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Old 1st March 2007, 11:34 PM   #11
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More on the "Nespa" thingy:

"What, pray tell, is this manufacturing defect? That's where incontrovertible proof gets fuzzy. One theory goes that during especially high-speed duplication -- the norm for most commercial pressings -- the release agents that are applied to the CD mold stampers end up between substrate and protective surface as inclusions. These microscopic bubbles prevent complete adhesion of layers to purportedly interfere with the laser reader. The Nespa treatment is claimed to somehow "flash evaporate" or "burn off" these inclusion bubbles through the CD's permeable polycarbonate. The end result is audibly better sound through more accurate data retrieval."

If this thing removes bubbles, they should be visible before and gone after the treatment. All that is required to show what this device does is a simple microphotograph. How does one "evaporate" a bubble in solid plastic, anyway? It seems to me you'd have to liquefy the plastic and allow the bubble to rise to the surface and burst. Hmmm. I don't think I want anyone melting my CDs.

As with everything else that purports to "improve" CDs, it completely ignores the error correction built into the coding in the data on the disc. The coding allows PERFECT reconstruction of bad bits. It isn't masking, it is reconstruction of the original data. It can't get better. It is perfect.

As long as there are narrow-minded people with money in their wallets there will be scoundrels to relieve them of the burden of having to carry it.

No sense in dancing around it- a person would have to be stupid to spend thier money on something like this.

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Old 1st March 2007, 11:47 PM   #12
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Aluminum can be magnetized momentarily. Alternating magnetic fields can be measured under power lines run with aluminum wire Ė just ask the kids with the feet growing out of their foreheads. ; ) Kidding! I donít buy the power line/cancer thing anyways. After all, Iím sitting in front of a 17Ē monitor thatís belting out lots-o'-fields.

Why would CDs become magnetized during the manufacturing process in the first place? When theyíre stamped? When they are coated or printed? Move a CD near a compass Ė if it has even a slight field, the needle will deflect. Didnít think so.

And, what about the DC motor rotating the CD, or the linear-optics positioner, or even the lens focusing coil? All those parts generate a magnetic field and/or are influenced by magnetics, yet players seem to continue to work fine.

Demagnetizing CDs is just another high-profit-margin piece of snake-oil for low-IQ-margin audiophiles.
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Old 2nd March 2007, 01:25 AM   #13
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Quote:
Originally posted by DCPreamp
Aluminum can be magnetized momentarily.
Nope, it just acts as a conductor that allows the electricity to create a magnetic field. The aluminum is never magnetised itself.
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Old 2nd March 2007, 02:10 AM   #14
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Weeeeeeelllllll.... sorta, but not really. Aluminum is paramagnetic, so it retains no field when the applied field is removed, but it does have a slight field when in the presence of an external magnetic field. The response is pretty small, about 10ppm of susceptibility, so this is really a quibble.

Your bottom line is right, CDs have no residual magnetism to remove, but you knew that.
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Old 2nd March 2007, 03:03 AM   #15
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Quote:
Originally posted by DCPreamp
And, what about the DC motor rotating the CD, or the linear-optics positioner, or even the lens focusing coil? All those parts generate a magnetic field
That's exactly how the CDs get magnetized. It isn't at the pressing plant, it's over time in the CDP. The demagnetizer removes or neutralizes that accumulated magnetic charge.

This gradual magnetizing of CDs is one of the main reasons why CDs "wear out" and start to sound bad over time. They don't wear out physically, but they get magnetized which wreaks havoc with the CD player and pick up. Jitter and error rate go up as the CD gets more and more magnetized. Demagnetizing (degaussing) from time to time will bring the CD back to a neutral and cleaner sounding state.
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Old 2nd March 2007, 03:31 AM   #16
AJT is offline AJT  Philippines
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Quote:
CDs have no residual magnetism to remove, but you knew that.
of course! i started this thread to reinforce what i know...
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Old 2nd March 2007, 03:55 AM   #17
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Quote:
Originally posted by panomaniac


That's exactly how the CDs get magnetized. It isn't at the pressing plant, it's over time in the CDP. The demagnetizer removes or neutralizes that accumulated magnetic charge.

This gradual magnetizing of CDs is one of the main reasons why CDs "wear out" and start to sound bad over time. They don't wear out physically, but they get magnetized which wreaks havoc with the CD player and pick up. Jitter and error rate go up as the CD gets more and more magnetized. Demagnetizing (degaussing) from time to time will bring the CD back to a neutral and cleaner sounding state.
You are extraordinarily misinformed.

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Old 2nd March 2007, 04:23 AM   #18
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Quote:
Originally posted by panomaniac



This gradual magnetizing of CDs is one of the main reasons why CDs "wear out" and start to sound bad over time. They don't wear out physically, but they get magnetized which wreaks havoc with the CD player and pick up. Jitter and error rate go up as the CD gets more and more magnetized. Demagnetizing (degaussing) from time to time will bring the CD back to a neutral and cleaner sounding state.
The residual magnetic field of a CD that has been played several hundred times is an easily measurable quantity. Yet it remains beneath the dignity of the people selling these things to provide even one data point.
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Old 2nd March 2007, 04:37 AM   #19
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Quote:
Originally posted by I_Forgot
You are extraordinarily misinformed.
Not really. Just being silly, that's all.

My post was pure and utter nonsense. I just made it up as I wrote it.
But see how easy it is to come up with a hare-brained theory that actually sounds good - if you don't know the facts?

That's how a lot of this BS get sold. In fact my story is too easy to disprove, so it's not that good after all. Replace magnetism with "quantum effects" or "Huna energy" or some such and it will be hard to disprove.

Sorry to lead anyone down the magnetized garden path.

BTW, I_F - you are extraordinarily polite. You should have ripped me a new one.
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Old 2nd March 2007, 04:48 AM   #20
jlsem is offline jlsem  United States
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Quote:
Aluminum is paramagnetic, so it retains no field when the applied field is removed, but it does have a slight field when in the presence of an external magnetic field. The response is pretty small, about 10ppm of susceptibility, so this is really a quibble.
100% pure aluminum is paramagnetic, but like copper, there is enough iron as an impurity in commercially available samples to swamp their paramagnetic properties.

Having said that, demagnetizing cds to improve the sound is a absurd notion.

John
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