CDs, ripping vs playing: do you need a quality transport for ripping CDs?

[MajorFubar]

They may well have done but if the ripped files were still identical then it makes no difference really.

 

[manicm]

They may well have done but if the ripped files were still identical then it makes no difference really.

Well my new laptop's drive does not like error correction on EAC at all. Which sort of reinforces my notion that things like AccurateRip are red herrings.

 

[steve_1979]

If it's any consolation I rip CDs with a £30 computer DVD/CD drive.

Cor you must be rich. My DVD ripper was only a tenner.

It stil produces perfect rips though (as will any correctly functioning CD/DVD drive) and I've checked them against that online database just to be sure.

 

[MajorFubar]

Off-topic yet still related...I still wait with baited breath for someone to take me up on the offer I made on here years ago (sorry, cannot find the thread).

Basically I said if someone can lend me their mega expensive transport I'll record the signal from its digital output (ideally optical but I can manage coaxial), compare it to a recording from the digital output of my £50 BD player and pair them together side by side in a DAW to see if they truly were different. If the two recordings were different they would have failed a digital null test. If they were the same they would have passed a null test. No room for subjectivity, it was a plain and simple scientific test with an indisputable outcome.

The cynical side of me can only assume I haven't ever been taken up on the offer because no one wants me to prove their £1,000+ CD transport sends the same information out of its SPDIF socket as my £50 BD player. Same as how James Randi still has his $1M, which for years he has tried and failed to give away to the first person who can prove two speaker cables with comparable electrical spec's sound different.

 

[chebby]

Yeah, but what if one is encased in 15kg of "milled from a solid billet of aerospace grade alloy" and "internally wired* with 100 percent Phantolum Cryoxilate DBM**" etc?

* Externally wired proved tricky in early research.

** Discovered by marketing.

 

[thewinelake.]

Major - wouldn't your test be missing out on time-domain errors? So people would start using the J-word to undermine your test?

 

[shadders]

Off-topic yet still related...I still wait with baited breath for someone to take me up on the offer I made on here years ago (sorry, cannot find the thread).

Basically I said if someone can lend me their mega expensive transport I'll record the signal from its digital output (ideally optical but I can manage coaxial), compare it to a recording from the digital output of my £50 BD player and pair them together side by side in a DAW to see if they truly were different. If the two recordings were different they would have failed a digital null test. If they were the same they would have passed a null test. No room for subjectivity, it was a plain and simple scientific test with an indisputable outcome.

The cynical side of me can only assume I haven't ever been taken up on the offer because no one wants me to prove their £1,000+ CD transport sends the same information out of its SPDIF socket as my £50 BD player. Same as how James Randi still has his $1M, which for years he has tried and failed to give away to the first person who can prove two speaker cables with comparable electrical spec's sound different.

Hi,

Just to reiterate what others have stated, computers would not work if the low cost CD drive, or DVD drive could not read the CD or DVD bit perfectly.

A top of the range CD transport therefore can only modify the bit stream from the optical or coaxial in terms of jitter. Coaxial connects the earths/0volts together on equipment, hence noise may be an issue. In addition, the noise from the CD player or DVD player power supply or electronics may be an issue for analogue reproduction.

Regards,

Shadders.

 

[andyjm]

Off-topic yet still related...I still wait with baited breath for someone to take me up on the offer I made on here years ago (sorry, cannot find the thread).

Basically I said if someone can lend me their mega expensive transport I'll record the signal from its digital output (ideally optical but I can manage coaxial), compare it to a recording from the digital output of my £50 BD player and pair them together side by side in a DAW to see if they truly were different. If the two recordings were different they would have failed a digital null test. If they were the same they would have passed a null test. No room for subjectivity, it was a plain and simple scientific test with an indisputable outcome.

The cynical side of me can only assume I haven't ever been taken up on the offer because no one wants me to prove their £1,000+ CD transport sends the same information out of its SPDIF socket as my £50 BD player. Same as how James Randi still has his $1M, which for years he has tried and failed to give away to the first person who can prove two speaker cables with comparable electrical spec's sound different.

Hi,

Just to reiterate what others have stated, computers would not work if the low cost CD drive, or DVD drive could not read the CD or DVD bit perfectly.

A top of the range CD transport therefore can only modify the bit stream from the optical or coaxial in terms of jitter. Coaxial connects the earths/0volts together on equipment, hence noise may be an issue. In addition, the noise from the CD player or DVD player power supply or electronics may be an issue for analogue reproduction.

Regards,

Shadders.

In the spirit of full disclosure of facts, audio CDs and CD-ROM are not the same. The audio CD is defined by the 'Red book', CD-ROM by the 'Yellow book'.

The capacity of an error correction system is defined by how many errors it can detect, and how many it can correct in a given block size of data. The yellowbook standard can cope with more errors than the redbook standard. This makes sense, a one bit in error on a software package on a CD ROM could mean the package is useless, a one bit error in a WAV file is undetectable.

The downside is that more error correction means more redundant data which takes up space, so the usable data capacity of a redbook audio CD is higher than a yellowbook CR ROM. Probably a reasonable trade off.

So, the upshot of this is that you can't compare audio CDs with CD-ROM and imply that because there aren't errors with one, there won't be errors with the other as the capacity to absorb errors is different.

Having said all of this, CDs are so good these days that absent a knackered drive or knackered CD, reads are bit perfect. My cheapo Dell has an equally cheapo DVD drive, probably no more than £20 worth. In over 100 rips recently, I have not had a single rip that has needed a re-read (you can hear the head drive grind away and re-position) or failed the cyclic redundancy check of the accurate rip database - and this is reading the disc at 20x its original design speed. Quite a testament to the guys at Sony and Philips who came up with the system in the first place.

 

[insider9]

Off-topic yet still related...I still wait with baited breath for someone to take me up on the offer I made on here years ago (sorry, cannot find the thread).

Basically I said if someone can lend me their mega expensive transport I'll record the signal from its digital output (ideally optical but I can manage coaxial), compare it to a recording from the digital output of my £50 BD player and pair them together side by side in a DAW to see if they truly were different. If the two recordings were different they would have failed a digital null test. If they were the same they would have passed a null test. No room for subjectivity, it was a plain and simple scientific test with an indisputable outcome.

The cynical side of me can only assume I haven't ever been taken up on the offer because no one wants me to prove their £1,000+ CD transport sends the same information out of its SPDIF socket as my £50 BD player. Same as how James Randi still has his $1M, which for years he has tried and failed to give away to the first person who can prove two speaker cables with comparable electrical spec's sound different.

If I ever have one you can count me in. Assuming they were not bit perfect I'd suggest a little experiment to see how bad the imperfections are. By changing the phase of one signal, overlaying both and listening to what's left. Would be really interesting and likely not at all pleasant.

 

[MajorFubar]

If I ever have one you can count me in. Assuming they were not bit perfect I'd suggest a little experiment to see how bad the imperfections are. By changing the phase of one signal, overlaying both and listening to what's left. Would be really interesting and likely not at all pleasant.

You're spot on and that's exactly the process behind the test. Digital audio is just signed integers, for 16 bit it's -32,767 to +32,767 with two zeros just to confuse you. (Or it might be 32,768 with one zero; I forget). Either way, when you invert the phase, what you're really doing is turning all the positive numbers to negative and all the negative numbers to positive. So two identical files will mathematically null each other to complete silence when you align them sample-perfect.

Though like others have already said, no doubt I'd still get some who dispute the results. More than in any other doctrine or hobby it would seem, some hifi enthusiasts will always try to find some way to disprove the credibility of indisputable tests and results, rather than just admit to being wrong

 

[shadders]

Off-topic yet still related...I still wait with baited breath for someone to take me up on the offer I made on here years ago (sorry, cannot find the thread).

Basically I said if someone can lend me their mega expensive transport I'll record the signal from its digital output (ideally optical but I can manage coaxial), compare it to a recording from the digital output of my £50 BD player and pair them together side by side in a DAW to see if they truly were different. If the two recordings were different they would have failed a digital null test. If they were the same they would have passed a null test. No room for subjectivity, it was a plain and simple scientific test with an indisputable outcome.

The cynical side of me can only assume I haven't ever been taken up on the offer because no one wants me to prove their £1,000+ CD transport sends the same information out of its SPDIF socket as my £50 BD player. Same as how James Randi still has his $1M, which for years he has tried and failed to give away to the first person who can prove two speaker cables with comparable electrical spec's sound different.

Hi,

Just to reiterate what others have stated, computers would not work if the low cost CD drive, or DVD drive could not read the CD or DVD bit perfectly.

A top of the range CD transport therefore can only modify the bit stream from the optical or coaxial in terms of jitter. Coaxial connects the earths/0volts together on equipment, hence noise may be an issue. In addition, the noise from the CD player or DVD player power supply or electronics may be an issue for analogue reproduction.

Regards,

Shadders.

In the spirit of full disclosure of facts, audio CDs and CD-ROM are not the same. The audio CD is defined by the 'Red book', CD-ROM by the 'Yellow book'.

The capacity of an error correction system is defined by how many errors it can detect, and how many it can correct in a given block size of data. The yellowbook standard can cope with more errors than the redbook standard. This makes sense, a one bit in error on a software package on a CD ROM could mean the package is useless, a one bit error in a WAV file is undetectable.

The downside is that more error correction means more redundant data which takes up space, so the usable data capacity of a redbook audio CD is higher than a yellowbook CR ROM. Probably a reasonable trade off.

So, the upshot of this is that you can't compare audio CDs with CD-ROM and imply that because there aren't errors with one, there won't be errors with the other as the capacity to absorb errors is different.

Having said all of this, CDs are so good these days that absent a knackered drive or knackered CD, reads are bit perfect. My cheapo Dell has an equally cheapo DVD drive, probably no more than £20 worth. In over 100 rips recently, I have not had a single rip that has needed a re-read (you can hear the head drive grind away and re-position) or failed the cyclic redundancy check of the accurate rip database - and this is reading the disc at 20x its original design speed. Quite a testament to the guys at Sony and Philips who came up with the system in the first place.

Hi,

Yes, agreed, the error correction in CD-ROM is more robust than Audio CD. As you have stated, you have ripped many CD's and no issues. If one were to experiment with ripping, you could rip the same file 10 times, and perform a checksum, and see if they differ. You shoud get 10/10 success.

Regards,

Shadders.