Here's how a CD is made


cdc
THANKS for posting the heads-up Ccc. Fascinating article. It's quite a miraculous technology to a simple man like myself.

I was particularly intrigued by this passage and accompanying footnote and would be interested if anyone else had observed similar results:

"Another example of how two discs with identical data sound different is the strange case of copying (in the digital domain) a CD to a CD-R (a CD made on a CD recorder); the CD-R sounds better than the disc from which it was made. Although the data are identical, the CD-R's HF signal looks much better than that of the mass-manufactured CD (footnote 5).

Footnote 5: At the 1992 Winter CES, Meridian's Bob Stuart copied a CD to a CD-R of music that engineer and high-end retailer Peter McGrath had recorded. Bob played the original CD, then the CD-R. Seconds into the CD-R, Peter jumped from his chair and exclaimed, "That's impossible!"

Marco
Excellent find Cdc and thanks for providing a link to this article. Very informative and easy to understand / follow along with. Truly one of Robert Harley's better works. Sean
>
Thanks for the link, it was a very interesting article. I was especially intrigued by the CD-testing machine described at the end - I wonder what such a device could reveal about the quality of CD-R blanks from different manufacturers.
Thanks Cdc, This was the best and most easy to understand read on Cd's I've ever come across.

Dave
Very interesting. So much for perfect. The forever part will take a little longer to evaluate.
Thanks to Stereophile too. For all the bashing that goes on, they do have some good stuff in there.
Years ago, I purchased a laboratory grade of optical lens cleaner from a chemical lab. It was guaranteed to meet lab specs (read, almost zero trace residue) in terms of residue, or film, left on the cleaned surface. It was extraordinarily expensive, but one cleaning of a cd, and wow, more clarity and, actually, similar but not the same, greater volume. It sounds odd unless you think about it. That is, the surface of a cd, is contaminated with whatever particulate matter floats in the air, not to mention possible finger prints etc. So, I tried an experiment, an ABX for all of those who know what that is. And invited people into an audio store to listen. First we played a disc, then a cleaned disc, and it was obviously better. Then we played the original cleaned disc, versus a copy of the disc, transfered onto a new cdr, which was cleaned prior to transfer, and it was the best of all!! Everyone was stunned. But, like Bob Stuart, everyone who could, jumped from their chairs in excitement. IT WAS BETTER IN EVERY WAY. The best part is, you can clean a disc, and a day later get the same improvement,(not cumulatively better, just returning to the pre/post, cleaned version) after it has been, "contaminated by airbourne particulate matter". Think of it this way, when you first remove a glass from the diswasher, or just having removed it from just very hot water, after it dries, it is literally squeeky clean. Yet after it sits in the cabinet and becomes contaminated, it is no longer squeeky. That is the unseen, with the naked eye airbourne matter build up, I suppose.
This stuff really works, and can be purchased from the lab directly. If anyone wants their name, I can look on my ten year old gallon, and supply it if you email me. I am not affiliated with them in any way, and don't sell it! It is easy to use. I just use, cleaned out bottle with a spray top, that was originally used for something else. Then wipe with a very soft, (small cut pieces of soft, tee shirt cotton) to clean and dry. Do not use cloth not laden with soap residue from laundering, or colored fabrics with bleeding dyes.
Email me if your interested.
Larry