What is the life expectancy of magnetic tape?

91r100gs said:
I have not yet run into a VCR tape that has started to break down. Many of my self recorded tapes are from the infancy of the format. Still play probably about a third of them every few years or so.

Good for you buddy and I hope they continue to give you enjoyment :)
 
They all lose a little bit (by the laws of physics) when played, but the higher bias ones maybe have more to lose. When you play a burned CD or DVD, that is photographic film and each pass of the read LASER exposes it just a little bit more...Ironically (well maybe not), vinyl might be better than any of them.

This is not scientifically accurate. The laws of physics suggest that higher coercivity reduces the risk of magnetostrictive effects on tape, except in the cases where ferric-cobalt instability arises under physical pressure. Recordable optical media such as CD-R and DVD+/-R do not use a film. They use a dye that is physical altered under tremendous heat. Reading lasers do not provide much of any heat, and they do not affect the edge of the heat mark if the dye chemistry is stable. It is the change in angle of the reflected light off the edge of the marks that provides the data. Vinyl is prone to damage, and each playing of a vinyl record causes groove deformation by the stylus. Eventually that deformation fails to recover, even from the use of the best shaped styli, and there is an increase in short wavelength distortion and a decrease in output. There is also the problem of air-born debris being embedded in the grooves in some cases that can cause permanent or semi-permanent clicks in the medium and, since the medium is analogue, in the content.
 
I hope this is relevant. I have quite a few tapes of all sorts and I work on tape decks of all sorts, particularly 8-tracks. 8-tracks and cassettes had a bad reputation for longevity at one time. I firmly believe that this was due to poorly maintained tape decks. Back in the day they were never cleaned and damaged the tapes. My experience today is that given a properly maintained deck and a tape that is not already physically damaged even 30 or 40 year old tapes will play and record well. Even most of the old cheap pre-recorded ones. Tape that decomposes on its own is a rarity, as has been said here. It is more often damaged by a gooey tape path or being mechanically reversed without being stopped. Rewind them first if they haven't been played, Stand them on end when not in use. Clean the tape path and then don't worry.
 
This is not scientifically accurate. The laws of physics suggest that higher coercivity reduces the risk of magnetostrictive effects on tape, except in the cases where ferric-cobalt instability arises under physical pressure. Recordable optical media such as CD-R and DVD+/-R do not use a film. They use a dye that is physical altered under tremendous heat. Reading lasers do not provide much of any heat, and they do not affect the edge of the heat mark if the dye chemistry is stable. It is the change in angle of the reflected light off the edge of the marks that provides the data. Vinyl is prone to damage, and each playing of a vinyl record causes groove deformation by the stylus. Eventually that deformation fails to recover, even from the use of the best shaped styli, and there is an increase in short wavelength distortion and a decrease in output. There is also the problem of air-born debris being embedded in the grooves in some cases that can cause permanent or semi-permanent clicks in the medium and, since the medium is analogue, in the content.

I made a mistake mentioning the REASON for it rather than the reason for it.

Even if you had a material that offers no resistance to be magnetized, demagnetized and remagnetized and therefore cost nothing in the way of flux, you are still making an electric current out of it.

Like every time you run a PM motor under load, you extract some of the magnetism from the magnets, the same is true of speakers. with decent materials this take a really long time, but is still happening.
 
The magnetic pigment used in recording media, whether ferric, cobalt-modified ferric, chromium dioxide, or metal, consists of billions of crystals with a single, permanent, magnetic domain. It is never erased or reduced. The only thing that changes when recording or erasing these particles is altering the magnetic orientation to modify the patterns of the prints.
 
I have worked with the Library of Congress and several record labels for preserving and sometimes restoring magnetic tapes and even optical media. The concerned parties are very interested in preservation; but they typically lack the knowledge of manufacturing, physics, and chemistry required for a full understanding of the media they protect. In many cases, members of these organizations publish recommendations that simply reorganize and repeat what they uncovered in their research; and many misunderstandings are repeated time and again. In other cases, there is a marketing reason for publishing what amounts to nonsense--such as the article for an "IBM scientist" who claimed optical discs would last only a couple of years (he was promoting IBM magnetic cartridges)--and many "scientific" journals and publications picked up and repeated his story. In other cases, a medium manufacturer might imply that the defects in his product are inherent in all similar products. Ampex has a done a great job in spreading the "sticky tape syndrome" as a caution for all tapes when it was actually a failure on their part to do sufficient testing. Journalists too often do too little to check and verify their stories when the topic is one of frightening readers.
Exactly, and I had a Quantegy rep (who replaced some bad 227 they sold me after they bought 3M) tell me to my face that it was a selective effort by Ampex to "spread the blame". Outside of those tapes, I've had very little to no problem with any TOTL tape made before or since. Just two more cents.
 
I have Type I,II and IV tapes recorded in 1980 of my live performances that sound as good as they did the day they were made. I run into this all the time on Music forums. There's a demographic cleavage between what people's experiences were with recording tapes for cars/Walkmen (which sounded great until the tape was eaten or the shell or tape warped from heat and UV) and folks that recorded tapes and sheltered them properly. Pfeiffer's 1955 Reiner/Also Sprach is still killing it when you hear it reproduced on one of the Classic or Analog Productions SACD's, tapes or LP's. I own a fair sized library of pre-recorded Open Reel tapes and they've held up just fine. But you can't abuse them or ride around for months/years with them in your car. The early 2-tracks don't like being mishandled. But you can still play them back just fine.
 
I've never had a problem with the quality or signal retention of videotapes, but there's a definite difference between the "bargain of the week" and the tapes that cost around Eight 1985 dollars each.
The complaints I had mainly had to do with the quality of the formats themselves. But that's not Audiokarma appropriate. Videokarma, maybe...
 
This is not scientifically accurate. The laws of physics suggest that higher coercivity reduces the risk of magnetostrictive effects on tape, except in the cases where ferric-cobalt instability arises under physical pressure. Recordable optical media such as CD-R and DVD+/-R do not use a film. They use a dye that is physical altered under tremendous heat. Reading lasers do not provide much of any heat, and they do not affect the edge of the heat mark if the dye chemistry is stable. It is the change in angle of the reflected light off the edge of the marks that provides the data. Vinyl is prone to damage, and each playing of a vinyl record causes groove deformation by the stylus. Eventually that deformation fails to recover, even from the use of the best shaped styli, and there is an increase in short wavelength distortion and a decrease in output. There is also the problem of air-born debris being embedded in the grooves in some cases that can cause permanent or semi-permanent clicks in the medium and, since the medium is analogue, in the content.
And if you try really hard, while using very good to excellent gear, you might, one day, after Seventy or Eighty years, be able to discern a difference. I have Shaded Dogs from the 50's and '60's that still sound GREAT. Your average Styx record from 1979 (or any LP after the Arab Oil Embargo)? Not so much. Groove deformation can be minimized to the point of near irrelevance. What you say is unequivocally true for folks that put quarters on top of their "phonograph needle" equipped tonearms of Emerson good record players". That damage mounts up FAST.
 
Sometime in the early to late 1950s, my dad and uncle each purchased Knight "Portable" Half-track mono Reel to Reel decks. From then until 1971 when my dad passed away, they'd send a 3" reel in lieu of a letter with news of the week and a chess move. I have six of those tapes and, aside from the numerous splices from broken tape stock, they still sound fresh and clean. Now if I could just find someone in Brooklyn to deoxify the pots on my AKAI GX-4000D, I could convert them to digital.
 
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