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Posted

There are special alcohol based sprays for CD cleaning and treatment. Some are really costly. Sometimes they work wonders with skipping discs, and they can improve the soundstage, depending on your player. Many  consider this voodoo, but I trust my ears, and my wife confirmed what I was hearing during before/after comparisons. It is just 0s and 1s, but a cleaner data signal can make a difference.

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Posted
1 hour ago, Kevin Bresnahan said:

There have been several reports over the years of people washing CDs like this and having the label side and reflective layer wash away. After reading this, I stopped washing CDs. :)

Well, washing is not indicated if you have something with a glued on sticker - it will come off and screw up the reflective layer.  Most cds and dvds you get are not like that.  Washing is ok for most cds if they don't play, IMO. 

Posted
2 hours ago, mikeweil said:

There are special alcohol based sprays for CD cleaning and treatment. Some are really costly. Sometimes they work wonders with skipping discs, and they can improve the soundstage, depending on your player. Many  consider this voodoo, but I trust my ears, and my wife confirmed what I was hearing during before/after comparisons. It is just 0s and 1s, but a cleaner data signal can make a difference.

The science of the CD playback system says that this cannot be true. The 1's and 0's are converted to an analog signal. That's it. If the 1's and 0's are messed up beyond the ability of the error correction, you don't get different analog, you get no analog or noise (ticks, pops).

Posted
2 hours ago, Stompin at the Savoy said:

Well, washing is not indicated if you have something with a glued on sticker - it will come off and screw up the reflective layer.  Most cds and dvds you get are not like that.  Washing is ok for most cds if they don't play, IMO. 

Any hints on how to remove label stickers without impairing the "rest" of the CD-R? 
(A question because of my problems described in my earlier post about labels that have come detached along the outer and inner circumference(s) - but not nearly enough to allow them to be peeled off yet apparently enough to upset playability of the CDs)

Not that I have high hopes because the data layer may have become damaged anyway, but a try is a try ...

Posted

Well, I'm talking about full-size LABELS on CDs (i.e. CD-Rs). I.e. almost the same diameter as the CD itself. Price stickers (or similar) are a totally different category, and I'd guess cardboard LP sleeves (that the sticker is attached to) are MUCH less sensitive to mistreatment (with potentially dire results) than CD-R discs. :w;)

Posted
1 hour ago, Big Beat Steve said:

Well, I'm talking about full-size LABELS on CDs (i.e. CD-Rs). I.e. almost the same diameter as the CD itself. Price stickers (or similar) are a totally different category, and I'd guess cardboard LP sleeves (that the sticker is attached to) are MUCH less sensitive to mistreatment (with potentially dire results) than CD-R discs. :w;)

Those are going to be pretty tough to work with.  I suppose the best you can do is try to rip the disk as soon as you get it and keep backups in case of sticker failure...

Posted

Most solvents, alcohol, acetone etc. could damage the playback layer. The physical action of peeling it off could also affect it. I think I would use one that you'd be less unhappy damaging and trying alcohol first, acetone (some nail polish removers are pure acetone) second and see if that works.

Posted

Thanks for your suggestions. This is more or less what I was afraid the turnout would be.
Though I really cannot see how the disc that plays with that significant distortions can be ripped or copied to give better results on the disc the files are copied to.
In fact I had already tried to copy one of the affected CD-Rs via my CD burner but the burner refused to continue after the first reading step. 
The sound distortion is hard to describe but is just what it was on the occasional CD-R that had failed in the past (after a couple of years). Except that on those older CD-Rs the sound got worse towards the final tracks (indicating that data had started to fail from the outer edge towards the center) . Whereas with the CD-Rs I recently got and turned out to be bad, the sound improved towards the final tracks (without getting perfect), which to me seems to indicate that the center area where the label clearly had started to peel was affected more because the CD rotates faster when the laser reads the music data in that zone and slower as it advances towards the outer edge.

On one CD-R (that I found a bit more important to salvage, though it is no desert island CD either ;)) I tried to remove the label manually but it was only the already detached section that came off (both round the center hole and near the edges). But that neither improved nor worsened the playback sound. 

So I guess I'll at least try to make "next-generation" CD-R copies of those that are still intact. In preparation of other CD-Rs that might come my way from that source and that might be historically more important to safeguard for the future.  (Different story ... ;))

Posted

Ripping hard-to-play CD-Rs in a PC drive using Exact Audio Copy can allow you to rip that disc because it does multiple reads of problematic areas and can maybe get that data off. In my experience, it doesn't work often. I found that turning on burst mode helps but with burst mode on, you can get click-filled audio too.

Posted
20 hours ago, Kevin Bresnahan said:

The science of the CD playback system says that this cannot be true. The 1's and 0's are converted to an analog signal. That's it. If the 1's and 0's are messed up beyond the ability of the error correction, you don't get different analog, you get no analog or noise (ticks, pops).

That's the response I always get. Then please explain to me why we hear a difference. And how does error correction react to changes in the data it reads. The signal reading is improved. Like removing a fingerprint or the like.

22 minutes ago, Kevin Bresnahan said:

Ripping hard-to-play CD-Rs in a PC drive using Exact Audio Copy can allow you to rip that disc because it does multiple reads of problematic areas and can maybe get that data off. In my experience, it doesn't work often. I found that turning on burst mode helps but with burst mode on, you can get click-filled audio too.

With Exact Audio Copy you copy the flaws, too, possibly. 

Posted
39 minutes ago, mikeweil said:

That's the response I always get. Then please explain to me why we hear a difference. And how does error correction react to changes in the data it reads. The signal reading is improved. Like removing a fingerprint or the like.

The data is the data. Improving the reading of the data doesn't change the data itself, it just makes it easier to read.

Let's say that the data on a CD is not music. Let's say it's a .doc file. If this disc has a thumb print on it that causes readback errors that error correction can fix, you are not going to open a different document. You're gong to get the document - the only document. It will say whatever was written in it when it was saved to that file. It will not change that document to say something completely different.

CD music playback is simply a way to open a file. Unlike a file like a .doc file, these files are opened sequentially. That is the only difference between CD playback and opening a file. A document file gets opened and buffered until the whole file is read. CD "files" (music files) open as they're read.

Let me ask you to try this instead. Take one of your messed up CDs and rip a track to a .WAV file. Then, clean it up. After, rip that same track to .WAV file again. Play those two ,WAV files and hear for yourself.

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