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Wash, Cut, Polish & Demagnetize

As I sat and read through the most recent threads on the "Agon" forum, I noticed a thread regarding "Glossary of Audio Myths". I noticed several comments regarding "greening" and demagnetizing CDs.

Without delving too deeply into the effects of laser light diffraction, deflection, dispersion and reflecting light from adjacent tracks creating "jitter", and to avoid reduntantly examining the fact that the aluminum "wafer" in a CD is not always just aluminum, but in many cases aluminum "alloy", I would like to attempt to dispel a few of these "myths".

Many CD manufacturing facilities use a coating of mold release agents on the manufacturing machinery and on the plastic substrate material in the actual CD to facilitate ease of handling throughout the manufacturing process. Somewhat similar to spraying a cooking pan with "PAM" to reduce sticking. The residual amounts remaining on the CD upon completion of manufacturing should be removed as it will cause minor deflection and loss of focus of the laser beam. Specialty chemicals are available specifically for this purpose. I wash the CDs thoroughly using Dawn dishwashing liquid and very warm water. I cannot confirm that this process is as effective as using the specialty chemicals, but it leaves the CD surface extremely clean and seemingly free from any "oily" feel.

I then cut the edge of the CD using an Audiodesk CD cutter. This process reduces the amount of laser scatter from exiting through the outer edge of the CD and flooding the inside of the CD transport with reflected laser light. By cutting a bevel on the edge of the CD, you actually reduce the edge surface area by which the diffracted laser light can disperse. Some may feel that this a bit excessive, but we must keep in mind that the results of these treatments are cumulative.

The next process involves applying CD "Green" to the beveled edge. The properties of the color value of the Green used in the majority of these coatings tend to absorb any stray laser light. I still, to this day, have not been able to figure out why Green is the color of choice although, I have been told that it is simply the values of each of these colors (Red laser light and Green) that work together in unison to "neutralize" the light. The initial washing of the CD also helps to enhance the adhesion of the green coatings.

Upon allowing the CD green to dry, I then apply CD diamond using 100% cotton balls, and polish using again, cotton balls. CD diamond is an optical enhancer similar to Optrix,
Vivid, etc. and also contains a anti-static component. Most of these "optical enhancers" work by simply filling in microscopic pores in the CD surface permitting a more direct transmission of the laser beam through the plastic substrate material to the actual CD surface.

The last step involves demagnetizing the CD using a Furutech RD-2 CD demagnetizer. CDs, contrary to what most people believe can and will become magnetized. The results are a less black background, a general "haze" and loss of detail. If Cds were made using pure aluminum with NO trace elements, this step might not be required.

The results of all this? Pretty damn amazing. Again, recognizing that the results of all of these steps are cumulative, when all is said and done, the improvement is quite significant. Although these steps may sound somewhat time consuming, each CD actually only takes about three minutes to complete.

I hope I have provided some insight as to "dispelling" some of these myths. I can, and will, stand by this process as time and time again these enhancements have made CDs a lot more listenable. And, I have dropped the jaws of many non-believers after they have heard the actual results.

Any comments regarding this process are welcome. Happy listening.


128x128buscis2
geoffkait's avatar
geoffkait
23,365 posts
 
interesting?

http://www.physics.umd.edu/lecdem/services/demos/demosk2/k2-46.htm
buscis2's avatar
buscis2 OP
468 posts
 
Sean, May I?
Cdc, in response to your questions, in order:

:The Audiodesk preferred bevel angle is 38 degrees plus or minus 30 minutes (1/2 degree).

:There is no corner radius. Edge thickness (at the outermost portion of the CD after beveling should be approx. .025".

:Yes, it is the outside diameter only that gets cut.

:You could in fact purchase a bench lathe to perform the same operation. But you could also purchase a $300,000 Mikro Seiki CNC machining center and create a CNC command string to go along with it.
If you were to use a bench lathe you would need to fabricate a fixture to maintain flatness of the CD while the machining operation was being performed. If the CD were to deflect under the pressure of the contact of the cutting tool, The recommended 38 degree cutting angle would not be maintained.

:See my preceeding post for the CORRECT Furutech website. Sorry.

:In regards to "ferrous impurities", that is not the only contributing factor to magnetism. The Furutech site will explain further.

: I have no familiarity with "optical oils" being used in conjunction with application to the CD surface. I stress REMOVING any releases, oils or other impurities from the CD surface.

:I assume when you say you tried Novus #1, you were applying it to clean the CD's surface. Novus #2&3 are scratch removers as Novus#1 is merely a plastic polish used for plastic and or polycarbonate surfaces.
The manufacturers of most of the optical enhancers will explain that their products are "filling in" microscopic imperfections in the CD's plastic surface, enhancing light transmission of the laser reader.

Cdc, I hope this provides the clarification you requested. And Sean, I didn't mean to "butt in", but I did want to respond to Cdc's questions addressed to me, and I figured I would kill several birds with one stone.

sean
6,231 posts
 
No problem Buscis. As i've mentioned, these forums should be about sharing and learning for the good of the community, regardless of who can help provide the info. I couldn't remember the exact cutting angle anyhow : )

As far as trying to duplicate the results on some type of homebrew equipment or a lathe, all i can say is be very careful. Splintering CD's would not be fun nor very cost effective. In extreme cases, it might not be very healthy either if bits and pieces of shrapnel come flying out at high speed.

As a side note, the Audio Desk unit has variable rotational speed and spins at a max of 9000 rpm. I always start off slowly and then build up speed. If you try to crank it up and then bring the cutting edge into contact with the disc, the cutting edge can either gouge the disc and / or crack it or get hung up on "casting flash" or a burr. Either way, the results are not pretty and the screeching sound will make you aware of a problem RIGHT away. I found this out the hard way when i did not clamp the disc down tight enough. The cutting edge caught the disc and held it in place while the platter continued to spin at 9 grand. As such, you have to have a very secure method of clamping the CD into place and hold it there under load while one is "trimming" the disc.

As to my "belief" in the effectiveness of the "de-magnetizing" or "anti-stat'ing" CD's, i do think that the results are audible even if they aren't measurable.

With that in mind, I would not call the results "plain as day" but i do think that the noise floor is reduced and the presentation is slightly more natural sounding. If one is to get the full benefit of such a treatment though, the plastic disc tray and mechanism that are so commonly found in most machines would also have to be "treated". Personally, i wipe down the tray and everything else that i can easily access inside the machine with "Static Guard" after applying it to a cloth. If you are going to do this, DO NOT wipe off the lubricant that might have been applied to the rails of the transport mechanism. The increased drag could result in the mechanism binding up and doing premature damage to the drawer motor. Sean
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cdc
1,757 posts
 
Buscis2 thanks, that pretty much explains it except which side is the bevel? Is the label side or read side larger in dia after beveling? I'll give this a try with Steely Dan's "Two Against Nature" since I have a couple of them.
I followed your link and if this works for you that's fine. But I looked up aluminum alloys in Machinery's Handbook and aluminum is alloyed with copper, silicon, Manganese, Magnesium, or Chromium. Alloying composition listed down to .06%. So any iron impurities would be less than .06%.
Have you ever tried to magnetize aluminum foil? Okay, I am stupid enough to be sucked into trying this. Although I don't have a pulsed capacitance magnetizer I can get high enough to prove (to myself at least) whether it can be done.
Yes you could use a CNC turning center. You could also use an NC milling machine with a bevel cutter and interpolate a circular cut. But the point I was making is that the same job could be done for less money than your typical "audiophile" equipment.
Yes I radially polish the disc using a microfiber lense cleaning cloth from Walmart ($1.99) and Novus #1. A little heavy breathing to fog up the CD shows up areas that need further polishing. Vocals, for example, are clearer using Novus than just a plastic cleaner alone IMS. I did not like other polishes like Mapleshade Microsmooth as it put scratches in the CD. Novus doesn't.
buscis2's avatar
buscis2 OP
468 posts
 
Hi Cdc, The bevel is applied to the data side. The label side is the larger diameter (actually unaltered diameter).

As you probably read, Furutech feels that the impurities in the aluminum in conjunction with the ferrous metals in the paint that provide the ability to become magnetized. I don't know.
I can tell you that there is a definite improvement in the sound with just using the Furutech alone.

You and I are absolute agreement on the cost of the Audiodesk @ $600.00. It's ridiculous. But then again, I also think it's ridiculous for someone to spend $6000.00 for a set of speaker cables. Yet many people do it. I personally feel that an investment of $600.00 becomes more understandable if you consider the amount of money you may have invested in your CD collection. I have over 700 CDs. figure that out at an average of $12.00 a CD.

Yes, Novus is a great product although I have never thought of using it on CDs. Hmmm.
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