Reviewing the Furutec Demag
- Thread starter Gregadd
- Start date
the benefit of some tweaks are somewhat easily accepted for various reasons; but many are met with degrees of skepticism all the way up to outright scorn and vilification.
the performance advantage of de-maging media would likely fall between 'somewhat skeptical' and 'scorn' catagory (not quite vilification) the degree of which likely relates to the level of technical training of the 'considerer'. so one needs some pretty solid 'proof' most likely including a few listening sessions before a mind could change. and most/many would still fight the idea even if they heard it. note that the files Bruce is offering are not exactly de-mag'ing, they are for using a particular Tourmaline Gun (not all of which are created equal). so if you hear those differences you have not really heard 'de-mag'ing'.
my guess is that not one person who read this thread has changed their mind based on this thread unless it included listening sessions.....and likely it would require at least a couple of them.
added note; at the risk of igniting a new finger pointing thread; vilification is generally assigned to stuff like 'Intellegent Chip' or the 'Crazy little Clock'. De-mag'ing is a bit less 'radioactive' than that stuff. i have no opinion on either of those 'gems'.
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i suppose that WBF (and in particular 'General Audio Discussions') is mostly about expressing one's own views and dancing the dance of respectful interaction. so your comment is no surprise. i doubt that many here click on threads in the hopes that their mind will be changed today. (not that there is not an interest in learning, but that's mostly about new product or music).
and i'm not saying this is bad, unexpected, or that it needs to change. and i'm not saying that i'm any different than anyone else.
i'm not trying to de-rail the thread; and go ahead and delete this post if it is any sort of problem. it's only that expectations on side changers regarding a doubious tweak should be pretty low.
That's getting ahead of ourselves.First thing would be to show that a cartridge can pick up such infinitesimal reduction in magnetic field. Imagine using your simple voltmeter to read .0002 ohms. Not possible because the leads of the voltmeter has more resistance than that. By the same token, someone has to show that the cartridge output changes at all over its baseline noise. I suspect it will not. Because if it did, then the magnetic field from the motor would cause far more damaging results.
Amir,
Unhappily I do not have access to a Furutec Demag, so I can only write on the technical side.
We have been assuming that the so called magnetization of the record is something uniform, forgetting that a magnet is a dipole and a record can have many with different orientations. As the record is spinning, and EMF is due only to variance of magnetic flux, your comparison with the voltmeter is not valid - both the resistance of the leads and the 0.002 resistor show the same dependence on current and voltage. Also the magnetic field of a dipole varies with the distance to the 4th power - it is why cartridges are not affected by the magnetic flux of the motor. The LP is quite close to the coils of the cartridge.
As the magnetic field of the Earth has no effect, comparisons with it are out of scope.
The Furutec measurements only show something changes in the static magnetization of the LP - good for advertising, as they show something changes, nothing else.
Until now no side has provided enough technical evidence that the other is wrong.
I see no problem with your post. I think there is sufficient anecdotal and scientific evidence to form a hypothesis and to conduct a study. I think assumtpions that Furutech is wrong is just as invalid as asuuming that it does work. Attacking its creators and supporters serve only to polarize the parties. Michael Fremers 'character has no bearing at all on the efficacy of the product.
Thanks for your participation
That was not meant as analogy to demag but rather, to demonstrate that just because you change the input of something (resistance on the ohmmeter leads), its output does not necessarily change. Hence my point that one needs to first prove that the 10% reduction in magnetism of the record will show up on the output of the cartridge. I don't have any data on how much magnetic flux there is in a cartridge and the minimum for it to create a voltage above noise. Does someone have that?
LP may be closer to the part of the LP that it is playing. It is not close to the rest of it. Also, keep in mind that the same claims are used for CDs and cables, neither one of which works on the principal of flux conversion to electricity.
It has no effect probably because the magnet inside the cartridge is a lot stronger. If this were not the case, then the mere movement of the tonearm in the air would generate electricity. That said you are right that the movement of the LP accentuates that effect. Will it make 20,000 times more difference just to match Earth's magnetic field?
That is the only measurement that is needed. If I have a magnet, I measure it the same way. We don't mix the characterization of magnet with how it will be used.
Something tells me if this were so easy and true, then the manufacturer would have done and there would be a ton of other devices including some at $19.95
.We can try putting an interference coil with a spurious signal nearby above the cartridge and apply a variable signal increasing the amplitude until it is audibly detected by DBTs during playback.
The shape of the signal would be critical. As the geometry would be simple we could compute the magnetic fields easily.
Let us keep it separate - but CDs spin much faster than LPs and have focusing systems that can be affected by electrostatic and magnetic fields. I still have a Peter Belt CD mat ...
As far as see it, it will depend on the arrangement of the magnetic dipoles in the LP .
Something tells me if this were so easy and true, then the manufacturer would have done and there would be a ton of other devices including some at $19.95
Again, as I do not have access to a DEMAG I can not find how it works . Perhaps the old reel tape bulk erasers do the same.
I am having trouble following what the plan is with the testing lol.
Is it to measure the analogue output from the phono or to digitize the output for comparison, or something else?
Also how are LPs being chosen?
For me this comes back to the conversation I had with mike Lavigne where he has two identical LPs both using the same stamper (this is critical) but one using standard black vinyl compound and one without the carbon black, also removal of the carbon black may also change formula relating to use of Barium,wax,etc.
Personally I feel any testing should involve 2 identical LPs as desribed above, or if being very picky 3 identical LPs; where two (so one is a control LP and never treated) are the standard black vinyl and 3rd is the superior vinyl compound/carbon black excluded.
Still relating to testing this may be of interest.
Paul Miller decided to look at further measurements for cartridges, this led him to investigate groove modulations that is applicable to the left and right of the "V" groove wall, and apply this against the group test.
This is a brief part of what he said:
I find this interesting as I wonder how much of an interaction (IF there is anything magnetic or other is involved such as static) is required to start messing up the L+R and L-R as outlined by Paul.
Cheers
Orb
Is it to measure the analogue output from the phono or to digitize the output for comparison, or something else?
Also how are LPs being chosen?
For me this comes back to the conversation I had with mike Lavigne where he has two identical LPs both using the same stamper (this is critical) but one using standard black vinyl compound and one without the carbon black, also removal of the carbon black may also change formula relating to use of Barium,wax,etc.
Personally I feel any testing should involve 2 identical LPs as desribed above, or if being very picky 3 identical LPs; where two (so one is a control LP and never treated) are the standard black vinyl and 3rd is the superior vinyl compound/carbon black excluded.
Still relating to testing this may be of interest.
Paul Miller decided to look at further measurements for cartridges, this led him to investigate groove modulations that is applicable to the left and right of the "V" groove wall, and apply this against the group test.
This is a brief part of what he said:
It is interesting to not that the worse this became the lower the reviewer enjoyed the cartridge (seemed a more notable trend than any other measurement given such as crosstalk ).
I find this interesting as I wonder how much of an interaction (IF there is anything magnetic or other is involved such as static) is required to start messing up the L+R and L-R as outlined by Paul.
Cheers
Orb
That is for good reason. This will be the mother of all tests to conduct!
As I noted earlier from a line used by Ethan, the bigger the claim, the bigger the proof. If we assume that the people who have heard the difference don't have systems that suck without it, then we are compelled to agree that the difference heard is small. As it should be with a 10% reduction in such small magnetic field. So characterizing it and making sure it is not variation from playback to playback is important. Seeing how delicate both the LP and cartridge are, we must rule out differences in successive playback in those. I would think the whole act of picking up an LP, putting it on the machine and taking it off might make the same small differences through change of temperature, how flat the LP is, the level of static electricity in it, change in distribution of dust and other particles in the grooves, etc.
I am not an LP person but I would think that if we bought two LPs, there is no assurance they are identical. So a test first needs to be run to determine that. Observer bias would be quite high there as one thinks that they should sound the same. I my book, a test where you play one LP, stop, and then play another LP is not going to product good results when the difference is tiny as would be the case between these LPs. The test then needs to be conducted on two identical playback systems. I know how to do this with digital sources. Not sure how to do that with turntables, putting aside the much higher cost of such a set up.
And the above is just to test the two identical LPs without using this device! With the device, the world gets far more complicated. Who is to say that the LP doesn't get remagnetized as soon as we put it on the turntable? If we don't understand its mechanism for how it performs its job, then it is hard to know how to make sure its characteristics are maintained, reduced or improved in the handling of it.
So if anyone wants to test this, it should be for fun and not any attempt to create scientific proof. As audiophiles, that is all we should care about anyway
.Now, there is another angle which is to test the people who hear big differences. That can be accomplished with your method of buying two LPs, treating one and not the other in another room and then playing them in sequence. I would think since the differences heard are said to be big and enough to convince anyone who listens, then stress of blind testing should not wipe it out. If it does wipe it out, then that would be another data point to have at least. BTW, if a preference is found, I would reverse everything and see if the effect is repeated.
I have not kept up with all of this at this point, but no matter what tests there are going to be problems including the memory of the listener and the fact that after the stylus has run through the grooves of the vinyl the vinyl takes time to just return to shape. So these are major obstacles. And, you can not use different vinyl pressings because each one sounds different. So, even if there is an actual improvement (and I would not be surprised though it may be slight) it is going to be extremely difficult to demonstrate much less prove.
Rich
Rich
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...the bigger the claim, the bigger the proof.
This is intuitively correct but actually false. The quantum and method of proof is constant. The more we disbelieve something the less we are willing to accept the proof. Whatever it is.
This is intuitively correct but actually false. The quantum and method of proof is constant. The more we disbelieve something the less we are willing to accept the proof. Whatever it is.
You are right in general but not in specific
. You implicitly stated why. Reason is due to another truth: there is no such thing as a perfect test. Indeed, as i am fond of saying, each test sucks. The good ones simply suck less! If you assume that as fact, that every test has flaws, then a test that proves the effectiveness of such a device needs to far more right than say, showing difference between speakers. Since expense and effort level typically escalates with the need to be more proper and accurate, we reserve that for situations where a higher bar is required.
I am not a lawyer and I am sure you will correct me if this wrong but I thought burden of proof was different for civil cases vs criminal. To the extent the jury or judge can only examine a limited set of facts put forth, then a different bar is established for each type since the consequences are different (in one case losing money, in the other, going to jail). So the laws of imperfect proof are different than the ideal.
If we assume that the people who have heard the difference don't have systems that suck without it, then we are compelled to agree that the difference heard is small.
(...)
So if anyone wants to test this, it should be for fun and not any attempt to create scientific proof. As audiophiles, that is all we should care about anyway
Amir,
Although the notion of small and large is relative, my system does not suck if I swap my preamplifier with a solid state one and I consider that the difference is very large.
The mysterious reason why sometimes some excellent sounding systems "suck"unsurprisingly when we make a change is difficult to guess.
By different reasons we can have similar effects with speaker positioning. In some rooms we can move the speakers without big changes in sound quality, but in another ones moving the speakers 10 cm away from the best position the sound becomes horrible.
I think the "suck" test grade will depend more on the system than on the possible (?) DEMAG effect.
As you say, it will be a lot of fun!
That's a standard skeptical position and it makes a lot of sense. I can claim the moon is made of green cheese, and insist everyone else must prove me wrong. To a reasonable person with a junior high education that's no different than claiming you can demagnetize an LP and improve the sound.
But in this case there's another reason to put the burden of proof on the believers. Or rather, on the vendor. If the US had more effective consumer protection laws, the vendor would be required to show proof of performance before being allowed to sell the product. I'm not advocating a "nanny state," but clearly consumer protection laws are mostly a good thing. Just think how many more of these doohickeys they'd sell with actual proof of performance. So it's in the vendor's interest to prove their claims. But they can't do that, and they know it.
--Ethan
That is for good reason. This will be the mother of all tests to conduct!
As I noted earlier from a line used by Ethan, the bigger the claim, the bigger the proof. If we assume that the people who have heard the difference don't have systems that suck without it, then we are compelled to agree that the difference heard is small. As it should be with a 10% reduction in such small magnetic field. So characterizing it and making sure it is not variation from playback to playback is important. Seeing how delicate both the LP and cartridge are, we must rule out differences in successive playback in those. I would think the whole act of picking up an LP, putting it on the machine and taking it off might make the same small differences through change of temperature, how flat the LP is, the level of static electricity in it, change in distribution of dust and other particles in the grooves, etc.
I am not an LP person but I would think that if we bought two LPs, there is no assurance they are identical. So a test first needs to be run to determine that. Observer bias would be quite high there as one thinks that they should sound the same. I my book, a test where you play one LP, stop, and then play another LP is not going to product good results when the difference is tiny as would be the case between these LPs. The test then needs to be conducted on two identical playback systems. I know how to do this with digital sources. Not sure how to do that with turntables, putting aside the much higher cost of such a set up.
And the above is just to test the two identical LPs without using this device! With the device, the world gets far more complicated. Who is to say that the LP doesn't get remagnetized as soon as we put it on the turntable? If we don't understand its mechanism for how it performs its job, then it is hard to know how to make sure its characteristics are maintained, reduced or improved in the handling of it.
So if anyone wants to test this, it should be for fun and not any attempt to create scientific proof. As audiophiles, that is all we should care about anyway
Now, there is another angle which is to test the people who hear big differences. That can be accomplished with your method of buying two LPs, treating one and not the other in another room and then playing them in sequence. I would think since the differences heard are said to be big and enough to convince anyone who listens, then stress of blind testing should not wipe it out. If it does wipe it out, then that would be another data point to have at least. BTW, if a preference is found, I would reverse everything and see if the effect is repeated.
Lol Ok with you now
Relating to whether 2 lps can be identical, they will be exceptionally close if they are manufacturerd from the same stamper in modern manufacturing.
This is due to stampers used today have to do only a small fraction of LPs they did in the past, furthermore as there is far less manufacturing the press and cool times for each LP are greatly increased that ensure uniformity for all LPs from the same stamper.
Basically to press an LP you take the studio master Lacquer and electroplate it, this gives you a plated master and from this you create a mother or multiple mothers.
Each creation of a mother subtly destroys the master so usually the number done is limited to not damage it.
In the same way a mother can create stampers and again from what I understand the more stampers a mother is used to create the more it is subtly destroyed.
Stampers suffer wear and tear, so they deteriorate depending how many LPs they press.
So when comparing the difference in vinyl compounds (most modern audio LP manufacturers ensure quality is better than in the past even for standard LPs), the vastly limited number of LP manufactured today, the greater time allowed in the process,etc ensure today that discrepancies are marginal for quality LPs using the same stamper.
Anyway I guess if anyone does decide to do any testing themselves, please make sure you can get 2 LPs that are from the same stamper and one is their higher quality vinyl-without black carbon, and if the cost does not bother a 3rd standard LP that will not be treated so this becomes a control (for comparing the treated standard and treated higher quality-none carbon LP).
Interested if anyone does do this, looks like only you at moment Mike hehe
Gary, let us know what you decide to do.
But if using specific measurements relating to the LP-cartridge, it might be worth considering my earlier post relating to Paul Miller's measurements on cartridges.
Thanks
Orb
I had some time to think. Maybe I overstated my case a little. If you submit a thesis at MIT I think they all have to follow the same protocol. You are right about the law AMiR. here is a difference between criminal and civil. Indeed there are more divisions and more standards. The proof is the same whiitin those disciplines. That's' true whether it's murder or simple assault. The same for medical malpractice or a traffic accident.
I was of the the opinion there was only one scientifc method with respect to proof. That stands no matter what your level of agreement or doubt is.
I was of the the opinion there was only one scientifc method with respect to proof. That stands no matter what your level of agreement or doubt is.
garylkoh
WBF Technical Expert (Speakers & Audio Equipment)
Interested if anyone does do this, looks like only you at moment Mike hehe
Gary, let us know what you decide to do.
But if using specific measurements relating to the LP-cartridge, it might be worth considering my earlier post relating to Paul Miller's measurements on cartridges.
Thanks
Orb
I've always been pretty skeptical about demagnetizing an LP, so I don't own one. But if I can get a hold of one, I'll make recordings of the same LP pre- and post- demagnetizing. Then, the only variable will be groove wear (playing the LP twice in quick succession), power (your neighbor turns on the microwave oven), and operator bias (I make a better/worse recording because the LP has been demagnetized).
I can plainly see that this test will never be conducted to the satisfaction of most people. For those who believe in demag there will be something wrong and for those who don't believe in demag there will be something wrong. I'm still willing to listen to what Gary comes up with and form my opinion though.
Michael Fremer did this and there were measurement-recorded playback differences, however Ethan and a few others argued the case that the measurement/recording will change between each play so it did not mean much - this could be a valid point and one that then required more control testing or process.
There was pros and cons in the discussion but again because of the way of the discussion it was impossible to convince the measurements meant anything, and fell back on theory.
I really think for this to work you are going to need one you demag and one as a control and ensure they came from the same stamper; i.e. the LPs as mentioned by Mike Lavigne.
Without this, unfortunately no side will be convinced.
And I am definitely interested in the difference between the improved compound-no carbon black and the standard press LP.
But then I am only curious about what may be happening and as a digital fan boy it does not affect my listening hehe.
Cheers
Orb
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