later that demonstrably sound advanced ideas may be developed....in my experiance...
I believe passionately that the proponents of a given theory should from the outset be able to expound on it's tenets in lay language to anyone who may care to listen, without invoking advanced mathematics....
In otherwords, the material should be at their fingertips, they should be fluent in their chosen discipline, and almost literally feel the later in their fundament....
This is why i object strongly to 'experts' who give demonstrably incorrect advice to enthusiasts on the grounds that their 'experiance' and reputation is necessary and sufficient to justify blind faith in their panaceas.
![mikeks[1].jpg](/community/data/attachments/27/27859-94307ccdc696ff980abded318fc91fd0.jpg)
Mike
Welcome to the 21st century. When we watch the news the reporters ask "How do you feel about XX" not, "What do you think about XX". They're not the same. Both can be valid, but they're not the same.
Myself, I don't get to worked up about any of this. It ain't worth the effort, it's just a hobby for most and hobbies are supposed to be fun, relaxing and enjoyable.
I love seeing the math on the site. One can not argue with the numbers but I also believe that there is much that we still don't know. Much that the math has yet to address. We knew for a long time that the earth was flat and that the sun went around the earth. Galileo spent a long time under house arrest for that last one.
I design a lot of pro/studio gear, mainly mic-pre's. One client may want a hard, edgy, in your face sound and the next client wants the sound of an old API type iron transformer. Does this make one design "wrong" and one "correct?" Granted, the missions of hi-end and studio gear are not the same but my only concern is if the client is happy.
Mike
Welcome to the 21st century. When we watch the news the reporters ask "How do you feel about XX" not, "What do you think about XX". They're not the same. Both can be valid, but they're not the same.
Myself, I don't get to worked up about any of this. It ain't worth the effort, it's just a hobby for most and hobbies are supposed to be fun, relaxing and enjoyable.
I love seeing the math on the site. One can not argue with the numbers but I also believe that there is much that we still don't know. Much that the math has yet to address. We knew for a long time that the earth was flat and that the sun went around the earth. Galileo spent a long time under house arrest for that last one.
I design a lot of pro/studio gear, mainly mic-pre's. One client may want a hard, edgy, in your face sound and the next client wants the sound of an old API type iron transformer. Does this make one design "wrong" and one "correct?" Granted, the missions of hi-end and studio gear are not the same but my only concern is if the client is happy.
Mike
Yes, as a bad drawer, i took a long time doing it
Some imagine of one special brain man....a little "out of the world"... thinking deeply with his books under arm.... and not wondering if he is safe in ground (in earth) or dreamin with his deep ideas that are so good to think that he forgot to see where he is walking.... some genius mind i tried to make...my image of him is this one...of course are not real thing.
Despite my words showed oposite, some try to ask him to put the feet over the brake pedal, as some people is turning nervous with his knowledge and ideas, i really like him.... this is strange to you "Anglo"..... Englanders and Saxons people....but i like him... and i am the way he is, but not so clever as he is.
In the radio, not the Ham bands, i am the Sitting bull, the trucker destroyer....i haunt them to disturb them... asking if they know what their wife is doing rigth now!... those things....learning terrible english words! hehehe...it is funny to my...put batteries on them.
This way, i sniff easy my "partners".
But he could not realise he is putting Batteries and moving people here or there...maybe he do not know he astounding power...but he has the brigth of the stars.... astucy...clever, fast.
A very impressive man he is.... you will not believe....i am sure about that...but i like him
regards,
Carlos
Some imagine of one special brain man....a little "out of the world"... thinking deeply with his books under arm.... and not wondering if he is safe in ground (in earth) or dreamin with his deep ideas that are so good to think that he forgot to see where he is walking.... some genius mind i tried to make...my image of him is this one...of course are not real thing.
Despite my words showed oposite, some try to ask him to put the feet over the brake pedal, as some people is turning nervous with his knowledge and ideas, i really like him.... this is strange to you "Anglo"..... Englanders and Saxons people....but i like him... and i am the way he is, but not so clever as he is.
In the radio, not the Ham bands, i am the Sitting bull, the trucker destroyer....i haunt them to disturb them... asking if they know what their wife is doing rigth now!... those things....learning terrible english words! hehehe...it is funny to my...put batteries on them.
This way, i sniff easy my "partners".
But he could not realise he is putting Batteries and moving people here or there...maybe he do not know he astounding power...but he has the brigth of the stars.... astucy...clever, fast.
A very impressive man he is.... you will not believe....i am sure about that...but i like him
regards,
Carlos
If I understand this, you people are confused about Otala and his efforts.
First, Matti Otala found, back in the 1960's, by accidently miswiring a power amp, that negative feedback was a problem with the subjective performance of audio circuits. Otala found that when both the open loop bandwidth increased and the feedback was reduced, the amp sounded better.
He then read, as I did at the time, the IEEE paper by Daugherty and Greiner, "Some Design Objectives for Audio Power Amplifiers." 'IEEE Transactions Audio Electroacoustics' pp43-48 Mar 1966.
This article stipulated the QUALITATIVE aspects of TIM distortion, and it was the first to state "... the power amplifier frequency response WITHOUT FEEDBACK that determines the desired pre-amplifier frequency response." This means that the OPEN LOOP RESPONSE has to be higher than 20KHz for optimum operation, according to the D&G article.
Matti then worked on the QUANTITATIVE aspects of TIM distortion with several papers, and he kept the two criteria as important: Low feedback, high open loop bandwidth.
By 1975, many people pointed out that SLEW RATE seemed to be at the heart of TIM. Well it is, except that it is an END CONDITION, like clipping in power amps. It is the behavior, BELOW clipping that is most important, so Matti developed measurements of TIM that occurred below slew rate limiting, and there was plenty of TIM distortion in the 741 type op amps, under almost any reasonable situation. Some individuals found that you could even reduce TIM with an open loop bandwith with only a few hundred cycles or so, if the slew rate was made high and the circuit was fairly linear. Why then, did Matti cling to the 20KHZ open loop bandwidth first put forth by D&G? Well, he found that circuits still sounded better with high open loop bandwidth.
So he put TIM under a more general classification called DIM. DIM contains PIM as well as TIM and maybe other distortion contributions. For the last 25 years it is DIM that we have been working at, the TIM problem being understood.
In 1980, Matti wrote a paper on PIM. This was countered by Bob Cordell,who also tried to minimize the importance of TIM, previously. A personality problem? I think so. Kind of like Mikek and me on this website. So far as I can determine, PIM is not improved by the addition of negative feedback or at least is made worse by reduction in open loop feedback.
I think that PIM is why global negative feedback is still a problem. I could be wrong, but I will design my circuitry to have the highest open loop bandwidth possible, consistent with other requirements.
First, Matti Otala found, back in the 1960's, by accidently miswiring a power amp, that negative feedback was a problem with the subjective performance of audio circuits. Otala found that when both the open loop bandwidth increased and the feedback was reduced, the amp sounded better.
He then read, as I did at the time, the IEEE paper by Daugherty and Greiner, "Some Design Objectives for Audio Power Amplifiers." 'IEEE Transactions Audio Electroacoustics' pp43-48 Mar 1966.
This article stipulated the QUALITATIVE aspects of TIM distortion, and it was the first to state "... the power amplifier frequency response WITHOUT FEEDBACK that determines the desired pre-amplifier frequency response." This means that the OPEN LOOP RESPONSE has to be higher than 20KHz for optimum operation, according to the D&G article.
Matti then worked on the QUANTITATIVE aspects of TIM distortion with several papers, and he kept the two criteria as important: Low feedback, high open loop bandwidth.
By 1975, many people pointed out that SLEW RATE seemed to be at the heart of TIM. Well it is, except that it is an END CONDITION, like clipping in power amps. It is the behavior, BELOW clipping that is most important, so Matti developed measurements of TIM that occurred below slew rate limiting, and there was plenty of TIM distortion in the 741 type op amps, under almost any reasonable situation. Some individuals found that you could even reduce TIM with an open loop bandwith with only a few hundred cycles or so, if the slew rate was made high and the circuit was fairly linear. Why then, did Matti cling to the 20KHZ open loop bandwidth first put forth by D&G? Well, he found that circuits still sounded better with high open loop bandwidth.
So he put TIM under a more general classification called DIM. DIM contains PIM as well as TIM and maybe other distortion contributions. For the last 25 years it is DIM that we have been working at, the TIM problem being understood.
In 1980, Matti wrote a paper on PIM. This was countered by Bob Cordell,who also tried to minimize the importance of TIM, previously. A personality problem? I think so. Kind of like Mikek and me on this website. So far as I can determine, PIM is not improved by the addition of negative feedback or at least is made worse by reduction in open loop feedback.
I think that PIM is why global negative feedback is still a problem. I could be wrong, but I will design my circuitry to have the highest open loop bandwidth possible, consistent with other requirements.
John Curl, what a honor to be so close, have on thead before and other after yours.
People told me you are the best in our forum.
I am happy, i learned a lot here in our forum, i could understand you completely.
In the past i could not do that.
My God John, if someone could convince you to spend sometime sitting to hear some perception classes.... in Psychology area.....joining this impressive knowledge with some human perception inputs...this will result great!
If not already done, as i can see you are considering the differences related the theories and real practical results.
One day i will have one picture with your sign over...my God.... the "God!" John Curl personally talking with me!
Not joking, not sascarm or ironic words...this is feeling...happy and proud.
regards,
Carlos
People told me you are the best in our forum.
I am happy, i learned a lot here in our forum, i could understand you completely.
In the past i could not do that.
My God John, if someone could convince you to spend sometime sitting to hear some perception classes.... in Psychology area.....joining this impressive knowledge with some human perception inputs...this will result great!
If not already done, as i can see you are considering the differences related the theories and real practical results.
One day i will have one picture with your sign over...my God.... the "God!" John Curl personally talking with me!
Not joking, not sascarm or ironic words...this is feeling...happy and proud.
regards,
Carlos
john curl said:
No.
john curl said:
No.
john curl said:
http://diyaudio.com/forums/showthread.php?postid=420044#post420044
john curl said:
Cordel (and later Cherry) showed from first pricincipals, bespoke instrumentation, and appropriate quantitative analysis that PIM is negligible in feedback amps....
....and that small amounts that may be detected open-loop, promptly disappear with the application of sufficient feedback....consistent with Baxandal.
john curl said:
john curl said:
Open-loop bandwidth is a meaningless quantity in itself.....
This is probably the most indefatigable myths in audio never-never land...
That soooo many intelligent people should be consumed by this piece of heroic nonsense is marvellous in itself...
In fact what is desirable is maximal loop transmission across the audio band...
To maximise the later, reduce singularities in foward path (usually no more than two discrete or compound stages of gain), and make these as linear as possible before closing the major loop....
john curl said:
Just because Cordell soundly disproved Otala and his obscurantist notions does not mean he had a 'personality problem'....
...and...No!...I most certainly do not have a 'personality problem' with your Lordship...
Mathematic true cannot be discussed
But that reality aplied to human beeing is confuse.
My Maid say when clipping, that the sound is "strong"
My audiophile friends said this is awfull
Old amplifiers full of TIM and IMD are good to hear
New amplifiers distortionless is not good to hear
This way, i suppose, Enginneers runned to Scope and Meters... this way, good metering, good Mathematics good sound!
This way the personal differences between groups of people, preferences and ear characteristics, home ambience and a lot of things was erase out from the context.
This way, no doubts the scopes are very happy
But what about people?
Must be flexible... and accept some new ideas, as 1 added to 1 can be 3 or 4, and not only a childreen stupid joke, if female and male.... 1 more 1 can variate a lot!
The distortionless amplifiers sounds awfull, in my idea, of course you can disagree, and you can be rigth related the majority of population.
I suppose we have not already a good study related that subject, also human perception is not something studied by Electronic Engineers that will go to develop audio amplifiers, that ,I am suposing, you can informed me if i am wrong, i will be happy if wrong...very happy and very confused, because amplifiers are beeing made to spectrum and scopes.
So, comproving things with Mathematic is proven that the scope will be satisfied.
regards,
Carlos
But that reality aplied to human beeing is confuse.
My Maid say when clipping, that the sound is "strong"
My audiophile friends said this is awfull
Old amplifiers full of TIM and IMD are good to hear
New amplifiers distortionless is not good to hear
This way, i suppose, Enginneers runned to Scope and Meters... this way, good metering, good Mathematics good sound!
This way the personal differences between groups of people, preferences and ear characteristics, home ambience and a lot of things was erase out from the context.
This way, no doubts the scopes are very happy
But what about people?
Must be flexible... and accept some new ideas, as 1 added to 1 can be 3 or 4, and not only a childreen stupid joke, if female and male.... 1 more 1 can variate a lot!
The distortionless amplifiers sounds awfull, in my idea, of course you can disagree, and you can be rigth related the majority of population.
I suppose we have not already a good study related that subject, also human perception is not something studied by Electronic Engineers that will go to develop audio amplifiers, that ,I am suposing, you can informed me if i am wrong, i will be happy if wrong...very happy and very confused, because amplifiers are beeing made to spectrum and scopes.
So, comproving things with Mathematic is proven that the scope will be satisfied.
regards,
Carlos
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