Indeed, I agree, lighten up.
For 25 years I have had this argument with a well-known audio personality here in Sydney. No matter what I said, that 'damping factor' was a myth, it just didn't work. Talk about Deja Vu. I will only say that this was the previous owner of Pymble Hi-Fi on the leafy upper North Shore of Sydney.
But I finally got him to see it, and this is how:
I purposely built a transconductance amplifier, took me just a day (other than a few tweaks later on) and I have published this extremely simple amplifier here on DiyAudio.
I then invited him over and played the amp for him into the Elsinore Mk6 speakers, which have an LCR that EQ's the alignment in the electrical domain, that means that it becomes a voltage divider overcoming motional EMF.
I played Joe Morello 'Take Five' drum solo,the DMP recording, at a very much concert level (the speakers are very sensitive and flat in-room sown to near 25 Hertz), and it rocked.
I simply asked him: "This amplifier has an output impedance of 270 Ohm, where is the damping factor?"
It finally set in and he said: "How have they been getting away with it?"
He also said: "But I have heard one amplifier being replaced by another one with higher damping factor and I heard an improvement?"
The answer was simple - he was listening to a better amplifier with better performance - others have gone from high to low damping factor and has heard an improvement, so it is at best a 50-50 thing.
Now how does this relate to NCores?
The low output impedance makes them totally insensitive to load and because there is serious engineering behind it, the ability to deal with serious loads and not just low output Z, which is only part of it - and like I said, it is a great amp that I am enjoying listening to right now.
But Bruno did say it at AES 2007:
Euphony In Action! Rising THD vs frequency profile has
a recognisable sonic signature.
• HF is only mildly affected except in very bad cases.
• Bottom end becomes extremely “tight”, “powerful” and “controlled”.
• Often attributed to “huge current reserve” of behemoth power stage.
Really caused by HF THD of sluggish amp.
• Propagates “Damping Factor” myth.
And that's that.
One of the greatest "quackery" in audio - and it simply won't die - even leading grown people to cry rather than give it up.
Amazing. Paul Klipsch sure got it right:
"To try to judge the real from the false will always be hard. In this fast-growing art of 'high fidelity' the quackery will bear a solid gilt edge that will fool many people" - Paul W Klipsch, 1953
For 25 years I have had this argument with a well-known audio personality here in Sydney. No matter what I said, that 'damping factor' was a myth, it just didn't work. Talk about Deja Vu. I will only say that this was the previous owner of Pymble Hi-Fi on the leafy upper North Shore of Sydney.
But I finally got him to see it, and this is how:
I purposely built a transconductance amplifier, took me just a day (other than a few tweaks later on) and I have published this extremely simple amplifier here on DiyAudio.
I then invited him over and played the amp for him into the Elsinore Mk6 speakers, which have an LCR that EQ's the alignment in the electrical domain, that means that it becomes a voltage divider overcoming motional EMF.
I played Joe Morello 'Take Five' drum solo,the DMP recording, at a very much concert level (the speakers are very sensitive and flat in-room sown to near 25 Hertz), and it rocked.
I simply asked him: "This amplifier has an output impedance of 270 Ohm, where is the damping factor?"
It finally set in and he said: "How have they been getting away with it?"
He also said: "But I have heard one amplifier being replaced by another one with higher damping factor and I heard an improvement?"
The answer was simple - he was listening to a better amplifier with better performance - others have gone from high to low damping factor and has heard an improvement, so it is at best a 50-50 thing.
Now how does this relate to NCores?
The low output impedance makes them totally insensitive to load and because there is serious engineering behind it, the ability to deal with serious loads and not just low output Z, which is only part of it - and like I said, it is a great amp that I am enjoying listening to right now.
But Bruno did say it at AES 2007:
Euphony In Action! Rising THD vs frequency profile has
a recognisable sonic signature.
• HF is only mildly affected except in very bad cases.
• Bottom end becomes extremely “tight”, “powerful” and “controlled”.
• Often attributed to “huge current reserve” of behemoth power stage.
Really caused by HF THD of sluggish amp.
• Propagates “Damping Factor” myth.
And that's that.
One of the greatest "quackery" in audio - and it simply won't die - even leading grown people to cry rather than give it up.
Amazing. Paul Klipsch sure got it right:
"To try to judge the real from the false will always be hard. In this fast-growing art of 'high fidelity' the quackery will bear a solid gilt edge that will fool many people" - Paul W Klipsch, 1953
Seems your question was malformed - it should have been '..., what is the damping factor?'. And the equation Julf's shared tells us the answer.
The mere fact that you cannot tell that I am differentiating between 'damping' and 'damping factor'?
I was definitely not born yesterday, I am in fact 64 and been designing various speakers since I was a teenager and my Father was designing loudspeaker systems for Philips even before then. I was using Thiele-Small Parameters, testing and modeling them, way before the rest of the world woke up to it - and indeed was hired to do such testing by companies and individuals. So I reckon I knew this stuff before you did.
The output impedance changes damping, but NOT damping factor.
And that is textbook !!!
And that really should be the end of it.
Hence Richard H. Small totally demolished the idea of 'damping factor' and through a mutual friend of Neville Thiele did likewise, as well as another friend who did a course with Thiele. Small only had an eye on damping - that any series R modifies the Qe damping and nothing beyond that.
Classic textbook.
Note, Small was only concerned with 'damping' as a function of the alignment - you are conflating two different issues here. It was 'damping factor' that he thought was laughable.
Yes indeed, and I have not contradicted them in any way !!!
I have only stated textbook stuff here.
I have an idea- a challenge for you: Would you like to frame a reply to Richard Small through me, in the sense, what would you say to him?
I think that is a fair question. And if you are fair, you would furnish that reply. I would be dying to hear it.
Lest all antipodeans are tarred with the same brush, can I make the following observations.
1. The ncore amp has been designed for low distortion
2. Its frequency response is relatively insensitive to load impedance.
3. It is efficient and has low standby current.
4. As a (good?) side-effect of the topology (related to 2?) it has low output impedance.
5. None of the reviewers of the sound of ncore (if I accurately recall 10,000 replies), favourable or otherwise, has reported that 4 was a factor in their response.
Do we need to have a discussion about damping factor, particularly one where one side says it is unimportant (or a myth) and the other side says it is unimportant!
Ian
p.s. To us, it is the northern hemisphere that is upside down.
1. The ncore amp has been designed for low distortion
2. Its frequency response is relatively insensitive to load impedance.
3. It is efficient and has low standby current.
4. As a (good?) side-effect of the topology (related to 2?) it has low output impedance.
5. None of the reviewers of the sound of ncore (if I accurately recall 10,000 replies), favourable or otherwise, has reported that 4 was a factor in their response.
Do we need to have a discussion about damping factor, particularly one where one side says it is unimportant (or a myth) and the other side says it is unimportant!
Ian
p.s. To us, it is the northern hemisphere that is upside down.
Hi Ian
I think the levity is welcome. But I think, other than water running in the opposite direction down the drain, everything down here works the same.
It actually doesn't help much when I inject that I am in fact Scandinavian.
That is made very clear.
And the low output impedance achieves that, no question.
As you would expect of Class D.
And good for the reasons above, in that context there is no issue.
There are good amplifiers and there are bad amplifiers. I would not have a pair of NC400 if I thought it was bad.
Good question. Only in the context of Julf's byline about "quackery" and his defense of what is a recognisable myth - and even Bruno Putzey, the NCore designer, said there were things that "propagated the Damping Factor myth", so it is hardly completely off topic. It looks like it is in the design brief.
Damping is very real, but Bruno is right in calling "Damping Factor" a myth. And he is agreeing with Thiele and Small who can't be brushed under the carpet.
Driving speakers with NCore amplifiers will ensure a flat frequency response under real loads, even difficult loads. That is a good thing. It's output impedance will also in many cases see a series inductor with a series resistance many times the Z out of the NCore, this in turn in series with the DCR of the Voice Coil. The NCore can only see the sum of the three, the speaker will look back and also see the same sum of the three. They cannot be separated. Its electrical damping, Qe is will be eroded by the modified sum divided by the DCR of ityself. That modifies damping and not damping factor.
I am sorry, but this is about as text-book as it gets.
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I believe the gain of both modules to be 26dB. It's stated in the datasheets on the hypex website, but for some reason I can't display them (old mac, old adobe version, shows all messed up)
Complete nonsense.
I have been waiting for you to turn up. Who is next?
Where is the 'brake' in this run-away-car?
A magic definition indeed. We need an explanation on how it controls the cone's motion.
Clearly Langford Smith is wrong? He coined it and refuted it with facts. So is Richard Small also wrong? Neville Thiele too? And Bruno Putzey too?
Let me at least have an honest answer on that please? They must all be wrong?
Damping is one thing and very real, but 'damping factor' is just a ratio, but as Shaw said, it has no reference to anything other than standing on sand. I agree totally with him.
I find this truly amazing and didn't realise you would push it this far. Dogma at its worst.
Like I said, quite willing to let this go as I know Julf is not comfortable, but the fact is not only indisputable, they are in fact demonstrably easy to show.
If anybody here is Sydney would like to see a demonstration so emphatic, let me know. I love to have visitors and you will be treated as an honourable guest. The demonstration has converted a number of people that for decades believed in this myth.
But if you want high 'damping factor' which just means low output Z, then no problem -you can have that. So the whole argument is rather mute.
But there is no cone control here - bottom line. This is an even greater myth than "all feedback is wrong."
You may disagree, fine, but that does not mean the facts are on your side.
It's a definition, a derived quantity. Whether or not you think it's important is irrelevant to the existence of the quantity. If source impedance exists, damping factor exists.
You are very good at quoting people, very poor at understanding what they said. If you read again what you quoted
Note the word marked in bold in your trademark kindergarten blue. No one here disagrees with that. Stereophile test amplifiers into synthetic loads so you can see how amplifier output impedance affects FR.
Amp gain may be the same but driver sensitivity will most likely be different.
Sent from my Nexus 4 using Tapatalk
Now you want me to feel paranoid?
Have you ever spoken to Small?
Nope!
Because I can tell.
This is all weirdly funny. This time I am actually enjoying it.
But should we not be talking about NCore amps. I have a pair. They are great. Hope you can try them sometime. I mean, isn't that why you are here?
Now THAT is funny.
If you believe in 'damping factor' you will love the NCores - if you don't believe in 'damping factor' you will love the NCores.
Topic settled.
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Now you want me to feel paranoid?
Have you ever spoken to Small?
Nope!
Because I can tell.
I am more interested in your misunderstanding of Smith and his quotation. You are misinterpreting him. Once more.
God help anyone wanting to go through this thread and find the rare quality tidbits relating to Ncore technology. I've never seen a thread so in need of an Executive summary with links to the very few useful posts. I compiled one once as I exhaustingly waded through this thread. Annoyingly I left it in an unsent email to myself that I have now lost. In comparison to 10,000 posts it was a rather short list.
Joe,
I think the best way to deal with your somewhat unorthodox approach is to leave it well alone and let it run out of steam, but there is one small detail I would like to address for the benefit of those here who haven't studied the basics of circuit theory:
The quote above is perhaps best suited as plant fertilizer.
As Scott pointed out, there is the small, pesky detail of Thevenin and Meyer-Norton, who state that any linear electrical network can be stated both as a voltage source in series with a resistance, or as a current source in parallel to a resistance. The two circuits are equivalent (that means they are the exactly the same, for those who don't like pretentious words).
A battery is both a current and a voltage source. Just like any other electrical source. We only have electrons, not "voltage" electrons and "current" electrons. Voltage and current are both aspects of the same physical phenomenon.
Yes, indeed, Thevenin's theorem was derived in 1853 (by Helmholtz) and Norton's in 1926, but I guess one must know and understand them - usually they are being thought as part of the freshman's course in circuit theory.
But I guess you will state that "they are just theorems, and a myth", and go on to quote Nikola Tesla, based on a personal conversation you had with him.
I think the best way to deal with your somewhat unorthodox approach is to leave it well alone and let it run out of steam, but there is one small detail I would like to address for the benefit of those here who haven't studied the basics of circuit theory:
The quote above is perhaps best suited as plant fertilizer.
As Scott pointed out, there is the small, pesky detail of Thevenin and Meyer-Norton, who state that any linear electrical network can be stated both as a voltage source in series with a resistance, or as a current source in parallel to a resistance. The two circuits are equivalent (that means they are the exactly the same, for those who don't like pretentious words).
A battery is both a current and a voltage source. Just like any other electrical source. We only have electrons, not "voltage" electrons and "current" electrons. Voltage and current are both aspects of the same physical phenomenon.
Yes, indeed, Thevenin's theorem was derived in 1853 (by Helmholtz) and Norton's in 1926, but I guess one must know and understand them - usually they are being thought as part of the freshman's course in circuit theory.
But I guess you will state that "they are just theorems, and a myth", and go on to quote Nikola Tesla, based on a personal conversation you had with him.
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