Article: Digital Vinyl: Temporal Domain

[Rexp]

Me too. Very good digital recordings of needle drops are indistinguishable on playback from the original vinyl - played back on the same system. I've personally experienced this and demonstrated it with others.

 

A properly done digital recording of vinyl has all those "vinyl like" qualities that vinyl lovers love. So the digital medium itself isn't the culprit or the limitation. I refer all of you to John Atkinson's review of the Ayre ADC, where he said he compared digital conversions of his own analog recordings to the original- in fact compared them "till his ears bled" - and said he couldn't tell them apart.

 

I'm not disputing that a digital copy can and should sound as good as the original analog recording but in reality if you listen to the 16/44 content of artist's like Frank Sinatra on Tidal, it does sound like utter crap compared to the analog original.

[firedog]

I'm not disputing that a digital copy can and should sound as good as the original analog recording but in reality if you listen to the 16/44 content of artist's like Frank Sinatra on Tidal, it does sound like utter crap compared to the analog original.

 

And that only proves they did a bad job remastering for digital. If I can make a recording at home on high quality audiophile equipment - nothing unusual or special - that sounds exactly - and I mean exactly - like the source, then certainly a record company can do the same.

[Rexp]

And that only proves they did a bad job remastering for digital. If I can make a recording at home on high quality audiophile equipment - nothing unusual or special - that sounds exactly - and I mean exactly - like the source, then certainly a record company can do the same.

Yes, you would think so wouldn't you...

[Le Concombre Masqué]

MOFI's SACDs of Frankie sound very good. Maybe it's a possible to claim a rebate if you swear you will listen only to the gorgeous perfect CD layer and not to the crappy bad tech misinformed misconceived SACD layer

And that only proves they did a bad job remastering for digital. If I can make a recording at home on high quality audiophile equipment - nothing unusual or special - that sounds exactly - and I mean exactly - like the source, then certainly a record company can do the same.

[james45974]

Well, from someone who has studied the math and knows as much about the subject as anyone alive (James Johnston, aka "JJ"):

 

The time resolution of a 16 bit, 44.1khz PCM channel is not limited to the 22.7µs time difference between samples. The actual minimum time resolution is equivalent to 1/(2pi * quantization levels * sample rate). For 16/44.1, that is 1/(2pi * 65536 * 44100), which is about 55 picoseconds. To put that in perspective, light travels less than an inch in that time.

 

Shannon and Nyquist stated that as long as you keep all components of the input signal below half the sampling frequency, you can reconstruct the original signal perfectly - not just in terms of amplitude, but in terms of temporal relationships too. They only addressed sampling, and assumed infinite resolution in amplitude. With a digital signal the precision is limited by the number of amplitude steps, leading to the above formula.

 

Edit; This is clearly illustrated in Monty's digital primer video, from about the 20 minute mark, and people still fail to understand it.

 

 

Resurecting an old comment on this thread, I am not a scientist or mathematician but I enjoy reading discussions such as this. I have watched Monty's video a few times. Do you have any other sources that I can do further reading as to why the time resolution of 44.1 is not limited to the time difference between samples? The formula given for the actual minimum time resolution is proving hard for me to grasp! Thanks!

[Jud]

MOFI's SACDs of Frankie sound very good. Maybe it's a possible to claim a rebate if you swear you will listen only to the gorgeous perfect CD layer and not to the crappy bad tech misinformed misconceived SACD layer

 

I thought you were talking about the group Frankie Goes to Hollywood, and was quite interested for a second.

[Don Hills]

Resurecting an old comment on this thread, I am not a scientist or mathematician but I enjoy reading discussions such as this. I have watched Monty's video a few times. Do you have any other sources that I can do further reading as to why the time resolution of 44.1 is not limited to the time difference between samples? The formula given for the actual minimum time resolution is proving hard for me to grasp! Thanks!

 

My math is rudimentary, so I can't help much. As I understand the formula, any signal that fits in less than half the sample rate is represented by more than two samples. To capture a difference in timing of that signal, it has to change at least one of the bits of at least one of the samples.

This paper may help:

https://web.archive.org/web/20060614125302/http://www.lavryengineering.com/documents/Sampling_Theory.pdf

[james45974]

My math is rudimentary, so I can't help much. As I understand the formula, any signal that fits in less than half the sample rate is represented by more than two samples. To capture a difference in timing of that signal, it has to change at least one of the bits of at least one of the samples.

This paper may help:

https://web.archive.org/web/20060614125302/http://www.lavryengineering.com/documents/Sampling_Theory.pdf

 

Thanks! Probably over my head but I'll give it a shot!

[Don Hills]

Thanks! Probably over my head but I'll give it a shot!

It's worth trying, it uses a minimum of math.

[board]

On 15/3/2017 at 0:51 PM, Jud said:

 

So many vinyl lovers' preferences may come to some extent from the fact that at least part of the time they're listening to better mastering. I completely agree with the proposition that mastering trumps resolution or even vinyl vs. digital.

 

 

And then folks get sucked in by plausible-sounding hypotheses that are incorrect, but they don't examine too closely since these hypotheses are in line with their preconceptions. I'm still in agreement, in fact perhaps more so than you: that Lipshitz and Vanderkooy article is steadfastly cited by lots of people whose DACs are doing sigma-delta modulation internally (yourself as well, perhaps?), and they don't seem to mind.

First: Like several others, I was very happy to see the comment that the author withdrew the article, and that his stated retraction was written at the very top. Good job! Most vinyl lovers, or "OCD audiophiles" (pardon my French) never admit anything (*cough* Fremer). So again, my compliments to you :-).

Then on to Jud's comments:

I completely agree! One of the most famous examples is Red Hot Chili Peppers' "Stadium Arcadium" which sounds horrible on CD, which is mastered by loudness lover Vlado Meller, while it sounds lovely on vinyl, which is mastered by Steve Hoffman (there's a comparison video by Ian Shepherd on Youtube if you haven't seen it). Although people have preferences then I believe there's usually consensus. I'm convinced most would prefer the vinyl edition of the RHCP album. I'm also convinced that most would choose the vinyl edition of Mike Stern's "Upside downside" from 1986 (the CD is "typical" 80s sounding: cold, thin and shrill).

Unfortunately, I've also come to realize lately that too much music, not only today (but especially today), is poorly produced or mastered. Up until recently I just thought people were exagerrating. Anyway, something is never going to sound good on either media if the master is poor, and yes, I do think the mastering for CDs in the 80s was less than stellar.

What I've found is that some extremely dynamically compressed, shrill and "hard" sounding CDs MAY sound subjectively "better" on vinyl precisely because they have lower fidelity. An example is Mastodon's "Once more 'round the sun", which is mastered by Ted Jensen and measures DR5 with the DR meter. The vinyl edition is actually tolerable to listen to, while the CD sounds very "hard". I assume the vinyl edition is cut from the same master, and then the vinyl material changes the sound a bit and so does my playback equipment, and perhaps the cutting engineer also used EQ to reduce the heavy amount of treble present. Other examples of this, albeit with slightly less compressed albums, could be the first 3-4 albums by Badly Drawn Boy.

I've found that this kind of effect (lower fidelity = more pleasant) usually starts to come into play when the CD measures around DR6 or lower.

[scottsol]

3 minutes ago, board said:

First: Like several others, I was very happy to see the comment that the author withdrew the article, and that his stated retraction was written at the very top. Good job! Most vinyl lovers, or "OCD audiophiles" (pardon my French) never admit anything (*cough* Fremer). So again, my compliments to you :-).

 

The retraction was from Chris, not the author.

[AlexMetalFi]

11 minutes ago, board said:

First: Like several others, I was very happy to see the comment that the author withdrew the article, and that his stated retraction was written at the very top. Good job! Most vinyl lovers, or "OCD audiophiles" (pardon my French) never admit anything (*cough* Fremer). So again, my compliments to you :-).

Then on to Jud's comments:

I completely agree! One of the most famous examples is Red Hot Chili Peppers' "Stadium Arcadium" which sounds horrible on CD, which is mastered by loudness lover Vlado Meller, while it sounds lovely on vinyl, which is mastered by Steve Hoffman (there's a comparison video by Ian Shepherd on Youtube if you haven't seen it). Although people have preferences then I believe there's usually consensus. I'm convinced most would prefer the vinyl edition of the RHCP album. I'm also convinced that most would choose the vinyl edition of Mike Stern's "Upside downside" from 1986 (the CD is "typical" 80s sounding: cold, thin and shrill).

Unfortunately, I've also come to realize lately that too much music, not only today (but especially today), is poorly produced or mastered. Up until recently I just thought people were exagerrating. Anyway, something is never going to sound good on either media if the master is poor, and yes, I do think the mastering for CDs in the 80s was less than stellar.

What I've found is that some extremely dynamically compressed, shrill and "hard" sounding CDs MAY sound subjectively "better" on vinyl precisely because they have lower fidelity. An example is Mastodon's "Once more 'round the sun", which is mastered by Ted Jensen and measures DR5 with the DR meter. The vinyl edition is actually tolerable to listen to, while the CD sounds very "hard". I assume the vinyl edition is cut from the same master, and then the vinyl material changes the sound a bit and so does my playback equipment, and perhaps the cutting engineer also used EQ to reduce the heavy amount of treble present. Other examples of this, albeit with slightly less compressed albums, could be the first 3-4 albums by Badly Drawn Boy.

I've found that this kind of effect (lower fidelity = more pleasant) usually starts to come into play when the CD measures around DR6 or lower.

I really wish Chris would allow someone to write about this stuff! Hint, hint, wink, wink! ;-)

In all seriousness though, I think more and more audiophiles are recognizing the fact that the promises of high-res audio, and to a certain extent vinyl, have more to do with the mastering behind them than their sampling rate.

I hope for everybody's sake that trend continues.

[board]

2 minutes ago, AlexMetalFi said:

I really wish Chris would allow someone to write about this stuff! Hint, hint, wink, wink! ;-)

In all seriousness though, I think more and more audiophiles are recognizing the fact that the promises of high-res audio, and to a certain extent vinyl, have more to do with the mastering behind them than their sampling rate.

I hope for everybody's sake that trend continues.

Are you winking at me?

Sorry, about my mistake about who retracted the article, but I was still happy to see that it was retracted :-).

[AlexMetalFi]

Just now, board said:

Are you winking at me?

Sorry, about my mistake about who retracted the article, but I was still happy to see that it was retracted :-).

No, at Chris.

[The Computer Audiophile]

3 minutes ago, AlexMetalFi said:

I really wish Chris would allow someone to write about this stuff! Hint, hint, wink, wink! ;-)

In all seriousness though, I think more and more audiophiles are recognizing the fact that the promises of high-res audio, and to a certain extent vinyl, have more to do with the mastering behind them than their sampling rate.

I hope for everybody's sake that trend continues.

Your email is still in my inbox. Been to busy with the site upgrade to respond. Please email your thoughts and ideas. I'm always open and searching for good writers. They are harder to find than most people think.

[scottsol]

On 3/16/2017 at 7:09 AM, firedog said:

 

 

Me too. Very good digital recordings of needle drops are indistinguishable on playback from the original vinyl - played back on the same system. I've personally experienced this and demonstrated it with others.

 

A properly done digital recording of vinyl has all those "vinyl like" qualities that vinyl lovers love. So the digital medium itself isn't the culprit or the limitation. I refer all of you to John Atkinson's review of the Ayre ADC, where he said he compared digital conversions of his own analog recordings to the original- in fact compared them "till his ears bled" - and said he couldn't tell them apart.

Please keep in mind that those transfers were done at 24/192 and that as I recall, at that setting the Ayre does no filtering.

It is also true that JA's conclusion is highly suspect. As he claims to be able to hear differences between DACs and has never found one to be audibly perfect, it is not possible for the digital playback to exactly match the analog source, even if the digital copy is perfect.

Finally, I have LP transfers made with the Ayre QA-9, and while there is no doubt they are imbued with "LPness", they don't sound identical to direct playback from the analog setup used in the transfer. Many people prefer these  LP transfers to hi res transfers from master tapes because they retain a lot of the LP sound, but they are not identical. 

[AlexMetalFi]

6 minutes ago, The Computer Audiophile said:

Your email is still in my inbox. Been to busy with the site upgrade to respond. Please email your thoughts and ideas. I'm always open and searching for good writers. They are harder to find than most people think.

Yeah, I had no idea you were in the middle of this. My apologies Chris for insinuating you were ignoring my request.

Chris, do me a favor and a at least respond so I have your direct address!

Cheers!

[board]

On 15/3/2017 at 0:34 PM, Fokus said:

 

Some didn't. But the various Sony PCM16** and F1 convertors did have dither from day one.

 

https://www.gearslutz.com/board/attachments/mastering-forum/25537d1161190991-old-sony-pcm-users-analogue-pcm-1983-.gif

Odd! Especially since Stanley Lipshitz says that it wasn't introduced in A/D converters until the mid 80s in the following video (this is the video I talked about when I said that even he said that early converters weren't very good), but maybe he was unaware of those particular converters you mention, although I don't really understand how your picture shows that it uses dithering (is it the lack of harmonic distortion?).

 

On a completely different note, then someone (I couldn't find the comment) mentioned something along the lines of "yeah, maybe digital is a superior technology, but CDs usually sound like shit, whereas the vinyl edition almost always sounds better, so maybe that's worth discussing instead of this stupid discussion about technology" (I'm paraphrasing a lot).

It would be a lot easier to have a debate about that if we didn't have to post 13 pages of comments correcting the vinylphiles in their flawed assesments of technology.

All that said, I think even the most hardcore objectivist, who would perhaps argue that he would choose the digital version in 99,9 % of the cases, simply because it has higher fidelity, would agree that we should strive for good sounding productions and masters.

As much as I dislike Michael Framer, then I agree with him about certain things (this or that album sounds good), and I think both I and the most hardcore pro-digital objectivist would agree with Framer that the music world would be a better place if most of the music produced nowadays was better produced and mastered.

So, what I'm trying to say is that, yes, we need a debate, preferably one where the head of Sony, Universal, mastering engineers, musicians, etc. would participate, so we can tell them that we want better sounding music - not just louder music. But I also think the hardcore subjectivists need to learn how to read and listen, rather than repeat the same old tired claims that have been disproved numerous times in the past. On the same note, some of the hardcore objectivists also need to "loosen up" a bit, instead of always saying "but it has higher fidelity, therefore I *have* to prefer this one to the one that I actually enjoy but which has lower fidelity" (CD/vinyl or speakers/amps, etc.).

On another note: I read a mastering engineer say that when bands ask for louder, louder, LOUDER mastering he makes one like he wants it and then makes a compressed one and adjust the volume levels to match, and the bands always choose the uncompressed one :-). Based on what I read, it's usually the artists, not the mastering engineers, who want louder masterings.

[Fokus]

Yes, the lack of (anharmonic) distortion components, and the presence of a nice and flat noise floor.

I once had schematics for an early Sony convertor, forgot which one, and it clearly had a zener-based noise source at its input. The concept of dither originated in the 40s. Old-school engineering textbooks sometimes contain circuits for dither sources.

 

I did not watch the SL movie. Perhaps he is meaning something else, such as the use of ADCs of more than 16 bit (Decca were early with this, and when did DG come with 4D?), followed with digital-domain dither and reduction to 16 bit? Or perhaps he was thinking of early digital editors, which indeed lacked dither during fades.

 

[esldude]

19 hours ago, Fokus said:

Yes, the lack of (anharmonic) distortion components, and the presence of a nice and flat noise floor.

I once had schematics for an early Sony convertor, forgot which one, and it clearly had a zener-based noise source at its input. The concept of dither originated in the 40s. Old-school engineering textbooks sometimes contain circuits for dither sources.

 

I did not watch the SL movie. Perhaps he is meaning something else, such as the use of ADCs of more than 16 bit (Decca were early with this, and when did DG come with 4D?), followed with digital-domain dither and reduction to 16 bit? Or perhaps he was thinking of early digital editors, which indeed lacked dither during fades.

 

I may have this wrong, and couldn't find anything definitive about those ADs.  I do believe the first ones had no dither.  I am thinking the Sony 701s which were pretty early were the first that used zener diodes as noise sources to provide random dither. 

 

I have seen reference that PCM 1610 and 1630 as well as the PCM F1 Sony units used one converter chip and switched between right and left channels thereby offsetting the sampling by one half of a sample period between channels.  Pretty much like the first Sony CD players used one chip and the two channels were offset by one half sample period. 

[Fokus]

3 hours ago, esldude said:

I may have this wrong, and couldn't find anything definitive about those ADs.  I do believe the first ones had no dither.

 

For the sake of archaelogy then. Here is a page of the PCM1630 maintenance manual. It clearly discusses the dither generator:

 

https://www.manualslib.com/manual/452275/Sony-Pcm-1630.html?page=68

 

Other thing I found browsing sevel forums:

-the dither level was insufficient for 14 bit use, so it only worked running at 16 bit

-the linearity of the early convertors was suspect, so that dither, in the end, may well have been a bit ineffective

-the 1610/1630 editor fader was undithered

 

BTW, the time-shared nature of early Sony convertors is a well known fact.

[Fokus]

I finally saw the Lipschitz film. He never says that dither was not used on recorders before the mid 80s.

 

What he says is that some older digital recordings suffered from audible quantisation distortion. He attributes this among others to problematic ADCs and the use of undithered fades during editing.

 

The part about the mid 80s, as I understand it, pertains to the development of dither theory, and the derivation of optimal dither. Before this, dither could be just about any noise. After Lipschitz and the others who looked into this more thoroughly it was cast in a mathematical frame and the correct amount and probability distributions were derived.

[esldude]

1 hour ago, Fokus said:

 

For the sake of archaelogy then. Here is a page of the PCM1630 maintenance manual. It clearly discusses the dither generator:

 

https://www.manualslib.com/manual/452275/Sony-Pcm-1630.html?page=68

 

Other thing I found browsing sevel forums:

-the dither level was insufficient for 14 bit use, so it only worked running at 16 bit

-the linearity of the early convertors was suspect, so that dither, in the end, may well have been a bit ineffective

-the 1610/1630 editor fader was undithered

 

BTW, the time-shared nature of early Sony convertors is a well known fact.

Good.  Thanks for providing the facts of the matter. 

 

So there was a switch on an internal board to turn dither on and it was set at a level of -82 dbm.  Which in this context I suppose is equivalent to -82 dbu. 

[board]

Okay, maybe I misunderstood what Stanley Lipshitz meant :-).

Anyway, this entire discussions seems to more or less have come to an end, and I see that as a good thing :-).

I will stop posting now, and I extend a thank you to everybody else who has contributed with helpful info and to Chris for posting his retraction of the article. I'm glad he's keeping the article up here including all the info to help others in the future :-).