CD error correction on CD players vs SACD players vs DVD players

I basically have two questions regarding error correction on playback units. Has error correction improved in the last five years? Do SACD players, DVD players and DVD-A players have superior error correction compared to standard CD players?

I ask this because I burned a CD-R with about 75 minutes of audio and there appears to be errors on the last few tracks. I first noticed when I played the disc on a portable Panasonic CD player that dates to about 1998. You can hear the player churning when it plays the last few tracks and eventually it starts to hiccup. I tried ripping the tracks with jitter correction on a PC with a DVD burner using jitter correction but that didn't do any good because the resulting wav files still had errors on them, something like white noise.

I thought the disc was useless but I popped it in a Panasonic DVD player and it played fine with no problems. It's two years old and is compatible with DVD-A but I don't think it's anything special. I bought it at Circuit City and it's supposed to be really good by your average consumer standards.

 

Simple. Some older players, and portable and car players just cannot easily negotiate non-standard CD lengths over 74 minutes. The original Redbook spec only specifies compliance for 74 minutes, so anything after that is a wild card.

However, if these players play commercial CDs over 74 minutes, it could be tha fault of the burner and/or the blank used.

 

What Grant said.

 

Yeah, I figured that but my original question was about error correction in playback units. Has the technology substantially improved in the last five years? Do SACD players, DVD-A and DVD players generally have better error correction than CD players when it comes to playing CDs?

 

CD (Redbook Audio) is beased on PCM encoding while SACD is based on DSD encoding. From my understanding, the most error-prone process in CD music production is at the glass-cutting process in which you write/burn CD/DVD discs. This is about using laser to make a series of holes on the reflective material layer of the disc. It's very hard to precisely control the amount of heat the writer wants to produce at the surface of the recording layer.

The amount of errors mostly depend on the quality of the burner machine and discs. Because melting is an irreversible process, once errors are detected during the verification time, only additional error-correction information can be written (append) to the end. And there will be no perfect error-correction scheme exists, meaning to correct any kind of error, i.e. only certain errors can be corrected.

PCM is very sensitive to bit-error on the disc, while DSD doesn't suffer from bit-error much. From this reason, some manufactures improve sonic quality in Redbook Audio CD by employing the best possible equipments and materials, like in XRCD, to reduce errors/jitters to the least. SACD claims to be better in this aspect. I'm not sure about DVD-A, using PCM.

In the CD (PCM encoding), you need to use standard error correction techniques, still the old ones, no matter what player you use. The answer to your question is no.

It is a fact that no CDR copies can be as good as original music CDs, due to the reasons above. If you want the best sonics from CDs, there is no choice.

 

Hi bordin ,

Factory pressed CDs are made by stamping the polycarbonate with a glass master thus making a pitted surface upon which a reflective material (usually aluminium but sometimes gold) is "sputtered".

CD-Rs are written to by heating the areas where a pit would normally be made in the pressing process such that the reflectivity at that point on the dye layer is reduced.

No extra arror correction is added as a result of errors detected during verification. CDs (pressed or burned) use error correction during encoding in an attempt to make it possible to rectify errors that inevitably occur during manufacture or burning. If in a particular case these errors exceed what is correctable using the standard redbook error correction scheme then the disc will play back with uncorrected errors, albeit masked by muting circuits or interpolated - the application of these processes depends upon a particular transport's design. This last point may be relevant to the original question - maybe C6H1206's old player tries to play the disc without masking the errors while the newer player mutes the output very briefly to mask the missing samples.

.

Not true. Firstly, any time-based errors (jitter) on an original CD can be rectified by ripping the disc and burning a CD-R of it assuming the burner can produce low jitter discs. Secondly, an original disc with errors that are unlikely to be corrected during playback in real time can be read many times over during ripping (using software such as EAC) to the point where the hard to read data can be extracted error free. Thus a CD-R burned from this ripped data may not have any of the hard to correct errors that were uncorrectable in real-time playback of the original.

 

I see. Thanks Mal for correcting my ignorance.

I still hear a lot of sonic differences in original CDs and CDs made by EAC, particularly subtle musical sounds. They almost disappear in CDR copies.

CD Players, comformed to Red Book Audio standard, can correct upto 220 Block Error Rates (BLERs). http://www.discdupe.org/i/bler.htm. I know gold discs have lower BLERs, around 20.

What are reasons why 24k-gold CDs sound better alumium ones ?

Is it because pressed aluminium CDs have BLERs greater than 220 ? So, they sound "bad". Using 24k-gold material can reduce BLERs to 20 (within the standard limit) ? So they sound good.

A friend of mine has explained to me about the effect of error/jitter while CD playing. Not sure it's right. There exists electrical interferences (noise) in the circuit, particularly distributed through the power supply channel. Power supply goes every where on the CD circuit board. So, any noise will go all over the circuit. It's why every expensive players have many separate power supply circuits, like 10+ or 20+.

The amount of jitters in digital electrical signalling also depends on how many time the circuit operates. Even DAC can correct errors to get correct "sounding" bits, it is still affected by the noise from such correction operations. If you can make the source CD has the least error, then you'll get the best sonics, regardless of error correction capability.

How about XRCD ? There is only one CD pressing facility of JVC Japan, equipped by an atomic clock. I know this is about error reduction, but don't know at what processes particularly ? I thought at pressing process.

 

I don't think it's the 75 minute playing time. I remember when the first 74+ minute CDs came out in the mid-late 80's. Only those with close to 79 minutes playing time created problems on some players. 75 minutes should never be an issue. Especially not with a player built in the 90's.