Graham Maynard said:
Graham,
I don't want to say gobbledegook because I assume this is rational thought converted to text. But as soon as I read this, before having seen powerbecker's and Bob's response, I thought, What on earth is he saying here. It is NOT unwillingness to discuss, but discussion is impossible if you have no clue what the other guy is saying. Is there no way to explain what you mean? This is waisting everybodies time.
Jan Didden
Graham,
I don´t like your florid explanations.
I and a few other are interested to get facts, technic call for concrete examples with numbers.
I am not interested to read technical poetry, and when I see for this a striking answer...so sorry I must laugh!
Regards
Heinz!
I don´t like your florid explanations.
I and a few other are interested to get facts, technic call for concrete examples with numbers.
I am not interested to read technical poetry, and when I see for this a striking answer...so sorry I must laugh!
Regards
Heinz!
I admit that I also cannot comprehend what Graham has been trying to say.
But I have a lot of respect for his knowledge, and as a gentleman.
AND I am still interested to understand what he is trying to explain.
Is there no other way to ask someone to explain himself in more layman terms (especially for non native speakers) and still be nice to one another ?
Yes, Graham, I am interested to know what you think are the advantages and disadvantages of zero global negative feedback, and what are the technical arguments behind.
Patrick
But I have a lot of respect for his knowledge, and as a gentleman.
AND I am still interested to understand what he is trying to explain.
Is there no other way to ask someone to explain himself in more layman terms (especially for non native speakers) and still be nice to one another ?
Yes, Graham, I am interested to know what you think are the advantages and disadvantages of zero global negative feedback, and what are the technical arguments behind.
Patrick
Graham Maynard said:
Graham,
That is the problem and probably source of misunderstanding.
Amplitude distortion in time, caused by amplitude and phase frequency characteristics,
is not considered to be non-linear distortion .
Non-linear distortion is a process that creates new harmonics when input is excitated by steady state sine wave of one single frequency.
Also, suddenly turned-on sine is noway a wave of single frequency. Its spectrum has harmonics up to infinite frequency, they are caused by sudden change of derivative at the moment when sine wave starts from zero (from straight line at time t = 0).
So the "first cycle distortion analysis" is saying more about linear distortion, rather than non-linear distortion.
So the "first cycle distortion analysis" is saying more about linear distortion, rather than non-linear distortion.
Hi PMA and others,
But in my simulations in #396 I suggested that anyone who has concerns about discussing the response of a suddenly starting sine should study the 10kHz traces after 100uS alone.
That is the differences caused to output terminal potential due to component induced amplifier inductance alone.
The output has been rendered non-linear due to the activity of 'Linear' current flows overcoming propagation delayed ampliutude linearity control in time.
Cheers ......... Graham.
But in my simulations in #396 I suggested that anyone who has concerns about discussing the response of a suddenly starting sine should study the 10kHz traces after 100uS alone.
That is the differences caused to output terminal potential due to component induced amplifier inductance alone.
The output has been rendered non-linear due to the activity of 'Linear' current flows overcoming propagation delayed ampliutude linearity control in time.
Cheers ......... Graham.
Graham Maynard said:
Graham,
I can relate with Bob's exasperation, given a long professional career based on a solid professional education, and a personal attitude of thorough, unrelenting attention to detail an coherence.
In that light, your highly intuitive well meant but oftentimes wrong mix of unrelated issues may result also in "awful personal insult", at least I have experienced that kind of feeling with several of your posts.
I believe most here do not consider you a dummy, but a veteran in matters audio lacking some aspects of formal training yet making do the hard way, building, listening and rebuilding as much as necessary to get satisfactory results.
I find stimulating to have discussions like this to keep lively, for they help dispell that cozy feeling of knowing all there is to know about something so "trivial" as audio amplification.
Which is far from trivial for sure, given the unholly mix of nonlinear power devices, reactive loads, exquisitely developed sense of hearing, and several different technology and topology means to achieve the same end.
Rodolfo
Graham Maynard said:
I translate the first sentence as follows:
"That is the Vout difference caused by Lout. "
Correct?
I'm gathering courage for the second sentence.
Jan Didden
Hi Jan,
Yes, BUT also the way the amplifier subsequently reacts to its own unavoidable generation of an error greater than would be the case where there was no propagation delay (self inductance) affecting output terminal control.
There was a point made about linearity and harmonics above.
Where any amplifier output is not a stable propagation delayed and perfectly magnified image of input, then the amplification response has been non linear; whatever the resulting error shape and its examinable harmonic characteristics.
Cheers ........ Graham.
Yes, BUT also the way the amplifier subsequently reacts to its own unavoidable generation of an error greater than would be the case where there was no propagation delay (self inductance) affecting output terminal control.
There was a point made about linearity and harmonics above.
Where any amplifier output is not a stable propagation delayed and perfectly magnified image of input, then the amplification response has been non linear; whatever the resulting error shape and its examinable harmonic characteristics.
Cheers ........ Graham.
Non-linear means that there is a different gain for different amplitudes in the input, i.e. gain si amplitude dependent.
Graham Maynard said:
Yoy are trying to create a definition of non-linear distortion that is different from the exisiting and accepted definition. You are again confusing us.
Jan Didden
Hi PMA,
Yes the NFB loop controlled gain changes in time, so what is wrong with my statement, OR, please tell me which expression you would prefer me to use.
Hi Jan,
No I am not trying to create a new definition.
The Definition known to us all is generally applied/used in time isolation, not time continuum.
Cheers ......... Graham.
Yes the NFB loop controlled gain changes in time, so what is wrong with my statement, OR, please tell me which expression you would prefer me to use.
Hi Jan,
No I am not trying to create a new definition.
The Definition known to us all is generally applied/used in time isolation, not time continuum.
Cheers ......... Graham.
Graham Maynard said:
Graham I apologize for characterizing your remarks that way; it is not meant to be something personal. It is just a reflection of the fact that I simply cannot decode what you are saying. Maybe someone else here on the board who agrees with you and thinks like you do can re-state in an understandable way what you are saying.
Bob
Graham Maynard said:
Graham,
this leads to nowhere. Gain change in time does not neccessarily mean non-linearity, as it may reflect perfectly linear behaviour, like RC circuit.
Non-linear means gain dependent on amplitude, even for DC. Of course, there is static non-linearity and dynamic non-linearity.
You mix everything in a one big pot. This brings confussion, though your intentions are good, as I believe.
... and don't forget that for the main amp there are NO gain changes in time. Whatever you do with feedback, the forward amp *always* works open loop, with all its non-linearity. The only thing the feedback loop does is modify the forward amp input signal.
Jan Didden
Jan Didden
Here we go again,
Those are my carefully chosen words.
If you do not understand my meaning that is okay, but to accuse me of using the wrong words for what I know I want to say is wrong of you Mike.
I guess I cannot convey intended meaning here.
When the back-EMF of a loudspeaker overcomes (esp class-AB) amplifier linearity the amplifier no longer behaves as everyone expects because as an output stage alternates between driving and damping it can be reverse driven through a fraction of its bias potential before the global NFB loop can regain control. The result is not linear; no matter what other ways I am told I ought to be describing the distorted waveform.
Jan, it is me who feels as if I have wasted my time illustrating the 'disfunction in time' effect and explaining how it arose in that multi-trace fundamental nulled simulation above.
Maybe someday others will use their simulators more innovatively, possibly with real time analysis. However I cannot, and I am not in any position to do more, so I will bow out and go back to enjoying the trustable reproduction outcome of my own findings.
Cheers ......... Graham.
Those are my carefully chosen words.
If you do not understand my meaning that is okay, but to accuse me of using the wrong words for what I know I want to say is wrong of you Mike.
I guess I cannot convey intended meaning here.
When the back-EMF of a loudspeaker overcomes (esp class-AB) amplifier linearity the amplifier no longer behaves as everyone expects because as an output stage alternates between driving and damping it can be reverse driven through a fraction of its bias potential before the global NFB loop can regain control. The result is not linear; no matter what other ways I am told I ought to be describing the distorted waveform.
Jan, it is me who feels as if I have wasted my time illustrating the 'disfunction in time' effect and explaining how it arose in that multi-trace fundamental nulled simulation above.
Maybe someday others will use their simulators more innovatively, possibly with real time analysis. However I cannot, and I am not in any position to do more, so I will bow out and go back to enjoying the trustable reproduction outcome of my own findings.
Cheers ......... Graham.