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I find that mold starts to develop in my CD collection. A number of CDs develop "holes" and cannot be played. They have been kept for ten years. I really miss them because they cannot be bought again.
I find very small holes on brand new SONY SACD discs. Should we control the moisture to store the collection?
It may be a good idea to make copies of CD using high quality CDR when it starts to develop mold and holes.
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Hi this subject and problem has cropped up numerous times in the last 20 years on CD. A number of different reasons are the cause....One is manufacturing fault...Another is also possibly caused by the chemicals used in the Labeling Ink..You will understand the the Label is right next to the CD layer...The other reasons are speculative,,the suggested Improvement of CD sound by putting them in a freezer was a potential disaster waiting to happen...along with chemical cleaning of the label side....leaving them in direct sunlight is suspect.
However The problem on Copy Cds ie computer burnt is far worse.
This is due to the chemical dye melting process which is the way they are produced...The variety of processes and dyes has produced frizbys in as little as a few months and they are heat sensitive....
The SACD discs have a layer somewhere near the physical centre of the disc..ie a sandwitch......to date this is the first report Ive heard of this mould on sacds....unless you have mis stated the problem....
I would suspect dvd or dvda to be more of candidate for attack than sacd....Dave
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raffells said:
Hi this subject and problem has cropped up numerous times in the last 20 years on CD. A number of different reasons are the cause....One is manufacturing fault...Another is also possibly caused by the chemicals used in the Labeling Ink..You will understand the the Label is right next to the CD layer...The other reasons are speculative,,the suggested Improvement of CD sound by putting them in a freezer was a potential disaster waiting to happen...along with chemical cleaning of the label side....leaving them in direct sunlight is suspect.
However The problem on Copy Cds ie computer burnt is far worse.
This is due to the chemical dye melting process which is the way they are produced...The variety of processes and dyes has produced frizbys in as little as a few months and they are heat sensitive....
The SACD discs have a layer somewhere near the physical centre of the disc..ie a sandwitch......to date this is the first report Ive heard of this mould on sacds....unless you have mis stated the problem....
I would suspect dvd or dvda to be more of candidate for attack than sacd....Dave
Dear Dave,
I read article about the quality of CD in Gold vs. Aluminium. It mentioned that gold oxidizes at a rate approximately 10 times slower than that of aluminum.
"Gold is more reflective and coats much more evenly than does aluminum. In practical terms, this means that during the manufacturing process, gold CDs are less susceptible to pinhole-sized errors that can plague an aluminum-made CD. In theory, a properly manufactured CD (gold OR aluminum) requires no error correction (oversampling), by the playback unit on which it is played. Compact discs made using gold are much more likely to achieve this potential of quality."
Regarding SACD, there is no mold discovered but pinholes are found on SACD manufactured by SONY. One of them is
Volodos tchaikovsky/rachmaninoff SONY Classical SH 93067
Regards,
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Hi ,,...Yep agree with Gold/alum oxidization but I am not sure that this was the analysis of pinhole failure.....The amount of degredation would be so small in a semi sealed CD...It was more likely chemically orientated....or manufacturing process going wrong.....
As for error correction on Cds....I am afraid its far more complicated than it seems......I could refer you to some brilliant articles which explain the effects of, vibration, beam deflection, lazer scatter, exterior influences ie electronics..,etc etc etc ,,D to A converters not withstanding ..
The CD player manufactures havent gone for oversampling with out a reason...
The heavy weight CD mechanism so called differnt improved sound is directly related to this... However It still produces a synthesized sound in the end,,,as do all digitalized sound processes.. The general feeling that UP sampling produces better nicer sound...If you delve into the logic/science behind this you will see that D to A chip design engineers are probably more important than the original 16 bit recording producers...you will also get strained eyesight and probably a headache.......Dave
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Post by Claude May 28, 2004 (5 of 7)
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In my collection of approximately 2000 CDs (60 SACDs), some of which are from the mid-80's, I have had only one that has become partially unreadable.
It is a 3CD set by Hyperion Records (Shostakovich - Preludes & Fugues op.87) from 1991. The last third of every CD from the set is unreadable due to increasingly frequent data errors
I guess the cause is a manufacturing error that causes the CD material to become intransparent (bronzing). This happened with CDs manufactured at a certain UK pressing plant, which changed it's manufacturing process as soon as the problem was known.
So I think this is not an issue that CD collectors should worry too much about. They should however treat the discs with care and store them well (out of direct sunlight)
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Post by zeus May 29, 2004 (6 of 7)
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Claude said:
It is a 3CD set by Hyperion Records (Shostakovich - Preludes & Fugues op.87) from 1991. The last third of every CD from the set is unreadable due to increasingly frequent data errors
The same thing happened to my set. I had the discs replaced for free. See below for details:
http://www.hyperion-records.co.uk/bronzed.asp
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Post by Castor May 29, 2004 (7 of 7)
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zeus said:
The same thing happened to my set. I had the discs replaced for free. See below for details:
http://www.hyperion-records.co.uk/bronzed.asp
The problem also occurs on ASV discs. I have just had two ASV and two Hyperion discs replaced by PDO in Blackburn, Lancashire, UK (about 10 miles from where I live!).
They are most helpful and will replace any bronzed CDs promptly. Send the faulty CDs back without cases or liner notes.
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