How to improve your CD sound quality and go blind all in one easy step!

[Roland68]

I have no words other than it looks like a hospital visit waiting to happen. My first thought was it was something to recover a scratched CD. I used to carefully dip them in solvents to dissolve the plastic and remove the scratches and then spin-dry them since I was a cheapskate in college. Not ideal, but it worked. But here, its just spinning the thing up to Dremel speed, and then cutting an bevel into the fluttering CD platter to reduce "diffraction" despite the equipment designers knowing full well how to properly design these things. And its digital... Like seriously. I'm sure this has been covered somewhere here before. But its just so absurd! Included is a probably now cliché Techmoan video (I know, *moan* lol...), which only adds to the goodness in that he just cranks it up to full tilt and sends it out of ignorance. Having experience using lathes and mills, I'm just cringing waiting for the disk to explode since its just wobbling around like crazy from all the surface vibrations. But since the video was posted, obviously that eventuality did not transpire. Somewhere, somehow, this has "raised" the bar in the subjectivist audiophile world. Cable lifters? nah... Sound condensing precious metal orbs? Nope. CD lathe? YE$$$ I'm sure this is terra cognita for ASR frequent fliers, but for the uninitiated like me it really takes the cake. But, after you get out of the hospital and go blind following an "incident", everything will indeed sound better, but likely be tinged with extreme instant regret.

In this thread you can see how young most of the users are, or how recently they have started this hobby.
This was one of the biggest themes on CD's in the 90's and early 2000's. Both the chamfering of the CDs with a device like this or a cutter, as well as the blackening of the edges with an edding.
But I can only advise you not to do this with original CDs, as this will permanently destroy the CDs (also with the Edding). After 27 years of experience, I can confirm that.

 

[Cars-N-Cans]

In this thread you can see how young most of the users are, or how recently they have started this hobby.
This was one of the biggest themes on CD's in the 90's and early 2000's. Both the chamfering of the CDs with a device like this or a cutter, as well as the blackening of the edges with an edding.
But I can only advise you not to do this with original CDs, as this will permanently destroy the CDs (also with the Edding). After 27 years of experience, I can confirm that.

Oh yeah that's stating the obvious! Did you try one at some point, out of curiosity? Irony is I could see something like this, but in modified form, coming back, and with a fancier marker to ensure all the bits don't fly out the sides when it spins up!

 

[RandomEar]

I am referring to roundness of physical disc. shaving the outer edge will allow a disc to be properly rounded and technically will reduce vibration. Of course, this assumes the disc has a uniform density (uniform density isn't much of an issue for cds).

No doubt it can't correct the position of data spiral but reducing vibration will make it easier to read the data since vibrations directly affect reflection of the laser bean.

It will make the outer perimeter of the disc round. But depending on how well the disc is centered when putting it in, it can actually increase the imbalance and cause more vibrations.

Since the disc is centered using a cylindrical protrusion (which has to have some slack/tolerance for all discs to fit) and not using a spring loaded centering cone or similar, the disc is not guaranteed to be centered properly in this device.

 

[Roland68]

Oh yeah that's stating the obvious! Did you try one at some point, out of curiosity? Irony is I could see something like this, but in modified form, coming back, and with a fancier marker to ensure all the bits don't fly out the sides when it spins up!

Otherwise I would have had no experience of what happened to the CDs afterwards
As soon as the edge of the CD is damaged, whether mechanically or chemically by solvents (edding), the CD gets fine cracks on the outside of the edge. Due to the faster escape of the softeners through the open surface at the edge, the material shrinks faster on the outside and begins to tear.

However, fine cracks are also caused by (mostly) improper processing, which are aggravated by the above-mentioned effect, but also by movement, bending and vibrations.

 

[Roland68]

I am referring to roundness of physical disc. shaving the outer edge will allow a disc to be properly rounded and technically will reduce vibration. Of course, this assumes the disc has a uniform density (uniform density isn't much of an issue for cds).

No doubt it can't correct the position of data spiral but reducing vibration will make it easier to read the data since vibrations directly affect reflection of the laser bean.

This problem does not exist in reality. It's just an invention of the manufacturers of these CD editing devices.
We investigated this with 2 manufacturers in the late 90s/early 2000s. An imbalance is most often caused by uneven coating or printing, but more often by poor centering. Therefore, drives were also developed that extremely reduced imbalance (Teac VRDS, Pioneer turntable drive, heavy and balanced pucks, etc.).

The CD processing devices on offer would also not be able to clamp a CD precisely. this would require an accuracy of 1/100mm or better. A spindle alone is in the 4-digit range. I don't even want to think about a recording with this accuracy.

 

[Cars-N-Cans]

Otherwise I would have had no experience of what happened to the CDs afterwards
As soon as the edge of the CD is damaged, whether mechanically or chemically by solvents (edding), the CD gets fine cracks on the outside of the edge. Due to the faster escape of the softeners through the open surface at the edge, the material shrinks faster on the outside and begins to tear.

However, fine cracks are also caused by (mostly) improper processing, which are aggravated by the above-mentioned effect, but also by movement, bending and vibrations.

I asked it without making said assumption to account for the potential desire for anyone willing to utilize such a contrivance to retain some anonymity.

But at any rate thank you for sharing your experience. Stating the obvious it confirms what I suspected would happen since polycarbonate is prone to cracking and crazing, not to mention the foil backing is also easily damaged by also delamination which could easily happen when using one of these.

 

[Cars-N-Cans]

This problem does not exist in reality. It's just an invention of the manufacturers of these CD editing devices.
We investigated this with 2 manufacturers in the late 90s/early 2000s. An imbalance is most often caused by uneven coating or printing, but more often by poor centering. Therefore, drives were also developed that extremely reduced imbalance (Teac VRDS, Pioneer turntable drive, heavy and balanced pucks, etc.).

The CD processing devices on offer would also not be able to clamp a CD precisely. this would require an accuracy of 1/100mm or better. A spindle alone is in the 4-digit range. I don't even want to think about a recording with this accuracy.

To continue, I'm assuming you used it to test for its "validity"? The result is obvious up front even without any real prior knowledge, so I have a hard time seeing any reason otherwise given what you stated. Perhaps it could have other uses like trying to physically "balance" a CD or something, but they are too imprecise for any real positive effect, not to mention there is not much to work with on the perimeter of the disk itself.

 

[Chrispy]

Is vinyl shaving a thing, too? Seems a green marker would be easier.

 

[Cars-N-Cans]

Is vinyl shaving a thing, too? Seems a green marker would be easier.

For LPs I would think all it would do is remove the lead-in for the needle and make your life harder than it already is with that format. Techmoan does a good job of explaining the motivation behind it, and on the surface it sounds sort-of plausible, but in reality simply using an absorptive coating with the same index of refraction would stop any sort of total internal reflection at the edge in the CD platter if it was even an issue, which it’s not. Balancing can be, but this seems to just ruin them.

 

[Punter]

The funny thing is that Audiophools see a CD as just a miniature LP. They are under the impression that there's something truly significant in how the disc is spun and the accuracy of the spinning. Fact is, the disc has to spin at the right speed (or thereabouts) which is controlled electronically. Then the laser reads off the pits and flats as ones and zeros. The stream of ones and zeroes is input to a chip which then buffers the ones and zeroes and then clocks them out at a crystal controlled frequency, hence the insignificant wow and flutter of a CD mech. From here it goes to the D to A chip and MUSIC!! All this allows for the forward error correction already mentioned and even if there is something slightly wrong with the spinny bit and the ones and zeroes, it all gets fixed by the system that engineers (real ones) built to make the system robust.