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Author Topic: Why Is There "Clipping" On The Last Few Remaining Tracks Of My CD ?  (Read 5814 times)

Offline neilep

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Dearest Unclothed Academic Sleweths,

As a sheepy I of course luff Cd's...Yep !!...Cd's are all I think of from the moment I awake to the moment I sleep.....Even blank ones monopolise all my waking thoughts. Cd's are my all time favourite small roundy things that are shiny and have data and stuff on them.

Look...here are some on my ceiling


I've run out of wall space..starting on the ceiling now !

I luff Cd's so much that I put music on them sometimes...Cd's are good for that...did ewe know that ?..

...anyway....the problem I have is that on a few of my Cd's that I have laid down some tracks on ...after quite a few plays a "clipping" noise appears towards the end of the CD !..Why's that then ?..do ewe know ?

As a firm believer in empirical study I snuk into my neighbours house at 3am this morning. He is a musician..so..it's logical to assume he will sound good stuffed into a CD player.. He gladly cooperated and with a playful banterish type struggle he allowed me to chloroform him. It worked it's magic and he was delightedly full of joy and glee with non-protestation as he allowed me to stuff him into his CD player. Well, after a good few hours of cattle prodding joyness I just could not get him entirely inside his CD player !!...sheesh !!......he must be a crap musician !!.......so no luck there !

Can EWE help me understand the nature of End-Of-CD-Clipping !

It is not fun-ness and puts me to a lot of trouble if I have to blatantly keeping copying Cd's sheesh !!

Hugs & shmishes


mwah mwah mwah mwah



neil
Is A Dirty CD..A Seedy CD ?
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« Last Edit: 06/09/2010 16:40:10 by neilep »


 

Offline peppercorn

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Hi Sheepy!

Is this-there clipping phone-omenon worse on CD-R's as opp to pressed CDs?

If its worse on the later tracks I imagine it is not clipping in the sense of overdriven transistors, etc. Instead it is probably 'dropped' data in the ADC causing an audio blip (better word someone?) that causes the upsetting noise ewe are experiencing.

In addition, you may find that your neighbour's 'musician-ness' is in an older format than the CD.
Or, alternatively he may have hidden 'port' that you can use to interface with his luffly sounds - more personally. You just have to find the right 'jack'  :o
 

Offline neilep

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Hi Sheepy!

Is this-there clipping phone-omenon worse on CD-R's as opp to pressed CDs?

If its worse on the later tracks I imagine it is not clipping in the sense of overdriven transistors, etc. Instead it is probably 'dropped' data in the ADC causing an audio blip (better word someone?) that causes the upsetting noise ewe are experiencing.

In addition, you may find that your neighbour's 'musician-ness' is in an older format than the CD.
Or, alternatively he may have hidden 'port' that you can use to interface with his luffly sounds - more personally. You just have to find the right 'jack'  :o

Thanks ewe thank ewe Dr Peppercorn....yes..these are Cd's that I personally have burned....but why do they play fine for the first 10-20 plays and then the 'clipping' manifests !..and only on the last 10 minutes or so ? .....Could it possibly be some kind of erosion via the laser ?...is the laser causing the dropping of data ewe mention ?


Thank ewe also for the advice re: the neighbour...I assure ewe all ports were inserted many times and the right jack was employed frequently !!..I think ewe have hit the right spot when ewe mention the old format....I returned later and spun him on his record-mobile player and there was indeed sound....though...to call it music would be deemed a very loose definition as I repeatedly needed to maintain pressure of the stylus within his spinning groove !
 

Offline graham.d

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Self burned CDs are worse in their reflectivity compared with manufactured CDs. This is not usually a problem in modern computer CD players or HiFi systems but can be a problem in older systems. It results from not having an Automatic Gain Control and Level Detection system in the Laser Detector. This may be worse near the centre of the disk where the linear spacings in the track directions are smaller. It is hard to say why this gets worse after multiple plays - the laser will not damage the disk in any significant way. Maybe handling the disk may be depositing something on the surfae (wool?). Could it be correlated with some other factor to do with the player rather than the disk - such as how long iy has been switched on or the temperature of the electronics. The reflectivity problem with burned CDs can often be improved if you can clean the laser lens - though this is sometimes hard to get at. Condensation, especially with in-car systems, can also be a problem.
 

Offline peppercorn

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Maybe handling the disk may be depositing something on the surface (wool?).
:D :D :D

Quote
Could it be correlated with some other factor to do with the player rather than the disk - such as how long it has been switched on or the temperature of the electronics.
Graham, that reminds me:  Noticing how hot the main IC got in a rather ageing CD player I once owned, which started skipping and exhibiting a similar effect as described by Sheepy, I super-glued an old ha'penny to the chips surface as an improvised heatsink.  It extended the units life by about a year!

 

Offline neilep

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Self burned CDs are worse in their reflectivity compared with manufactured CDs. This is not usually a problem in modern computer CD players or HiFi systems but can be a problem in older systems. It results from not having an Automatic Gain Control and Level Detection system in the Laser Detector. This may be worse near the centre of the disk where the linear spacings in the track directions are smaller. It is hard to say why this gets worse after multiple plays - the laser will not damage the disk in any significant way. Maybe handling the disk may be depositing something on the surfae (wool?). Could it be correlated with some other factor to do with the player rather than the disk - such as how long iy has been switched on or the temperature of the electronics. The reflectivity problem with burned CDs can often be improved if you can clean the laser lens - though this is sometimes hard to get at. Condensation, especially with in-car systems, can also be a problem.

Thank ewe very much indeed Graham. These are burned Cd's that I use specifically for the car. Further to your post I will trial them on my CD player at home and see if there is better reproduction...could this be an 'error correction' thing do ewe think ?.. As far as handling Cd's.....I am so anal about my music that I handle my Cd's with great precision.

I appreciate your response and the comments therein.
 

Offline RD

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CDs play from the inside to the outer, (opposite of a vinyl record), if your faults only occur at the end of the album it could be due to fingerprints on the rim which have accumulated by handling "10-20" times.

...causing an audio blip (better word someone?)

glitch ?

[BTW glitching is not the same as clipping ].
« Last Edit: 06/09/2010 17:58:57 by RD »
 

Offline neilep

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CDs play from the inside to the outer, (opposite of a vinyl record), if your faults only occur at the end of the album it could be due to fingerprints on the rim which have accumulated by handling "10-20" times.

BTW glitching is not the same as clipping.

Thanks RD..the term ' clipping' was used to indicate the way it sounds...it is very regular !!.....it certainly does sound like something may be gunked up in/on the disc then !...being just a ' copy' of a disc (for private use of course !) I sheepose it could be possible that I have somehow soiled the edges somehow (shock forror aghast !!)

Fortunately..I have one of these...


It's An Ultrasonic Cleaning Thingy !

and will give them a clean after an inspection !

 

Offline neilep

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Erhmmm........Here's a tip...don't use an ultrasonic cleaner to clean your recordered Cd's with !!




...or better still...read the manual for the very specific instructions for cleaning your Cd's



 

Offline neilep

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...unlike what I did..which was not !!
 

Offline Geezer

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Self burned CDs are worse in their reflectivity compared with manufactured CDs. This is not usually a problem in modern computer CD players or HiFi systems but can be a problem in older systems. It results from not having an Automatic Gain Control and Level Detection system in the Laser Detector. This may be worse near the centre of the disk where the linear spacings in the track directions are smaller. It is hard to say why this gets worse after multiple plays - the laser will not damage the disk in any significant way. Maybe handling the disk may be depositing something on the surfae (wool?). Could it be correlated with some other factor to do with the player rather than the disk - such as how long iy has been switched on or the temperature of the electronics. The reflectivity problem with burned CDs can often be improved if you can clean the laser lens - though this is sometimes hard to get at. Condensation, especially with in-car systems, can also be a problem.

I seem to remember that CDs are written from the inside towards the ouside, but I may have that wrong.
 

Offline SeanB

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The problem is that you probably are buying cheap CDR blanks. Try buying genuine Verbatim AZO disks ( they are branded VERBATIM and have on the packaging either AZO or SUPER AZO printed somewhere, and are generally a lot bluer on the bottom than the cheapies) as these are produced to a higher standard, and are made with a different technology ( although they are able to be written to by any CD writer) that provides a higher contrast in the recorded data. Record then at a lower speed ( 3-6 times at most) and this may help. Your car player may be an older model ( or use older technology) that is not very comfortable with the lower cost disk blanks. This is common in car players.

If this an issue with pressed disks as well, then you need to have the car player cleaned or adjusted ( although many are not able to be cleaned or serviced these days), or get a new one.

If you are unable to do so, then buy a cheap FM transmitter that you plug either a SD card, any USB mass storage device, or a personal media player. Cost here is around 6 pounds, and they are quite reasonable in sound quality, at least as good as FM radio, not CD quality, though MP3 is not that in most cases anyhow.

 

Offline neilep

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The problem is that you probably are buying cheap CDR blanks. Try buying genuine Verbatim AZO disks ( they are branded VERBATIM and have on the packaging either AZO or SUPER AZO printed somewhere, and are generally a lot bluer on the bottom than the cheapies) as these are produced to a higher standard, and are made with a different technology ( although they are able to be written to by any CD writer) that provides a higher contrast in the recorded data. Record then at a lower speed ( 3-6 times at most) and this may help. Your car player may be an older model ( or use older technology) that is not very comfortable with the lower cost disk blanks. This is common in car players.

If this an issue with pressed disks as well, then you need to have the car player cleaned or adjusted ( although many are not able to be cleaned or serviced these days), or get a new one.

If you are unable to do so, then buy a cheap FM transmitter that you plug either a SD card, any USB mass storage device, or a personal media player. Cost here is around 6 pounds, and they are quite reasonable in sound quality, at least as good as FM radio, not CD quality, though MP3 is not that in most cases anyhow.



Thanks Sean,

They are in fact TDK dedicated Music blank CD's..though it sounds like the ones ewe have cited are much better. I must admit though, in stores, it's difficult to find dedciated  "music" blank Cd's as they all seem to be bog standard data ones. However I do own a proper CD lens cleaner and will give the car CD a good clean. Yep, I do own an FM transmitter but I prefer the sound quality of a proper audio file rather than a compressed AAC or MP3.

Thanks again
 

Offline graham.d

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RD and Geezer, you are right about CDs being written from the middle outward. I had forgotten that.
 

Offline SeanB

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The Verbatim are sold as archival rated disks, good for a hundred years of storage ( at least that is the claim, but YMMV ) whereas the cheap disks are sometimes unreadable after 6 months of storage. I have read old backups on Verbatim media that I recorded 10 years ago, with no issue, whereas the cheap disks were either totally unuseable or had large numbers of errors.

I just was checking the old backups before I erased them, most were readable perfectly, although they were not so after 30 seconds in the microwave ( total data erasure for sure, the light show in the spindle of 50 was rather nice, and the smell of crisping plastic went away in a few minutes).
 

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