General discussion

1/27/06 How long do burned CD-Rs and CD-RWs last?

Jan 25, 2006 9:54AM PST
Question:

I recently read an article by a data storage expert who claimed that burned CD-Rs and CD-RWs can be expected to last only two to five years and not a whole lot more. I personally have commercially pressed CDs from the 1980s that still play fine, but I have begun to notice that some of my burned CD-Rs are beginning to skip, or not start (player shows "no disc"), or have a strange echo that was not on the original. This sounds serious! The expert suggests that for secure long-term storage, high -quality magnetic tape is the way to go. Are any of your readers beginning to notice this problem with their burned CDs, and are there other opinions about how to combat it? Are some burnable CDs of higher quality than others? What are the best storage methods for the discs that will make them last longest?

Submitted by: Carl N. of Cottonwood, Arizona

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Answer:


Factory-pressed CDs are totally different from recordable CDs. In a pressed CD, the data is literally "molded into" (actually pressed into) the media and will not disappear unless the CD is physically damaged. Recordable CDs use a dye that changes color or reflectivity when heated. There are different dye types commonly used in recordable CDs--phthalocyanine, azo, and cyanine, in particular--and they do not all have the same life expectancy and stability.

All of the studies that I have seen except one suggest that properly burned one-time media (-R media, but not -RW media; see below) has an expected life of decades to possibly even centuries. There was a study by NIST (a U.S. government agency, used to be the National Bureau of Standards) on the relative stability of different media here:

http://www.itl.nist.gov/div895/gipwog/StabilityStudy.pdf

You can see some comparisons in the NIST study of the different dye types. But this study did not attempt to extrapolate the data to a life expectancy, although it did provide data about the relative stability of the different dyes and reflection layers behind them.

However, opinions still differ as to how long such media will last. The OSTA (Optical Storage Technology Association), in a report here:

http://www.osta.org/technology/cdqa13.htm

suggests that optical recordable media will last 50 to 200 years. This observation is backed by quite a number of studies that I have seen done both by the media makers and others. However, some storage experts suggest numbers more in line with your question, for example the expert in this report suggests a life of only 2 to 5 years:

http://blog.eogn.com/eastmans_online_genealogy/2006/01/life_expectancy.html (I have a suspicion that this is the article that you read).

The bottom line is that you are not going to get one single answer that everyone agrees on, although I personally am confident that properly recorded CD-R media can last decades if not a century or two. These 3 articles provide a good starting point for understanding some of the variables involved, which include:

-Dye type
-Physical construction of the media
-Storage conditions (temperature, humidity, light exposure, mechanical stress, chemical exposure and air quality)
-Manufacturing conditions (can vary from batch to batch in otherwise identical media of the same brand)

Now let?s mention some other things that are relevant and important:

-The quality of the burner. A borderline defective burner can ?under expose? the media to the laser beam, producing a seemingly good recording (at the time of burning) that will ?fade? over time (failing weeks, months, years or decades sooner than it should have had the laser beam intensity been correct)
-Recording speed. Fast burns (52X) are probably less stable than somewhat slower burns (say 16x to 32x), but you can burn media too slowly also. There is a very good analogy here to photographic film and exposure levels. The dyes on a given media have a certain range of acceptable ?exposures? and outside of that range, you can either under or over expose the media to the laser beam. However, mechanical jitter and certain other variables (largely a function of the quality of the drive) generally will be unconditionally worse at faster speeds.
-Your own handling and storage practices. On a CD, the data ?exists? in a dye layer on the label side of the media. This can be scratched from the back (from the label side), which will literally and directly destroy the data. The front side is clear plastic but can also be scratched. While front side damage may make the data less readable or completely unreadable, the data is still intact and undamaged on the label side, and the scratches on the front can normally be removed by polishing the plastic. On recordable DVDs, the data is on a layer ?inside? the media, but the media is a laminate of several layers and can delaminate, destroying the data. Flexing ? even VERY minor flexing ? is particularly bad at causing such damage. And, also, recordable DVDs tend to fail from the outside in, so you can increase your success rate and decrease the incidence of failures by not recording such media beyond 80% to 90% of capacity, leaving the outside edge, where the failure rate is greatest and failure occurs first, blank anyway.

-Labeling: The glues in adhesive labels, or the solvents in pen-type markers, both applied to the label side (the side containing the data) can SLOWLY penetrate the reflective backing and dye layers and destroy the data. Therefore, for archival media, the safest policy is to not label the CD or DVD itself at all. If you do label it, with either a label or a pen, you are, at best, taking a chance with your data (hint: it is safe to write on the clear inner hub (where there is no data at all) with a suitable pen that won?t rub off).

And, finally, I would be remiss if I did not mention one other factor which is really huge: Eraseable ?RW? media is FAR less stable than one-time (?R?) media and should absolutely not be used for any permanent recordings of any kind whatsoever. There is no question that RW media can and does ?fade?. Although I?ve never seen failure of ?R? media that I could attribute with absolute certainty to dye instability, I routinely see ?RW? recordings that are unreadable after periods of months to a year or two when there is really no other explanation for the failure. I see this both on CD-RW and DVD+/-RW media, and I advise people in the strongest possible terms not to use ?RW? media for anything that they want to consider permanent. Since RW media is also both more expensive (a lot more expensive) and slower, from my perspective the decision to never even buy RW media at all is an easy one from my perspective.

Submitted by: Barry W. of North Canton, OH

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Comments
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CD life
Feb 6, 2006 9:19PM PST

Two questions:

1. How did you store the CDs?

2. What do you mean by "it's the same for MP3"?

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DVD-RAM
Jan 27, 2006 3:39PM PST

I have a DVD RAM Panasonic recoder and find the system very easy to use, producing superb copies of my old archived concerts of VHS material, and new off air stuff.

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Panasonic DVD RAM Recorders
Feb 25, 2006 11:03AM PST

I have TWO Panasonic DVD RAM Recorders and can certainly recommend this type of recorder. I have recorded over 1000 TV programs on the RAM Disks and the only problem I have had is that a DVD Head Cleaner must be used after continuous recording.You will know when cleaning is required as the picture tends toward fuzziness.

Any program is very easily erased from the RAM disk and re-recording on the same disk is quite simple. Just handle the disks with a little care.

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How long to burned CD-Rs and CD-RWs last?
Jan 26, 2006 6:54PM PST

In response to the question, what other media can be used for long-term storage, I would say the best options are either mini disc or DAT: I've had some minidiscs nearly ten years that are perfectly stable, whereas some CDs that are only two to three years old are already corrupting. If it's truly valuable to you, don't store on CD!

The compression ratio for DAT tape is much less severe than either Cd or minidisc, allowing a more 'natural' or 'faithful' sound or reproduction. The best medium, though, is probably high-grade magnetic tape, although you will need a high-speed tape recorder, ideally something like a Revox in good condition, and getting the tape can be a problem. I think this question corelates to the old vinyl/CD debate, where the purists insist that vinyl is the real deal, and CD an inferior storage medium. It all depends to what lengths you are prepared to go to store and reproduce music - vinyl is 'best', but to reproduce it you need good and often costly equipment that is high-maintenance. Magnetic tape is also non cost-effective and needs to be stored correctly. There's no free lunch with any of this, but cheap writable CDs are clearly not going to offer long-term stability.

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How long to burned CD-Rs and CD-RWs last?
Jan 26, 2006 8:00PM PST

crispianduck ~ HALLALUUAH!!! I've met another person that USES and BELIEVES in MINIDISCS!!!!
I know..it sounds like I'm a 'Lone Duck' on a target range here...but....You and I are a minority...when it comes to the so-called 'out-dated' minidisc.
I, as you, have recorded and still record with the minidisc hardware..ie..discs, player/recorder, etc,for well over 10 years and I POSITIVLEY can say that NONE of my recordings have lost any of their sound quality over this period.
I would venture to say that, in this forum, there are MANY that don't know what a 'minidisc' is ...nor have they ever seen one! Sony was waaay ahead of its time when they introduced this format for recording, and they truly knew what they were doing/up against when they began marketing them. I've had many people come into my recording studio and ask what ''that little disc'' is. I am not affiliated in any way with Sony nor ANY company, but I must say that once I begin talking and explaining to these 'newbies' about a format that came out some 10 years ago,has an encased disc with the capability of the same digital recording time as a 'full-size' CD, has no chance of getting scratched, never needs cleaning,can be re-corded hundreds of times, has the incredible feature of moving data (music) around on the disc, etc, etc, they are so impressed that they wonder why they have never heard of it!!
I'm sorry I rambled on this topic for so long, but when it comes to something that a person loves and it has PROVEN itself in the long haul...since THAT is what Carl N. is asking with his question about LONGEVITY of data on discs...I just couldn't help but rave about something I, as YOU, Chrispianduck, have EXPERIENCE with!!

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Minidisc is King!
Jan 26, 2006 11:09PM PST

The thing that does my head in, Sunsound 2, is that both DAT, and now minidisc, fell from favour because they could not be marketed as pre-recorded albums! All that money spent researching and developing a great digital storage medium, only for it to be dropped almost before it had had a chance to prove itself, with almost as little ceremony as the poor DCC (digital compact cassette)! I entirely agree with you about minidiscs - they are the most stable, most user-friendly medium out there, as you can move tracks around in any order you like, you can edit out gaps, and all in complete safety, as, like you say, the surface is protected by the disc's casing.

I suspect the real problem is that the average lay person doesn't want the hassle of a medium that was really intended, initially, to give DAT a run for its money in recording facilities, and to be used in field-recording by journalists. The problem essentially was that it was TOO GOOD! I.e., too complicated for people who don't actually care about the niceties of the medium, they basically want ease of use, which CD certainly gives you. It just doesn't offer much else of use! Ah well. It's good to know I'm not the only one out there who laments the decline of this great medium. Thanks!

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I too like minidisc, but not sony
Jan 27, 2006 1:01AM PST

The problem with minidisc is that they could have made a great removable media format, but sony chose not to let you use them that way, until very recently. The problem was not the technology, but the fact that sony was most concerned with protecting its copyrights. Inevitably, they gave in, but far too late, and minidsics are still hampered by forcing you to use their proprietary sonicstage software. I have bought three minidiscs over the years, but the only one I didn't return to the store is the oldest one. While it cannot hook up directly to a computer (expect via 1/8 inch stereo connectors), it does allow you to record music directly inputted to the device, something most minidisc players these days don't do. Way to go, sony.

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Minidisc Heaven
Jan 27, 2006 1:47AM PST

In the summer of 2000 I first fell in love with the Minidisc. It was a beautiful summer day, I had gone to Sport Check to buy a pair of roller blades, my last pair being roller balls. While agonizing over which pair I should get I decided to return my 3 week old 4 time broken MP3 player to the local London Drugs, this time for a full refund.

Then I went to Future Shop to see what they had, and I found my first Minidisc player, nothing else in my whole life, except vinyl, has brought me so much joy. The ability to move music around at a whim, to be able to delete the first little bit of silence, or the last little bit of silence.

Since my first Minidisc I have purchased one more, not because the other one broke, but because it came with a cool remote control. Since then they have come out with NetMD and Hi-MD, but I have yet to encounter a problem with my 2nd MD from the summer 0f '02 so I have decided not to get a new one yet. My original MD I gave to a friend who is a musician and he has benefited from it for the past 3 and a half years.

Sorry for my partial life story everyone, but I am trying to make a point that MiniDisc is the way to go. I still belive in MiniDisc and believe that it will make a come back, hopefully just like Vinyl.

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ZIP disk
Jan 27, 2006 9:35AM PST

ZIP disks are way better than CDs...they hold 50MB more and are much faster and wont get scratched. and they are relible and can be erased and written to as many times as you want and should last 30+ years.

i wish theyd sell music on them...

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RE: zip disks
Jan 27, 2006 2:40PM PST

I am extremely disappointed in Zip Disks - got a zip drive on a computer about 5 or 6 yrs ago - the DISK failed (drive still works) - with a LOT of info on it that I was using as backup - however I just had just taken all that info off my hard drive so it was then all LOST. Will never rely on one of those again!! Even went as far as sending it out to try to have one of those companies restore the info - for MUCH too much money, and VERY little success.

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hmmm...
Jan 27, 2006 5:10PM PST

i bought my zip drive after reading so many good things about them and they seem to be pretty good...

maybe i should do some more reserch befor i trust them to hold anything extrememly important...

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Zip drive
Jan 28, 2006 3:30AM PST

I too have a zip drive that came with my first computer 9 years ago. I have never had any problems with it and it's in my third computer now. I have some 40+ discs and it's getting harder to find them on sale like I used to do. Mine are 100mb discs and cannot hold very many RAW CR2 files so I mainly just save smaller good stuff on them.

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ZIP disks
Jan 29, 2006 8:45PM PST

I had similar problems with a ZIP drive. I used only name brand media (SONY and Verbatim). Sometimes the drive wouldn't even recognize that a disk was inserted. Thank heavens writable CD drives got cheap enough for an alternative.

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Zip disks are junk
Feb 16, 2006 2:17AM PST

I am the tech guy at the school district I live in and we have tried to use Zip Disks as a backup media with very poor success rates. We have had some older 100mb drives/disks and now have 2 of the 750MB drives and have had enourmous trouble with disk readibility. It seems like we go through more of those disks all the time because they drive won't read them when we go to backup. I hate to think what kind of situation we'd be in if we needed something off of them.

At about $13-$15 for a 750mb IOMEGA disk they are no bargain either. That's $0.0186/mb. Prices of cd's range greatly, but I know I've bought CD-R HP media in bulk for $0.175/disk = $0.00025/mb. That makes the zip disk cost about 74 times what the cd cost. Even if you consider a cd might cost twice this, at $0.35/disk that puts cost at $0.0005/mb, making the zip disk still 37 times more expensive.


DVD+/-R runs about $30-40/100 pack = $0.40/disk = $0.0000831/mb. This makes dvd media even a much better deal, and the zip disk even more rediculous at about 223 times the cost of a DVD.

I realize that a zip disk is of course re-writable and cd-r/dvd-r media is not, but with such a low cost you can use 74 cd's, or 223 dvd's for every one zip disk you would have used and still arrive at the same cost. A person could explore the notion of using RW media, which is higher priced, but the reialiability is lower.

If cd/dvd media is properly stored and cared for it will have a long enough viable lifespan for back up material, as backup material is often re-created regularly, hopefully daily.

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Sounds like a very familiar story
Jan 27, 2006 7:31PM PST

Wasn't it Sony who also produced the 'Beta' video format.
I rememeber seeing Minidisk advertised on a train in Japan in 1994, and this was the first and last I heard of it.

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Are all CDs crap then?
Jan 26, 2006 8:56PM PST

This is very disapointing news. If the life expectancy of burned CDs is that short then we're being ripped off on every level. I have bought licensed CDs from the store with the music on them and have had them wear out already, even after careful handleing. It's my personal opinion and experience that the label side of all CDs is far more fragile than the clear side as well. Accidently drop that CD and if the label side gets scratched say good by to any data that was there.

Are DVDs any different? If not better say all those VHS tapes people, we've been taken for a ride.

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Return the store bought
Jan 26, 2006 10:43PM PST

Return the store bought defective CDs! I notice that people do not demand quality or customer service as they should.
As far as homemade CDs my experience has been: find a brand that works for you, do not apply any labels, do not use colored blank media and do not burn audio/video CDs too fast. I record at 4X and have experienced problems with media recorded any faster and sometimes not right away.
Vinyl is not better than CD unless you don't play it and magnetic tape will fail faster than anything I have seen. It is flimsy, magnetic and drug across a head to access the media! Not friendly! Vinyl is subject to manufacuring defects (quite common) and you must put a needle on it. Vinyl collects dirt and debris that cannot be removed.
Taking care of recorded media is just common sense. Just don't abuse it, leave it in the sun etc etc. Back up your treasures and remember nothing lasts forever

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tape is verry reziliant.
Jan 27, 2006 10:06AM PST

we have tapes from the 70s and 80s that works and plays fine.

magnetic media is verry stable when its made right and can be expected to last 50+ years. optical could be too...but current ways of doing it are verry poor and the compaines who make them are allways trying to cut corners and make it as cheeply as possible, thus making crappy media that dosent last and wares out fast, or in some cases, dosent work at all.

moast tape mechanisems are verry gentle on the tape itself , the heads and the tape itself are verry smooth and there is virtualy no ware at all when the tape is pulled acress the head(for linear tape anyway, such as music cassettes and data tape). VHS and several other ones use a spinning head wheel wich is harder on the tape and can ware it out faster, but even then you have to play it 100s of times to ware it out. the only way tape can reely be damaged is by being exposed to strong magnetic feilds and if the reading machine "eats" the tape as it dose with some defective VCRs, but the only reason that happens is because once again...people try to make things as cheep as possible and they dont work as well as they could.

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Incorrect information
Jan 26, 2006 10:50PM PST

CD's do not inherently have ANY "compression ratio"; it is dependent on the audio file format. Over the counter audio CDs and ordinary data CDs do not use data compression at all.

Further, if we are talking about audio, tape is clearly the worst of all possibilities. Listen to the difference between tape and direct to vinyl or DDD CDs if you don't believe me.

And, magnetic tape is probably the least tolerant of all media when it comes to long-term storage.

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Tape can last longer than CDs
Jan 27, 2006 1:18AM PST

''Further, if we are talking about audio, tape is clearly the worst of all possibilities. Listen to the difference between tape and direct to vinyl or DDD CDs if you don't believe me.

And, magnetic tape is probably the least tolerant of all media when it comes to long-term storage.''

I disagree. I have tapes that are over 50 years old that play and sound fine.

''Opinions vary on how to preserve data on digital storage media, such as optical CDs and DVDs. Kurt Gerecke, a physicist and storage expert at IBM Deutschland, has his own view: If you want to avoid having to burn new CDs every few years, use magnetic tapes to store all your pictures, videos and songs for a lifetime.''

''To overcome the preservation limitations of burnable CDs, Gerecke suggests using magnetic tapes, which, he claims, can have a life span of 30 years to 100 years, depending on their quality. ''Even if magnetic tapes are also subject to degradation, they're still the superior storage media,'' he says.''

http://news.yahoo.com/s/pcworld/20060110/tc_pcworld/124312;_ylt=Ai37vcQ_9QLDd9BggQLS2aKs0NUE;_ylu=X3oDMTA3ODdxdHBhBHNlYwM5NjQ-

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Better yet
Jan 27, 2006 6:48AM PST

Simply use DVD RAM discs for precious data you want to keep for years and years. They should last 100 years and are far hardier than tape. You can also re-use/re-record on them 100,000 times. Tapes are generally good for the same 100 times of re-recording that RW CDs/DVDs are only good for.

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Tape re-recording and degradation
Jan 27, 2006 11:16AM PST

I'd say audio tape is good (well, good for tape) one recording. It degrades every time it is erased and every time it dragged across the heads.

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Tape degradation
Jan 27, 2006 2:00PM PST

Tape can degrade over time but to say it degrades every time it is played is to exaggerate. How much does it degrade? Does the 20k response degrade 1/100 of a db? I'd suggest that it is so little as not to be of a concern.

One story about Queen's "Bohemian Rhapsody" was that the tape was rewound and recorded over so many times to add all the voices that you could see through the tape. It ended up sounding fine.

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Tape audio
Jan 27, 2006 11:14AM PST

Every tape recording I have ever heard, including those made on top-of-the-line professional studio equipment, had unacceptable hiss on a system that could reproduce to 20 kHz

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Tape hiss
Jan 27, 2006 1:52PM PST

I don't know what you have listened to but Ampex recorders (350) made in the late 50s had a signal-to-noise ratio of 60 db full track. By the late 60s (model 440-B), that had increased to 70 db. You would have to be in a very, very quiet room to hear any hiss at that level. Add Dolby noise reduction and hiss is not a problem.

I don't think the Beatles recordings had any "unacceptable hiss."

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Apples to Oranges
Jan 30, 2006 1:13AM PST

60-70 dB s/n is very audibly inferior to the 80 dB you can get with direct to disc or 90 dB you can get with DDD. You can use dolby to take care of the hiss (but with some other side effects), but you'll still get saturation on the transients.

And that's with top-of-line decks and tape. Typical consumer tape was more like 40-50 dB s/n, whereas even a cheapo CD player is 80 dB.

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How little noise is enough?
Jan 30, 2006 12:28PM PST

No one can hear the difference between 70 and 80 db S/N ratio in a normal listening environment due to the background noise. Once noise is no longer audible, it does no good to lower it more! How about 100 db or 200 db!

The comment made was about tape hiss being "unacceptable."

" ...including those made on top-of-the-line professional studio equipment, had unacceptable hiss."

Now the comment is, "And that's with top-of-line decks and tape. Typical consumer tape was more like 40-50 dB s/n."

I was only speaking about professional decks and so were you. Don't know why consumer decks showed up. Not part of the discussion.

My point was that tape hiss was NOT "unacceptable" on "top-of-the-line" studio recorders. My comment about the Beatles recordings was not responded to. What recordings that they did had "unacceptable" hiss??? Are all AAD CDs unacceptable?

Recording a digital signal on magnetic recording tape may be the best archive available. I have 50 year old tapes that play fine on my Ampex recorders.

If you really want to compare apples and oranges listen to a tube Marshall stack. What do you think the S/N is on that!

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Relax
Feb 1, 2006 12:20AM PST

Ok, so I changed the subject to consumer equipment. I recommend you cut down on your coffee consumption.

And I maintain you can hear the difference between 60 and 80 dB: that's the contrast between the punch of a transient and a well-insulated studio background noise. People always use the "I can't hear the difference" argument to justify inferior performance.

And by the way, what is the substance that mysteriously appears on the recording and playback heads. Uh...could it be the tape coating? Do you really believe that makes no difference?

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Still waiting
Feb 1, 2006 11:47AM PST

Professional tape doesn't shed enough to be a problem. After the tape becomes burnished, very little continues to shed. In the usage of archive, you aren't playing a tape hundreds of time. Tape may indeed be an excellent archive medium.

"Every tape recording I have ever heard, including those made on top-of-the-line professional studio equipment, had unacceptable hiss.

Still waiting for you to point out the records made from tape that has " unacceptable hiss".

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(NT) (NT) All of them.
Feb 17, 2006 7:22AM PST

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