Wrong answer.
It is very good measurement for an audio amp, but incomplete. As soon as it is a single ended tube amp, the hardest measurement can be omitted.
My approach depends on what do I measure, and which weak point this thingy has. Then I figure out how to push the thingy into the directions that highlights symptoms of the weak point in question, like on the picture above I pushed up frequency of well visible sharp meander to observe phase behaviour.
Hi John,
Well, I see you are still long on talk and very shy on substance. In other words, no change in your personality at all. You really do like to get shots off in every direction, even though I haven't posted here for a bit and you saw fit to bring my name up.
All anyone has ever asked of you is to answer a question directly, and use your vast knowledge to explain the issue clearly. A simple request really.
Also, I'm not trying to knock you. You aspire to be something you are not, it's that simple. I have no problem being technical and not an engineer. Fragile ego there John?
I can see you on the ground of the base of said "intellectual cliff", right beside your moral abyss. Why not try a different approach? Try not to disrespect people around you for one. It doesn't reduce your importance to show good manners socially. In fact, you will probably see that social grace elevates a person's reputation.
I don't know John, your guidance here has the thread spinning it's wheels in a never ending donut. What a waste!
-Chris
Well, I see you are still long on talk and very shy on substance. In other words, no change in your personality at all. You really do like to get shots off in every direction, even though I haven't posted here for a bit and you saw fit to bring my name up.
All anyone has ever asked of you is to answer a question directly, and use your vast knowledge to explain the issue clearly. A simple request really.
Also, I'm not trying to knock you. You aspire to be something you are not, it's that simple. I have no problem being technical and not an engineer. Fragile ego there John?
I can see you on the ground of the base of said "intellectual cliff", right beside your moral abyss. Why not try a different approach? Try not to disrespect people around you for one. It doesn't reduce your importance to show good manners socially. In fact, you will probably see that social grace elevates a person's reputation.
I don't know John, your guidance here has the thread spinning it's wheels in a never ending donut. What a waste!
-Chris
Anatech, I really don't need this, and you, a moderator too.
The problem is with an intimate understanding of FM modulation, how it happens, what it looks like on a spectrum analyzer. I only have a partial understanding of this, so I am reluctant to 'teach' others about it. Yet, I have 'hit the books' and maybe the test equipment in future, to get a better understanding, so that I can even teach a wider audience, what we have found.
The 'smoking gun' is FIG. 3 of my Matti's and my AES paper on TIM. It is OBVIOUS from looking at the measurement, that there are extra distortion products that DO NOT REPRESENT what we would EXPECT from the test itself. Not knowing what they were, we just IGNORED them. After there was plenty of other distortion products in the same figure that showed what we were trying to measure and point out, at the time.
I have been shown that these are FM products, NOT IM products. How do we know? We know, because these products are NOT harmonically related to the test signal components and appear is completely unrelated to the test signal itself. Any engineer would get nervous over this, because that is not supposed to happen.
All I can ask of anyone or everyone, is to read up on IM distortion products, before telling me that I don't know what I am talking about. That is all I ask here.
The problem is with an intimate understanding of FM modulation, how it happens, what it looks like on a spectrum analyzer. I only have a partial understanding of this, so I am reluctant to 'teach' others about it. Yet, I have 'hit the books' and maybe the test equipment in future, to get a better understanding, so that I can even teach a wider audience, what we have found.
The 'smoking gun' is FIG. 3 of my Matti's and my AES paper on TIM. It is OBVIOUS from looking at the measurement, that there are extra distortion products that DO NOT REPRESENT what we would EXPECT from the test itself. Not knowing what they were, we just IGNORED them. After there was plenty of other distortion products in the same figure that showed what we were trying to measure and point out, at the time.
I have been shown that these are FM products, NOT IM products. How do we know? We know, because these products are NOT harmonically related to the test signal components and appear is completely unrelated to the test signal itself. Any engineer would get nervous over this, because that is not supposed to happen.
All I can ask of anyone or everyone, is to read up on IM distortion products, before telling me that I don't know what I am talking about. That is all I ask here.
It's like driving by a highway accident, and I keep telling myself "don't look" but still I slow down and can't keep myself from looking.
Still, all attitude aside, it seems the guy with the eye on the ball at the moment is Mr. Curl.
Not that the opinion of a bystander would be important to you, but this is the interweb after all, so even bystanders can post. I see a lot of armchair speculation and pseudo-science. Sure, that's fine, but seeing how serious you guys are, I think John's right on the money proposing "hitting the books" and the hardware. I mean, are you discussing figure x from a 1976 paper? Papers are not like vintage wine necessarily. If nothing's been done in the area since then, I'd say it's about time that someone turn on that measuring thingy and do some real hands-on research. If a lot has been done in the area and you're not up to date, well, then that's not very good is it?
Apologies if the tone is perceived as inappropriate, that's not what's intended; but I've spent some years in research (like some of you, surely), and if indeed you guys have some good ideas, and there's nothing wrong with chatting, as long as something real comes out of it. And however much I found John's attitude (in the past in general) repulsive, I have to give him most credit at the moment, for pointing in what I think is entirely the right direction.
Regards.
Still, all attitude aside, it seems the guy with the eye on the ball at the moment is Mr. Curl.
Not that the opinion of a bystander would be important to you, but this is the interweb after all, so even bystanders can post. I see a lot of armchair speculation and pseudo-science. Sure, that's fine, but seeing how serious you guys are, I think John's right on the money proposing "hitting the books" and the hardware. I mean, are you discussing figure x from a 1976 paper? Papers are not like vintage wine necessarily. If nothing's been done in the area since then, I'd say it's about time that someone turn on that measuring thingy and do some real hands-on research. If a lot has been done in the area and you're not up to date, well, then that's not very good is it?
Apologies if the tone is perceived as inappropriate, that's not what's intended; but I've spent some years in research (like some of you, surely), and if indeed you guys have some good ideas, and there's nothing wrong with chatting, as long as something real comes out of it. And however much I found John's attitude (in the past in general) repulsive, I have to give him most credit at the moment, for pointing in what I think is entirely the right direction.
Regards.
Thanks, IKO, even if you think of me as a repulsive guy. I am just trying to get audio designers up to date, and I have done so, without pay, and lots of derision, for several years. My business associates think me 'nuts' to do so, and they probably are right. I am working on several projects at the moment, why should I bother to teach people who might just use it against me, either with added knowledge gleaned from the discussion, or disparaging others to take me seriously, because I am so 'out there'?
At this time, I have 4 power amps that seem to work, and I get monthly royalties for. I am known for 2 preamps, one that started this thread, and another that is pretty good, at least, the audio mags think so.
I am working on 2 phono stages and one (very new) power amp at the moment, and a few other things. However, my business associates, some even more qualified than me, technically, would not give this thread the sweat off their brow, and that is why they don't jump in here. Perhaps they are right, and even Walt Jung doesn't bother to contribute, yet we have written a paper together and known each other for 35 years.
However, do you yet understand why they won't contribute here? ATTITUDE, and disrespect for major contributors to the audio art. I am only the messenger, just like the teacher trying to make progress at a tough high school, and failing for the most part.
At this time, I have 4 power amps that seem to work, and I get monthly royalties for. I am known for 2 preamps, one that started this thread, and another that is pretty good, at least, the audio mags think so.
I am working on 2 phono stages and one (very new) power amp at the moment, and a few other things. However, my business associates, some even more qualified than me, technically, would not give this thread the sweat off their brow, and that is why they don't jump in here. Perhaps they are right, and even Walt Jung doesn't bother to contribute, yet we have written a paper together and known each other for 35 years.
However, do you yet understand why they won't contribute here? ATTITUDE, and disrespect for major contributors to the audio art. I am only the messenger, just like the teacher trying to make progress at a tough high school, and failing for the most part.
Even through I dislike some of the "attitude" here , I still find you (I did group you in my "legend" subcategory of contributors ) very valuable as a source of historical and technical info worthy of further investigation (the internet).
Please do not give up , some of "us" take a while (like a new vintage).
OS
It is still: The three phases of an assertion.
1. "I've discovered a new phenomenon that makes me better."
2. Defend it by name dropping and using data obtained from an obsolete IC that probably doesn't apply to a competently applied design.
3. Avoid any further technical defense by attacking the intellegence, ethics, motivation, etc., of anyone who questions the phenomenon.
How about that everyone?
Looks like we're at Stage 3 again.
1. "I've discovered a new phenomenon that makes me better."
2. Defend it by name dropping and using data obtained from an obsolete IC that probably doesn't apply to a competently applied design.
3. Avoid any further technical defense by attacking the intellegence, ethics, motivation, etc., of anyone who questions the phenomenon.
How about that everyone?
Looks like we're at Stage 3 again.
Oh no, I don't think of you, as a person, as repulsive; in all honesty, I don't know who you are, we never met, we never spoke. I was only talking about the way you addressed other people in this thread. To your defense though, quite a few people addressed you likewise. I think it's the tone of the discussion that sometimes very much puts me off. As an outsider one gets the impression of little people squabbling, and I know you are not.
Anyway, the fact that you're sharing some of your knowledge is nice. At times it looks like you guys are almost trying to do some research.
I actually think that the people you mention might not want to contribute here because there's little in it for them. What can they get out of posting in these forums? If they wanted to collaborate with well known technical guys, they can be found in other places. If they wanted to teach other people about their great knowledge, they'd either write books, or articles for publication. And probably one other factor; they want to be paid for their time, and I see absolutely nothing wrong with that. It can take lots of time and effort to develop ideas and products. We can't expect everyone to be charitable or to have the same business model as Nelson Pass. Freebies are nice but I wouldn't want it if I knew it was taken from time with his family and kids. Hence I do appreciate the effort you put here; hard to tell what you're trying to do sometimes. But yeah, it'd be nice if everyone put attitude aside and stay focus on the ball.
And here ends my zero contribution, thank you all
Anyway, the fact that you're sharing some of your knowledge is nice. At times it looks like you guys are almost trying to do some research.
I actually think that the people you mention might not want to contribute here because there's little in it for them. What can they get out of posting in these forums? If they wanted to collaborate with well known technical guys, they can be found in other places. If they wanted to teach other people about their great knowledge, they'd either write books, or articles for publication. And probably one other factor; they want to be paid for their time, and I see absolutely nothing wrong with that. It can take lots of time and effort to develop ideas and products. We can't expect everyone to be charitable or to have the same business model as Nelson Pass. Freebies are nice but I wouldn't want it if I knew it was taken from time with his family and kids. Hence I do appreciate the effort you put here; hard to tell what you're trying to do sometimes. But yeah, it'd be nice if everyone put attitude aside and stay focus on the ball.
And here ends my zero contribution, thank you all
Well stated Pooge, at least you have clued me in as to your concerns.
First, I shown something, previously ignored in my own measurements.
Two, I have attempted to share my previous oversight and access its importance to audio design.
Three, as I stated to an 80+ year old man, who knows 100 times more than me on this subject, just last night, that I wished that I had studied my complex math better in school, so that I could more easily absorb FM modulation theory and be able to 'prove' its presence to my colleagues here.
Has anyone come to my aid on FM theory? I don't think so, even though we have some PhD's out there.
Bessel functions are a mathematical term, nothing more. This is not 'name dropping', any more than mentioning something regarding Hertz or Ohm are name dropping. Should I convert to 1000 cycles/second, rather than 1000 Hz, in order not to mention a famous name?
Kind of absurd, isn't it?
First, I shown something, previously ignored in my own measurements.
Two, I have attempted to share my previous oversight and access its importance to audio design.
Three, as I stated to an 80+ year old man, who knows 100 times more than me on this subject, just last night, that I wished that I had studied my complex math better in school, so that I could more easily absorb FM modulation theory and be able to 'prove' its presence to my colleagues here.
Has anyone come to my aid on FM theory? I don't think so, even though we have some PhD's out there.
Bessel functions are a mathematical term, nothing more. This is not 'name dropping', any more than mentioning something regarding Hertz or Ohm are name dropping. Should I convert to 1000 cycles/second, rather than 1000 Hz, in order not to mention a famous name?
Kind of absurd, isn't it?
Iko, your contribution has been significant to me.
It reminded me of my background, how I was raised, and why I don't so mind the 'rough and ready' dialogue of the bickering on this thread, compared with many others, perhaps raised differently.
I note that you come from Canada.
I haven't been to Canada for more than 55 years, but I remember 3 summers there, living on a horse race track with my father in Vancouver, BC. You should have heard the language spoken there, and then you might understand that words are just words to me and I am fairly immune to being 'shocked'. Your sensitivity is probably very different. I have to continually remind myself of this, in order not to through everything out, because of the sensitivity difference.
It reminded me of my background, how I was raised, and why I don't so mind the 'rough and ready' dialogue of the bickering on this thread, compared with many others, perhaps raised differently.
I note that you come from Canada.
I haven't been to Canada for more than 55 years, but I remember 3 summers there, living on a horse race track with my father in Vancouver, BC. You should have heard the language spoken there, and then you might understand that words are just words to me and I am fairly immune to being 'shocked'. Your sensitivity is probably very different. I have to continually remind myself of this, in order not to through everything out, because of the sensitivity difference.
Casting Stones
I am with ikoflexer here........sometimes you might not like Mr.Curl's attitude (believe me, I have been on the wrong side of it a few times) but I have learnt a lot from him.
Most of you armchair quaterbacks need to stop and consider that there might something to be learned here , or maybe trying to prove your own credentials is more important. If you disagree with Mr.Curl you are free to leave or better still prove him wrong with your own experiments. Sniping at him does no one any good and is counterproductive.
Mr.Curl has taught me a lot and almost always has been correct but always admitted when he has made a mistake or made a wrong turn..........something which most of his critics won't do. If you have concrete experimental proof that he is wrong ,please present it..........my bet is that he will be the first to acknowledge it. Let's make this discussion constructive for the benefit of all.
Now if we can only get Mr.Curl to Charm School.............
Jam
I am with ikoflexer here........sometimes you might not like Mr.Curl's attitude (believe me, I have been on the wrong side of it a few times
) but I have learnt a lot from him.Most of you armchair quaterbacks need to stop and consider that there might something to be learned here , or maybe trying to prove your own credentials is more important. If you disagree with Mr.Curl you are free to leave or better still prove him wrong with your own experiments. Sniping at him does no one any good and is counterproductive.
Mr.Curl has taught me a lot and almost always has been correct but always admitted when he has made a mistake or made a wrong turn..........something which most of his critics won't do. If you have concrete experimental proof that he is wrong ,please present it..........my bet is that he will be the first to acknowledge it. Let's make this discussion constructive for the benefit of all.
Now if we can only get Mr.Curl to Charm School.............
Jam
Standard text book derivation of an FM signal, the Bessel functions describe the magnitude envelope of the spectra. The frequencies present are all harmonically related to the input.
No, you need to do due diligence in finding the unexpected lines before making extraordinary claims.
No, you need to do due diligence in finding the unexpected lines before making extraordinary claims.
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