Jump to content

Laser rot, anyone?


Christiern

Recommended Posts

I just read a disturbing exchange on Steve Hoffman's board. As one whose fairly large LaserFisc collection succumbed to laser rot, I am disturbed by to learn that CDs may be suffering the same fate.

Here's a link to the discussion.

I'd be curious to hear from anyone here who has had (or heard of) this experience with CDs.

Link to comment
Share on other sites

I just read a disturbing exchange on Steve Hoffman's board. As one whose fairly large LaserFisc collection succumbed to laser rot, I am disturbed by to learn that CDs may be suffering the same fate.

Here's a link to the discussion.

I'd be curious to hear from anyone here who has had (or heard of) this experience with CDs.

Probably the same old story told on the Hyperion site - scroll and click on "bronzing". BRONZING I had some problems with discs manufactured at the plant mentioned and some from an Italian plant.

AFAIK, these problems were all caused by using the laserdisc formulations.

Link to comment
Share on other sites

I've been buying CDs prolifically since 1983 and have over the last few months gone through virtually my entire collection in creating an itunes music library. I only found two CDs that would not play, and one of those, I believe, was defective when I purchased it.

Link to comment
Share on other sites

I don't know if I'd use the word "common", but this is a known problem in the library/archives field. For this reason, archival masters (if stored on optical discs) are often commited to gold CD-Rs; the thought being that gold is closer to inert than aluminum and, thus, will take a great deal longer to react with the other substances among the disc: the plastic (Polycarbonate), the binder (adhesive), etc. Also, in the event of a colored disc, any dyes or pigments that might be involved as well.

Some links:

The NIST guide from 2003 includes a pretty good introcuction to the many components, layers, and competing substances among varying optical disc media.

There's also this site. I can't speak to its legitimacy, but it did inspire this article in 2004 so...

To Chuck's point, here's a list of comercially issued CDs known to exhibit bronzing. And like he said, all are European.

A Google search for "CD rot" will bring up a lot of hits...but read them at your own risk.

Link to comment
Share on other sites

I had one of the bronzing Hyperion CDs in question, and got a replacement - the problem was known to the label and stopped their cooperation with that pressing plant.

I have one other, which is Italian and just looks very transparent - but like vinyl, one doesn't expect thes discs to last forever .........

But these are the only defective CDs among several thousand.

Link to comment
Share on other sites

Probably the same old story told on the Hyperion site - scroll and click on "bronzing".  BRONZING I had some problems with discs manufactured at the plant mentioned and some from an Italian plant.

AFAIK, these problems were all caused by using the laserdisc formulations.

The only CD from my collection (2000+ discs, about 200 from the 80's) to have this effect was indeed a Hyperion release. I received replacement discs as soon as I reported the problem, 10 years after the purchase.

So, so far I had no CD loss though natural degradation.

I wish CD-Rs were that reliable. I had a batch of Fuji CD-Rs with Emusic downloads which became partly unreadable after just 3 years.

Edited by Claude
Link to comment
Share on other sites

I had one of the bronzing Hyperion CDs in question, and got a replacement - the problem was known to the label and stopped their cooperation with that pressing plant.

I have one other, which is Italian and just looks very transparent - but like vinyl, one doesn't expect thes discs to last forever .........

But these are the only defective CDs among several thousand.

Vinyl is actually pretty strong by comparison...barring any enviromnetal or structural dammage, that is. Shellac, though, is the ultimate workhorse, in terms of stability. One of the worst media is actually DAT. The shelf-life on those can sometimes be little more than a decade. I find that, despite much of our collection being 1/4" open reel tape, the DATs are in at least as much danger, as far as degradation is concerned.

Link to comment
Share on other sites

I had one of the bronzing Hyperion CDs in question, and got a replacement - the problem was known to the label and stopped their cooperation with that pressing plant.

I have one other, which is Italian and just looks very transparent - but like vinyl, one doesn't expect thes discs to last forever .........

But these are the only defective CDs among several thousand.

Vinyl is actually pretty strong by comparison...barring any enviromnetal or structural dammage, that is. Shellac, though, is the ultimate workhorse, in terms of stability. One of the worst media is actually DAT. The shelf-life on those can sometimes be little more than a decade. I find that, despite much of our collection being 1/4" open reel tape, the DATs are in at least as much danger, as far as degradation is concerned.

Is shellac less prone to warp-age? Is that why it noses out vinyl?

Link to comment
Share on other sites

Is shellac less prone to warp-age?  Is that why it noses out vinyl?

The quick and dirty answer is yes. Environmental conditions (read: heat) are the primary causes of warping. The others are [1] prolonged diagonal storage and [2] prolonged storage in horizontal piles. Basiaclly, storage in situations involving either uneven and prolonged support or uneven and prolonged pressure.

Something else to consider, though it's more of an institutional worry: discs should be rotated at regular intervals so as to avoid prolonged pressure on any one point along the perimeter of the disc. Not doing so can result in a kind of warping, rippled in appreance.

Under reasonable storage conditions (temp, RH, etc.) both formats should last a very long time. Shellac, I would argue, is better suited to handle heat...the most immediate cause of warping.

[EDIT: Of course, that answer only addressed warping. The other thought, as I understand it, is that there are fewer potential chemical reactions in a shellac-based disc than polyvinyl chloride. This is significant when considering the types of degradation that occur when discs are indeed stored under recommended archival conditions.]

Edited by Brandon Burke
Link to comment
Share on other sites

I have found cd rot in many of my cds. These were mostly (if not all) classical cds, and generally can be traced to a polygram-related pressing plant in Germany in the 1980s (e.g. for London/Decca, DG, etc.). This is apparently a documented case, and Polygram was willing to entertain a replacement for faulty cds.

Shit, despite the advertising, CDs aren't really perfect sound forever. My LPs from further back are still in fine condition, provided they haven't been abused.

Hock

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...