How Long do they last? Cd's and Cd-r's

[Jazztropic]

I have transfered some rare lp's to cd for ease of play and , well lp's can be a hassle sometimes.I want to maybe get some money out of the lp's but I am not sure how long the cdr's will last as compared to factory made cds.Since these lp's will most likely never be released on cd I do not want to take a chance.Anyone have a good answere or some incite on this subject?

thanks

Edited February 3, 2004 by Jazztropic

[Brandon Burke]

There is no way to accurately predict the lifespan of such new media without the use of accelerated aging, which is highly problematic. All that it really tells you is what happens to an object when you put in the environment you subjected it to in order to simulate "real" aging. The first generation of pre-recorded CDs are now suffering from a condition called "bronzing". This is due to the degradation of the metal layer. Most modern CDs (not CD-Rs) are thought to last anywhere from 10-50 years. I'm leaning toward 30-40. CD-Rs are manufactured in a different way. Also, if I remember right (my documentation is at the office), it takes a slightly different type of metal to melt at the temperature of the lasers used in CD burners. As such, it's a metal with more *give*. I've heard that CD-Rs last between 10-50 years as well but I'm thinking it's on the shorter side of that spectrum. There are CD-Rs made with a gold layer--this is discussed elsewhere on the board--because gold is almost completely inert and will show signs of degradation at a much slower rate. It is thought that they will last 100 years and they are the standard in music/sound archives when documents are digitized.

Keep your LPs. Vinyl and shellac--kept in a sound archival environment (40-70 F, 30-50% RH)--will last a very long time. They are the two most structurably stable environments upon which audio documents have been housed.

Edited March 4, 2004 by Brandon Burke

[JohnJ]

All I can say is that the CD's I bought twenty years ago still work perfectly.

[wesbed]

All I can say is that the CD's I bought twenty years ago still work perfectly.

I purchased Steely Dan's Gaucho on CD in 1985. It was my first CD purchase. It still looks and plays the same in 2004 as it did in 1985. Yes, nearly 20 years.

However, an Ella songbook CD I purchased in the late 1980s is now clear. You can see straight through the clear plastic. There is no remaining digital code to produce sound or tracking on the CD. I keep it just because it's strange... but I'd rather have the sound back on the CD.

Edited March 4, 2004 by wesbed

[Brandon Burke]

All I can say is that the CD's I bought twenty years ago still work perfectly.

Most of them do. Either way, it's 'known' problem in preservation circles and recognized as such by organizations like the Library of Congress and ARSC. Also, I'm not talking about (then) new copies of True Stories by the Talking Heads. I mean earlier CDs that were primarily used to house non-music data.

[Brandon Burke]

All I can say is that the CD's I bought twenty years ago still work perfectly.

I purchased Steely Dan's Gaucho on CD in 1985. It was my first CD purchase. It still looks and plays the same in 2004 as it did in 1985. Yes, nearly 20 years.

However, an Ella songbook CD I purchased in the late 1980s is now clear. You can see straight through the clear plastic. There is no remaining digital code to produce sound or tracking on the CD. I keep it just because it's strange... but I'd rather have the sound back on the CD.

Interesting. I'm not familiar with the metal layer of a CD disappearing outright. I'll have to ask around. (That'll give me something fun to do at work tomorrow.)

Do you mean to say that nothing but the ink has survived?

[wesbed]

Do you mean to say that nothing but the ink has survived?

I don't remember exactly. I've not examined the CD in a few years. If my memory is correct, it seems like the ink label is still intact. But the coding on the CD, where the see-through metallic-type layer should be, is gone. Only clear plastic remains.

It sort of faded slowly, over a number of years, starting at the outside of the CD and moving to the inside. I remember when I could play the first 3/4 of the CD, then only the first 1/2, then just the first 1/3. The last I checked, there was nothing left.

It caused me to wonder, several years ago, just how long a CD's life-expectancy would be.

Edited March 4, 2004 by wesbed

[Brandon Burke]

It caused me to wonder, several years ago, just how long a CD's life-expectancy would be.

You're not alone.

[rockefeller center]

A very practical way to archive music is to convert the wav into the lossless .shn format (which size is 50-70% of the original wav) and store it on hard disk. If my calculation is right, you can store over 500 hours of music in .shn format on a 160GB hard disk.

Unlike with CD-Rs, it's also very easy to make backups.

[Philip]

All I can say is that the CD's I bought twenty years ago still work perfectly.

I purchased Steely Dan's Gaucho on CD in 1985. It was my first CD purchase. It still looks and plays the same in 2004 as it did in 1985. Yes, nearly 20 years.

However, an Ella songbook CD I purchased in the late 1980s is now clear. You can see straight through the clear plastic. There is no remaining digital code to produce sound or tracking on the CD. I keep it just because it's strange... but I'd rather have the sound back on the CD.

Given where you live Wesbed, it must be humidity which caused the problem with the Ella CD.

[rockefeller center]

All I can say is that the CD's I bought twenty years ago still work perfectly.

I purchased Steely Dan's Gaucho on CD in 1985. It was my first CD purchase. It still looks and plays the same in 2004 as it did in 1985. Yes, nearly 20 years.

However, an Ella songbook CD I purchased in the late 1980s is now clear. You can see straight through the clear plastic. There is no remaining digital code to produce sound or tracking on the CD. I keep it just because it's strange... but I'd rather have the sound back on the CD.

Given where you live Wesbed, it must be humidity which caused the problem with the Ella CD.

If it must be the humidity, why is the Steely Dan CD still playing? There are many factors which have to be taken into account.

[connoisseur series500]

Tell you what, though.

Our collections will obviously not last forever. This is the big lesson I am getting out of reading this thread.

And here I've gone after a lot of older oop stuff with the age clock already ticking on them.

I better start listening to my collection!

[LAL]

Some more information, from a website on ancestry & genealogy:

(May be a good idea to backup favourite discs manufactured in the 80s in case they are the 'defective' ones)

Issues Affecting Physical Longevity

Because they are sturdier than floppy discs and magnetic tape, most people tend to think of CDs (CD-ROMs) as inert objects. Barring scratches, they should last forever, right? Maybe not.

CD-ROMs made when the technology was new in the early 1980s had problems with the protective lacquer coating not fully covering the disc. Aluminum can easily oxidize and when the lacquer did not cover the entire disc, the oxidation would eventually cause the disc to be unusable (except as a coaster). The early CD-ROMs also were labeled with inks that eventually reacted with the aluminum, which also caused the discs to fail.

Fortunately, CD manufacturers realized what was happening and made changes in the manufacturing process to ensure better lacquer coverage, and stopped using chemically reactive dyes. (CD-Rs use metals such as gold that do not oxidize.) But there continue to be issues affecting the physical longevity of a CD.

According to the technical pages of several CD manufacturers and trade associations, estimates vary widely as to the expected longevity of the media:

CD-ROMs are estimated to last anywhere from 30 to 200 years.

CD-Rs, before they are recorded, have an estimated shelf life of five to ten years.

CD-Rs, after recording, are estimated to last between 70 and 200 years.

CD-RWs are expected to last at least 30 years.

Because CD technology is only about twenty years old (and recordable technology is younger than that), these expected life spans are estimates based on accelerated aging tests. As the testers at Kodak put it, chances are that if there is a significant error, the disc won’t work. Either it works or it doesn’t.

How the discs are handled and stored can greatly affect their longevity. CD-Rs, with their dye layer, are especially prone to light. Leaving them on a desk can lessen the dye’s reactivity when passed through the recorder’s laser beam. The dye’s chemical state also makes for the shorter life span before they are recorded. As time goes on, the dye loses its ability to change from transparent to opaque. In other words, if you are only going to use one every six months, do not buy the 50-pack at your local warehouse club.

CD-RWs have a similar problem with their alloy layer. After so many recordings and erasures, the alloy loses its ability to change from one state to another. This is estimated to occur around the 1,000th recording.

There are many things that the user does that can shorten a disc’s life. Fingerprints and scratches are the most common. It is especially important that writable CDs not have fingerprints on them before they are written, as the fingerprint can scatter the laser beam from the recorder or weaken the ability of it to change the dye or alloy. In this case, the data can be jumbled or not be recorded at all—both of which can result in an unusable disc.

Genealogists are becoming more aware of proper methods of writing on photographs and in scrapbooks, including using acid-free pens. The same advice should be heeded when labeling CDs. As noted previously, early CD-ROMs had inks in the labels that ate away at the disc. The same can happen if the user writes on a disc with a solvent-based marker. Water-based permanent markers are preferred. Ball-point pens should be avoided, as they can cause a scratch that shows through the reflective layer. For safest results, writing should be kept to the clear center portion of the disc.

Stickers should be used only with the greatest of care. Labels that are applied off-center or with air bubbles and creases can cause the disc to spin out-of-balance. This is especially harmful in high-speed recorders and readers. Removing a label can also damage the disc’s surface, rendering it useless.

Temperature can act upon the longevity of a CD. Several of the accelerated aging tests used 25ºC (77ºF) with 40 percent relative humidity as a baseline. Cooler, drier conditions should be beneficial. Conversely, warmer and damper conditions are a detriment.

Wide fluctuations in these conditions are harmful. These conditions can occur when you leave discs in the back seat of your car in July while you are reading or in the trunk in the middle of winter when you are in the library.

[Claude]

CD-Rs, after recording, are estimated to last between 70 and 200 years.

Thanks for this interesting article, LAL.

I think the lifetime expectancy figures above refer to optimal quality discs. With the cheapest no-name CD-Rs they may be much lower. I've had some discs become unreadable within a few years, despite optimal storage.

So for data that are supposed to be stored a long time, such as digital photos or music, it is important to use good quality CD-Rs.

[LAL]

Yep agree with using quality CD-Rs, gold ones would be the ideal.

Just wondering if anyone has used the services of companies who specialise in reproducing CDs, DVDs (only for backup purposes)? Would the quality and longevity of discs be the same as or fairly similar to the original discs? I assume they use similar machinery as CD producers. Perhaps such services are illegal in the U.S and Europe or just not available? I have seen such services advertised where I am and contemplating using them rather than burning CD-Rs on the PC.

[connoisseur series500]

Probably would be a good idea to clean out my car. I've had the same cds in there subject to extreme temperature changes for at least a year. I should be changing the cds on a daily basis and not leaving them out there.

[Kevin Bresnahan]

Yep agree with using quality CD-Rs, gold ones would be the ideal.

You missed the point about CD-Rs in the article you posted... CD-R longevity has a lot more to do with the dye than the reflective material. Gold vs. silver is more for the CD-ROM application. When buying CD-Rs, it's the dye that's important not whether it's gold or aluminum. Both metals have very high reflectivity and both will last as long as the lacquer (label-side coating) does.

BTW, when applying any longevity equations to CDs or CD-Rs, it should be noted that audio is much more forgiving to errors than data. Therefore, applications, saved documents, etc., where the ones and zeroes are unscrambled to form commands and words are much less likely to survive as long a musical performance since digital audio has better error correction.

[RDK]

Hell, 50 years from now there probably won't be any working CD players left to even play those "antiquated" round silver things.

Anyone tried to retrieve data off those "old" 6" floppy discs lately?

[LAL]

Yep agree with using quality CD-Rs, gold ones would be the ideal.

You missed the point about CD-Rs in the article you posted... CD-R longevity has a lot more to do with the dye than the reflective material. Gold vs. silver is more for the CD-ROM application. When buying CD-Rs, it's the dye that's important not whether it's gold or aluminum. Both metals have very high reflectivity and both will last as long as the lacquer (label-side coating) does.

Yep. Guess I did. Thanks for pointing that out.

[Brandon Burke]

I'm not sure that's the case. Previously recorded CDs produced for comsumers are made with a stamping process. CD-Rs are made via a burning process. The diferneces are night and day. In the case of CD-Rs, the metal layer has to be weak enough to allow a lazer to "burn" though it. Previously recorded CDs, in their own way, are not worried about this luxury. Then again, preciously recorded CDs aren't living organisms with the ability to facilitate worrying. Regardless, the metal layer is indeed important since gold is almost completely inert and will not incite reactions with any neighboring compounds. And this is to say nothing for the fact that "regular" CDs (of any sort) are not made with silver so you're comparing them with a niche of the market that's even less prevailant than gold CDs (or CD-Rs).

Your point is well taken about dyes, however, which are indeed important in this equation. But what reputable company would incorporate unecessary (and potentialy damaging) dyes?

[Kevin Bresnahan]

I'm not sure that's the case. Previously recorded CDs produced for comsumers are made with a stamping process. CD-Rs are made via a burning process. The diferneces are night and day. In the case of CD-Rs, the metal layer has to be weak enough to allow a lazer to "burn" though it.

Brandon, you've made an erroneous assumption here... there is no "burning metal" while making a CD-R. The only thing burned is the dye.

A CD-R is made the exact same way as a regular CD except that the metal layer is perfectly flat and not all pitted like a manufactured CD. After plating, the metal layer is coated, also just like a regular CD... identical in process, in fact. After they make this "blank CD", they spray on the dye and then add another protective coating. If you look at a CD-R under a microsope (at an angle or else the light could reflect back), you might get an idea.

As I said, the only thing that "burns" during the CD-R burning process is the dye. The laser in a CD burner is far too weak to do any harm to the metal.

CD-RW is an entirely different beast. This "burn" is actually mutating the metal. CD-RWs are made with a special metal layer. This metal is affected by both temperature and magnetic fields. When you "burn" a 1 into a CD-RW, it is done by magnetically modifying the metal while the laser hits it. This causes a very, very slight disruption of the metal but just enough that the readback laser (lower power BTW) does not read a fully reflected light reading. This makes playback of CD-RWs a bit more tricky. The player must be able to discriminate between a weak '0' (because the CD-RW metal has a low reflectivity to begin with) and a '1' that is very close to a '0' in light power. In essence, the laser fires at the disc and reads the reflections. If it hits a "distorted" area, it gets less reflected power. It is hits a "flat" area, it gets back as much as that metal can reflect. There is no dye in a CD-RW.

Later,

Kevin

[Kevin Bresnahan]

Your point is well taken about dyes, however, which are indeed important in this equation. But what reputable company would incorporate unecessary (and potentialy damaging) dyes?

Aye, there's the rub!

Dye is everything. Everything. It has to be able to be burned with a low power laser. It also has to stay opaque forever (if it becomes translucent with time, it won't block the readback laser). Finding the right chemical composition that does this best is what is being fought out in the CD-R industry. I am not a chemist, but I believe the dye that seems to hold out best over time is PhthaloCyanine. It is clear to the eye. The main competitor is Cyanine, which is blue in color. I usually look for "clear dye" CD-Rs because I have read that PhthaloCyanine lasts longer. Of course, the maker of CD-Rs with Cyanine dye will claim there's is better. Who's right? Time will tell.

Later,

Kevin

PS. the dyes used in CD-Rs are listed here.