Are Jazz CDs making a comeback?

[mikeweil]

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.

[Stompin at the Savoy]

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. 

[Kevin Bresnahan]

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).

[Big Beat Steve]

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 ...

[Pim]

For stickers on my vinyl sleeves I use lighter fluid. Let it soak for 3 minutes and then try to peel it of gently 

[optatio]

25 minutes ago, Pim said:

For stickers on my vinyl sleeves I use lighter fluid. Let it soak for 3 minutes and then try to peel it of gently 

Me too ...

[Big Beat Steve]

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. 

[JSngry]

Just hold everything up to a light. If there's even the tiniest pinhole, it's game over.

[Stompin at the Savoy]

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. 

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...

[Kevin Bresnahan]

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.

[Big Beat Steve]

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 ... )

[Kevin Bresnahan]

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.

[mikeweil]

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. 

[Kevin Bresnahan]

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.

[Stompin at the Savoy]

6 hours ago, Kevin Bresnahan said:

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.

There are a couple of problems with this.  Unless a file is a random access file organization, typically it is a sequential access organization.  That means the file is read sequentially.  This includes .doc files.  Buffering is simply a way to read and hold some rows of the file (almost never all at once) in computer memory rather than go back to the disk for each line of data.  Buffering is something the operating system does transparently - you basically don't need to consider that as different from sequential read.  It's just a more sophisticated form of sequential read which is actually used in virtually all sequential reads.  Buffering also takes place on reads from a cd.  It has to in order to prevent variations in device/system read speed from affecting playback.  If some data bits are blocked by dirt on the disk, the byte those bits are part of becomes corrupted and possibly unreadable.  In some cases error correction can use checksum numbers - the sum total of the value of all the bytes for some 'block' or unit of the data - to figure out the corrupted bytes.  Often if there is enough missing the operating system cannot come up with a unique correction.  Mike Weil is correct in saying that if you can clean off some dirt and make missing bytes resolvable, the resulting output is different.

Edited 3 hours ago by Stompin at the Savoy

[Kevin Bresnahan]

No - it will sound as it was digitized. Not different at all. If you digitize a photo of a statue of liberty and the file gets corrupted, you don't get a picture of the Eiffel Tower.

In order for the analog output to have a different "soundstage", millions of bits would have to change. I'm not exaggerating here. A few seconds of music is 100's of thousands of bits. To change the frequencies and output levels, we're not talking a few bits flipped here & there... we're talking an entirely different sequence of data. It would be a totally different sequence to change the analog output that much.

[Stompin at the Savoy]

9 minutes ago, Kevin Bresnahan said:

No - it will sound as it was digitized. Not different at all. If you digitize a photo of a statue of liberty and the file gets corrupted, you don't get a picture of the Eiffel Tower.

In order for the analog output to have a different "soundstage", millions of bits would have to change. I'm not exaggerating here. A few seconds of music is 100's of thousands of bits. To change the frequencies and output levels, we're not talking a few bits flipped here & there... we're talking an entirely different sequence of data. It would be a totally different sequence to change the analog output that much.

If the file of a picture of the statue of L is corrupted, you don't get the Eiffel Tower but you do get a different version of the statue picture.  If enough is corrupted you will see degradation of the image.  Same is true of audio files.  Yeah, it might be the same tune but if there is enough corruption, there will be static and signal degradation.  Still more corruption and it becomes unplayable and the playback seizes up.

You are thinking it will take jillions of corruptions to affect the sound so it won't really be affected.  The problem is some drops of soda allowed to dry on a cd will affect jillions of spots!

Edited 3 hours ago by Stompin at the Savoy

[Kevin Bresnahan]

36 minutes ago, Stompin at the Savoy said:

Often if there is enough missing the operating system cannot come up with a unique correction.  Mike Weil is correct in saying that if you can clean off some dirt and make missing bytes resolvable, the resulting output is different.

There are 4 levels of error correction at play and even if they all fail, the first nasty correction is interpolation and the next step is muting. Neither of these levels will happen for a "dirty" disc, It would take a major scratch to cause these to kick in. The second level correction (muting) is sometimes audible (likely showing up as skips or pops) but not frequency or level shifts.

If the errors are so severe that muting can't be done, the disc skips.

6 minutes ago, Stompin at the Savoy said:

If the file of a picture of the statue of L is corrupted, you don't get the Eiffel Tower but you do get a different version of the statue picture.  If enough is corrupted you will see degradation of the image.

This is not true. If the file is so corrupted that it can't be converted to an image, you'll get a partial image, not a changed image. Did you never have a corrupted download of a photo? It's usually looks perfect and then simply chops off where the data is corrupted. In the early days of the Internet, this happened often.

[Stompin at the Savoy]

2 minutes ago, Kevin Bresnahan said:

There are 4 levels of error correction at play and even if they all fail, the first nasty correction is interpolation and the next step is muting. Neither of these levels will happen for a "dirty" disc, It would take a major scratch to cause these to kick in. The second level correction (muting) is sometimes audible (likely showing up as skips or pops) but not frequency or level shifts.

If the errors are so severe that muting can't be done, the disc skips.

I'm sorry but I disagree.  I've had noticeable static, muting, skips etc from dirt which were fixed by cleaning.

[Kevin Bresnahan]

It's technically impossible to get the type of modified analog output that is being described here. It's simply not possible to have frequency shifts and level shifts because of a couple of misread bits. NOT POSSIBLE.

4 minutes ago, Stompin at the Savoy said:

I'm sorry but I disagree.  I've had noticeable static, muting, skips etc from dirt which were fixed by cleaning.

Exactly!! Static. Muting. Skips. All can be the result of a dirty or scratched disc! Not "improved soundstage" or any type of frequency or level shift. Here, we agree.

[Stompin at the Savoy]

A good sized cloudy area on the surface of a cd is not a couple of misread bits. 

[Kevin Bresnahan]

1 minute ago, Stompin at the Savoy said:

A good sized cloudy area on the surface of a cd is not a couple of misread bits. 

But you agree that a cloudy area as most can cause static, muting or skips? It will not results in any audio shifts in frequency or levels, just noisy stuff like you describe.

[Stompin at the Savoy]

3 minutes ago, Kevin Bresnahan said:

But you agree that a cloudy area as most can cause static, muting or skips? It will not results in any audio shifts in frequency or levels, just noisy stuff like you describe.

Yes.  Static, muting, skips and seize up/crashes.  He may have perceived static as loss of sound stage.  There is no accounting for how degraded signal is perceived - it's subjective.  But the point is a significant amount of dirt does affect playback and sound quality.

This was the way several disks from Wes Montgomery Riverside box - which I got at an amazing low price - looked.  That's not a couple missing bits.

[Stompin at the Savoy]

41 minutes ago, Kevin Bresnahan said:

This is not true. If the file is so corrupted that it can't be converted to an image, you'll get a partial image, not a changed image. Did you never have a corrupted download of a photo? It's usually looks perfect and then simply chops off where the data is corrupted. In the early days of the Internet, this happened often.

I'm afraid you are incorrect about this, Kevin.  If you do a google image search on the phrase "distortions caused by corrupted photo files" you will see it is so. 

Edited 2 hours ago by Stompin at the Savoy

[Kevin Bresnahan]

4 minutes ago, Stompin at the Savoy said:

I'm afraid you are incorrect about this, Kevin.  If you do a google image search on the phrase "distortions caused by corrupted photo files" you will see it is so. 

Not at all. i just googled "distortions caused by corrupted photo files" and got stuff like this...

with the closest picture that looked like a distorted image looking so bad that an audio equivalent to this would not be listenable...

Most of the examples are just missing parts of the picture. In an audio file, this would be very audible.