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204.50.2.194
Scratched LPs are bad but how about scratched CDs? Open for discussion... we frequently hear about the sonic deficit of a scratched LP but seldomly hear about the sonic degradation from playing a scratch CD. The error correction in the CDP appears to playback a scratched CD without skipping but at what sonic expense?
Theo
Follow Ups:
with apologies to John Elison.
~ Pat O'Malley
I would probably like CDs far better if I were you.
~ Pat O'Malley
I only have a modest NAD533. Maybe you could buy one of those? Sell the SOTA, you would have plenty left over for Lps ...
~ Pat O'Malley
If the error correction algorithm can correct for the scratches then there is no sonic degradation. If the scratches take out too much information for proper correction, then you get gaps or blank spots and possible skipping. Sometimes CD-Rs go bad and develop static-like sound on certain parts or just short gaps. Unless the scratches are pretty bad though, the error correction algorithm seems to work wonders. I've got a couple of really scratched CDs that seem to play just fine.Also, if you happen to get a bad scratch on a CD that causes a glitch, sometimes it is possible to buff it out so the CD plays normally again. There are CD repair kits that contain a polishing compound to remove scratches.
Best regards,
John Elison
that CDs sometimes contain errors -- even ones that can be corrected. this is no big revelation.however, if one uses software such as EAC to copy the CD more carefully such that errors are fixed on a new CD-R (or stored in another format on an HD), then the CD can sound better.
my only guess as to why this can occur is that while a CDP *can* correct some/most/all of these errors, it has to do so on the fly and playback can be degraded in some way -- even before you start hearing dropouts/gaps.
i do think "bits are bits", but giving an audio copy program all the time it needs to make an accurate copy (and it does take a long time, sometimes to read & re-read the original) then makes the CDP's job easier.
not 100% sure why, but it does sound better. (Then qagain, i get better sound with playback from HD than CDP (and high-quality CDPs at that)--presumably because the HD is a more accurate device for reading information than a spinning CD. (yes, i know that a HD is a spinning disc.... :))
> not 100% sure why, but it does sound better. (Then qagain, i get better sound with playback from HD than CDP
> (and high-quality CDPs at that)--presumably because the HD is a more accurate device for reading
> information than a spinning CD. (yes, i know that a HD is a spinning disc.... :))I recently met a guy on this Vinyl Asylum that believes the same thing. In fact, this guy is a recording and mastering engineer and we've been trading CD-Rs. He also has a SME 30/2 turntable with van den hul cartridge, so he likes vinyl, too. Actually, he thinks vinyl sounds better than digital. ;-)
Anyway, at his insistence, I copied a number of CDs to my hard-drive using EAC and connected my computer to my DAC with an optical connection. Personally, I couldn't hear the slightest difference. I matched volumes and switched between CD and computer with remote control. If there is a difference, it is too subtle for my ears to hear.
I think I hear as well as any 59-year old male; therefore, I don't think the difference is significant, at least for older audiophiles.
Best regards,
John Elison
hi, john:
did you try the test with any scratched discs? i have found this to be true (and audible) when dealing with a scratched, albeit playable, disc.i do have a friend who is far more anal -- errr, careful -- than i am, and he has used EAC a number of times to copy problem CDs via EAC to high-quality CDRs and has reported positive results. i've just attributed the results to reduced read errors.
i assume that besides the error rate correcting on your cdr, you are also taking into account the error rate on the cd-r?
i don't understand what you're saying, but the basic thing that happened was:
1) identify CD with errors
2) copy CD to CDR and correct errors (not real-time)
3) verify CDR is error free
4) play CDR and realize it sounded better than CD with errors being corrected in realtime.
No, I didn't try any scratched CDs. The two that I have seem to play perfectly in my CD player, but they are older CDs and there fidelity is not that great, anyway. Furthermore, I do not like the music so it probably wouldn't make any difference to me. If they played with greater fidelity, I would simply like the music less. ;-)I'm not ready to scratch up a good CD in order to test your hypothesis. Sorry!
Best regards,
John Elison
my friend had some CDs that either played but had problems or didn't play at all in his CDP.he found many errors on the discs when using EAC. consequently, he made new CDRs that were confirmed to be error-free.
the CDRs now either played or (for the ones that had played with problems) played and sounded better.
i'm not trying to start a digital vs vinyl debate, or a 'when are bits better than other bits' discussion... or even whether MoFi gold CDRs are better than generic ones...
i'm simply saying that taking all the time one needs to create a disc/file that is error free had an audible impact (not debatable -- as there were cases where it was sound vs no sound at all/gaps). the hypothesis is that the removal of the CDP's need to use error-correction was the sole factor in this.
no need to scratch up your own CDs. in fact, these were some commercial CDs that my friend had purchased with no visible damage at all....that still wouldn't be read by his CDP.
one possibility: his CDP was at-fault, and somehow the copies were more compatible with his player. the offending CDPs either played with errors (or not at all) on my ML-9600, though.
Certainly I am not trying to start a good bits versus bad bits debate either. The fact is, audible or not, error correction in a CDP does affect the sound theoretically (always) and practically (sometimes). Some CDP are better correcting errors than others. Some TT setup plays scratched LPs better than others (or makes scratch more tolerable). The only thing I can conclude is that comparing CD versus LP is a crapshot at best unless playback equipment can be somehow certified for this kind of comparison, and the test CD and LP are made from the identical master.
Theo
...in my posts i was making a comparison of an error-laden commercial CD vs. one where that same CD was copied to CDR but the errors were fixed.
To be clear here for myself..Scratches can create unrecoverable errors on cd's. Now, you can make a copy of a cd that has lower error rate or corrected errors from the orignal but I thought according to the Cross Interleave Reed Solomon coding, there is no such thing has an "error-free" cd, just lower or higher error rates. The low rates are easily corrected by the player, and when the error rate is high, well, it's not so easy.
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