I never tried it, but, there have been several manufacturers who have designed their products for the same result (absorbing stray light from being reflected back onto the surface being read). I believe Esoteric coats the inside of its transport for that purpose, and Naim also relies on surface treatment to absorb light and a light-tight lid on its top model, again for the same purpose.
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If it is true, how does it work?
If you believe something works then your mind will often trick you into thinking it did something positive.
If you can't measure a difference and demonstrate it repeatedly with measurements from independent labs - then forget it. 99.9% of the time it is just your mind playing tricks.
I tried the Greenlite pen on a few cd's that I thought sounded brittle. Mapleshade's Afterglow was one of them.
It sounded better to me with the edges painted green. I problable will get another copy of it to make a better compairison.
I do not as rule apply it to my cd's.
I like to tweak and it did not cost that much.
Give it a try, I'm not sure if they still make it.
The straight green marker and other green products approach does not work. You need to start with a layer of yellow, then a layer of blue, finished off with a final and yet lighter layer of yellow. While the end color is green, it is the layering of the blue and the yellow that is addressing the stray laser and preventing it from being reflected back onto the read surface of the disc. Additionally, if you find that the slit between the drawer mechanism and the face plate of your CDP seems a bit large, I have found that placing 16 layers of electrical tape in alternating colors of yellow blue yellow also greatly improves the sound of a new CD when you put it in your player. But perhaps it is the hour long process of removing the tape, removing the old CD, spending lots of time waiting for the marker layers to dry before applying the next and then putting all that tape on that makes me so eager to listen that I just think it sounds better.
This is very funny, and I have a couple of comments I'm tempted to make. But I'm staying out of this one. I made a flippant post about the Ionic Hair Dryer CD Thingee and the next day I met a chemical engineer who specializes in ionic processes who said it would probably work as claimed.
Anyway, whether you color the edges of your CDs, or make fun of those who color the edges of their CDs, have fun.
A simple easy to hear improvement in every CD follows the one-time insertion of "Codename Turquoise CD tray masking kit" into the CD tray.
Available from machinadynamica.com
This is similar in concept to what is built-in to CD players by Esoteric and Naim
as mentioned in the very first post above by Larryi.
I once heard a demonstration of a cd player with red leds inside the drawer. When they were turned on, it stopped playing. Red light other than the laser's within the drawer can harm the sound. I tried green and black edge treatments which at the time seemed modestly effective. I have discovered, however, that recent cd cleaners, such as Audio Top and Walker Ultra Vivid, negate any benefit from the edge treatment. I guess this might because the red light from the laser is less diffracted.
Also as I now have a music server, ripping to a harddrive seems unaffected by diffraction. In short, I no longer use edge treatment although at one time I thought it had a small benefit.
this issue has just been beat to death..it's not one to be settled with argumentation and/or preaching....you have to do your own empirical test ....listen and then let your ears decide. If you want some honest although anecdotal data just go to Tweak Audio. And by the way some CD treatments actually do improve the sound of a standard CD when compared to a similar untreated CD. Also (no relation to the dealer) try MaxxHORN CD Treatment. It's the best I have heard and it seems to have an additive effect if you use it with Mapleshade CD treatment regimen. All in all the treatment of CD's is best done with a glass of wine, beer or whatever.....it's a pain in the but...however sometimes it really works. By the way have fun painting and treating those little silver CDs because anyway you sketch it your significant other is bound to think your nuts!
I'll tell ya what does make a difference: trueing the runout of CDs via an Audiodesk lathe. I had a dealer do this to several of my CDs while auditioning some gear a couple of years ago with my wife; we did A/B (before and after) listening and in every case there was an improvement in clarity and depth. My wife confirmed and she is a huge audio skeptic with WAF at a constant "11"
One of these days I'm gonna break down and get one.
I'll tell ya what does make a difference: trueing the runout of CDs via an Audiodesk lathe.
There may be an explanation for this - power to adjust the laser tracking will be sinusoidal/periodic if the CD wobbles and the laser is constantly readjusting - to keep tracking.
If the power supply ioslation to the DAC is less than robust/adequate then this signal may affect jitter. Ed Meitner demonstrated years ago - that if you blasted a CD player with a speaker that you can get the CD's to resonate at around 1000 HZ - which then created feedback and jitter into the clock. Random jitter is ok - but precise periodic jitter of specific nature is MUCH more likely to become audible.
On the other hand - if you place your CD player inside a cabinet with a closed door and protect it from high frequencies then you should not have too much cause to worry about what Ed Meitner discovered.
The wobbly disc is another matter - as equipment designers can and should deal with this issue as laser readjustments will be periodic and related to disc rotation speed - in essence something that would be expected to happen. A DAC completely separated from the transport with a decent PLL algorithm that reduces jitter may help and the good news is that it will probably fix everything - whereas I have my doubts whether a lathe can be precise enough - those CD tracks are awful narrow...
Shadorne, everyone thinks the AudioDesk trues the radius of the cd. It doesn't. It puts a angle on the edge that extends only half-way through its thickness. It thus is really just directing the light diffused through the plastic downward. You could trim both sides. That would true the radius. I did that with several discs with some benefit, but you need to be very careful not to scratch the disc and it takes too much time for the additional benefit.
With improved cleaners, as for the painting of the outer edge, I found little benefit, which again suggests that it is not disc wobble.
With improved cleaners, as for the painting of the outer edge, I found little benefit, which again suggests that it is not disc wobble.
That would make it harder to explain. The reflections then would need to be enough for the CD player to resort to interpolating some unread data. ( which does occur on badly damaged/scratched CD's but should not be the normal way of things )
For more info to see how CD players do a lot of checking on what they read see this. It is kind of like the game Mastermind board game or Cluedo - after a while you have enough redundant data to be sure what you have hidden from view (or in teh case of a CD what data was misread). For sure audio CD's do not have as much redundant data for cross checking accuracy as a CD-ROM disc(where a single error could mean that software will not run on the computer) - but it should be more than enough to weed out errors from misread bits due to odd scattered reflections of light...
Shadorne, the new cleaners also make scratched discs more readable or at least less likely to cause the cd player to err or pop. I think the laser's rays merely reflect on the sensor with little diffraction elsewhere.
I still remember the demonstration with the red leds. The player just stopped.
Something has removed the modest benefits of painting the edges on discs, perhaps I err in attributing it to more transparent discs.
The blade on the disc trimmer should be positioned such that the entire edge of the disc is timmed at an angle, not just half the edge. What good would it do to trim half the edge, as the light would still be directed out the half that wasn't beveled? The other advantage of beveling the entire edge is that it makes the disc symmetrical, cutting back on wobbling during play.
Tbg, please take the time to read the many reviews for the trimmer. You will find that the trimmer is intended to bevel the entire surface of the edge. Reasons for beveling the edge completely include (1) eliminating surface imperfections on the edge, (2) truing up round of the disc and (3) redirecting the scattered laser light, none of which would be accomplished, or completely accomplished, if only half the edge was beveled.
Lastly, can I point out CD cleaners do not perform any of the functions of the disc trimmer, therefore should not be viewed as replacements for the trimmer?
I rest my case. :-)
Geoffkait, I doubt if the reviewers noticed. This nonsense about truing the disc is present in all of them without any suggestion that they altered the instructions.
I suspect that less scattering of the laser's light on a more transparent surface would result in less light exiting from the outer edges and thus the loss of the benefits I was getting from the AudioDesk.
I too rest my case as I suspect readers are bored by now.
According to web page you provided, "The edge of the beveled disc should be 0.2 mm." Since the edge of an unbeveled discs is around 1 to 1.3 mm, that 0.2 mm thickness is only about 1/5 to 1/6 of the original thickness. Probably best to leave a very slight edge so as not to cut oneself on the edge while handling and help prevent chipping.
So, half is not enough according to manufacurer. Edge should be beveled about 80-85% of the way through
The scattering occurs below the surface and when laser hits the edges of the pits and lands....
Actually, it does, or very nearly. The rotating arm/blade cuts a perfect circle, so the circle formed on the upper surface of the disc by the bevel is perfectly round. Enough mass is removed from the edge during circumcision that the disc should be much more balanced while spinning. You can ignore the little 0.2 mm nub left on the edge.
(http://www.tweakaudio.com/EVS-2/CD_tweaks.html) Everything in the electromagnetic spectrum has a specific wavelength/frequency, and in most examples, can/will be either absorbed or reinforced by some other wavelength/frequency(if present). Red light is no exception, and it just happens that the wavelengths of green and black absorb red's. It comes back down to: If you can hear and appreciate the difference(given a system able to resolve it)- enjoy it! If not- DON'T!! Perhaps the wearing of green pantyhose would reflect something entirely different.......
I found a few extra Cirkulus cd disc enhancers in my stash. I'll send you one to try. I painted the top surface of one of mine with AVM. If I were to paint the inside with AVM it would increase the thickness and may not load properly with my up graded PS Audio transport. The disc wouldn't be a problem with top loads such as your Shanling. The Cirkulus sits over the entire top surface of the disc including the edges. Like a perfectly flat bottle cap. There should be no edge reflection.
With regard to trimming the discs, I suspect that doing this is for reasons other than "balancing" the disc. My company manufacturers equipment for the optical disc industry where we have an 85-90% worldwide market share. Every disc that is manufactured goes through rigorous in-line inspections with lasers, etc. . . Part of this process includes the scudderer which is part of the chemical distribution process of coating the disc. Beside the injection molding process, the scudderer is the area of disc replication that causes the greatest amount of rejected discs. Based on this, my suspicion is that a less than perfect distribution of the coatings is what is to blame for inbalanced discs. Could this be a build up at the very outer edge of the disc? Sure, but since it would be unusual for an inbalanced disc to pass tolerance inspections by later and testing equipment, the likelihood that all the planets would align and the "truer" device would correct the problem is not going to be very high. Only a very small percentage of discs should need to be trued, as they should have been rejected in-line (typical disc rejection rate varies from 6% down to about 2-3% at the best plants).
As for shattering the discs with the "disc truer", I would be very surprised by this. Polycarbonate is very hard material and quite difficult to shatter. As part of a developmental project, we build several disc eraser units for Microsoft to use at the lines (versus away from the lines, such as in a warehouse - were we alread make disc destruction systems that are required by Microsoft if a vendor company replicates discs on their behalf). The disc eraser prototype systems ran the disc between two special surfaced rollers under very high pressure and made the discs impossible to read (the key being that no dust was produced, allowing them to be run directly at the production line). Never once during this testing process did we have a disc shatter or break, even during a malfunction of the equipment. One can moderately easily break or shatter a disc in ones hands, but this requires bending the disc beyond the point of strength of the PC, which while not tough is not something one would do as a mistake. In most cases, you could take a hammer to a disc wih light to moderate force without the disc shattering, unless the edge of the hammer is used and the disc is not on a flat surface.
While I joked about the green edges above, I do actually use a CD absolver mat when playing CDs. How much good does it do? It has been so long since I started using it, I can't honestly say that I know it makes any difference. But it has become habit.