Ferrite inductors do the job technically. They reduce noise according to their LCR impedance and saturation behavior. If you specify the inductor correctly then the technical performance will be about what you predicted.
Maybe what you wanted to know is whether they sound bad despite that fact?
Maybe what you wanted to know is whether they sound bad despite that fact?
So what, if the correction still works the data is complete, no improvement. Dont all CD players buffer the data then clock it from there so your read speed can vary a lot as long as the average is correct? So again no improvement.
It may well be that these filters actually couple HF noise into the ground in common mode, and that may be causing audible issues ie you end up with HF noise flowing in the interconnect shield as a result.
I don’t use filters other than a 0.1 uF X cap across the transformer primary and I always spec an interwinding screen. I measured 1.3 nF pri to sec on a 1200 VA part and < 100 pF with the interwinding screen. This is a great way to reduce HF common mode noise because the loop impedance is dramatically increased.
I don’t use filters other than a 0.1 uF X cap across the transformer primary and I always spec an interwinding screen. I measured 1.3 nF pri to sec on a 1200 VA part and < 100 pF with the interwinding screen. This is a great way to reduce HF common mode noise because the loop impedance is dramatically increased.
Are there any affordable SMPS units with inter-winding screens?
There are some here that say so, but as far as I can see it's an extremely small minority. The vast majority get along fine with ferrite parts when they are chosen correctly.
There are some here that say so, but as far as I can see it's an extremely small minority. The vast majority get along fine with ferrite parts when they are chosen correctly.
There is that 'claim' word again. Should we take it out of the vocabulary? Or make it a command "Thou shall not make a claim" and keep the straight-jacket ready for anybody that the constabulary has deemed to have made a claim. What next? A noose?
And can we have a proper definition of the world "audiophoolery" as my Webster seems to have either omitted it or it is not a proper word?
Is it just a pejorative? Definition of pejorative: "Adjective, a word or expression that is pejorative is used to show disapproval or to insult someone." Yep, that sounds about right.
Seriously though, it really does sound like freedom of thought and expression is being clamped down upon. Galileo would not approved, he was guilty of making a 'claim' and it took 350 years for the said 'authority' to say sorry.
So what is the expression, something about a bath, water and a baby?
If somebody is guilty of fraud, which seems to be the added implication, then there are other bodies out there to deal with that. Not here. In the meantime, let people make claims, some of them might even be true. Is that so horrible?
Consider this:
Niels Bohr to Wolfgang Pauli: "You are right, your theory is indeed crazy, but that is not the issue for us. The issue is whether your theory is crazy enough to be true."
Everthing is in your "If". CIRC do not allow mistakes, on your opinion ?
May I suggest you to compare a good CD with a 3 years old copy on DAT ?
(I believe you know what I'm talking about ;-)
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There are special techniques used in SMPSU transformers to reduce common mode noise coupling. IIRC, IBM had some patents on this stuff. Basically, the screen is tied to the +HV line and a cap from +HV to 0V (which sits close to neutral).
Claim is not a bad word, in fact psychologists use it quite freely including to describe their own claims. It can mean:
*state or assert that something is the case, typically without providing evidence or proof.
*an assertion of the truth of something, typically one that is disputed or in doubt.
Regarding the term Audiophoolerly, I used as shorthand for beliefs of cause and effect in the field of audio that are not consistent with the standard model of physics. I meant no untoward connotations as to the character or other characteristics of individuals making claims.
I would agree that there has been some tendency at times for engineers to jump to conclusions that something can't be affecting sound when the real problem is that a claim was made that something was audible at some point in time, and the claim includes a theory of cause and effect that is conflict with standard model physics. It would help if people would just describe what occurred perceptually under whatever conditions were known to them and leave out the theorizing. Then, if the engineers would assume the perceptual experience occurred for some unknown reason other than hallucination, their job is to see if they can explain how such a thing could happen. In other words, assume something did happen, what could explain it? I think Jakob2 sort of alluded to something along the lines of what I am trying get at here, which was maybe to the effect that sometimes thinking can be too narrow and conclusions drawn too quickly, thus errors made in arriving at the belief the something must be physically impossible. All the more likely if the engineers are operating in debate mode rather than truth seeking mode.
*state or assert that something is the case, typically without providing evidence or proof.
*an assertion of the truth of something, typically one that is disputed or in doubt.
Regarding the term Audiophoolerly, I used as shorthand for beliefs of cause and effect in the field of audio that are not consistent with the standard model of physics. I meant no untoward connotations as to the character or other characteristics of individuals making claims.
I would agree that there has been some tendency at times for engineers to jump to conclusions that something can't be affecting sound when the real problem is that a claim was made that something was audible at some point in time, and the claim includes a theory of cause and effect that is conflict with standard model physics. It would help if people would just describe what occurred perceptually under whatever conditions were known to them and leave out the theorizing. Then, if the engineers would assume the perceptual experience occurred for some unknown reason other than hallucination, their job is to see if they can explain how such a thing could happen. In other words, assume something did happen, what could explain it? I think Jakob2 sort of alluded to something along the lines of what I am trying get at here, which was maybe to the effect that sometimes thinking can be too narrow and conclusions drawn too quickly, thus errors made in arriving at the belief the something must be physically impossible. All the more likely if the engineers are operating in debate mode rather than truth seeking mode.
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In both Optical Disc and DAT media EFM decoders, the presence of E32s (uncorrectable errors) will trigger interpolation to conceal the lack of actual data. If there is no indication for the user to see this happen, all bets are off whether one, the other, or likely both are not reproducing accurate data. Most people are not concerned with bit-accuracy and just want to hear the damn music...so manufacturers leave this indicator out of the design. Why would they want to reveal the presence of an error when 99.999% of people can't hear it, and don't care?
This was the genius to digital storage of music as sold to the general population...
Howie
I shake your hands. it was my wink about DAT. I remember the red diode that was blinking with errors could be, sometimes, confused with the power one.
Reading the comment of my interlocutor, i was thinking: "Who has phantasms ?"
It is like the eternal life of the CDs. I had a lot of them stored with vinyls for two years in a friend's wet cellar. The number of CDs found unreadable, the metalization eaten by molds, while the Vinyls were intact!
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One of the first areas I looked at and worked on when I got into audio was the ac, quickly figured out that the ground was pretty noisy, and that simple, effective, common mode filtering works pretty well.
Still playing around with that, but not as much.
I missed out on the recent gb for the active bridge, would really like to find out how those sound.
Still playing around with that, but not as much.
I missed out on the recent gb for the active bridge, would really like to find out how those sound.
It is a word that is not easy to replace. But I agree with much of what you just said.
I am most comfortable with instances when cause and effect can be demonstrated. I much prefer it that way. But maybe every phenomena cannot be that way, for example I am not yet totally convinced about Jack Bybee's 'Purification Devices' and I am sure others here are too. Yet I tolerate the fact that some like what they do. I am yet to hear them work, but that does not mean they don't? The explanation is that they work on some quantum level, perhaps, but as Feynman said, nobody understand quantum mechanics. So I still have an open mind on Bybees, even if cause and effect is something I don't see.
I am working on speaker distortion measurements right now and what I am looking for, only cause and effect will satisfy me. If they are successful, it will become an explanation for what RNM said early, that putting an 8 Ohm resistor across the speaker causes a noticeable increase in sound quality.
He perceptively said he felt that it was the back-EMF of the speaker. I believe he is instinctively correct, and I am setting out to prove it. I have heard that sonic improvement too. Many have. I have already proven to satisfaction (peers) that the back-EMF of a driver is a measurable impedance. That gives me a number that changes with frequency and can also be used mathematically. Some maths have indeed emerged that show it proves that the motion, the sound or dBSPL of the driver, is directly correlating to the value of that back-EMF impedance, because it impedes the current through the voice coil. No claims as things have a stage or two to go. And it will conform to standard, and cause and effect. It is the cause that should come as a surprise, but some will say "should have seen that" - so that is the correct process...
The idea here is whether this 8 Ohm parallel resistor causes lower harmonic distortion heard in the driver and that it can be measured?
If this is the case, then the mechanism I believe will surprise, I even tried to explain it to Earl Geddes, but he would have none of it. But the measurement will be everything. What is interesting is this, earlier measurements with current sources (so-called current drive) actually points to the measurement that I have devised will be successful. The distortion changes when you go from voltage to current drive. Thiele pointed to something about reactive current five decades ago (I live in Sydney where Thiele-Small made their mark) and has stuck with me. So I am hopeful.
If successful, I will have it peer reviewed among my kind of people before going fully public, it will be open to falsification. So now my 'claim' will become validated. I am setting things up right now and very carefully.
BTW, I have come across a world class mathematician who said that maths can't be falsified. I would love anybody here to comment on that. What did he mean? I think I know what he means, but do others?
Back EMF can't directly be impedance because as you know, EMF, Electromotive Force is measured in units of Volts, and impedance is measured in (complex) Ohms. In physics, this is part of what is referred to as dimensional analysis. Part of doing any math problem in physics is making sure that the units come out right.
Oh, so we should ignore it? '-) Come on Markw4, try to keep an open mind. Equations aren't everything. Audio problems and solutions are the real thing. IF a change makes a positive difference in sound quality, then it is probably real. Perhaps you should try the change when you are sober, or without other drugs in your system. Do you hear it then? Well, if yes, maybe, just maybe, there is something real happening, even if it is not immediately measurable with standard measuring equipment, even the good stuff.
Hello Zung.
In my experience, yes ferrite materials anywhere within the audio system are recipe for 'bad' (nasty/evil lol) sound.....crossovers inductors and Class D output inductors for a start.
This also applies anywhere downstream of the AC plug including clipon filters or IEC power inlet modules normal or medical grade.
Ferrite does work as advertised in filtering current flows and this is very useful and has nice audio benefits, however ferrite also adds a flavour or signature of it's own that permeates the length of the system.
This signature is a hardness or 'extras' in the highs and noisy/grainy decays that do not belong and are quickly fatiguing.
I am presently exploring testing methodologies to flesh out/measure system changes when 'tweaks' like ferrite cable filters are applied.
Some filter modules run powdered iron toroids I believe.....I have not tried subjective/objective testing/comparison of powdered iron but will do so.
Clipon filters are useful for instant OTF AB comparison......a few trials and you ought to start hearing the sound of the particular ferrite pretty clearly......beware.
Dan.
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That would be right now, same as last night. I suffer from insomnia, sleep apnea, and sometimes sleep deprivation. It is said to be just bad for something like driving as being intoxicated. Easy to see how you could mistake one for the other though, since you don't don't know much about severe insomnia, but a lot about the other thing.
Regarding my words to Joe, I was trying to nicely explain there is a problem. I thought it was nicer than other people who just say, "nonsense!" and don't explain why there is an issue.
Indeed you are right, the EMF can indeed be measure in Volts, don't for a moment think I do not know that, indeed I cannot count the times I have said that it is a voltage source. A microphone is a voltage source.
But I just don't think you have connected the dots and if you had, then you would see that indeed it has an opposing force on the current produced by the amplifier. If you think in that way, measure the total impedance of a driver at a selected frequency, then measure the DC resistance of the voice coil. Subtract that from the total impedance and the remainder is the back-EMF impedance of the driver at that frequency. So that voltage generator will cause the current from the amplifier and you now have it's equivalent impedance. Trust me on this, it is what it is - and now also been recognised by others.
So indeed it is the EMF that constricts current, indeed while explaining this to a knowledgeable friend, he saw it as an anti-force, or a force that is 180 degrees out of phase. Interesting way of looking at it, one that had not occurred to me.
The beauty here is its simplicity, that we can, as a load on the amplifier as a voltage source, consider that the impedance is seen is in two parts. Only the voltage and current that causes heat to be dissipated in the voice coil. You should know this, right? But in fact it is the current that causes motion of the coil in the gap. That motion causes a motional impedance, then you have the inductive back-EMF, the point is that these are in series and hence current is impeded - so there you have it. Or think of it this way, it is current that gets impeded, not the voltage. An impedance measurement and graph of a driver, Ohm on the left X axis and frequency on the lateral Y axis, this is what the driver does to the current, not the voltage. Hence the impedance above the Re DC resistance is the back-EMF impedance. And you can definitely put an Ohm value.
Does this now make better sense?
Please trust me on this, there is sound (ahem) proof of this, see the attachment when a driver, where the change in dBSPL can be predicted by the degree of current being impeded and using the value "Total Z minus Re." and hence this back-EMF impedance is for real and can be used mathematically to coincide with change in current and hence dBSPL variations.
Please note that 6R here represents the Re of the driver and there is an equivalence between voltage and current if that 6R is purely resistive. Any change in dBSPL is caused by the back-EMF impedance. This equivalence test has already been peer reviewed, yet not publically published in a paper yet. The numbers do not fail.
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