Hypex Ncore - Page 53 - diyAudio
Go Back   Home > Forums > Amplifiers > Class D
Home Forums Rules Articles diyAudio Store Gallery Wiki Blogs Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Class D Switching Power Amplifiers and Power D/A conversion

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Closed Thread
Thread Tools Search this Thread
Old 12th October 2011, 09:10 PM   #521
tengizk is offline tengizk  United States
diyAudio Member
Join Date: Aug 2011
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.
Old 12th October 2011, 09:17 PM   #522
diyAudio Member
Join Date: Mar 2004
Location: At the output stage
Send a message via Yahoo to mr_push_pull
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
Old 13th October 2011, 07:20 AM   #523
diyAudio Member
Join Date: Apr 2004
Location: BE/NL/RW/ZA
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.
There's a time for everything, and this is not it.
Old 13th October 2011, 07:23 AM   #524
diyAudio Member
Join Date: May 2002
Location: Switzerland
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.

Old 13th October 2011, 07:39 AM   #525
diyAudio Member
abraxalito's Avatar
Join Date: Sep 2007
Location: Hangzhou - Marco Polo's 'most beautiful city'. 700yrs is a long time though...
Blog Entries: 145
Send a message via Yahoo to abraxalito
Originally Posted by DSP_Geek View Post
I haven't run across this pre-echo so what came to mind was the pre-ringing familiar to anyone who's worked with linear phase FIRs. How does pre-echo manifest itself in a system? It implies a fair amount of stored state, so that's of some interest to me.
I believe this paper by the late Julian Dunn to be canonical:

The heart ... first dictates the conclusion, then commands the head to provide the reasoning that will defend it. Anthony de Mello
Old 13th October 2011, 09:12 AM   #526
AP2 is offline AP2  Italy
Join Date: Dec 2009
Location: Italy
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)

Roberto P.
Old 13th October 2011, 09:48 AM   #527
diyAudio Member
Join Date: Apr 2004
Location: BE/NL/RW/ZA
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...olume_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.
There's a time for everything, and this is not it.

Last edited by Bruno Putzeys; 13th October 2011 at 09:58 AM.
Old 13th October 2011, 09:52 AM   #528
diyAudio Moderator
pinkmouse's Avatar
Join Date: Apr 2002
Location: Rotherham, England

Chaps, can we stop the personal stuff please.
Rick: Oh Cliff / Sometimes it must be difficult not to feel as if / You really are a cliff / when fascists keep trying to push you over it! / Are they the lemmings / Or are you, Cliff? / Or are you Cliff?
Old 13th October 2011, 10:42 AM   #529
diyAudio Member
Join Date: Apr 2009
Originally Posted by phase_accurate View Post
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.
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.
Old 13th October 2011, 11:08 AM   #530
diyAudio Member
Join Date: Apr 2004
Location: BE/NL/RW/ZA
Originally Posted by pieter t View Post
Mind you, when active on this forum like Bruno is right now you should know that you have to explain things over and over.....
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.

Originally Posted by pieter t View Post
By the way, following this thread it might be a good idea to move it to the Vendor's Bazaar, where IMHO it belongs.
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.
There's a time for everything, and this is not it.

Closed Thread

Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
Hypex Ncore vs. NAKSA AlliumPorrum Class D 1 26th May 2015 06:36 PM
Problem with Hypex Ncore Koifarm Class D 29 13th October 2014 06:32 AM
Any news on hypex ncore 2.0? JZatopa Class D 1 13th August 2013 10:30 AM
Hypex UcD700 vs NCore Earbound Class D 25 15th March 2013 04:10 PM
Building a Hypex Ncore... Jabbejokker Class D 0 7th March 2013 09:08 PM

New To Site? Need Help?

All times are GMT. The time now is 02:48 PM.

vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright 1999-2017 diyAudio

Content Relevant URLs by vBSEO 3.3.2