Bruno, thanks for the clarification. I wonder if you would consider sharing the results of the audible IMD product measurements for multitone signal with the fundamentals within the power bandwidth and not just below 20 kHz. Despite there seems to be no de-facto standard for this kind of audio performance metric, it would totally disambiguate the topic and would also be a very cool differentiator for ncore.
AP2, may I dare to respond. will all due respect, your English is indecipherable, and (if it's not obvious) this is not helping you at all. if you want to get an answer, have someone translate for you. but if you're just trying to raise controversy just for the fun of it (not saying that you are), please find some other place.
PS: bringing up the NuForce in any context whatsoever name doesn't aid credibility either
PS: bringing up the NuForce in any context whatsoever name doesn't aid credibility either
Roberto. Once again, you are deliberately misreading what I say. Ncore is not limited to 20kHz. Not in any way. I have never said that it is, and I'm going to categorically state that the reverse is true. There is nothing in Ncore that limits bandwidth to 20kHz. The frequency response plot is published. The only thing I'm saying is that if you want to make measurements that correlate well with musical performance, you should not get sidetracked by small rises of THD for harmonics above 20kHz, or try to combat these. Instead, test HF linearity using an IMD test and stop reading at 20kHz. This does not imply that supersonic HD is bad. Quite the reverse. You do know that Ncore has 53dB of loop gain all the way out to 20kHz (do you know of any other class D amplifier with 53dB of loop gain at such high frequencies?) Well, 20kHz is only the point where loop gain drops below 53dB. Which means that at 50kHz, loop gain is still higher and distortion still lower than that of any other class D amplifier. If you didn't think maths were easy as you suggested earlier, you might have actually done them and realised this without my having to point this very basic fact out. You simply can't get enormous loop gains inside the audio band without still having a goodish bit left at higher frequencies. You're just embarrassing yourself by making claims about the outband behaviour of Ncore. As I explained earlier, the outband behaviour of Ncore can be validly inferred from its inband behaviour and the loop gain plot. Both are published. Do your homework.
If you wish to substantiate your claim that your design has superb performance (either below or above 20kHz), go ahead and post measurements. Or talk substance. As a class D designer you should be able to talk about the nitty gritty of class D. But stop taking gratuitous swipes at other people's work. On a previous occasion you have accused me of lying (when presenting hum-free distortion spectra) and recently you've tried arguing that spending time on maths automatically renders one unable to do the electronic implementation right. If I ever saw a nonsequitur this is it. Now you're trying to push the audiophile "over 20kHz" button simply because I say that the spectrum below 20kHz is the one that's more important by a long shot, and you completely forget that in order to work as well as it does my amp, by necessity, has to have above-average performance above 20kHz as well.
I understand you've got some wares to hawk. Well, fine, open another thread saying how wonderful it is. Prove your own merits. Publish your own measurements. But stop aimlessly trolling a thread about another class D product, forcing people to go out of their way to point out how meaningless some of your comments are.
I didn't want to raise the matter of linguistics myself, but I think it would help if you posted an Italian version alongside the English. I can read Italian.
If you wish to substantiate your claim that your design has superb performance (either below or above 20kHz), go ahead and post measurements. Or talk substance. As a class D designer you should be able to talk about the nitty gritty of class D. But stop taking gratuitous swipes at other people's work. On a previous occasion you have accused me of lying (when presenting hum-free distortion spectra) and recently you've tried arguing that spending time on maths automatically renders one unable to do the electronic implementation right. If I ever saw a nonsequitur this is it. Now you're trying to push the audiophile "over 20kHz" button simply because I say that the spectrum below 20kHz is the one that's more important by a long shot, and you completely forget that in order to work as well as it does my amp, by necessity, has to have above-average performance above 20kHz as well.
I understand you've got some wares to hawk. Well, fine, open another thread saying how wonderful it is. Prove your own merits. Publish your own measurements. But stop aimlessly trolling a thread about another class D product, forcing people to go out of their way to point out how meaningless some of your comments are.
I didn't want to raise the matter of linguistics myself, but I think it would help if you posted an Italian version alongside the English. I can read Italian.
I also guess that some misunderstandings are the reason why Bruno is a little grumpy now. I don't think that AP2 did it deliberatley. I guess it is just the language barrier.
Bruno is actually someone who is enjoyable to discuss with. But he has also better things to than trying to explain the same things over and over.
Regards
Bruno is actually someone who is enjoyable to discuss with. But he has also better things to than trying to explain the same things over and over.
Regards
I believe this paper by the late Julian Dunn to be canonical:
http://www.nanophon.com/audio/antialia.pdf
Hi,
Bruno, I also have to put my face in public.
My goal is not to devalue your product.
I have no interest in pushing the amp DXA. (I think it is obvious, since the sale to the public is blocked).
it is obvious that we have very different design philosophies, in particular, in solving the problems of class D. I have not focused on the super feedback (because the audiophile high-level, does not want this, as does not want a unregulate SMPS). I have no doubt that you know how it sounds with an amp the voltage that moves, especially at low power. therefore, need not explain.
You have many fans in this forum, the same ones who constantly said to me, read the papers of Bruno. I looked and?
Unfortunately, there is the marketing and so I can not speak freely to Ing. Bruno.
Do not worry, your fans will buy your NCore the same.
I'm left with a curiosity: why when I published the thread "DXA-400," said the first, we see the behavior, then, that is not my project?
Attack is a good sign for me.
I open a new thread? I first need to invent "Tom5S".
For Fans, you're Jesus. to me you're a good engineer with a narrow viewing angle. (I will not be offensive)
Regards
Roberto P.
Bruno, I also have to put my face in public.
My goal is not to devalue your product.
I have no interest in pushing the amp DXA. (I think it is obvious, since the sale to the public is blocked).
it is obvious that we have very different design philosophies, in particular, in solving the problems of class D. I have not focused on the super feedback (because the audiophile high-level, does not want this, as does not want a unregulate SMPS). I have no doubt that you know how it sounds with an amp the voltage that moves, especially at low power. therefore, need not explain.
You have many fans in this forum, the same ones who constantly said to me, read the papers of Bruno. I looked and?
Unfortunately, there is the marketing and so I can not speak freely to Ing. Bruno.
Do not worry, your fans will buy your NCore the same.
I'm left with a curiosity: why when I published the thread "DXA-400," said the first, we see the behavior, then, that is not my project?
Attack is a good sign for me.
I open a new thread? I first need to invent "Tom5S".
For Fans, you're Jesus. to me you're a good engineer with a narrow viewing angle. (I will not be offensive)
Regards
Roberto P.
Re "What The Audiophile High End Wants": they want good sound. Many think that low feedback and regulated supplies are the way to get good sound but most don't give a hoot so long as the result is there.
You are making a very interesting reversal of positions here by accusing me of marketing-speak. Think about it: if I were to design stuff according to what is the most popular way of designing amps (e.g. low feedback), wouldn't that be playing commercial games? I'd have to dispense nebulous prose to justify such behaviour because there'd be no technical arguments. Things like vaguely suggesting that "you know what the other way of doing it sounds like don't you?" Well I blerrie well do and it sounds better.
I expressly choose not to pander to popular belief. I can fully argue, based on purely technical arguments, why the bad reputation of NFB is undeserved. I hope that you have no issues with the fact that I try to present my arguments in pleasant prose (http://www.linearaudio.net/userfiles/file/letters/Volume_1_BP.pdf). Are you seriously suggesting that it is for commercial reasons that I'm taking the unpopular path? And how does my first trying collecting the evidence behind the feedback myth before choosing which technical route make me narrow-minded?
And where are you finding marketing in the AES paper (AES E-Library Globally Modulated Self-Oscillating Amplifier with Improved Linearity )? There is a slight difference between "white papers" and "academic papers". The former may be glossy, the latter must stand on its own technical merit. I take it you've read it so go ahead and tell me where the sales pitch is.
As it stands you've offended several members of this forum by accusing them of religiously following a personality cult and you've made vague claims to the effect that there just so much marketing in what I write but you weasle out of having to say just where.
You're vaguely but strongly accusing me of having a narrow view. Really? Are you aware that I started life building (and selling) valve amplifiers and solid state linear amplifiers? That I used to be a low-feedback proponent until audible facts forced me to reconsider? Can you guess who pulled off the design of world's only pure DSD truly zero-feedback class D amp ( AES E-Library A True One-Bit Power D/A Converter )? Did you know I have a life beyond designing amps? How about discrete AD/DA converters and passive and active loudspeakers? Do you know I have recorded several CD's?
Just in what manner is my view narrow? In that I am constantly adjusting it to the facts I encounter en route and have arrived at one which isn't yours? Or is it just your narrow view about me that you are projecting? Perhaps it's you who's focusing on me as a person, not the people who merely like what I do.
You are making a very interesting reversal of positions here by accusing me of marketing-speak. Think about it: if I were to design stuff according to what is the most popular way of designing amps (e.g. low feedback), wouldn't that be playing commercial games? I'd have to dispense nebulous prose to justify such behaviour because there'd be no technical arguments. Things like vaguely suggesting that "you know what the other way of doing it sounds like don't you?" Well I blerrie well do and it sounds better.
I expressly choose not to pander to popular belief. I can fully argue, based on purely technical arguments, why the bad reputation of NFB is undeserved. I hope that you have no issues with the fact that I try to present my arguments in pleasant prose (http://www.linearaudio.net/userfiles/file/letters/Volume_1_BP.pdf). Are you seriously suggesting that it is for commercial reasons that I'm taking the unpopular path? And how does my first trying collecting the evidence behind the feedback myth before choosing which technical route make me narrow-minded?
And where are you finding marketing in the AES paper (AES E-Library Globally Modulated Self-Oscillating Amplifier with Improved Linearity )? There is a slight difference between "white papers" and "academic papers". The former may be glossy, the latter must stand on its own technical merit. I take it you've read it so go ahead and tell me where the sales pitch is.
As it stands you've offended several members of this forum by accusing them of religiously following a personality cult and you've made vague claims to the effect that there just so much marketing in what I write but you weasle out of having to say just where.
You're vaguely but strongly accusing me of having a narrow view. Really? Are you aware that I started life building (and selling) valve amplifiers and solid state linear amplifiers? That I used to be a low-feedback proponent until audible facts forced me to reconsider? Can you guess who pulled off the design of world's only pure DSD truly zero-feedback class D amp ( AES E-Library A True One-Bit Power D/A Converter )? Did you know I have a life beyond designing amps? How about discrete AD/DA converters and passive and active loudspeakers? Do you know I have recorded several CD's?
Just in what manner is my view narrow? In that I am constantly adjusting it to the facts I encounter en route and have arrived at one which isn't yours? Or is it just your narrow view about me that you are projecting? Perhaps it's you who's focusing on me as a person, not the people who merely like what I do.
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Mind you, when active on this forum like Bruno is right now you should know that you have to explain things over and over.....
By the way, following this thread it might be a good idea to move it to the Vendor's Bazaar, where IMHO it belongs.
Indeed I think that's an occupational hazard for anyone who wants to explain anything. It's part of life. For example, 40 years from now I'll still be telling people how to dither a quantizer. I can live with that so long as people don't start yelling "digital volume control just doesn't sound good!" in my face.Mind you, when active on this forum like Bruno is right now you should know that you have to explain things over and over.....
I can sympathise with the sentiment. Perhaps we could stimulate more in-depth technical discussion. Not about ears and opnions and stuff but actual operation. That would make it worth reading even for people who aren't planning to buy anything.
AP2, you obviously have some kind of axe to grind and I don't care about the details. but...
I have not focused on the super feedback (because the audiophile high-level, does not want this, as does not want a unregulate SMPS)
don't you understand that stating publicly something like that lowers your credibility even more? I'm SICK of the audiophile web pages I keep seeing displaying lines like "0% feedback = 100% musicality!" (with an exclamation mark, as if that should convince me for good). sometimes I wonder if people stating things like that really did any sort of testing at all to draw such extreme conclusions. really want my opinion? THAT is hype and marketing. anyone can come up with an audiophile website with all the regular folklore "no feedback, no opamps, only class A, only discrete, short signal paths, silver wire transformers, audio grade caps etc".
I can swear that I personally met people in the audio manufacturing world which admittedly base their designs on the latest trend in audio folklore. I'm totally ok with you adding to that crowd but AGAIN, can you please preach somewhere else?
sorry for the rant guys, but what the guy wrote was the latest thing I was expecting to read here.
I have not focused on the super feedback (because the audiophile high-level, does not want this, as does not want a unregulate SMPS)
don't you understand that stating publicly something like that lowers your credibility even more? I'm SICK of the audiophile web pages I keep seeing displaying lines like "0% feedback = 100% musicality!" (with an exclamation mark, as if that should convince me for good). sometimes I wonder if people stating things like that really did any sort of testing at all to draw such extreme conclusions. really want my opinion? THAT is hype and marketing. anyone can come up with an audiophile website with all the regular folklore "no feedback, no opamps, only class A, only discrete, short signal paths, silver wire transformers, audio grade caps etc".
I can swear that I personally met people in the audio manufacturing world which admittedly base their designs on the latest trend in audio folklore. I'm totally ok with you adding to that crowd but AGAIN, can you please preach somewhere else?
sorry for the rant guys, but what the guy wrote was the latest thing I was expecting to read here.
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Bruno, your commercial interest is obvious, you've bassically foced me into spending $10 on the AES paper. you're exposed.
in all honesty, I will buy the paper as soon as I get home (I have a one year AES subscription). I remember Bruno mentioning something about the "power DAC" concept a while back in the official UcD FAQ thread. if I recall correctly he said that the approach has severe limitations that prevent it from competing with regular class-D topologies. correct me if I'm wrong.
Hi,
I have not accused you of doing marketing. I said that it is linked to marketing (if I explain the reasons for the choices you make about your product, it is obvious that the product suffers. I meant to say, I do not have the freedom to discuss whether some of your choices are really good (for a product high end). for PA, all is ok.
I do not have which is mentioned or alluded to any religion.
High-End: I do not mean to colored or super capacitor components. (this is just a game of high-end commercial).
There are some parameters "fixed" important (before other extended attributes), to declare that an amplifier can have a good realism in reproducing the timbre, dynamics and resolution.
For the limited point of view, this is not offensive (I understand that a primary doctor does not want to hear it). I do not want to compete with you (would not be fair on my part). but if you asked me how many degrees ranging my applications, I can provide sufficient doc, from hydrodynamic to neurological applications hardware / software.
my advice is: shows the extended features of your amp. (if they are excellent (I think so) no one will have nothing to say. but it is not fair for you to use your fame to convince an audiophile than a SMPS Unregulated power is fantastic supply. even if we use an AB amp with 5 transistors, the first thing we need is a PSU. not a sub-modulation of soft percussion or bass on the voice. that what he hears?
--
For AES, I'm sorry, but when I wanted to solve the linearity of the modulator, I did not go on reading. just for curiosity, DXA with the current concept of modulation, was born in 2006. This is perfectly demonstrable.
As is demonstrable that when hypex did not have a SMPS, my DPS-400 was the first (perhaps because it is simple and ingenious) to finish on your table. (not problem on this)
Regards
I have not accused you of doing marketing. I said that it is linked to marketing (if I explain the reasons for the choices you make about your product, it is obvious that the product suffers. I meant to say, I do not have the freedom to discuss whether some of your choices are really good (for a product high end). for PA, all is ok.
I do not have which is mentioned or alluded to any religion.
High-End: I do not mean to colored or super capacitor components. (this is just a game of high-end commercial).
There are some parameters "fixed" important (before other extended attributes), to declare that an amplifier can have a good realism in reproducing the timbre, dynamics and resolution.
For the limited point of view, this is not offensive (I understand that a primary doctor does not want to hear it). I do not want to compete with you (would not be fair on my part). but if you asked me how many degrees ranging my applications, I can provide sufficient doc, from hydrodynamic to neurological applications hardware / software.
my advice is: shows the extended features of your amp. (if they are excellent (I think so) no one will have nothing to say. but it is not fair for you to use your fame to convince an audiophile than a SMPS Unregulated power is fantastic supply. even if we use an AB amp with 5 transistors, the first thing we need is a PSU. not a sub-modulation of soft percussion or bass on the voice. that what he hears?
--
For AES, I'm sorry, but when I wanted to solve the linearity of the modulator, I did not go on reading. just for curiosity, DXA with the current concept of modulation, was born in 2006. This is perfectly demonstrable.
As is demonstrable that when hypex did not have a SMPS, my DPS-400 was the first (perhaps because it is simple and ingenious) to finish on your table. (not problem on this)
Regards
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