Forget storage comparison. Even the same storage can sound different with different file copying methods

[jabbr]

Questions:

 

Can jitter be stored in a CD?

I'd prefer saying: "effects of jitter"

 

Jitter generated by the ADC during recording is stored?

 

The effects of jitter as alterations in values are stored.

 

Is there any ADC in the ripping or reading process?

If the jitter can be stored in a CD, why it can't be in HDD or SSD?

Lucky we are, MFM, AFM, SEM exist

 

I see where you are going... reasonable. Wouldn't 24 bit values of which 21 are significant be less subject to linearity issues in the lsbs?

 

DSF files ?

 

But certainly power spikes etc can affect the ADC ... of course script kiddies are protected from that because it is well known that the C# vm guarantees linear power suckage for 'parallel' array ops. It's all in the RFC...

[plissken]

Questions:

 

Can jitter be stored in a CD?

Jitter generated by the ADC during recording is stored?

Is there any ADC in the ripping or reading process?

If the jitter can be stored in a CD, why it can't be in HDD or SSD?

Lucky we are, MFM, AFM, SEM exist

 

Jitter is a real time phenomenon and it can't be stored as you make a copy.

 

There could be jitter in the realtime mastering. That would simply be part of the analog signal that is recorded from mic's and amplified instruments. But that is a mastering problem and not a reproduction problem. I'm not sure any of us here would retain a CD or downloaded track with pronounced jitter.

 

There is no ADC in the ripping / reading process. Data on a disk (HDD, SDD, Flash) is all digital. It's not an analog process unless you are making an argument that MR head in an HDD are "analog".

 

So, other than really poor mastering, jitter can not be introduced in the reproduction phase of copying a file and not have an error introduced.

[Hailey]

A quote from :

DiskFresh | Product Information | windows defrag utilities | Fact-Reviews.com

'In order to keep the data signal from fading, you need to re-write the data. This is often known as “hard disk maintenance”, and should be done 3 or 4 times a year.

 

While it does not prevent data from being corrupted or deleted, it can go a long way towards ensuring that the magnetic signal does not fade away completely. The way it works is to read every sector of the drive, and then re-write the data found there, provided the drive reported no errors. If this is done on a regular basis, the magnetic signal of every part of the drive will be refreshed long before the signal fades or becomes ambiguous.'

 

 

Is it really so? Does re-writing help to keep the data intact? Could someone comment on it please?

 

 

http://superuser.com/questions/284427/how-much-time-until-an-unused-hard-drive-loses-its-data

[mansr]

Questions:

 

Can jitter be stored in a CD?

Jitter generated by the ADC during recording is stored?

 

Jitter in the ADC clock used during recording/transfer is encoded into the resulting sample values and thus implicitly stored wherever the data stream goes. That's probably not what you had in mind here.

 

The data on a CD uses an NRZ coding with an embedded clock implied by the pit/land transitions. It is of course possible for the some jitter to be present in the position of these transitions. However, this low-level bit clock is unrelated to the timing of audio samples. CD audio by definition has a sample rate of 44.1 kHz, and the time of a given sample is thus exactly 1/44100 s after the preceding sample. It doesn't matter how a particular bit is placed on the disc provided it is within the tolerances required for correct recovery. The timing of bits being read off the disc should not influence the DAC sample clock used for actual playback. Rather, the CD spindle speed should be regulated such that the resulting bit rate on average matches a reference crystal oscillator.

 

Maybe it's possible to build a terrible CD player where the DAC clock is directly tied to the bitstream clock. I have no idea why anyone would do such a thing given that there must still be a reference oscillator somewhere in the system.

 

Is there any ADC in the ripping or reading process?

 

In a sense, yes. There is a circuit that converts the intensity of the reflected laser beam to high/low digital levels. However, I would call this a level detector rather than an ADC.

 

If the jitter can be stored in a CD, why it can't be in HDD or SSD?

 

Traditional CD playback is synchronous. The data readout rate from the disc is matched to the playback rate. A hard drive, in contrast, is asynchronous. The host computer issues requests for (ranges of) sectors, and the drive returns the data at some later time, with NCQ/TCQ the responses are not even necessarily in the same order as the requests. Importantly, the internal transfer rate (and rotational speed in the case of an HDD) has no relation whatsoever to the playback rate of stored audio. This difference might perhaps lead to the mistaken belief that CD audio is somehow influenced by jitter in the raw bitstream.

 

Moreover, when a CD ripped and the data written to some other form of storage, no information about the timing of the read bits is retained anywhere. Even if it did matter for direct playback, it matters not in the slightest when ripping.

[alfe]

Jitter in the ADC clock used during recording/transfer is encoded into the resulting sample values and thus implicitly stored wherever the data stream goes. That's probably not what you had in mind here.

 

The data on a CD uses an NRZ coding with an embedded clock implied by the pit/land transitions. It is of course possible for the some jitter to be present in the position of these transitions. However, this low-level bit clock is unrelated to the timing of audio samples. CD audio by definition has a sample rate of 44.1 kHz, and the time of a given sample is thus exactly 1/44100 s after the preceding sample. It doesn't matter how a particular bit is placed on the disc provided it is within the tolerances required for correct recovery. The timing of bits being read off the disc should not influence the DAC sample clock used for actual playback. Rather, the CD spindle speed should be regulated such that the resulting bit rate on average matches a reference crystal oscillator.

 

Maybe it's possible to build a terrible CD player where the DAC clock is directly tied to the bitstream clock. I have no idea why anyone would do such a thing given that there must still be a reference oscillator somewhere in the system.

 

 

 

In a sense, yes. There is a circuit that converts the intensity of the reflected laser beam to high/low digital levels. However, I would call this a level detector rather than an ADC.

 

 

 

Traditional CD playback is synchronous. The data readout rate from the disc is matched to the playback rate. A hard drive, in contrast, is asynchronous. The host computer issues requests for (ranges of) sectors, and the drive returns the data at some later time, with NCQ/TCQ the responses are not even necessarily in the same order as the requests. Importantly, the internal transfer rate (and rotational speed in the case of an HDD) has no relation whatsoever to the playback rate of stored audio. This difference might perhaps lead to the mistaken belief that CD audio is somehow influenced by jitter in the raw bitstream.

 

Moreover, when a CD ripped and the data written to some other form of storage, no information about the timing of the read bits is retained anywhere. Even if it did matter for direct playback, it matters not in the slightest when ripping.

 

Is there an ADC in HDD and SSD? or it's all digital like post 77 is claiming.

[mansr]

Is there an ADC in HDD and SSD? or it's all digital like post 77 is claiming.

 

There's obviously a level detector somewhere. I disagree with calling such devices ADCs, especially when discussing audio topics.

[alfe]

There's obviously a level detector somewhere. I disagree with calling such devices ADCs, especially when discussing audio topics.

Then read this presentation again: http://home.npru.ac.th/piya/Document_KMUTNB/Lec09.pdf

[plissken]

Then read this presentation again: http://home.npru.ac.th/piya/Document_KMUTNB/Lec09.pdf

 

If you are going to post something like this it helps to make an argument with it.

 

HDD's are binary devices. There is no analog waveform to read like tape or vinyl. Most common HDD read heads are of the MR type. They read magnetic fields at the physical interface layer.

 

Even Ethernet comes down to an analog layer at some point. It's ADC for the wire or platter portion. But it has nothing to do with real time audio since these are asynchronous events.

 

The current audio that you listening to on a computer could have been placed in RAM 5 seconds ago. Any jitter five seconds ago during the fetch to cache would have ceased to exist 4.99999 seconds ago.

[alfe]

If you are going to post something like this it helps to make an argument with it.

 

HDD's are binary devices. There is no analog waveform to read like tape or vinyl. Most common HDD read heads are of the MR type. They read magnetic fields at the physical interface layer.

 

Even Ethernet comes down to an analog layer at some point. It's ADC for the wire or platter portion. But it has nothing to do with real time audio since these are asynchronous events.

 

The current audio that you listening to on a computer could have been placed in RAM 5 seconds ago. Any jitter five seconds ago during the fetch to cache would have ceased to exist 4.99999 seconds ago.

 

Lucky that you exist to explain me my daily job. Bye

[plissken]

Lucky that you exist to explain me my daily job. Bye

 

You either have point to make or you don't/can't.

 

Based on your posts that isn't your daily job. IMO.

[alfe]

Waisting my time with ignoramus, I'm done with this forum, wish you the best all of you except the bounty assehole.

[mansr]

You either have point to make or you don't/can't.

 

Based on your posts that isn't your daily job.

 

I already told you what you are, you want me to repeat.

 

Calm down, both of you.

[plissken]

Calm down, both of you.

 

I never exited a calm state. I'm just trying to figure out what point he's trying to make. If he was either a hardware designer or wrote device level software I would expect a cogent, reasoned, well thought out point.

 

I'm simply pointing out what I see as a false claim. It's par for the course around here it seems.

 

I've certainly not had to resort to calling anyone here an asshole. Delusional and Stupid? Yes because those are base terms that I feel I can backup.

 

Stupidity is ignorance left willfully uncorrected. I don't think I have the right to be just down and out mean, but I'm also not required to coddle with my responses.

[plissken]

Waisting my time with ignoramus, I'm done with this forum, wish you the best all of you except the bounty assehole.

 

If you can backup the 'Ignoramus' I'm all ears. Not sure how you quantify the 'asshole' comment other than you are taking up a position that you don't understand, aren't willing to learn how it works, and becoming entrenched because you see a slide in HDD encoding that uses the term ADC and, I'm postulating, that you believe it is related to audio somehow and you aren't willing to go beyond that point in your understanding.

 

Disequilibrium is a prerequisite for growth.

[jabbr]

I never exited a calm state. I'm just trying to figure out what point he's trying to make. If he was either a hardware designer or wrote device level software I would expect a cogent, reasoned, well thought out point.

 

I'm simply pointing out what I see as a false claim. It's par for the course around here it seems.

 

I've certainly not had to resort to calling anyone here an asshole. Delusional and Stupid? Yes because those are base terms that I feel I can backup.

 

Stupidity is ignorance left willfully uncorrected. I don't think I have the right to be just down and out mean, but I'm also not required to coddle with my responses.

 

On the internet everyone knows you're a DAC

[Paul R]

...

...

...

And so for these possibilities as well as a number of other issues some of which I've had in a very noticeable fashion on my own system, I've adopted and advocate the "NAA" architecture where the audio PC is low power, discless and isolated by fiber optic Ethernet.

 

As you know things are always more complicated that they appear *but* I think the storage media issue is a red herring because it would go away if the proper buffering and isolation techniques were employed.

 

In this we are in 100% agreement. I tend to think the best sound is easiest to extract from the low power, resource sipping lightweight players. While the higher power, CPU soggy, transcode capable big honking servers are an absolute necessity for *using* the playback system. In other words, it adds the needed and highly desired convenience factor.

[kumakuma]

If you searched using Google you would find that Al has patents in the Optical disc area !

He knows infinitely more in this area than a loudmouth like you ever will.

 

It might be me or it might be a language issue but I have found Al's often cryptic posts to be more frustrating than educating.

 

I contrast this with John Swenson who is able to explain highly technical subjects in a way that even I can understand.

 

If he has decided to leave us (again) I will truly miss Al's sense of humour and I hope he will reconsider this decision.

[sandyk]

It might be me or it might be a language issue but I have found Al's often cryptic posts to be more frustrating than educating.

 

Unfortunately, because it is Alfe's day job, he has to be careful how much direct information that he provides which may be commercially sensitive.

[kumakuma]

Unfortunately, because it is Alfe's day job, he has to be careful how much direct information that he provides which may be commercially sensitive.

 

Then perhaps he shouldn't participate in technical discussions in public forums...

 

Providing links to information that only he understands the significance of helps no one.

[sandyk]

Then perhaps he shouldn't participate in technical discussions in public forums...

 

Providing links to information that only he understands the significance of helps no one.

 

I think you may find that members such as Mansr and some others are able to benefit from the links that Alfe provides. However, for the rest of us it is likely to be way too technical ?

With one breath you are saying that you will miss his sense of humour, and with the next breath you are saying that perhaps he shouldn't participate in technical discussions in public forums !

Speak with a forked tongue why don't you !!!

[plissken]

If you searched using Google you would find that Al has patents in the Optical disc area !

He knows infinitely more in this area than a loudmouth like you ever will.

 

Good for him. Too bad his expertise doesn't seem to make it in thread. Now if you are done appealing to authority I'll stick to the facts of the matter.

 

Maybe some other person here with some patents can call others an ignoramus or asshole instead of just presenting data and research to back their position.

 

So did he get the patent for the green marker or the blue marker that you run around the edge of a CD?

[kumakuma]

I think you may find that members such as Mansr and some others are able to benefit from the links that Alfe provides. However, for the rest of us it is likely to be way too technical ?

With one breath you are saying that you will miss his sense of humour, and with the next breath you are saying that perhaps he shouldn't participate in technical discussions in public forums !

Speak with a forked tongue why don't you !!!

 

Every time I give you the benefit of the doubt and try to engage you in a civil discussion, you find a way to insult me. I'm out of here.

[jabbr]

Then perhaps he shouldn't participate in technical discussions in public forums...

 

Providing links to information that only he understands the significance of helps no one.

 

I find the articles invaluable and learn from reading them. If they are too technical then don't bother (it won't harm you to ignore nor will it harm you to ack that there are technical details supporting something)

 

I don't get the impression that alfe is here to sell anything. John Swenson does a nice job of explaining the rationale behind his designs, yet alfe does a nice job of pointing to existing literature. Those are both different strengths. I have had some enormously experienced teachers whose style is not to spoon feed, rather to make you figure it out for yourself. Certainly some of the best teachers I've had.

 

In any case I find it humorous that some people can be so condescending without knowing the background of whom they are being condescending to. (I'm not accusing you in particular, just picking this post to respond to)

 

Just remember that not everyone here is being paid to explain things.

 

I would also suspect that regarding the particular topic of this thread, alfe is perhaps one of the worlds experts. Perhaps.

[sandyk]

Now if you are done appealing to authority I'll stick to the facts of the matter.

 

 

Is it any wonder with nasty and obnoxious members like you, that very few industry professionals even bother to remain as posters in this forum ?

Long term members will realise just how many highly experienced industry professionals we have lost in recent years due to know-it-alls like yourself questioning their expertise.

[kumakuma]

Is it any wonder with nasty and obnoxious members like you, that very few industry professionals even bother to remain as posters in this forum ?

Long term members will realise just how many highly experienced industry professionals we have lost in recent years due to know-it-alls like yourself questioning their expertise.

 

Where was I nasty and obnoxious to Alfe?

 

Where did I question his expertise?

 

I merely said that I often find his responses cryptic and frustrating to read.