CDR Quality
To simplify things . . . buy Japan Made Media.
OK, let’s make things a little complicated. CDRs are made of several elements, dye, coating, etc. The most important appears to be the dye, although, I have read conflicting information about this. There is a pretty cool program called CDR Idenifier, you can download a copy at www.webweaver.nl/CDR-Identifier.zip (220K download); although, this may not provide completely accurate information. When using this program you need to have the disc in a CD Writer. If this link does not work please contact me and I can get you a copy of the program. Although it is not 100 percent accurate I still use it periodically and find it useful.
One piece of information you may be able to retrieve is the “Strategy”. Some have reasoned that “Long Strategy” must be better than “Short Strategy” which may or may not be true. I read the following on an e-mail list . . .
“"Long" and "short" strategy dyes, as used in CD-Rs, have *nothing* to do with the longevity of the disc (they refer to the details of the behaviour of the dye when exposed to laser light). In fact, some "short-strategy" dye types have a specified shelf life that is *longer* than that of "long-strategy" dyes.”
Personally I pay more attention to the type of dye, (i.e. Phthalocyanine, Cyanine, Azo, Etc).
I have also read and agree with the following . . .
-The best protections against degradation are:
- use good quality discs for your master/archival copies (which should ideally be SHN, FLAC, or some other lossless format, rather than audio CD)
Why SHN, FLAC or some other lossless format ?
“It's the extraction methods used by software. Copying an audio CD is NOT the same as copying a data CD. That is the problem.
If you use a program like Exact Audio Copy and compare an extraction to something like, oh, Music Match, or EZCD Creator, you will find that they are not bit for bit identical.”
Once you get the flaw-free extraction, by converting to SHN/FLAC you’ll skip having to do another extraction. Most flaws are introduced to recordings during the DAE (Digital Audio Extraction), I also believe extraction may be more wearing on your drive than simply copying file but I could be wrong about that one. Once you have the flaw-free extraction converting to SHN/FLAC mean you won’t have to do the extraction again if you need to burn another CD. Just convert the SHN/FLAC back to WAV and burn. As an added bonus you can have MD5 verification files so you can quickly verify the Compressed file is accurate before decoding and burning.
Another benefit to having archived to a Compressed format is that you will likely be able to fit a two disc show on one disc for the archive. I have several two discs show that for my archive/back-up are compressed in a loss-less format to one disc.
There are several benefits. But regardless it is always wise to have a back-up copy incase your original is unavailable (i.e. stolen, lost, broken, or just defunct for one reason or another). If you don’t back-up to a Compressed format then yes back-up to an Audio format. Another good back-up is having as many people as possible have a copy, trade, trade, trade. Then if you lose something the chances of getting it back are increased.
“Another popular misconception is that digital errors and artifacts come from "bad burns", and that you shouldn't burn at high speeds, etc. The fact is that virtually all errors in copying are created during *extraction*, not burning. With this in mind, as Tony said, when you copy an SHN CDR, you are merely copying data, but when you copy an audio CDR, you are extracting digital audio...a much more fragile process.”
- store discs carefully (both blank and those that have been burned)
- share copies widely - treat the trading community as an extended backup service :-)”
I also found these other comments with links . . .
“sorry to burst your bubble but CDRIDENTIFIER NOR ANY TOOL THAT READS THE DISC "ATIP" AREA FOR MANUFACTURER INFO SHOULD BE RELIED ON TO IDENTIFY DISCS WITHOUT OTHER EVIDENCE TO REINFORCE YOUR CONCLUSION....
read on to learn more about CDRidentifier & similar tools, like the function built-into "plextools" (or whatever it is called)
http://www.cdrfaq.org/faq02.html#S2-38
http://www.cdrfaq.org/faq02.html#S2-33
unfortunately you cannot take the info that you get from that type of program as 100% reliable...it can be wrong regarding the dye type, & the manufacturer etc....some reasons for this are given at the links above...another reason is that the information as to who makes what is no longer publicly available, and that the programs that make the identifications do so based on old information which at one time was freely available to the public
i've found that the info is usually correct, or at least helpful in identifying something....but i also try to find other evidence of my eyes examining the discs, reading on the 'net regarding what the dyes look like or documentation that discusses what brands are sourced by who (hard to find, although quite a bit is at CDRMEDIAWORLD), etc b4 i decide whether to believe the info read from the ATIP
mike richter's CDRPRIMER is another good source for learning about this kind of stuff
http://www.mrichter.com/cdr/primer/primer.htm
http://www.mrichter.com/cdr/primer/blanks.htm
some specific comments on a CD-R techie list discussing the use of a CDRIDENTIFIER type utility reinforce this bad news:
"There are two basic problems here - though the idea is sound. First, the identification on the disc is not definitive. What is read is at best the name written to the master from which the stamper was made which was then used to create the blanks. I trust that some major manufacturers control the use of those masters and stampers to ensure that their name does not show up where it shouldn't, but that's not true for all hardware or all names. So you may well read a name there which signifies nothing.
Second, the translation from what's written into the ATIP into the brand name is now encoded - and there's a fee for retrieving it. That's why the programmer of CD-R Identifier has dropped the product (though it can still be retrieved from his site without support). Old stampers will still translate, but that won't hold much longer.
All you can count on is that if two discs have *different* values in the ATIP, they were not made with the same stamper and are likely to perform differently. If two agree, there's a chance that they'll match, but no more than that."
one way to be sure that your discs are Taiyo-Yuden made though is to just look at the inner circle.....for all T-Y's that i've seen, the inner circle of discs are slightly "frosty" looking rather than being a clear inner ring, and they have a 13 character alphanumeric serial number stamped across the inner ring of each disc in a straight line rather than a semi-circular fashion which most manufacturer's use
of course this could change as the manufacturers do different things over time, and it is tough to keep up with it all (TDKs used to be my favorite brand when they made their own media, which seems like ages ago).....for now i try to buy media made in japan, & avoid the media made in taiwan”
Some other interesting quotes I ran across . . .
http://www.mrichter.com/cdr/primer/primer.htm
Most of what you 'hear' about CD-R is false
What was true yesterday may be false today; what is scheduled for tomorrow may never happen
The most common cause of failure in writing CDs is the action or inaction of the operator
http://www.cdrfaq.org/faq02.html#S2-38
Subject: [2-38] What's an ATIP?
(2002/12/11)
ATIP is an acronym for Absolute Time In Pregroove. All CD-R and CD-RW discs have a pre-cut spiral groove that wobbles slightly. The groove keeps the write head tracking properly, and the wobble (sinusoidal with a frequency of 22.05KHz) provides timing information to the recorder. The wobble is frequency-modulated with a +/-1KHz signal, which creates an absolute time clocking signal, known as the Absolute Time In Pregroove (ATIP).
In the lead-in area, which is at the start of the disc, the ATIP signal can be read to get some information about the disc. The only really useful bit of information is the number of blocks on the disc, which is determined by the length of the pre-formed groove.
The ATIP signal also holds some information about the disc's construction and manufacturer, but see section (2-33) for some comments about their usefulness. http://www.orangeforum.or.jp/e/reference/index.htm used to have ATIP information, but the "Disc Identification Method" link is now password-protected.
http://www.cdrfaq.org/faq02.html#S2-33
Subject: [2-33] Who *really* made this CD-R blank?
(2000/09/03)
Many of the "big name" media manufacturers don't actually make their own media. Instead, they buy from other manufacturers and stamp their logo on the discs. Generally speaking, this isn't a bad thing, because the discs were certified good enough that the Big Brand was willing to put the company name behind the product.
If you have a picky recorder or player, though, it helps to be able to try several different pieces of media. If you buy several different brands, and they're all coming from the same manufacturer, chances are they'll all behave the same way, and your time and money will be wasted.
So... how do you tell who really made a piece of media? The short answer is: you don't.
It's tempting to believe that CD-R media identifier applications (e.g. section (6-2-9)) will give you the answer you need. Unfortunately, the data you get is unreliable at best. Charles Palmer, from cd-recordable.com, had this to say about the manufacturer identification:
"Two components that many users of these programs always take as gospel are Media Manufacturer and Dye Data. These two readings are next to worthless. The reason for this is that many CD-R manufacturers (like CD-Recordable.com) purchase their stampers (the nickel die that all CD-R substrates are molded from) from 3rd party sources. These 3rd party sources (either other disc manufacturers, or mastering houses) encode the data that these 'Identification' programs read, at the time that the original glass master is encoded. The 'Manufacturer' information that is encoded is usually the name of the company that made the master. Since stampers made from that master will be sold to disc manufacturers the world over, all of discs that those manufacturers produce from those stampers will contain the same 'Manufacturer' information. Information which is obviously quite erroneous and irrelevant. Very seldom will the 'manufacturer' information encoded on a CD-R actually tell you anything other than who made the original master. [...]
The second piece of data (the dye type) is also dubious. Because most master/stamper configurations are designed to be matched to specific dye types (Phthalocyanine, Cyanine, Azo, Etc), the 'Dye' information that is encoded when the master is produced indicates the type of dye that the master was designed for. This of course, does not assure that the manufacturer that buys and uses this stamper will be using it with the dye that it has been designed for. It is quite possible that a stamper/dye combination is used by a CD-R manufacturer that contradicts the 'dye' information encoded on the master. Therefore that information becomes as potentially misleading as the 'Manufacturer' data discussed earlier."
The only reliable piece of information in the "ATIP" region is the disc length. See section (2-38) for further remarks.
Given all this various information, I still periodically use the CD Identifier and I always buy Made In Japan Media.
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