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Hydrogenaudio Forum => Scientific Discussion => Topic started by: KMD on 2012-03-13 11:49:51

Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: KMD on 2012-03-13 11:49:51
What sample rate and  bit depth , dithered, would create a digital recording with the same bandwidth and signal to noise ratio as vinyl
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: dhromed on 2012-03-13 11:57:26
Somewhat below Redbook.
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: Kees de Visser on 2012-03-13 12:32:20
This old thread gives some answers:
http://www.hydrogenaudio.org/forums/index....showtopic=35530 (http://www.hydrogenaudio.org/forums/index.php?showtopic=35530)
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: KMD on 2012-03-13 12:50:19
Ok so I'm getting 44Khz 12 Bit from there.  People are happy listening to Vinyl but would they be happy listenning to 44/12Bit Digital ? This is relevant to the formats discussion.  Would anyone like to convert a CD to 44/12 dithered so people on the forum can hear what it sounds like.
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: pdq on 2012-03-13 13:14:57
There was a listening test here a few years back. Someone took a 44/16 clip and converted it, with dither, to 15, 14, etc. bits. As I recall, most people could distinguish 11 bits, some 12 bits, and very very few could tell 14 or 15. (I could be wrong about the details, but I'm too lazy to search for the thread).
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: 2Bdecided on 2012-03-13 13:40:14
Ok so I'm getting 44Khz 12 Bit from there.  People are happy listening to Vinyl but would they be happy listenning to 44/12Bit Digital ? This is relevant to the formats discussion.  Would anyone like to convert a CD to 44/12 dithered so people on the forum can hear what it sounds like.
People have been listening to 32kHz 14-bits companded to 10-bits throughout the UK and much of Europe for years...
http://en.wikipedia.org/wiki/NICAM (http://en.wikipedia.org/wiki/NICAM)

lossyWAV often keeps less than 12-bits, without audible degradation...
http://wiki.hydrogenaudio.org/index.php?title=LossyWAV (http://wiki.hydrogenaudio.org/index.php?title=LossyWAV)

That thread linked by Kees de Visser almost has it nailed. You'd need some weird pre/de-emphasis and maybe companding or noise shaping to make the digital as bad as vinyl at the frequency extremes. Even then, the digital would still be distortion-free (unless you clip).

Cheers,
David.
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: KMD on 2012-03-13 13:49:57
The question is  do  very low signal to noise ratio digital formats sound the same as analogue formats of the same signal to noise ratio
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: 2Bdecided on 2012-03-13 14:15:21
The question is  do  very low signal to noise ratio digital formats sound the same as analogue formats of the same signal to noise ratio
Not unless you shape the noise to match. And even then, no, because analogue will have distortion and clicks/pops that the digital won't.

The lispy tracing distortion of vinyl is generally unwanted, but some people like the minor harmonic (they may say euphonic) distortion and other colourations of particular playback equipment.

Cheers,
David.
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: KMD on 2012-03-13 14:26:35
If people think vinyl LP sounds better than 12 Bit dithered  digital then the signal to noise based analysis of HD audio that is being discussed on the other thread is not sufficient. It would be interesting to hear an 8 bit dithered file compared to a 16 Bit file with analogue noise added to make the signal to noise ratio the same as the 8 bit file.
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: 2Bdecided on 2012-03-13 14:39:34
If people think vinyl LP sounds better than 12 Bit dithered digital..
Who said this? All the comments above are to point out the opposite.

Cheers,
David.

Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: John_Siau on 2012-03-13 14:41:06
What sample rate and  bit depth , dithered, would create a digital recording with the same bandwidth and signal to noise ratio as vinyl

DSD demonstrates that 1 bit is sufficient to achieve a SNR that is much better than vinyl.  The answer is that the word length must be at least 1 bit.

The bandwidth question is not quite as straightforward.  44.1 kHz is the minimum sample rate that will fully reproduce all audible frequencies while providing some room for the filter transition band.  The answer is that the sample rate must be at least 44.1 kHz.

The combination of sample rate, bit depth, and dithering method will determine the what combinations produce sufficient SNR within the audio band.  A 1-bit system at 44.1 kHz would produce a 6 dB SNR at best.  For every bit-depth, and dithering method, a sample rate can be chosen to produce the desired SNR.  If we choose the minimum sample rate, 16-bits are more than sufficient to capture the full SNR of the vinyl recording.

Please note that 44.1/16 is capable of delivering all frequencies up to 20 kHz at full amplitude.  Vinyl disks cannot deliver high frequencies at full amplitude.  For this reason, high frequencies were always limited when mastering vinyl.  44.1/16 has far more dynamic range at high frequencies than can be recorded on a vinyl record.  The engineer can create a brighter mix on a CD, and this is often done.

The source material recorded on vinyl records must be mastered to fit the physical limitations of the format.  The physics of the cutting head and the playback needle put significant constraints on the amplitudes that can be recorded at various frequencies.  For this reason, vinyl masters are usually mixed differently than CD masters.
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: KMD on 2012-03-13 15:01:12
listening tests at super high quality are hard to perform and the target differences are minute and thus lead to argument and uncertanty. But if the 8bit dithered file and the 16 bit file with analogue noise added have a different quality to the listener then it follows that a signal to noise based analysis alone to define the optimim quality of digital is not sufficient. It would be informative to both sides of the discussion. Then go to 4 Bits dithered. At some point a particular quality of the digital file will or will not be revealed. If it exists at low quality then it follows that it exists at high quality and if not why not.
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: Rotareneg on 2012-03-13 16:34:26
If it exists at low quality then it follows that it exists at high quality and if not why not.


I agree, the existence of heavily scratched and warped gramophone records clearly indicate the obvious poor quality of phonographs in general.
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: krabapple on 2012-03-13 18:50:58
listening tests at super high quality are hard to perform and the target differences are minute and thus lead to argument and uncertanty. But if the 8bit dithered file and the 16 bit file with analogue noise added have a different quality to the listener then it follows that a signal to noise based analysis alone to define the optimim quality of digital is not sufficient. It would be informative to both sides of the discussion. Then go to 4 Bits dithered. At some point a particular quality of the digital file will or will not be revealed. If it exists at low quality then it follows that it exists at high quality and if not why not.



Are you actually reading the answers you're getting on this thread?
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: Arnold B. Krueger on 2012-03-21 10:29:53
listening tests at super high quality are hard to perform and the target differences are minute and thus lead to argument and uncertanty.


I would take that difficulty and uncertainty as a message from Mother Nature: There is very little here to hear.

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But if the 8bit dithered file and the 16 bit file with analogue noise added have a different quality to the listener


Which is like saying that since battery acid and soda pop are both acid...  The error here is excluding both the middle and also the fact that we are comparing extreme opposite ends of a spectrum of stimuli.

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then it follows that a signal to noise based analysis alone to define the optimum quality of digital is not sufficient.


That's a truism because SNR does not include the effects of linear and nonlinear distortion.

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It would be informative to both sides of the discussion.


This sort of thing is only informative to people who haven't done their homework.

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Then go to 4 Bits dithered.


That's a non sequitor and it is also just plain nuts.

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At some point a particular quality of the digital file will or will not be revealed.


Yet another trivial truism.

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If it exists at low quality then it follows that it exists at high quality and if not why not.


You seem to need education on the concept of the law of diminishing returns and the facts of the thresholds of reliable human perception. You want links to help you get started on your homework, or what?
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: Arnold B. Krueger on 2012-03-21 10:43:37
What sample rate and  bit depth , dithered, would create a digital recording with the same bandwidth and signal to noise ratio as vinyl



Maybe 11 or 12 bits, and maybe 35 or 40 KHz. 

This is a little hard to say exactly because the digital performance limits implied are hard walls, while  the limits of analog are sort of like padded walls. However, the analog room is very much smaller and can never be enlarged. The digital room can be made as large as you want to pay for.

For example,  while a LP can be made with 35 KHz bandwidth, it can't carry much data at that frequency and the data is highly corrupted not to mention difficult to play usefully and easy to destroy during playback. The LP format starts loosing dynamic range and adding audible distortion beginning around 5 KHz.  Vinyl has severe power bandwidth problems at both ends of the audible spectrum.

Vinyl also has massive inherent jitter, and is typically made from analog tape recordings that have relatively massive jitter. The best analog tape recorder ever sold as a commercial product has about 1,000 nanoseconds or a million picoseconds of jitter on the best day of its life, and needs frequent (weekly, daily) maintenance to perform that way. Every recording that any regular consumer ever listened on vinyl was much worse.

A comparable digital recording is scrupulously clean very close to Nyquist,  has full bandwidth at high levels, is very easy to recover fully, does everything right down to DC, has inherent jitter that can be reduced arbitrarily,  and is very durable.
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: icstm on 2012-03-22 11:45:36
^^^ so isn't quite funny that all those ppl who were happy with Vinyl are now seeking better than CD sound quality through their SACDs and the general discussion on >16/44 formats!
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: greynol on 2012-03-22 13:02:06
While CDDA only goes to 22k, I don't believe it has been demonstrated to be insufficient for non-placebophile consumption.
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: Porcus on 2012-03-22 14:49:25
jitter


Is that synonymous to what we used to call wow & flutter, or is there more to it?
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: Nessuno on 2012-03-22 14:54:11
^^^ so isn't quite funny that all those ppl who were happy with Vinyl are now seeking better than CD sound quality through their SACDs and the general discussion on >16/44 formats!


On the contrary: it is perfectly coherent from vinyl worshippers to praise something that, to theirs eyes, pushes digital signals further towards the "infinite resolution" of analogic... 
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: pdq on 2012-03-22 15:01:43
jitter


Is that synonymous to what we used to call wow & flutter, or is there more to it?

Yes, wow and flutter are both jitter, just in different frequency ranges.
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: Arnold B. Krueger on 2012-03-22 19:44:39
jitter


Is that synonymous to what we used to call wow & flutter, or is there more to it?


Wow, flutter, and jitter are all examples of FM distortion.
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: Glenn Gundlach on 2012-03-23 03:29:18
jitter


Is that synonymous to what we used to call wow & flutter, or is there more to it?


Wow, flutter, and jitter are all examples of FM distortion.


Jitter is comparatively easy to process out. Wow and flutter more difficult since there is no timing reference in the signal.

Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: Woodinville on 2012-03-23 10:48:12
jitter


Is that synonymous to what we used to call wow & flutter, or is there more to it?


Wow, flutter, and jitter are all examples of FM distortion.


Jitter is comparatively easy to process out. Wow and flutter more difficult since there is no timing reference in the signal.




Except for being able to sense the bias signal and resample that out of a tape signal, or analyze the signal for periodic jitter components for an LP.
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: DonP on 2012-03-24 12:26:20
Jitter is comparatively easy to process out. Wow and flutter more difficult since there is no timing reference in the signal.


If the jitter happened in A/D, what is your timing reference?

Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: pdq on 2012-03-24 13:05:39
If such jitter were a problem (which it is not) then it is conceivable that a reference tone could be added into the analog signal, then filtered out of the digital data. Of course, the analog reference tone is likely to have much more jitter than the A/D.
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: Ethan Winer on 2012-03-24 19:05:39
all those ppl who were happy with Vinyl are now seeking better than CD sound quality through their SACDs and the general discussion on >16/44 formats!

Yes, and I see this in pro audio circles too. The same recording engineers who love analog tape lament that even the best digital converters aren't transparent enough for them. Sheesh.

--Ethan
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: DonP on 2012-03-25 12:41:16
If such jitter were a problem (which it is not) then it is conceivable that a reference tone could be added into the analog signal, then filtered out of the digital data. Of course, the analog reference tone is likely to have much more jitter than the A/D.


No reason to think A/D jitter is any less of a problem than D/A jitter.  Just like non-OFC power lines going down the highway are just as much a problem as a non-gourmet power line from the wall to your amplifier.
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: Woodinville on 2012-03-26 10:03:28
all those ppl who were happy with Vinyl are now seeking better than CD sound quality through their SACDs and the general discussion on >16/44 formats!

Yes, and I see this in pro audio circles too. The same recording engineers who love analog tape lament that even the best digital converters aren't transparent enough for them. Sheesh.

--Ethan


It's amazing what you can do with a bit of oversampling and M/S distortion.
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: Fandango on 2012-03-26 10:18:39
^^^ so isn't quite funny that all those ppl who were happy with Vinyl are now seeking better than CD sound quality through their SACDs and the general discussion on >16/44 formats!

Yep, they live and breathe the excluded middle.
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: Arnold B. Krueger on 2012-04-15 12:42:38
^^^ so isn't quite funny that all those ppl who were happy with Vinyl are now seeking better than CD sound quality through their SACDs and the general discussion on >16/44 formats!

Yep, they live and breathe the excluded middle.


It's all about bragging rights.
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: icstm on 2012-04-16 09:49:56
all those ppl who were happy with Vinyl are now seeking better than CD sound quality through their SACDs and the general discussion on >16/44 formats!

Yes, and I see this in pro audio circles too. The same recording engineers who love analog tape lament that even the best digital converters aren't transparent enough for them. Sheesh.

--Ethan


It's amazing what you can do with a bit of oversampling and M/S distortion.
I am clearly having a Monday morning sydrome...
Why are they using those things? 
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: cdroid on 2014-09-02 07:36:47
So I didn't read each and every one of these posts, but I wanted to weigh in on something that I thought would help your understanding. Most of what I am about to say is a summary of information I got from a conversation with one of my audio engineering instructors. The rest is information from various course books I have had to read as well as some of my own conclusions from all this material.

Your original question was what the sample rate and bit depth equivalents are for vinyl, and someone already accurately answered that it is 44k and 12 bit. Your next question was whether or not someone would just as much enjoy a digital recording at the same specs and the answer is too complicated to have a yes or no answer, but theoretically yes. Here is some elaboration on the subject. For starters, I will point out two factors that commonly cause vinyl to have a "better" sound than digital formats.
1. The most common way we listen to music now is by MP3 or some other "lossy" file type. What I mean by "lossy" is that an MP3 (and some other common file types) are actually compressed; the file has pieces of information that are removed and then approximately replaced during playback. The problem with this is that the lost information is never truly recovered with great accuracy after it has been compressed. We also need a DAC (digital to analog converter) to play back digital files. The DAC takes the ones and zeros stored on the computer and translates them to sound. Most people are simply using the DAC that is built into their portable MP3 player or computer, which typically doesn't sound very good.
2. Vinyl playback systems have a magnetic system that actually smooths over the choppiness of what can be considered gaps between the bit positions and samples. High quality DACs would have similar responses but as I have already discussed, most people do not use high quality DACs.

So what I hope I just properly explained is that although digital has by far surpassed analog, vinyl typically sounds better because the digital delivery systems we use have not caught up to the quality that is available.
Let me suggest that any good audio system will have good preamps, good amps, and good speakers. A good vinyl system will also have high quality cartridges and a good digital system will have high quality, lossless audio files and good DACs. Failing to have high quality components in either playback system will cause it to sound inferior when compared to the other.
Also consider that although digital recording and storage has surpassed analog, the digital signal processing has not yet surpassed the quality of analog signal processing. Consider that a song completely recorded and mixed in the box (on a computer with no analog gear besides the ADC and DAC) will sound inferior to the same song mixed on comparable analog gear. Professional studios will typically have all their microphones run through an analog soundboard with the direct outs of each channel running to a Pro Tools HD rig where it is recorded. Then to mix the Pro Tools HD rig is sent back to the channel where the audio engineer will mix (sometimes aided by plugins in Pro Tools) on the analog board with analog gear inserted on the channels as need. A stereo mix-down will be recorded back to the Pro Tools HD rig instead of to tape. A digital recording will likely not sound better than an analog recording if the quality analog gear is absent. However, plugins are catching up as more processing power becomes available and many plugins have become indistinguishable from their analog counterparts to the untrained ear.

Now I hope I can explain why digital actually is better than vinyl. For starters, Vinyl can be scratched and warped while these and other imperfections are not found in digital. Also, it only takes 44k and 12 bit to surpass analog, but modern Pro Tools HD rigs can actually go up to 192k and 32bit. With a high quality playback system, a lossless audio file with these specs will blow any analog system out of the water. Also, vinyl tends to have a serious drop-off in frequency response after about 17k. You'll notice older people typically prefer vinyl, but that's because you tend to lose hearing over 16k as you age. I would also speculate that they've been listening to vinyl for long enough that the imperfections (like the pops and clicks and crackling of vinyl that I don't really enjoy) have actually become part of the musical experience to them. Digital audio obviously doesn't have this 17k drop-off, so to younger ears there is actually more information on digital audio that can be defined in layman's terms as 'air' or 'presence'. This would greatly increase the tone of a digital recording since many of those tones above 17k are part of the harmonic overtone series on an instrument (I won't even try to explain that one, google it if you don't know it) which would make a recording sound closer to the live performance.

Now there is one more thing to consider about the experience of listening to a vinyl, and I've already touched on the idea that perhaps imperfections have been ingrained as part of the music. It is true that harmonic distortions found in analog gear are sonically pleasing, but we can still experience those tones either in the signal processing stage of mixing or after playback by using tube amps or preamps and other processors after the DAC.
What we need to consider is that music is inherently a spiritual, for lack of a better word, experience. We describe music as being part of your soul, part of that illogical part of you that can't be monitored as brain activity. Music has a quality that is sacred. By listening to music on low quality systems and by putting it everywhere (in the car, in the grocery store, on our commercials, literally everywhere; even in places that drag the music through the mud) we've taken away this sacred quality of music.
On top of that, we turntables are typically plugged into high quality sound systems. Digital audio is usually compressed and played back through your iPod on apple headphones. We've devalued our music this way. If you put on a vinyl, you have to work a little bit to hear the music. First you have to find the vinyl you want and you can't just load up your favorite playlist. Then you have to listen to that album; otherwise you must drop the needle on the song you want and risk damaging your album. You also must typically clean the vinyl with a proper cleaning device and then your vinyl is played back on a high quality system. Going through this whole process physically and mentally prepares you to enjoy the music.
If you really want to enjoy digital music, you must similarly prepare yourself physically and mentally to appreciate the music on a high quality system.

I hope I have done a good job in clarifying all the discussion around vinyl and digital and explained what other people might not have been able to.
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: Kohlrabi on 2014-09-02 08:59:17
1. The most common way we listen to music now is by MP3 or some other "lossy" file type. What I mean by "lossy" is that an MP3 (and some other common file types) are actually compressed; the file has pieces of information that are removed and then approximately replaced during playback. The problem with this is that the lost information is never truly recovered with great accuracy after it has been compressed. We also need a DAC (digital to analog converter) to play back digital files. The DAC takes the ones and zeros stored on the computer and translates them to sound. Most people are simply using the DAC that is built into their portable MP3 player or computer, which typically doesn't sound very good.
Everything mixed up with everything else. First, lossy compression is not a huge problem, and properly mastered music from CD, converted to MP3s, will blow any Vinyl record out of the water. And I don't know how you get the impression that most DACs are bad. There might be some bad ones around, but it's even more difficult and challenging setting up a good enough Vinyl playback system. So I can just as well argue that "most people" who listen to Vinyl are getting a subpar experience as well. We cannot know what people use, but there are enough good DACs around.

2. Vinyl playback systems have a magnetic system that actually smooths over the choppiness of what can be considered gaps between the bit positions and samples. High quality DACs would have similar responses but as I have already discussed, most people do not use high quality DACs.
The quality of even shitty current PC onboard audio DACs far surpasses the theoretical possibilities of Vinyl. And a tiny Sansa Clip+ will beat every Vinyl setup imaginable.

So what I hope I just properly explained is that although digital has by far surpassed analog, vinyl typically sounds better because the digital delivery systems we use have not caught up to the quality that is available.
No, digital music reproduction has surpassed Vinyl ages ago. The problem is the production/mastering quality of digital recordings.

Also consider that although digital recording and storage has surpassed analog, the digital signal processing has not yet surpassed the quality of analog signal processing.
Sadly, I don't have any experience in that, but I very much doubt that.

Now I hope I can explain why digital actually is better than vinyl. For starters, Vinyl can be scratched and warped while these and other imperfections are not found in digital. Also, it only takes 44k and 12 bit to surpass analog, but modern Pro Tools HD rigs can actually go up to 192k and 32bit. With a high quality playback system, a lossless audio file with these specs will blow any analog system out of the water.
Those extra bits are great for processing and production, but will add nothing to the perceptible audio quality. "Redbook" 16 bit and 44.1kHz is good enough for our species.

By listening to music on low quality systems and by putting it everywhere (in the car, in the grocery store, on our commercials, literally everywhere; even in places that drag the music through the mud) we've taken away this sacred quality of music.
The current problem with modern music is not whether digital is "good enough", or whether "the people" have "good enough" gear, but the production quality of music. Dont' blame the recipient, the customer, for the bad quality of music. The responsible parties are producers, audio engineers, and artists. The customer can just buy what's out there, but the average production quality (in certain genres) has steadily fallen since the early 90s.

On top of that, we turntables are typically plugged into high quality sound systems. Digital audio is usually compressed and played back through your iPod on apple headphones. We've devalued our music this way. If you put on a vinyl, you have to work a little bit to hear the music. First you have to find the vinyl you want and you can't just load up your favorite playlist. Then you have to listen to that album; otherwise you must drop the needle on the song you want and risk damaging your album. You also must typically clean the vinyl with a proper cleaning device and then your vinyl is played back on a high quality system. Going through this whole process physically and mentally prepares you to enjoy the music.
If you really want to enjoy digital music, you must similarly prepare yourself physically and mentally to appreciate the music on a high quality system.
My opinion is that the whole mystifying of the playback experience is audiophile nonsense talk. You aren't appreciating the music more by using an inferior and inconvenient playback system, you're just cultivating an elitist aura. Everybody can do as he or she pleases, by all means, but the implied sense of superiority by some Vinyl enthusiasts is ridiculous. Be wary, from my experience, if something is termed "audiophile", it sure is special, inconvenient, and sounds bad.
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: mjb2006 on 2014-09-02 09:15:31
cdroid, welcome to the forum. You will find that we are not perfect, but we generally don't allow people to get away with repeating folklore as fact, and your post is full of "audiophile" red flags. Some things you do get right, but others, not so much.

Most people are simply using the DAC that is built into their portable MP3 player or computer, which typically doesn't sound very good.

It "doesn't sound very good"? Really? In what way? DAC technology has been pretty stable for 20, 25 years. Has there been a sudden decline in the quality of DACs lately?

Vinyl playback systems have a magnetic system that actually smooths over the choppiness of what can be considered gaps between the bit positions and samples. High quality DACs would have similar responses

Well, every phonographic stylus, magnetic or not, traces the groove continuously, producing an analog waveform (or pair of waveforms, for stereo). However, the notion that there's something to "smooth" is a myth. If the waveform is sampled at a particular rate (44100 Hz, for example), then the motion that the stylus is subjected to between the sample points only contributes to frequency content above one-half the sample rate (e.g., frequencies above 22050 Hz, well above the limits of human hearing).

It's kind of a mess, but you should look over Vinyl Myths (http://wiki.hydrogenaud.io/index.php?title=Myths_(Vinyl)) page in the wiki before making any more dubious claims vinyl.

Also, even if you know some of this stuff already, please take the time to review these presentations by someone way smarter than you and me put together:


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Consider that a song completely recorded and mixed in the box (on a computer with no analog gear besides the ADC and DAC) will sound inferior to the same song mixed on comparable analog gear.

You have not defined inferior, so your statement is meaningless. There will be differences, sure, and you may have a preference for one over the other, but how is your preferred sound superior and the other inferior? (rhetorical question, really)

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modern Pro Tools HD rigs can actually go up to 192k and 32bit


True, and 32-bit is actually floating-point so it has exponentially greater resolution than 16 or 24-bit integer, but what's the point if it all sounds the same? Do we need ultraviolet, infrared, X-rays and gamma rays in our photo albums, too?

Might as well add to your reading list:


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Vinyl tends to have a serious drop-off in frequency response after about 17k.

So does human hearing. As for the frequency limits of vinyl, my understanding is that it really depends on how and when it was mastered, with what cutting equipment. Some cutters roll off within the upper range of human hearing like you say, but others extend a bit further into the ultrasonic territory.
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: 2Bdecided on 2014-09-02 10:23:38
Consider that a song completely recorded and mixed in the box (on a computer with no analog gear besides the ADC and DAC) will sound inferior to the same song mixed on comparable analog gear.

You have not defined inferior, so your statement is meaningless. There will be differences, sure, and you may have a preference for one over the other, but how is your preferred sound superior and the other inferior? (rhetorical question, really)
He's quoting a widely believed and spectacularly stupid opinion in the pro audio/mixing world: that somehow adding numbers (digital / In The Box) is genuinely inferior and lower quality than adding voltages (analogue / Out Of The Box). Even when the source is digital. Even when the "analogue" mixing requires D>A, mixing, A>D. There's a whole industry set up around providing analogue mixing devices for all-digital rigs.

Where the difference really sits is in the processing applied to the tracks and mix: essentially the comparison is between software plug-ins (in the box) and physical pieces of hardware (out of the box). Obviously these often sound different. It's hard to imagine the level of experimental controls you'd need to apply to ensure that they sounded the same (all other things being equal). Often people get a better result from a stand-alone piece of kit than from a DSP plug-in that some marketing department said was equivalent. This should surprise no one. Sometimes the kit is simply better (not in terms of 24-bit vs 32-bit minutia, but in terms of doing the broad job better), sometimes the fact it's separate means it has buttons and dials which enable the human operator to do a better job, even if the actual processing (if you set the same parameters in the software DSP "equivalent" was the same).

The bizarre thing is that there are many people who call themselves audio engineers who attribute the difference in sound, not to all the above, but to adding voltages rather than numbers.

It's a strange world. And, like the audiophool world, where there's money to be made from their lack of understanding, equipment manufacturers are more than happy to indulge it. A business that only sells to people with a perfect graphs of science and blind testing, who also happen to have excellent hearing and discernment, plus the funds to make expensive purchases - that business is not going to be nearly as profitable as the one that takes money from anyone willing to spend it.

Cheers,
David.
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: Arnold B. Krueger on 2014-09-02 16:10:00
So I didn't read each and every one of these posts, but I wanted to weigh in on something that I thought would help your understanding. Most of what I am about to say is a summary of information I got from a conversation with one of my audio engineering instructors. The rest is information from various course books I have had to read as well as some of my own conclusions from all this material.


The following post might be entitled "Misapprehension city". ;-)

Quote
Your original question was what the sample rate and bit depth equivalents are for vinyl, and someone already accurately answered that it is 44k and 12 bit.


Oh, someone was being optimistic about vinyl?

Quote
Your next question was whether or not someone would just as much enjoy a digital recording at the same specs and the answer is too complicated to have a yes or no answer, but theoretically yes. Here is some elaboration on the subject. For starters, I will point out two factors that commonly cause vinyl to have a "better" sound than digital formats.


Cut to the chase. If the vinyl version of a song is well mastered, and the digital version is badly mastered then the vinyl version may be able to overcome of of the inherent sonic detriments that are part and parcel of vinyl and actually sound better. That is about it. There is a reason why vinyl was dumped by just about everybody with a brain in the 1980s and it has to do with bad sound quality.


Quote
1. The most common way we listen to music now is by MP3 or some other "lossy" file type. What I mean by "lossy" is that an MP3 (and some other common file types) are actually compressed; the file has pieces of information that are removed and then approximately replaced during playback. The problem with this is that the lost information is never truly recovered with great accuracy after it has been compressed. We also need a DAC (digital to analog converter) to play back digital files. The DAC takes the ones and zeros stored on the computer and translates them to sound. Most people are simply using the DAC that is built into their portable MP3 player or computer, which typically doesn't sound very good.


That would be two common misapprehensions in one.

(1) Common lossy file formats are now highly perfected and if you give them a reasonable number of bits to play with and a good encoder the sound quality absolutely and positively blows vinyl into the next universe.

(2) Common DACs are now also highly perfected and now we have to jump over several alternative universes to find one where DAC sound quality, even DACs in $40 digital players, are any kind of an audible problem.


I know the two most common technique to formulate the above misapprehensions which are to do sighted evaluations and to listen to people who do sighted evaluations. One is riskier and more commonly invalid than the other. ;-)


Quote
2. Vinyl playback systems have a magnetic system that actually smooths over the choppiness of what can be considered gaps between the bit positions and samples.


Misapprehension number 3: There are no gaps between the samples in a digital file.

Quote
High quality DACs would have similar responses but as I have already discussed, most people do not use high quality DACs.


Obviously, you've never done anything technical with digital audio or done any studies of it based on credible sources. 

I just gotta give you some friendly advice. There are some people around here get impatient with the intellectually lazy and the otherwise intellectually challenged.


Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: mjb2006 on 2014-09-03 05:07:37
Quote
Your original question was what the sample rate and bit depth equivalents are for vinyl, and someone already accurately answered that it is 44k and 12 bit.


Oh, someone was being optimistic about vinyl?


The 12-bit number comes from digitally recording from a turntable (i.e., ripping vinyl). The recording software's peak meter shows that the noise floor, when the needle is playing an unmodulated part of the groove, hovers around something like 50 to 70 dB below peak, depending on I-don't-know-what. So that's why we say you need 10-12 bits or so, just to make sure you get everything above the noise floor. Really, though, that peak is dominated by the motor rumble and tonearm resonance. Roll off the EQ below 30 Hz and the peak drops quite a bit. What does this mean for the bit depth? Well, who knows. Maybe you need more bit depth. But then, music on vinyl generally is mastered as loud as possible to keep the SNR down, so maybe you need less.

Here's a recording I made of an unmodulated groove that takes up a whole side of a 12" record, for your analyzing pleasure: (click) (http://hyperreal.org/~mike/tmp/ha/vinyl,%20turntable%20&%20electrical%20noise,%208s%20intro,%2014m29s%2033%e2%85%93%20RPM%20unmodulated%20groove.flac)
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: lithopsian on 2014-09-03 11:51:54
Quote
Misapprehension number 3: There are no gaps between the samples in a digital file.

Well technically there are "gaps" between samples.  That's kind of what a sample is, a specification of the waveform at a specific point, saying nothing about other points.  The bit most people misunderstand is that samples at a particular interval represent only a single possible waveform (within the accuracy of the available bits and assuming a high frequency cutoff at half the sampling frequency).  There are no "steps" as so often drawn to bamboozle the innocent, no possible output other than the one that was originally encoded to digital form.

To re-iterate, the output from even a modest DAC is *exact*, not a smoothed-over version of a series of jagged steps.  This is why even cheap DACs produce high quality output.  The only things "wrong" with the output are the filtered-out high frequencies and quantisation noise (almost always dithered to a low level general noise floor) from the discrete bit depth intervals.
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: Arnold B. Krueger on 2014-09-03 19:15:00
Quote
Misapprehension number 3: There are no gaps between the samples in a digital file.

Well technically there are "gaps" between samples.


In what alternate universe?

Quote
That's kind of what a sample is, a specification of the waveform at a specific point, saying nothing about other points.


Not at all.

One of the prerequisites  for proper sampling is low pass filtering the analog signal so that there are no components at or above the Nyquist frequency. That enforces a rule that says that all of the points between the samples are known quantities, which means that if you know the sample points you know everything about the other points.

Come on guy, this is digital audio 101, first few lectures if not the first lecture!


Quote
The bit most people misunderstand is that samples at a particular interval represent only a single possible waveform (within the accuracy of the available bits and assuming a high frequency cutoff at half the sampling frequency).  There are no "steps" as so often drawn to bamboozle the innocent, no possible output other than the one that was originally encoded to digital form.


..and therefore no empty spaces with unknown data, no gaps at all.


Quote
To re-iterate, the output from even a modest DAC is *exact*, not a smoothed-over version of a series of jagged steps.  This is why even cheap DACs produce high quality output.


Making that true is the responsibility of the low pass  filter that is always on the output of a proper DAC.

Quote
The only things "wrong" with the output are the filtered-out high frequencies and quantisation noise (almost always dithered to a low level general noise floor) from the discrete bit depth intervals.


Thing is, those are all reducible to small amounts that vastly improve on anything that was ever done with analog recording of any kind.

Keeping analog signals pure enough for good digital processing is generally a challenge. It seems like every time someone comes out with a hot new ADC/DAC chip, they have to come up with an improved op amp to go with it.
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: lithopsian on 2014-09-03 19:45:17
I wonder if you are being deliberately obtuse.  Sampling is exactly the process of specifying the amplitude of a waveform only at particular points.  By the process you describe, this is sufficient to mathematically reproduce the entire waveform (subject to the given caveats), but the samples are just that: individual points.  Just because all the samples taken together are sufficient to reproduce the waveform does not mean that an individual sample has anything at all to say except at one particular time.  The samples are required to be considered together in order to derive the state of the waveform in between each sample.
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: pdq on 2014-09-03 20:18:37
I wonder if you are being deliberately obtuse.  Sampling is exactly the process of specifying the amplitude of a waveform only at particular points.  By the process you describe, this is sufficient to mathematically reproduce the entire waveform (subject to the given caveats), but the samples are just that: individual points.  Just because all the samples taken together are sufficient to reproduce the waveform does not mean that an individual sample has anything at all to say except at one particular time.  The samples are required to be considered together in order to derive the state of the waveform in between each sample.

I don't think that what you two are saying is that different. Yes, a sample represents a signal at an instant in time, but because the signal had been bandwidth-limited, the sample contains information from before and after that instant.
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: audiophool on 2014-09-03 21:41:24
I don't think that what you two are saying is that different. Yes, a sample represents a signal at an instant in time, but because the signal had been bandwidth-limited, the sample contains information from before and after that instant.

Isn't that beside the point? lithopsian was not talking about the information contained in samples.

I have a signal in continuous time. I sample it at various discrete points in time. I don't have a continuous function anymore.

I get that under certain conditions, the discrete samples are sufficient to recover the original continuous-time function, but that's an entirely different issue. It's still true that there is a gap --  a positive distance -- between any two points in time s =/= t at which the continuous-time signal has been sampled.

I am not in this field and maybe, I have the wrong metric in the back of my mind. Still, I find Arnold's way of talking about this very confusing.
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: Green Marker on 2014-09-03 21:52:06
I think the average audiophile reading this would simply not 'get it'. Simply making statements that claim there are no gaps, when of course the audiophile knows there are, and mentioning low pass filters that the average audiophile equates with a turned-down treble control, is like a couple of old plumbers telling the new apprentice to go and get a glass hammer while winking at each other!

The average audiophile would need to be told that the filter at each end is not just any old low pass filter, but must have a specific mathematical response that ensures that what comes out at the far end is continuous and exactly like what went in i.e. that the 'digital bit' is only half of the system. The audiophile will benefit from being told that the filter does not just perform a linear-ish interpolation, but fills in *the gap* between digital samples with a precise curve that can exceed the amplitude of the adjacent samples.

It must be stressed that any experiences they've previously had with "8 bit audio" were probably on systems that did not use anything like the correct filters or dither. Many audiophiles will assume that the lowest 8 bits of their CDs sounds just like a Commodore 64 playing Manic Miner, and that going to 16 bits just hides that grunge a little lower down. They do not realise that 8 bit audio sounds just like 16 bit audio, but just a little noisier (not more distorted or 'crunchy').

It's all in the Xiph video, of course (which is great) but it is clear that some people miss vital points.

Once they understand all that, they can begin to appreciate how imprecise vinyl is, and how 12 bit equivalence seems very optimistic indeed.
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: Kohlrabi on 2014-09-04 00:02:27
I get that under certain conditions, the discrete samples are sufficient to recover the original continuous-time function, but that's an entirely different issue. It's still true that there is a gap --  a positive distance -- between any two points in time s =/= t at which the continuous-time signal has been sampled.

I am not in this field and maybe, I have the wrong metric in the back of my mind. Still, I find Arnold's way of talking about this very confusing.
What Arnold says is that for a properly antialiased/low-passed sampled signal there is only one completely determined possible solution for the waveform, thus also the points between the sample points are determined. To quote:[quote author=Shannon link=msg=0 date=]If a function x(t) contains no frequencies higher than B cps, it is completely determined by giving its ordinates at a series of points spaced 1/(2B) seconds apart.[/quote]Of course by low-passing you discarded any higher frequency information before, and you had to as a prerequisite, as is evident from the first part of the quote.

I think it's more helpful to go over to the frequency domain, and think of audio signals as oscillations with certain frequencies. After sampling with a low-pass filter, the recorded samples allow you to continuously reproduce all of the recorded oscillations/frequencies below half the sampling frequency. Now it should be pretty evident that there is no "gap", at least regarding frequency/information content. If you want to think in the time domain, the sampling frequency defines the time spacing or time "gaps" between the sample points. But the points in these gaps correspond to higher frequencies. Also, if you assume time is not quantised, it is impossible to sample "gaplessly". But as I quoted above, this is also unnecessary for reproduction of the (relevant, low-passed) information.
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: Green Marker on 2014-09-04 05:45:10
I get that under certain conditions, the discrete samples are sufficient to recover the original continuous-time function, but that's an entirely different issue. It's still true that there is a gap --  a positive distance -- between any two points in time s =/= t at which the continuous-time signal has been sampled.

I am not in this field and maybe, I have the wrong metric in the back of my mind. Still, I find Arnold's way of talking about this very confusing.
What Arnold says is that for a properly antialiased/low-passed sampled signal there is only one completely determined possible solution for the waveform, thus also the points between the sample points are determined. To quote:[quote author=Shannon link=msg=0 date=]If a function x(t) contains no frequencies higher than B cps, it is completely determined by giving its ordinates at a series of points spaced 1/(2B) seconds apart.
Of course by low-passing you discarded any higher frequency information before, and you had to as a prerequisite, as is evident from the first part of the quote.

I think it's more helpful to go over to the frequency domain, and think of audio signals as oscillations with certain frequencies. After sampling with a low-pass filter, the recorded samples allow you to continuously reproduce all of the recorded oscillations/frequencies below half the sampling frequency. Now it should be pretty evident that there is no "gap", at least regarding frequency/information content. If you want to think in the time domain, the sampling frequency defines the time spacing or time "gaps" between the sample points. But the points in these gaps correspond to higher frequencies. Also, if you assume time is not quantised, it is impossible to sample "gaplessly". But as I quoted above, this is also unnecessary for reproduction of the (relevant, low-passed) information.
[/quote]
Who is this explanation for? If it is for an engineer or a mathematician then they probably know it already. If it is for a curious audiophile who understands how a needle tracks a wiggly groove, but has suspicions about how digital audio can achieve the same thing, then you are losing him at "frequency domain".... "Shannon"... "information theory"....a function x(t)"...

This chasm in understanding is where the myths and superstitions about digital audio have crept in.
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: mjb2006 on 2014-09-04 06:12:23
You hit the nail on the head. In the typical audiophile's view, there's just no way that samples can represent whatever the waveform is doing in between the sample points, unless the waveform just happens to be that one specific, tight curve. "What if the waveform is all squiggly in between the sample points? What if it's a square wave?"

What needs to be demonstrated is that the filter removing the frequencies above the Nyquist removes the between-sample squiggles such that the samples do represent this smoothed-out curve perfectly, and that this smoothing doesn't result in any crucial information being lost. Thus, those squiggles weren't contributing anything to the frequency components below the Nyquist. (That's right, right?)

IIRC, Monty's video shows some of this, but relies too much on his calm reassurances rather than a demo of every step of the process, both in simple terms and with a real-world example.
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: Kohlrabi on 2014-09-04 09:18:19
Who is this explanation for? If it is for an engineer or a mathematician then they probably know it already. If it is for a curious audiophile who understands how a needle tracks a wiggly groove, but has suspicions about how digital audio can achieve the same thing, then you are losing him at "frequency domain".... "Shannon"... "information theory"....a function x(t)"...

This chasm in understanding is where the myths and superstitions about digital audio have crept in.
By the way, in the following, when I say 'you' I mean the general 'you', not you, Green Marker:

I'm sorry, but if someone decides to talk about audio, signal processing and so forth I expect him to do some basic research himself. There are a vast amount of sources on the net to read up on this. This is as easy as it gets, beyond going out on a limb and giving a lecture on these matters. If someone chooses to be ignorant about these matters it's fine by me, but he should show a little dignity and please just stop talking about it. If you want to stay a child and expect that others spoon-feed you your information you should stay away from grown-up discussions. It's nobody's job here to teach, but some of us are really doing some steps towards the uninitiated.

What needs to be demonstrated is that the filter removing the frequencies above the Nyquist removes the between-sample squiggles such that the samples do represent this smoothed-out curve perfectly, and that this smoothing doesn't result in any crucial information being lost. Thus, those squiggles weren't contributing anything to the frequency components below the Nyquist. (That's right, right?)
Why does it "need to be demonstrated"? It has been shown and it's inside the mathematics and the explanations of the Shannon-Nyquist theorem. What needs to be done is that people who claim something back that up with evidence and at least acknowledge current scientific knowledge. We aren't all experts in these matters (I'm very far from it), but it's common discussion "rule" to back up or demonstrate some knowledge about the topics you talk about. Contrary to politics, art, and entertainment topics here are not only a matter of opinion.
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: 2Bdecided on 2014-09-04 10:05:35
Here is the process:

1. pick a sampling frequency
2. input signal
3. remove everything above half that sampling frequency using a filter
4. do your fancy digital sampling at that sampling frequency
5. remove everything above half the sampling frequency using a filter
6. output signal

No one says the input signal equals the output signal. There's two filters in there. They change the signal.

However, what is mathematically proven with as much certainty as 2+2=4 is that as long as you have stages 3 and 5, stage 4 makes absolutely no difference. Its presence or absence from the process is completely undetectable at the output. Take a while to understand that. It's pretty fundamental.

Sampling does not change the output if the right filters are in place.

Hence what matters, both in theory and in practice, is not sampling but filtering.

It is possible to design and realise (in the real world) a filter that will remove everything above half the sampling frequency to as good an accuracy as you want. The stuff you don't want can be made 180dB lower than the stuff you do want. That's a change equivalent to taking something that's as loud as a jet engine next to you, and reducing it so much that it becomes inaudible even in the quietest room on the planet. Hence the requirement to "remove" the frequencies above half the sampling frequency has been met.

You're left with only one potentially audible issue: did the filter (actually, both filters in series) mess up something that you can hear? It is possible to design and realise (in the real world) a filter that doesn't even touch anything below half the sampling frequency, again to as good an accuracy as you want. Any "faults" can again be made 180dB lower than the loudest signal. For all intents and purposes they just don't exist. It's better than the purest piece of wire you can imagine.

Up to a given frequency, it's perfect. Beyond that frequency, everything from the original signal has gone. Some people are concerned about the hard transition between those two states (at about 22kHz for CD audio), but you can soften the transition without breaking anything, as long as you soften it downwards.

Again, the question isn't about sampling. It's about filtering. Can you hear a filter that removes everything above 22kHz?

Cheers,
David.
P.S. there's quantisation too.
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: 2Bdecided on 2014-09-04 10:12:13
What needs to be demonstrated is that the filter removing the frequencies above the Nyquist removes the between-sample squiggles such that the samples do represent this smoothed-out curve perfectly, and that this smoothing doesn't result in any crucial information being lost. Thus, those squiggles weren't contributing anything to the frequency components below the Nyquist. (That's right, right?)

IIRC, Monty's video shows some of this, but relies too much on his calm reassurances rather than a demo of every step of the process, both in simple terms and with a real-world example.
Monty's video includes exactly this from about 4 minutes in...
http://xiph.org/video/vid2.shtml (http://xiph.org/video/vid2.shtml)
...showing exactly what you want from about 5 minutes with high frequency sine waves. Square waves at 17:50.

Good enough?

Cheers,
David.
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: Vietwoojagig on 2014-09-04 12:35:41
Maybe this is the right discussion to ask a question that came into my mind after watching Monty's video.

I understand that only one band limited signal is able to pass the samples perfectly to reconstruct the original band limited signal.
But how does the DAC know how to construct the signal between two samples. Does it do some math inside? Or to be more concrete: how are all the volts created that form this smooth curve?
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: 2Bdecided on 2014-09-04 13:12:15
It's convolved with (filtered by) a sinc pulse. That's it. Perfect reconstruction. It's pretty easy to do in practice, with ridiculous (i.e. far more than you need) amounts of precision.


However, you can use anything or nothing for the reconstruction filter. All the differences between what you have and what you want are above fs/2 (i.e. above 22kHz for a CD), hence your ears can't hear them, hence they don't matter. Really. Let your ears be the reconstruction filter.

Unfortunately ultrasonic junk like that interferes with non-ideal real-world equipment, so it's good practice to filter it out. Otherwise intermodulation distortion can cause the ultrasonic junk to have an effect within the audible range, or even damage equipment.


Also, the filter transition (between pass band and stop band) is often softened - so that instead of letting through everything up to 22.05kHz and stopping everything over 22.05kHz, it lets through 21kHz, stops 22kHz, and has a transition between. Or even it lets through everything up to 18kHz, stops everything above 22kHz, but has a 4kHz transition band in between where things are reduced but not eliminated. This is totally equivalent to using a perfect sinc pulse, and then applying the softened filter - so it's still conceptually "perfect" but then it also reduces the amplitude of everything above 18kHz.

Cheers,
David.
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: mjb2006 on 2014-09-04 15:37:42
What needs to be demonstrated is that the filter removing the frequencies above the Nyquist removes the between-sample squiggles such that the samples do represent this smoothed-out curve perfectly, and that this smoothing doesn't result in any crucial information being lost. Thus, those squiggles weren't contributing anything to the frequency components below the Nyquist. (That's right, right?)

IIRC, Monty's video shows some of this, but relies too much on his calm reassurances rather than a demo of every step of the process, both in simple terms and with a real-world example.
Monty's video includes exactly this from about 4 minutes in...
http://xiph.org/video/vid2.shtml (http://xiph.org/video/vid2.shtml)
...showing exactly what you want from about 5 minutes with high frequency sine waves. Square waves at 17:50.

Well, just to be sure, I watched them again, and my impression is the same. The fundamental concepts people need are provided by the videos in bits and pieces, a little at a time. You get a little bit in the first video at 4:30, and then in the second video at 7:00, 17:50, and 21:00. And then there's even some in Monty's responses to comments on the evolver.fm repost of the 24/192 article.

It's also all in different contexts. The stuff at 7:00 is great but it's all in the context of stairsteps. The stuff at 17:50 gives you some important info, but it's in the context of taking the mystery out of the Gibbs Effect. There's nothing demonstrating music and analog sources in there... and there shouldn't be, at first, but people need to see both the simplified fundamental concept and at least one example they can relate to.

It's just a lot to ask people to set aside whatever they believe about analog v. digital, watch all this video, glean very specific pieces of info from different parts of it, and integrate it with their impression of what's going on in record grooves and the digital sampling thereof. Pointing to Monty's work is the best we can do right now, but we should be able to do better.
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: Thad E Ginathom on 2014-09-04 18:11:50
Speaking as a self-selected sample of one...

Monty's videos were the turning point in my getting a better understanding of digital audio. Yes, I thought that sampling meant that stuff was left out, and that the wave form of digital music actually looked like steps --- and the more the better.

I'm a maths duffer, and graphs tend to freeze my brain. Even so, after watching Monty, I've been able to take in stuff from others who have the knack of making the depth of this stuff accessible to the likes of me, like JJ Johnston. I still have not reached the point where I can take in the equations, or where I do much more than take all that sync stuff except on trust from real mathematicians.

It may not be true of sample rates, but the more the merrier is certainly true of down-to-earth and accessible explanation of this stuff. Whoever wants to pile in with more will find a willing audience of people like me.

The other basic misconception amongst audiophiles, is that they suppose it to be a sampling theory, rather than a sampling theorem. Even the academic ones don't seem to appreciate the big difference.

EDIT:Whoops, can't spell theorem. Just shows how academic I'm not!
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: Green Marker on 2014-09-04 19:53:28
However, you can use anything or nothing for the reconstruction filter. All the differences between what you have and what you want are above fs/2 (i.e. above 22kHz for a CD), hence your ears can't hear them, hence they don't matter. Really. Let your ears be the reconstruction filter.


OK, I'm risking showing my ignorance here, but as I understand it, if we don't have the correct filter, the frequency response trails off gradually well before we approach Nyquist. Intuitively, that is because we are simply joining the dots with a 'non-ringing' filter which cannot create the peaks between samples that the sinc filter does.

Quote
It is already at -3.2dB by 20kHz

http://myweb.tiscali.co.uk/g8hqp/audio/CDsample.html (http://myweb.tiscali.co.uk/g8hqp/audio/CDsample.html)

edit: quote & link, plus added "well before we approach Nyquist"
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: Arnold B. Krueger on 2014-09-04 20:50:42
However, you can use anything or nothing for the reconstruction filter. All the differences between what you have and what you want are above fs/2 (i.e. above 22kHz for a CD), hence your ears can't hear them, hence they don't matter. Really. Let your ears be the reconstruction filter.


OK, I'm risking showing my ignorance here, but as I understand it, if we don't have the correct filter, the frequency response trails off gradually well before we approach Nyquist. Intuitively, that is because we are simply joining the dots with a 'non-ringing' filter which cannot create the peaks between samples that the sinc filter does.

Quote
It is already at -3.2dB by 20kHz

http://myweb.tiscali.co.uk/g8hqp/audio/CDsample.html (http://myweb.tiscali.co.uk/g8hqp/audio/CDsample.html)

edit: quote & link, plus added "well before we approach Nyquist"


Not the best article in the world.

Producing ADC/DAC pairs that have loss on the order of -0.1 dB at 20 KHz was commonly done in the 1980s.  The Sony CDP 101 was one of the two first CD players introduced to the public in 1982, and it had analog reconstruction filters. The Philips CD-100 was introduced about the same time and it had digital filters and oversampling.
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: Green Marker on 2014-09-04 20:56:22
Producing ADC/DAC pairs that have loss on the order of -0.1 dB at 20 KHz was commonly done in the 1980s.  The Sony CDP 101 was one of the two first CD players introduced to the public in 1982, and it had analog reconstruction filters. The Philips CD-100 was introduced about the same time and it had digital filters and oversampling.

True I'm sure, but not answering the point I was i.e. that any, or no filter will do.
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: Arnold B. Krueger on 2014-09-04 22:34:25
Producing ADC/DAC pairs that have loss on the order of -0.1 dB at 20 KHz was commonly done in the 1980s.  The Sony CDP 101 was one of the two first CD players introduced to the public in 1982, and it had analog reconstruction filters. The Philips CD-100 was introduced about the same time and it had digital filters and oversampling.

True I'm sure, but not answering the point I was i.e. that any, or no filter will do.



That of course depends on "will do" means. If we are talking about LPs or analog tape, then - 3.2 dB @ 20 KHz at FS is pretty darn good.
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: Green Marker on 2014-09-04 23:04:57
That of course depends on "will do" means. If we are talking about LPs or analog tape, then - 3.2 dB @ 20 KHz at FS is pretty darn good.


So in our hypothetical conversation with the vinyl-oriented audiophile we have gone from digital audio being theoretically exact, to saying that joining the dots with straight lines (just as he imagined they were) and being -3dB down at 20kHz is darn good. Hmm...
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: saratoga on 2014-09-04 23:11:35
However, you can use anything or nothing for the reconstruction filter. All the differences between what you have and what you want are above fs/2 (i.e. above 22kHz for a CD), hence your ears can't hear them, hence they don't matter. Really. Let your ears be the reconstruction filter.


OK, I'm risking showing my ignorance here, but as I understand it, if we don't have the correct filter, the frequency response trails off gradually well before we approach Nyquist.


If you have no filter, the frequency response is infinite, and therefore never trails off.  You'll accurately reproduce many images of the signal at higher and higher frequencies.

Of course an infinite bandwidth is impossible in the real world, so even if you don't include a filter, something in your circuit will act as one, and eventually the frequency response rolls off.  In some applications the ability to produce or record image/aliased frequencies is desired, in which case no filter is used.  In this case, the response typically rolls off quite badly by about 2 or 3 times the Nyquist limit, although that can be tuned and in some cases is much greater.

Intuitively, that is because we are simply joining the dots with a 'non-ringing' filter which cannot create the peaks between samples that the sinc filter does.


If the bandwidth is infinite you don't join the dots at all.  The signal instantly reaches the value specified, and then instantly decreases back to zero again until the next sample comes along.  This is what enables reproduction of image frequencies (replicas of your signal at frequencies above Nyquist).  This is not physically possible of course, so in practice you'll generate little sinc(x) functions (or something very close to them) around each sample.  As the bandwidth increases the sinc() functions get narrower and more delta-like.
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: Kohlrabi on 2014-09-04 23:28:07
So in our hypothetical conversation with the vinyl-oriented audiophile we have gone from digital audio being theoretically exact, to saying that joining the dots with straight lines (just as he imagined they were)
Who said that? It doesn't matter how you join the dots, it's just a graphical representation. Yes it's a stairstep, or straight lines, or wavy spline lines. But this is completely, utterly unimportant, and just a pretty picture for visualization. Sampling works the same regardless of how your software or scope represents the joining of sample points.
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: Green Marker on 2014-09-05 00:04:32
So in our hypothetical conversation with the vinyl-oriented audiophile we have gone from digital audio being theoretically exact, to saying that joining the dots with straight lines (just as he imagined they were)
Who said that? It doesn't matter how you join the dots, it's just a graphical representation. Yes it's a stairstep, or straight lines, or wavy spline lines. But this is completely, utterly unimportant, and just a pretty picture for visualization. Sampling works the same regardless of how your software or scope represents the joining of sample points.

Ah, you see, this is exactly the problem. We're not talking about a mere representation, but literally how the dots are joined together before feeding the signal into the amp. We are now being told that any filter at all will do, or even no filter at all, which is not what the Xiph video says, for one.

To say that a filter-less DAC does not have a roll-off before Nyquist because in that case the frequency response is "infinite" is the very definition of semantics. Using a theoretically-correct filter (or as close as is practical) will give us a perfect (or as near as practical) response. By leaving the filtering to the amp or the listener's ear will give us a perceptible treble roll-off (and other nasties, probably). Why can't we simply agree that a digital sampling system needs a theoretically-correct (sigh, or as near as practical) reconstruction filter?
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: saratoga on 2014-09-05 00:16:26
To say that a filter-less DAC does not have a roll-off before Nyquist because in that case the frequency response is "infinite" is the very definition of semantics.


In so much as it is a trivially true statement, yes.

By leaving the filtering to the amp or the listener's ear will give us a perceptible treble roll-off (and other nasties, probably).


No absolutely not.  Otherway around:  you can't have roll off without something to provide filtering.  An infinite bandwidth means an infinitely high frequency response and zero roll off.

Does that make sense?  Its only once you have something filtering (either a reconstruction filter or else the limited bandwidth of the wires and chips themselves) out higher frequencies that you get roll off (which makes sense since roll off is literally just the filtering out of higher frequencies.

Why can't we simply agree that a digital sampling system needs a theoretically-correct (sigh, or as near as practical) reconstruction filter?


It depends on what you mean by "needs".  In practice it probably doesn't matter if the filter cuts off near Nyquist or not, although its a good idea because it will tend to make things a lot easier for your speakers afterwards.  If you're going to pump a lot of ultrasound into your equipment, you'll need to make sure they have the capacity to handle that power, and low enough distortion that you don't hear any intermodulation.
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: Green Marker on 2014-09-05 00:36:01
No absolutely not.  Otherway around:  you can't have roll off without something to provide filtering.  An infinite bandwidth means an infinitely high frequency response and zero roll off.

Does that make sense?  Its only once you have something filtering (either a reconstruction filter or else the limited bandwidth of the wires and chips themselves) out higher frequencies that you get roll off (which makes sense since roll off is literally just the filtering out of higher frequencies.


Here's a link to a document that contains a picture of the frequency response of an unfiltered DAC. It droops all the way to Nyquist and you get images out to infinity...

http://www.analog.com/static/imported-file...ials/MT-017.pdf (http://www.analog.com/static/imported-files/tutorials/MT-017.pdf)

The energy in the images are useless to us and cannot be heard (they're ultrasonic) so "perceptibly" (as I said) there is a treble roll-off without the correct filter. An inverse sinc filter (or as near as practical, as I have to state round here, every time!) will correct the roll-off and suppress the images. Perfect!

edit: *inverse* sinc filter
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: saratoga on 2014-09-05 00:53:46
No absolutely not.  Otherway around:  you can't have roll off without something to provide filtering.  An infinite bandwidth means an infinitely high frequency response and zero roll off.

Does that make sense?  Its only once you have something filtering (either a reconstruction filter or else the limited bandwidth of the wires and chips themselves) out higher frequencies that you get roll off (which makes sense since roll off is literally just the filtering out of higher frequencies.


Here's a link to a document that contains a picture of the frequency response of an unfiltered DAC.


That is not what you have linked.  That is actually the frequency response of a zero order hold DAC.

You may find this wikipedia article helpful in understanding that document:

http://en.wikipedia.org/wiki/Zero-order_hold (http://en.wikipedia.org/wiki/Zero-order_hold)

It droops all the way to Nyquist and you get images out to infinity...


A zero order hold DAC does not have an infinite bandwidth.  As your link notes, it has a 3.92 dB loss at Nyquist, meaning that its bandwidth is less than half the sampling rate.  In contrast, a typical DAC will have a bandwidth greater than half the sampling rate, and an infinite bandwidth DAC actually has an infinite bandwidth.

An inverse sinc filter (or as near as practical, as I have to state round here, every time!) will correct the roll-off and suppress the images. Perfect!


This is true for a zero order hold DAC, but not for a real DAC, which is what people in this thread are discussing...
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: Arnold B. Krueger on 2014-09-05 01:29:40
That of course depends on "will do" means. If we are talking about LPs or analog tape, then - 3.2 dB @ 20 KHz at FS is pretty darn good.


So in our hypothetical conversation with the vinyl-oriented audiophile we have gone from digital audio being theoretically exact, to saying that joining the dots with straight lines (just as he imagined they were) and being -3dB down at 20kHz is darn good. Hmm...


No, the  hypothetical conversation with the vinyl-oriented audiophile got derailed from a middle-of-the-road well-designed  modern digital audio system to some Frankenstein system that someone made up.

There actually were a few cheapo-cheapo DACs with no output filters in the middle 1990s, but they are long gone. And there a few naive audiophiles who have built retro-freako, one-of-a-kind basement project DACs with the same problems. You can't stop people from doing crazy things in the privacy of their own homes.

Let's clarify this. The digital domain is as both theoretically and practically exact unless someone goes out of their way to introduce changes.

Unfortunately the analog systems on either side of the digital domain are as crappy and inexact as they ever were for a given amount of processing.  The big improvement over the past 20 or more years is that by moving most of the processing and all of the storage and data transmission into the truly perfect digital domain, we've done away with the need for most of that analog crap.
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: Green Marker on 2014-09-05 08:42:16
No, the  hypothetical conversation with the vinyl-oriented audiophile got derailed from a middle-of-the-road well-designed  modern digital audio system to some Frankenstein system that someone made up.


An excellent way of putting it!
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: 2Bdecided on 2014-09-05 11:02:29
To say that a filter-less DAC does not have a roll-off before Nyquist because in that case the frequency response is "infinite" is the very definition of semantics. Using a theoretically-correct filter (or as close as is practical) will give us a perfect (or as near as practical) response. By leaving the filtering to the amp or the listener's ear will give us a perceptible treble roll-off (and other nasties, probably). Why can't we simply agree that a digital sampling system needs a theoretically-correct (sigh, or as near as practical) reconstruction filter?

I refer you to my previous posts.
This is perfection:
http://www.hydrogenaud.io/forums/index.php...st&p=873787 (http://www.hydrogenaud.io/forums/index.php?s=&showtopic=93998&view=findpost&p=873787)

The second half of this is still perfection within the audible range:
http://www.hydrogenaud.io/forums/index.php...st&p=873795 (http://www.hydrogenaud.io/forums/index.php?s=&showtopic=93998&view=findpost&p=873795)


Let me explain it further. The first filter (anti-alias filtering, before sampling) is vital. If it's wrong, and lets in any frequency components above fs/2, the audio signal within the audible range is irreversibly damaged.

If you want to see the same waveform at the output, the second filter must be perfect too. Then you can visually (and mathematically) demonstrate that the overall process is perfect, and sampling does nothing to the signal.

If you don't filter, and output instantaneous (or near instantaneous) samples, then what you get is still perfect within the audible range. All the differences are above 22kHz.

If you don't properly "filter", but just output the sample values with zero-hold (i.e. a stair-step), then the frequency response gets multiplied by a sinc filter*: 3dB down at fs/2. But this is a really important thought experiment: if you still don't do "proper" filtering, but take the stair-steps, add a little filter that's the inverse of the sinc filter within the audible range (i.e. something that's does nothing at DC, and boosts 3dB at fs/2, with the right slope in between) the result, within the audible range, is perfect. The waveform looks really strange - steppy and now with little flicks/overshoots on the edge of each step - yet within the audible range, the result is perfect. All the visual difference is due to differences outside the audible range. The wierdy steppy waveform with flicks is exactly what you want in the audible range, plus lots of ultrasonic junk that you can't hear.

Get it? Perfect reconstruction is easily possible. It's desirable because it lets you look at the waveform as say "it's exactly the same", and it present a clean and easy signal to amplifiers and speakers, free from ultrasonic junk that may make them distort. But if you do no reconstruction at all, or stair-step reconstruction plus a little high frequency boost, the signal within the audible range is STILL perfect. All the stair-steppy-ness, and even the weird beating / amplitude modulation you see when sampling, say, 20kHz at 44.1kHz - all the stuff you see that wasn't in the original signal is above 22kHz, and so (if speakers didn't have a tendancy to distort when fed with high levels of ultrasonics, making the inaudible become audio) would be inaudible.


The point of all this? Some people like to say "ah well, digital sampling might be perfect in theory, but you can't make the filters good enough for it to be even half-decent in practice". Rubbish. 1) you can. 2) you don't even need to (except your speakers would prefer it if you tried to do a reasonable job!).

Cheers,
David.

P.S. If the filters are imperfect within the audible range, then they change the signal in the way that they change the signal. No more, no less. It's not magic. So if someone builds a filter that attenuates the signal by 3dB at 18kHz, then that's what it does. But it doesn't do something worse than that just because it's part of a DAC. The worst anyone ever did ina  DAC filter is still better than 99% of cartridges used for playing vinyl, and despite audiophile folklore, it doesn't magically become worse just because it's applied to digital audio rather than analogue.


* = a sinc shape in the frequency domain, not the time domain - don't get confused by sinc cropping up again here. You may recall from a previous post that you want a sinc filter - but that was a sinc shape in the time domain which gives you a flat response in-band in the frequency domain. Whereas here you have a sinc shape in the frequency domain, because of all those unwanted flat-tops in the waveform in the time domain. The time and frequency domains are related like this - it's a fascinating subject, but probably not one for today.

EDIT: spelling!
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: Arnold B. Krueger on 2014-09-05 12:54:46
No, the  hypothetical conversation with the vinyl-oriented audiophile got derailed from a middle-of-the-road well-designed  modern digital audio system to some Frankenstein system that someone made up.


An excellent way of putting it!


Nevertheless, the devil must be given his due. Even doing something crazy by leaving off the final low pass filter produces a system that is still far better than vinyl.
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: xnor on 2014-09-05 12:57:39
A sinc filter is an ideal low pass filter.
DC to fc: 1 = 0 dB
fc: 0.5 = -6.02 dB
fc up: 0 = -inf dB
response (http://www.cg.tuwien.ac.at/~theussl/DA/img124.gif) (pi on the x-axis would be fc)

Zero-order hold on the other hand is simply a bad low pass filter, like the rectangular window.
Roll-off to fc (about -4 dB), nulls only at multiples of the original sample rate.
response (http://www.diracdelta.co.uk/science/source/r/e/rectangular%20window/image-002.jpg) (0.5 on the x-axis would be fc)
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: cdroid on 2014-09-06 02:44:27
I've read some of your responses and I'm slightly upset to be perfectly honest. First allow me to respond by qualifying myself.
No, I am not a hobbyist. I am a student with a certificate in digital audio and I'm currently working towards an AA. I spent all morning discussing digital audio theory with my professor who would adamantly disagree with the responses I've read. No, my post was not riddled with audiophile lore, it was riddled with facts from my course books. I have also chosen this as my career path and am literally paid to know these things.

First I will discuss the MP3 and DAC related posts that many people commented on.
Yes, MP3 lossy compression actually is a serious problem and we can actually test that very simply;
Grab a CD with Red Book specifications. Now, set your iTunes to decode to AAC. Burn the disk to AAC. Now listen. Then set your iTunes to decode to WAV. Now listen.
I did this test a couple days ago because I'm looking at upscaling my entire iTunes library when I sync to a NAS server on my internal network, and I noticed a huge improvement even on small shotty speakers over my shotty DAC on my iMac.
If you can't hear the difference from this test, then you're probably a hobbyist with untrained ears. Look at the file difference. The WAV files are going to be almost 5 times the size of AAC files. The AAC encoder is dropping a whole lot more audio information than you'd care to admit. And put AAC vs. WAV aside for a second, I think we can all agree that AAC is better quality than MP3. How much more will the difference between MP3 and WAV be?

Now let's start talking DACs. Just so you have a feel of where I'm coming from; I no longer am impressed by Avid Venue DACs (or preamps, but that's another issue) or the last couple generations of Pro Tools HD DACs (again, Avid Preamps suck). I was, however, impressed with the MIDAS and Digico DACs. In the studio I would be happy with UAD Apollo DAC as well as Apogee DAC.
In the more affordable range, I used to use PreSonus for DAC and I thought it was hot but that was about 5~6 years ago now. Now I use the new Behringer DACs and I'm very happy for the price. When I need high fidelity quality for mixing or mastering, I use my MOTU interface and have been satisfied.
Obviously I don't expect the consumer market to invest in pro audio equipment just to listen to music (you should), so I would recommend the Behringer UCA222; it will do the trick. I haven't personally tried the consumer grade products or USB headphone amps but I'm sure they'd be sufficient.
I also just realized that perhaps I should qualify what I meant when I said that computer DACs don't sound good. If you own a tower and you have anything near a half decent sound card in there, then you've likely got a quality DAC. What I was talking about is laptops or all in one computers with the sound card built into the motherboard. Laptops, phones, and All in one computers have always packed 10 pounds of crap into a 5 pound bag (this is why I'm going to build a tower to replace my Macbook Pro) and you can't trust those DACs to do their job. I was using my MacBook Pro to listen to music, and then substituted my UCA222 I mentioned earlier for my built in DAC and noticed a pretty massive quality increase.

I saw a person argue that DACs have been stable for 20~25 years (I do not kid you, go read the second or third post from mine, it will give you a good laugh if you understand digital audio and computer theory) which is preposterous since digital recording was only available to the consumer about 25 years ago. My professor who has used Pro Tools since it was called Sound Tools would have argued that even 20 years ago it was new and unstable technology, and if you asked him I think he'd argue that even the last generation of Pro Tools HD DACs are unstable (the new architecture of HDX is a lot better).
There are a few things that effect DAC quality (besides being inherently vulnerable to errors) including noise, harmonic distortion, max sample rates, and dynamic range.

One of the biggest issues with cheaper DACs like the ones in phones and the like is the signal to noise ration. When you use cheap parts you're going to get noise.

I don't feel like reading the rest of the responses tonight because I really am just not in the mood for that. Surprise; it upsets me to spend 8 hours with a college professor and another hour or two reading suggested course material only to log onto my computer to have a hobbyist refer me to some youtube videos and wiki pages.
To the smart alek referring me to wiki pages; read Audio Engineering 101. It will serve as a decent intro so you can launch into some better primers to the audio world like Principles of Digital Audio: Sixth Edition. The first chapter of Principles of Digital Audio will go over computer language such as binary and hex and help you understand exactly what lossy encoders do.
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: cdroid on 2014-09-06 02:59:44
I forgot to reply to the post that irritated me the most. I had said that DSP (digital signal processing) has not surpassed analog processors, and some dude who admitted he has no experience said he doubts it. For starters, when you see Chris Lord Algae selling his LA-2A, then you can believe that the CLA-2A plugin has surpassed analog. In the meantime, all the pros are exporting their Pro Tools HDX recordings back into an analog soundboard using analog gear for inserts and there is a reason for that.

Digital coding has become a lot better, especially since the UAD 2 procs are using the new SHAARC chips. Those UAD plugins have become good enough that The Black Keys are mixing all in the box, but they're pioneering that trend and no one else (except post engineers) are really following suit. Even though the new Pultec eq from UAD is a lot better than the legacy one, it doesn't compare to the classic Pultec tubes (or the new ones since Pulse Technics is back on Sweetwater). People are still buying or building tube LA-2As even though a UAD proc with the LA-2A plugin collection is cheaper. This is because mathematics can't replace the sound of a good tube. The plugins are just algorithms, and these algorithms become increasingly complex the closer these engineers try to model the way the classic gear responds to different signals and setting tweaks.
Digital plugins that aren't modeled after analog gear are missing most of the harmonic distortions that are sonically pleasing. You won't see engineers trading out their racks of gear for UAD, and you won't see engineers trading out their analog soundboard for Slate VCC. Anyone who owns a Studer would laugh at the A800 plugin for UAD.

Now, go talk to guitarists about Amp modeling. Go ahead, I dare you to open that can of worms. Rush is the only major band using amp modeling, and they're still using real heads.
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: splice on 2014-09-06 04:17:45
Sigh... this place needs a :facepalm: icon.

I've read some of your responses and I'm slightly upset to be perfectly honest. First allow me to respond by qualifying myself.
No, I am not a hobbyist. I am a student with a certificate in digital audio and I'm currently working towards an AA. I spent all morning discussing digital audio theory with my professor who would adamantly disagree with the responses I've read. No, my post was not riddled with audiophile lore, it was riddled with facts from my course books. I have also chosen this as my career path and am literally paid to know these things. ...


You might take a moment to examine the CVs of the people in this discussion. You will find they used to be like you once, but now they're older and know a lot more.


First I will discuss the MP3 and DAC related posts that many people commented on. ...


If you did your homework, you would know that some of the people here code perceptual compression algorithms and design DACs for a living. The phrase "teaching your grandmother to suck eggs" springs to mind. 

... some youtube videos and wiki pages.  ...


Do you know who Chris (Monty) Montgomery is and what he does for a living?
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: splice on 2014-09-06 04:22:36
... when you see Chris Lord Algae selling his LA-2A ...


If you're going to hold Chris up as an example, you ought to at least spell his name correctly.

I think the rest of your post would be better posted over in the Purple Place.
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: sld on 2014-09-06 04:56:04
First I will discuss the MP3 and DAC related posts that many people commented on.
Yes, MP3 lossy compression actually is a serious problem and we can actually test that very simply;
Grab a CD with Red Book specifications. Now, set your iTunes to decode to AAC. Burn the disk to AAC. Now listen. Then set your iTunes to decode to WAV. Now listen.
I did this test a couple days ago because I'm looking at upscaling my entire iTunes library when I sync to a NAS server on my internal network, and I noticed a huge improvement even on small shotty speakers over my shotty DAC on my iMac.
If you can't hear the difference from this test, then you're probably a hobbyist with untrained ears. Look at the file difference. The WAV files are going to be almost 5 times the size of AAC files. The AAC encoder is dropping a whole lot more audio information than you'd care to admit. And put AAC vs. WAV aside for a second, I think we can all agree that AAC is better quality than MP3. How much more will the difference between MP3 and WAV be?

Please perform a double-blind test to back your claims up. If the difference is trivial to distinguish, an ABX of it would be a cinch to perform at <0.01 confidence.

As for the rest of your diatribe... we'll patiently wait for the responses to that as the earth spins around to the other side. You have a lot to learn and a lot to unlearn. One being that you have to concede that your professor may be as wrong as you when applying DA concepts to the real world.
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: probedb on 2014-09-06 09:14:30
The first chapter of Principles of Digital Audio will go over computer language such as binary and hex and help you understand exactly what lossy encoders do.


You do know LAME developers use this forum don't you? As did/do the developers of FLAC etc.

You make the completely incorrect assumption that because it's a forum that everyone here is someone just messing about in their spare time with this stuff.
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: Green Marker on 2014-09-06 09:20:44
In the meantime, all the pros are exporting their Pro Tools HDX recordings back into an analog soundboard using analog gear for inserts and there is a reason for that.

Hi cdroid

I had no idea that this was going on! However, my scepticism with this sort of thing knows no bounds, and that is because of basic psychology i.e. that we are all susceptible to 'expectation bias' and all its variants, and that even the most hardened professional cannot avoid it. There was a little example of this a couple of months back on a BBC radio programme where they got some professional recording gurus to describe what they were hearing when comparing standard CD with 'high res'. They could hear extra warmth, detail, "reverberant tails" etc. etc. But it turned out that the producer had mistakenly given them the files in the wrong order or some such (or done it deliberately - I can't quite remember), and they ended up with egg on their faces despite their guru status. If a "pro" decides that audio sounds better when patched through an analogue mixing desk, or played back via a gramophone, it simply has no effect on me. These same "pros" are probably deeply dismissive of audiophiles and would laugh if we suggested they should use $1000/m cables in their studios or raise them on little ceramic supports. It's all the same thing, in my opinion.
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: KozmoNaut on 2014-09-06 10:26:53
Please perform a double-blind test to back your claims up. If the difference is trivial to distinguish, an ABX of it would be a cinch to perform at <0.01 confidence.


I think an ABX test between an analog piece of gear and the digital counterpart could be passed relatively easy in some cases, considering a lot of them probably don't sound 100% identical despite being made for the same effect or purpose. But just because they're slightly different, who's to say which one is objectively "the best"?

Why would the analog version be "the best" only because it's older? What if most people happen to like the sound of the digital version (ie. a more accurate and precise signal treatment)?

At that point, we're moving into subjective opinions.
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: mjb2006 on 2014-09-06 11:07:44
I'm impressed. Not many people can read Principles of Digital Audio, including its chapter on perceptual coding, and come away spouting nonsense like AAC must be discarding gobs of important data, just because it's way smaller than WAV.
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: Arnold B. Krueger on 2014-09-06 12:34:32
Please perform a double-blind test to back your claims up. If the difference is trivial to distinguish, an ABX of it would be a cinch to perform at <0.01 confidence.


I think an ABX test between an analog piece of gear and the digital counterpart could be passed relatively easy in some cases, considering a lot of them probably don't sound 100% identical despite being made for the same effect or purpose.


Given the range of quality levels of equipment that exists, from $10 portable CD player on up, the above would appear to be a truism. It seems to skip over the meat of the controversy.

The meat of the controversy includes false ideas such as the following:

(1) No piece of digital gear can sound good because of all of the inherent flaws in digital audio including the missing data between the samples.
(2) Only exceptionally well-engineered gear that is highly expensive can sound good.
(3) Every piece of audio gear has its own obvious characteristic sonic signature due to the different designs and parts that are used.


and so on.
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: Arnold B. Krueger on 2014-09-06 12:38:57
I've read some of your responses and I'm slightly upset to be perfectly honest. First allow me to respond by qualifying myself.
No, I am not a hobbyist. I am a student with a certificate in digital audio and I'm currently working towards an AA. I spent all morning discussing digital audio theory with my professor who would adamantly disagree with the responses I've read. No, my post was not riddled with audiophile lore, it was riddled with facts from my course books. I have also chosen this as my career path and am literally paid to know these things.

First I will discuss the MP3 and DAC related posts that many people commented on.
Yes, MP3 lossy compression actually is a serious problem and we can actually test that very simply;
Grab a CD with Red Book specifications. Now, set your iTunes to decode to AAC. Burn the disk to AAC. Now listen. Then set your iTunes to decode to WAV. Now listen.
I did this test a couple days ago because I'm looking at upscaling my entire iTunes library when I sync to a NAS server on my internal network, and I noticed a huge improvement even on small shotty speakers over my shotty DAC on my iMac.
If you can't hear the difference from this test, then you're probably a hobbyist with untrained ears. Look at the file difference. The WAV files are going to be almost 5 times the size of AAC files. The AAC encoder is dropping a whole lot more audio information than you'd care to admit. And put AAC vs. WAV aside for a second, I think we can all agree that AAC is better quality than MP3. How much more will the difference between MP3 and WAV be?


Two words: sighted evaluation. Doing DBTs involving lossy encoding are very easy to do, and I'm surprised that many people's alleged education has skipped over this.

Quote
Now let's start talking DACs. Just so you have a feel of where I'm coming from; I no longer am impressed by Avid Venue DACs (or preamps, but that's another issue) or the last couple generations of Pro Tools HD DACs (again, Avid Preamps suck). I was, however, impressed with the MIDAS and Digico DACs. In the studio I would be happy with UAD Apollo DAC as well as Apogee DAC.
In the more affordable range, I used to use PreSonus for DAC and I thought it was hot but that was about 5~6 years ago now. Now I use the new Behringer DACs and I'm very happy for the price. When I need high fidelity quality for mixing or mastering, I use my MOTU interface and have been satisfied.



Same two words: sighted evaluation. Doing DBTs involving DACs and ADCs  are also very easy to do, and I'm surprised that many people's alleged education has skipped over this.


Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: Kohlrabi on 2014-09-06 16:15:34
I've read some of your responses and I'm slightly upset to be perfectly honest. First allow me to respond by qualifying myself.
No, I am not a hobbyist. I am a student with a certificate in digital audio and I'm currently working towards an AA. I spent all morning discussing digital audio theory with my professor who would adamantly disagree with the responses I've read. No, my post was not riddled with audiophile lore, it was riddled with facts from my course books. I have also chosen this as my career path and am literally paid to know these things.
Irrelevant (http://en.wikipedia.org/wiki/Argument_from_authority). I'd argue the other way around, it's pretty sad that you can certified without basic knowledge about lossy encoding:
If you can't hear the difference from this test, then you're probably a hobbyist with untrained ears. Look at the file difference. The WAV files are going to be almost 5 times the size of AAC files. The AAC encoder is dropping a whole lot more audio information than you'd care to admit. And put AAC vs. WAV aside for a second, I think we can all agree that AAC is better quality than MP3. How much more will the difference between MP3 and WAV be?
I'd also like to know how your line of reasoning can explain that AAC can sound better than MP3 while using less bits per second. Didn't the AAC encoder drop more information than the MP3 one? Shouldn't that already have shown you that your reasoning is flawed, that you contradict yourself in just the next sentence?

One of the biggest issues with cheaper DACs like the ones in phones and the like is the signal to noise ration. When you use cheap parts you're going to get noise.
Have you actually looked at measurements of MP3 player and phone DACs? copper has a nice selection of RMAA results (http://outpost.fr/rmaa/), and you can easily find lots more. While these might not be good enough for producers and engineers, most of them are just fine for consumer audio reproduction.

I forgot to reply to the post that irritated me the most. I had said that DSP (digital signal processing) has not surpassed analog processors, and some dude who admitted he has no experience said he doubts it. For starters, when you see Chris Lord Algae selling his LA-2A, then you can believe that the CLA-2A plugin has surpassed analog. In the meantime, all the pros are exporting their Pro Tools HDX recordings back into an analog soundboard using analog gear for inserts and there is a reason for that.
And do you care to elaborate on that reason? Or is it just "because they are pros" (http://en.wikipedia.org/wiki/Argument_from_authority)? I guess it gives a warmer and fuzzier feeling to work in the analog domain. Because you really can't trust computers to add and multiply numbers.
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: Thad E Ginathom on 2014-09-06 19:12:23
I've read some of your responses and I'm slightly upset to be perfectly honest.


Good. So you should be. Now turn that into something by learning from some of the people here. You have no idea what a rich resource you have stumbled into.
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: Wombat on 2014-09-06 19:48:10
Time to fire up my old gear and listen a Burr Brown PCM63 (1990) with Burr Brown OPA627 (1989) listening to a full digital DDD recording done by Telarc in 1981, The Nutcracker.
Now i really have to wonder what part of digital audio is better understood now?
The uncountable really bad sounding recent records is only a sign of a declining art by strange audio engineers to me.
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: Kohlrabi on 2014-09-06 20:26:01
The uncountable really bad sounding recent records is only a sign of a declining art by strange audio engineers to me.
Leads one to wonder if that is somehow related to the claim that "pros" are using analog gear again.
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: saratoga on 2014-09-06 20:37:09
No, I am not a hobbyist. I am a student with a certificate in digital audio and I'm currently working towards an AA. I spent all morning discussing digital audio theory with my professor who would adamantly disagree with the responses I've read. No, my post was not riddled with audiophile lore, it was riddled with facts from my course books. I have also chosen this as my career path and am literally paid to know these things.


hahaha
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: xnor on 2014-09-06 22:04:05
I have studied UFOlogy, and as such I can tell you with certainty, that aliens visit us regularly. I am literally an expert in this field, so you can trust me that I relay this information 100% accurately.

I am offended, however, that y'all seem to reject that fact.
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: Arnold B. Krueger on 2014-09-07 00:01:14
I saw a person argue that DACs have been stable for 20~25 years (I do not kid you, go read the second or third post from mine, it will give you a good laugh if you understand digital audio and computer theory)


I don't know where you got the idea that anybody thinks that DACs have been stable for 20-25 years.

There have been one general area of great change being price/performance. The change has been in two directions, the first being higher performance and the second being lower prices for a given amount of performance.  The technological revolution has been the introduction and development of sigma-delta converters, However sigma delta converters are nothing new - the basic technology goes back to 1962.  In the early 1990s (22 years ago) they became the predominate converter technology, based on digital logic with sufficiently high speed coming down in price.

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which is preposterous since digital recording was only available to the consumer about 25 years ago.


All consumers need is digital playback, and digital playback has been available to consumers since 1982 which is 34 years ago. I guess that some revisionist history is being bandied about.

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My professor who has used Pro Tools since it was called Sound Tools would have argued that even 20 years ago it was new and unstable technology, and if you asked him I think he'd argue that even the last generation of Pro Tools HD DACs are unstable (the new architecture of HDX is a lot better).


Here's a news flash - Pro Tools is not the sole center of the universe, and like so many *name* products, technologically it hasn't always been that great. Furthermore, it has been tied to proprietary hardware, and hoping for an organization to get both hardware and software right is a big expectation.

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There are a few things that effect DAC quality (besides being inherently vulnerable to errors) including noise, harmonic distortion, max sample rates, and dynamic range.


That's all true, but the law of diminishing returns affects converters just like everything else. Numbers are just numbers, and specs are just specs. Whats of the essence is determining the performance level that is required to have good sounding recording and playback.


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One of the biggest issues with cheaper DACs like the ones in phones and the like is the signal to noise ration. When you use cheap parts you're going to get noise.


This isn't a discussion about telephones, its about professional recording hardware and quality consumer playback hardware. That all said many of the DACs in most portable music players, smart phones and the like are really quite good - about as good as the first and second generation CD players which is really quite good.

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I don't feel like reading the rest of the responses tonight because I really am just not in the mood for that. Surprise; it upsets me to spend 8 hours with a college professor and another hour or two reading suggested course material only to log onto my computer to have a hobbyist refer me to some youtube videos and wiki pages.


I'm hoping that you aren't getting he most out of your university experience, because I'd be really ticked off if I thought that what I was hearing here is good rendition of their best.

Also, don't confuse HA with your typical consumer hifi forum. There are pros here, and there are people with good audio credentials.

Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: xnor on 2014-09-07 01:06:17
The Sony CDP-101, released in 1982, had only one "major" flaw: due to production costs they only used 1 DAC for both channels.

Sure, its low-level linearity was not awesome (still better than vinyl) because they didn't use oversampling (which was however also available in 1982 in the Phillips CD100), but other than that it was an excellent product.
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: Arnold B. Krueger on 2014-09-07 15:58:23
The Sony CDP-101, released in 1982, had only one "major" flaw: due to production costs they only used 1 DAC for both channels.

Sure, its low-level linearity was not awesome (still better than vinyl) because they didn't use oversampling (which was however also available in 1982 in the Phillips CD100), but other than that it was an excellent product.


I've had two CDP 101s that were still operational available to me for detailed testing. Mine died in the early 90s and was disposed of in the garbage.

The non-use of oversampling was the biggest problem, but it didn't manifest itself as low level nonlinearity, it manifests itself as the frequency response and phase ortifacts of the all-analog LCR brick wall  low pass filter.

The shared DAC made itself known as a half-sample delay between the channels which added more phasing effects.

The low level nonlinearity was just fine - no evidence of it at all or shall we say it was randomized by dither and therefore had no audible or measurable consequences.

Jitter was just fine, too.

With pink nose or certain choral works the FR and phase funnies have been detected in DBTs.  It was mentioned by the SR "All CD players sound the ame?" article.

The next generation CD players that came out in the mid-90s were sonically blameless.
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: xnor on 2014-09-07 17:26:30
Oh yeah, the min phase brick wall, how could I forget that? It's hard to believe that some audiophiles still use something like that today ...

But from a purely technological point of view: they could have used 2 DACs. Oversampling was available too. That was over 30 years ago!
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: mjb2006 on 2014-09-07 17:41:25
@Arnold
Quote
I don't know where you got the idea that anybody thinks that DACs have been stable for 20-25 years.

cdroid got that idea from me, when I said almost exactly those words in this thread, in response to his implication that expensive new-ish DACs are required in order to have good sound quality.

I'm no hardware expert, but I'm under the impression that newer DACs are not doing anything substantially different than those of the mid-1990s. They're smaller, cheaper and generally have even better specs now than before, but they're not the weak link in his playback chain, because all the technological innovations that really mattered for sound quality were made by the mid-'90s and would've been in pretty much any soundcard by the late '90s.

If that assertion is incorrect, or if saying the technology is "stable" in that regard is inappropriate, then I apologize, but the rest of your post seems to suggest that we are on the same page here. I mean, if we change out his DAC with one from 1996, everything else the same, is it going to make any difference whatsoever in a blind test?

That's not to say that he necessarily gets ideal sound from his example of a low anchor, his iMac's internal audio hardware. I have no way of knowing. Maybe, like a lot of on-board soundcards, it picks up noise from other parts of the system. That wouldn't be an issue with the DAC's operational specs, though, as he seems to believe.
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: Arnold B. Krueger on 2014-09-07 19:47:54
Oh yeah, the min phase brick wall, how could I forget that? It's hard to believe that some audiophiles still use something like that today ...

But from a purely technological point of view: they could have used 2 DACs. Oversampling was available too. That was over 30 years ago!


Bingo!

2 DACs and oversampling was exactly the technology that the competitive Philips/Magnavox CD-100 used. It probably worked better, but one of them in working condition just never happened to fall into my hands.

However. in general even the CDP-101 with its minor warts and all was a huge sonic and convenience improvement over any kind of analog, then or now.
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: Arnold B. Krueger on 2014-09-07 20:05:07
@Arnold
Quote
I don't know where you got the idea that anybody thinks that DACs have been stable for 20-25 years.

cdroid got that idea from me, when I said almost exactly those words in this thread, in response to his implication that expensive new-ish DACs are required in order to have good sound quality.


It's really about the exact choice of words, and how they are interpreted.

Speaking out against the false idea that expensive new-ish DACs are required in order to have good sound quality is justified by the relevant facts.

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I'm no hardware expert, but I'm under the impression that newer DACs are not doing anything substantially different than those of the mid-1990s.


Based on professional journals, 1992 was the year that Sigma-Delta converters became a viable mainstream technology because the cost of producing the high speed mixed signal chips that they are implemented with crossed over into financial viability about then. Note that the core technology dated back to 1962, but awaited semiconductor technology to catch up with it. 

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They're smaller, cheaper and generally have even better specs now than before, but they're not the weak link in his playback chain, because all the technological innovations that really mattered for sound quality were made by the mid-'90s and would've been in pretty much any soundcard by the late '90s.


Consumer sound card technology was lagging mainstream consumer digital music player during the 1990s and up until 2005 or so. The first sound card with true 16 bit performance was probably the Turtle Beach Pinnacle/Fiji which was on the market in the middle 90s, ran $250-400 depending on model and features. Cards like the DAL CardDeluxe introduced around Y2K were among the first that exceeded Redbook performance.

Cards like the LynxTWO introduced a few years later had the latest greatest converter chips from the leading producers and dynamic range and THD equal or better than 115 dB.

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That's not to say that he necessarily gets ideal sound from his example of a low anchor, his iMac's internal audio hardware. I have no way of knowing. Maybe, like a lot of on-board soundcards, it picks up noise from other parts of the system. That wouldn't be an issue with the DAC's operational specs, though, as he seems to believe.


http://www.geocities.jp/k_hyodo_2000/Comparison/iMac.htm (http://www.geocities.jp/k_hyodo_2000/Comparison/iMac.htm)  suggests competitive performance for an on board audio intgerface ca. 2005 but not Redbook quality.
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: wswartzendruber on 2014-09-08 08:03:06
I skipped about half of the thread, but am I the only one here who finds the question in and of itself absurd?  This discussion has gotten crazily in-depth, but all of it sits on top of a flawed premise.

Digital is by definition fixed and accurate; analog is not.  The two do not operate on the same principles.  Because of this, they are fundamentally not comparable.

Here are some factors off the top of my head for digital:

1. What is the sampling format?
2. What DAC is used?

And for the vinyl?

1. What is the molecular composition of the vinyl?
2. What needle and cartridge are used?
3. What is the weight balance of the cartridge?
4. What drive system is used?
5. What physical insulation is the turntable sitting on?
6. What pre-amp is used?
7. What is the ambient temperature?
8. What is the ambient humidity?
9. What angle of rotation is the turntable at?
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: Thad E Ginathom on 2014-09-08 09:50:20
If one is young (or even not so young, like me) and full of misconceptions, then one is very likely to ask questions that are based on false premises. Necessarily, one has to be prepared to take a knock or two in the process and, I believe, we should just be glad that there people willing to patiently explain and straighten us out. The threads are often useful, as the misconception of one must be the misconception of many.

Don't know how I would have felt about all that when I was "student-"aged: even 40-plus years on I can still pig-headed. I guess young Mr cdroid is just starting on this path where the learning is as much human as technical

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Hey, so I just got bullied off another forum (I probably should have just hung out here, those guys weren't very nice and they didn't seem to understand the audio world outside of the theoretical) and I had some questions about what we were discussing; The quality of digital vs. the quality of vinyl.
Hope I put this under the right tab, the only other place to put it that made sense was beginner questions but this seems a bit advanced compared to the other questions there and I'll be asking for in-depth answers rather than basic explanations ...

Gearslutz (http://www.gearslutz.com/board/geekslutz-forum/952963-vinyl-digital.html)
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: 2Bdecided on 2014-09-08 09:59:12
Digital is by definition fixed and accurate; analog is not.  The two do not operate on the same principles.  Because of this, they are fundamentally not comparable.
You just compared them 
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: Arnold B. Krueger on 2014-09-08 10:51:10
I skipped about half of the thread, but am I the only one here who finds the question in and of itself absurd?  This discussion has gotten crazily in-depth, but all of it sits on top of a flawed premise.

Digital is by definition fixed and accurate; analog is not.  The two do not operate on the same principles.  Because of this, they are fundamentally not comparable.


There is no requirement that things being compared operate on the same principles.

For example, hydrocarbon fuel power and nuclear power operate on fundamentally different principles. Yet there are books of comparisons between the two. Someone wants to build a power plant, and the first thing they do,  they have to choose.

The true requirement is that to be compared, the things being compared have to have comparable functions.

And now to twist things around, both analog and digital do operate on comparable principles.  They code information in accordance with schemes based on information theory.

One thing that may surprise many is that digital preceded analog in the human development of means of information transfer.


Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: Arnold B. Krueger on 2014-09-08 10:57:18
Digital is by definition fixed and accurate; analog is not.  The two do not operate on the same principles.  Because of this, they are fundamentally not comparable.
You just compared them 


Not only that but they were compared very badly. Illogical logic and non factual facts!

Digital is not accurate except within its own domain. It is always an approximation of outside reality. What the illogical and poorly informed don't seem to understand is that analog is also an approximation of outside reality.
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: xnor on 2014-09-08 12:03:09
But analog has infinite resolution!!!!1111111
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: Arnold B. Krueger on 2014-09-08 13:49:08
But analog has infinite resolution!!!!1111111


That (as we both know) audiophile myth is a testimonial to widespread ignorance of Shannon's Information Theory even 66 years after the publication of his seminal paper:

Shannon, C.E. (1948), "A Mathematical Theory of Communication", Bell System Technical Journal, 27, pp. 379–423 & 623–656, July & October, 1948. PDF.

But it seems so intuitively clear... ;-)
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: mjb2006 on 2014-09-08 20:18:47
If one is young (or even not so young, like me) and full of misconceptions, then one is very likely to ask questions that are based on false premises. Necessarily, one has to be prepared to take a knock or two in the process and, I believe, we should just be glad that there people willing to patiently explain and straighten us out. The threads are often useful, as the misconception of one must be the misconception of many.

Don't know how I would have felt about all that when I was "student-"aged: even 40-plus years on I can still pig-headed. I guess young Mr cdroid is just starting on this path where the learning is as much human as technical

Well stated. It's too bad he feels he was "bullied" and driven away from the forum. There's not much that can be done about that, though, if he isn't even willing to read and think about the responses and questions asked of him, and he's unwilling to consider the possibility that some of his knowledge wasn't entirely correct because either he misunderstood aspects of the information sources he holds in high regard, or the sources themselves were flawed.

It's not unusual to take great comfort in feeling very certain and very right about whatever we've learned, especially when the information came from sources we regard as authorities. But I think there's a real divide between people who, in situations where it's really no big deal, can let go of that certainty and its associated comfort, and those who can't. For topics like the nature of reality and what happens when you die, I can understand some people being very passionate and digging in their heels when their beliefs are challenged. But for something like analog/digital comparisons, and whether one can really hear a difference between this and that, it's shocking just how many people will allow that to be the hill they die on. If I learned tomorrow that everything I thought I knew about audio was wrong, I'd be like, "oh, wow, that's pretty crazy, but okay"—much like I did after doing some blind testing—whereas others, possibly even a younger version of myself, cover their ears and run.
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: splice on 2014-09-08 23:13:01
... Well stated. It's too bad he feels he was "bullied" and driven away from the forum. There's not much that can be done about that, though, if he isn't even willing to read and think about the responses and questions asked of him, and he's unwilling to consider the possibility that some of his knowledge wasn't entirely correct because either he misunderstood aspects of the information sources he holds in high regard, or the sources themselves were flawed. ...


Go over to the Purple Place and search for a thread started by cdroid in the last couple of days.
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: wswartzendruber on 2014-09-09 00:26:26
Digital is not accurate except within its own domain.

Ding ding ding!  We have a winner.

Digital is infinitely accurate within its own domain.  That was my whole point in saying it's not comparable to analog.  What I did not say, however, is that it's infinitely precise.  Because it obviously isn't.
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: xnor on 2014-09-09 00:41:28
As long as you stay digital you can pretty easily achieve arbitrary precision. If you used numbers as big as they are being used in cryptography, you'd have multiple thousands of decibels of SNR.

But the ~300 dB of 64-bit floating point ("double precision") is usually enough even for demanding DSP algorithms.
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: pdq on 2014-09-09 00:53:28
I believe 64 bit float has a range of 300 decades, not dB.
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: xnor on 2014-09-09 01:08:18
Significand precision is 64-11 = 53 bits.

20*log10(2^53) = 319 dB


300 decades would be 10^300, a 1 followed by 300 zeros.
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: pdq on 2014-09-09 01:22:19
The smallest value that can be represented in 64 bit float is 2^-1024 or 10^-308.
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: saratoga on 2014-09-09 01:29:25
Precision and range are not the same thing.  DP has a range of about +/- 10^308 and a precision of 52 bits (about 16 decimal places or 320 dB).
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: pdq on 2014-09-09 01:58:34
In that case 64 bit integer (379 dB) would be a better use of the bits.
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: Kohlrabi on 2014-09-09 09:00:57
In that case 64 bit integer (379 dB) would be a better use of the bits.
You only need that precision if you do lots of sums of large and small numbers, where the result would vanish, and that loss of precision might be noticeable later. So precision is not always the best choice if you just need (dynamic) range.
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: Arnold B. Krueger on 2014-09-09 09:56:09
Digital is not accurate except within its own domain.

Ding ding ding!  We have a winner.


No, we have a recitation of generally accepted scientific truth.

Quote
Digital is infinitely accurate within its own domain.  That was my whole point in saying it's not comparable to analog.


Analog and digital are still entirely comparable. They can and frequently are used to do the identical same things.  The performance of either can be characterized using the identically same generalized measures.

Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: xnor on 2014-09-09 12:24:10
In that case 64 bit integer (379 dB) would be a better use of the bits.

Sure, floating point is a tradeoff. SNR for dynamic range. As long as you are within a certain range, 0 dBFS to roughly -66 dB, you are better off with integers.
Higher level and you get clipping. Lower level and the SNR will decrease.
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: saratoga on 2014-09-09 13:17:00
We use only integer in Rockbox (no floating point unit) and it is quite painful to maintain high snr.  You can of course do it but you must carefully consider the scaling of each operation to avoid excess rounding error. I do not recommend it if you can avoid it.
Title: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: pdq on 2014-09-09 14:03:23
Indeed, an integer DSP will often have something like a 40 bit MAC register when working with 32 bit integers for that reason.
Title: Re: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: Arnold B. Krueger on 2017-07-14 10:56:18
Jitter is comparatively easy to process out. Wow and flutter more difficult since there is no timing reference in the signal.

If the jitter happened in A/D, what is your timing reference?

Any known, steady signal from the analog input. Candidates include: Power line hum, switchmode power supplies, video displays, HVAC, etc.

Celemony's Capstan  (http://www.celemony.com/en/capstan ) is a $5K product that claims to be able to exploit such things.
Title: Re: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: Crysist on 2017-10-03 01:23:04
Coming back to the original topic of this thread, I have some questions.

I've seen the 65 dB figure around and I can definitely agree on that, having looked at the noise of some needledrops. However, how good or bad does it get and within what tolerance of a "max signal" are they referenced? For example, I've seen in the manuals of various tape recorders a lot more standardization with regards to these tolerances. The S/N ratio is calculated at a fixed reference, or explicitly a number of dB above the reference. (they may note their S/N is at reference, or at +3 dB above it, etc.) Additionally, I've seen some figures for third-harmonic distortion for different signal levels relative to reference.

Are there any as-detailed looks at specs on lathe cutting or are there too many more variables? (cutting, THEN the performance of the playing needle!) If there a reference amplitude for disc cutting? Any figures for distortion as it relates to level above any such reference? And then signal-to-noise ratio relative to that reference?

Separately, I'm curious about the 18 kHz figure for frequency response. With what reference is this chosen to be the max as well? Some amount of distortion or some amount of roll off? I've seen spectrograms which show distortion products creating 'false' high-frequency content, but does anyone know of any more precise tests? Any pure HF tones cut into vinyl? Maybe sweep up to 20 kHz and see how the original fares vs the added distortion?

If anyone has any materials I'd love to see them!

Oh, and does anyone know of the type of noise vinyl records exhibit? (or maybe the record plus the preamp?) Is it pink? Brownian? It seems like it's one of them, but turns white past some point.
Title: Re: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: DVDdoug on 2017-10-03 21:23:45
Quote
The S/N ratio is calculated at a fixed reference, or explicitly a number of dB above the reference. (they may note their S/N is at reference, or at +3 dB above it, etc.)
Usually, S/N is measured with the maximum "signal", especially if you are the manufacturer.  ;)    But, it's up to the record company to define their maximum.   I don't know if there is a universal 0dB reference for records.      The RIAA curve complicates things because the "dB" level is going to be measured before EQ (but probably after bandpass filtering).

Vinyl loudness wars existed before digital loudness wars...  It's a question of how loud you can go without mis-tracking and of course that depends on the playback cartridge.   I remember a million years ago, Stereo Review Magazine would test cartridge tracking with the cannon shots from a particular recording of the 1812 Overture. 

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Separately, I'm curious about the 18 kHz figure for frequency response.
I don't know where that came from.  Certainly vinyl is capable  of going above 20kHz.   I believe the highest and lowest frequencies are rolled-off for tracking and to maximize the "signal" with stuff you can hear.   Again, that's up to the record company. 

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Oh, and does anyone know of the type of noise vinyl records exhibit? (or maybe the record plus the preamp?) Is it pink? Brownian? It seems like it's one of them, but turns white past some point.
The worst is impulse noise ("snap", "crackle", and "pop") and I assume there's white noise behind that.   That's all RIAA filtered, which I believe would be between pink and Brownian.    Of course the preamp does add noise.   I've mostly heard hum, perhaps with some RIAA filtered white noise.    It's been a long time since I listened to records, but from what I remember preamp noise was only noticeable when the record wasn't playing...  Record surface noise was the BIG problem.
Title: Re: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: Arnold B. Krueger on 2017-10-04 00:51:19
Coming back to the original topic of this thread, I have some questions.

I've seen the 65 dB figure around and I can definitely agree on that, having looked at the noise of some needledrops. However, how good or bad does it get and within what tolerance of a "max signal" are they referenced? For example, I've seen in the manuals of various tape recorders a lot more standardization with regards to these tolerances. The S/N ratio is calculated at a fixed reference, or explicitly a number of dB above the reference. (they may note their S/N is at reference, or at +3 dB above it, etc.) Additionally, I've seen some figures for third-harmonic distortion for different signal levels relative to a reference.

Analog clipping is the equivalent of digital FS.

The LP equivalent of clipping is trackability. Please see the 2 attachments for representative graphs of trackability.

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Are there any as-detailed looks at specs on lathe cutting or are there too many more variables? (cutting, THEN the performance of the playing needle!) If there a reference amplitude for disc cutting? Any figures for distortion as it relates to level above any such reference? And then signal-to-noise ratio relative to that reference?

Lathes have been able to cut untrackable records for many generations of lathes. Indeed, one of the problems of cutting LPs is cutting something that can be tracked by the customer's gear. If your target market is the mass market including people with lower incomes, the boss makes you be very conservative about making LPs that track on cheap players with say, crystal cartridges.

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Separately, I'm curious about the 18 kHz figure for frequency response. With what reference is this chosen to be the max as well? Some amount of distortion or some amount of roll off? I've seen spectrograms which show distortion products creating 'false' high-frequency content, but does anyone know of any more precise tests? Any pure HF tones cut into vinyl? Maybe sweep up to 20 kHz and see how the original fares vs the added distortion?

If you can track it, you can equalize it to be flat. In modern times there is not too much reason to be worried about raw frequency response as long as the dynamic range is available.

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Oh, and does anyone know of the type of noise vinyl records exhibit? (or maybe the record plus the preamp?) Is it pink? Brownian? It seems like it's one of them, but turns white past some point.

The noise floor has several contributors that can vary all in their selves like turntable rumble. You could occasionally "hear" noises in the recording studio and recording gear on LPs, but on CDs it is they who set the effective noise floor.
Title: Re: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: Crysist on 2017-10-09 01:29:20
Usually, S/N is measured with the maximum "signal", especially if you are the manufacturer.  ;)    But, it's up to the record company to define their maximum.   I don't know if there is a universal 0dB reference for records.      The RIAA curve complicates things because the "dB" level is going to be measured before EQ (but probably after bandpass filtering).
There is for tape... it would be nice if records had one. So, in reference to what has any maximum been used? Just for cutting the records?

Also, I see some test LPs use terms of "+0dB" or some number above that; for example, Hifi news test lp has a track called "Bias setting: 300Hz tone, both channels +18dB". 18 dB above what exactly?
Vinyl loudness wars existed before digital loudness wars...  It's a question of how loud you can go without mis-tracking and of course that depends on the playback cartridge.   I remember a million years ago, Stereo Review Magazine would test cartridge tracking with the cannon shots from a particular recording of the 1812 Overture. 
Ohoho! Was it the Telarc recording?
I don't know where that came from.  Certainly vinyl is capable  of going above 20kHz.   I believe the highest and lowest frequencies are rolled-off for tracking and to maximize the "signal" with stuff you can hear.   Again, that's up to the record company. 
Definitely, but I'm only curious about the relationship between what is still in the original input signal into the lathe and what distortion gets added. Even if it is rolled off, a bunch of HF distortion is added, it seems.
The worst is impulse noise ("snap", "crackle", and "pop") and I assume there's white noise behind that.   That's all RIAA filtered, which I believe would be between pink and Brownian.    Of course the preamp does add noise.   I've mostly heard hum, perhaps with some RIAA filtered white noise.    It's been a long time since I listened to records, but from what I remember preamp noise was only noticeable when the record wasn't playing...  Record surface noise was the BIG problem.
Only the "noise floor" I meant, sorry for being unspecific! But yeah, it seems they tend to make the noise quite "pinkish".
Analog clipping is the equivalent of digital FS.

The LP equivalent of clipping is trackability. Please see the 2 attachments for representative graphs of trackability.
Lathes have been able to cut untrackable records for many generations of lathes. Indeed, one of the problems of cutting LPs is cutting something that can be tracked by the customer's gear. If your target market is the mass market including people with lower incomes, the boss makes you be very conservative about making LPs that track on cheap players with say, crystal cartridges.
Those graphs are telling of what range of frequencies they can track, but are they any use towards getting some solid figures in terms of dB for Hz? (is cm/s ~ dB? or maybe log(cm/s)?) It seems like a cartridge's frequency response would be better-suited. And even then, it varies for what catridge is picking it up.

Hm, these seem to be a bit difficult to factor into a conclusive measure of the "performance" of the format. Having the system limited in all these seperate ways.

If only this were easier! The "tape varies from around 10-13 'bits'" was so nice and easy to verify, too nice... dang LPs.

Perhaps just using needledrops and analyzing an unmodulated groove is all we can do here.

On that note, do you or anybody here know how the frequency response of cartridges is determined? I imagine doing trackability would give too variable resuts and using any sort of test LP wouldn't help either in accuracy. Do they have some special testbed where they can test this, to wiggle the needle around accurately?

If you can track it, you can equalize it to be flat. In modern times there is not too much reason to be worried about raw frequency response as long as the dynamic range is available.
I suppose not, but getting a similar result of how distortion rises with frequncy on an LP would be useful. Maybe a the cutting head from a lathe has such a spec?

Thank you for your responses.
Title: Re: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: splice on 2017-10-09 02:38:38
There is for tape... it would be nice if records had one. So, in reference to what has any maximum been used? Just for cutting the records?

Also, I see some test LPs use terms of "+0dB" or some number above that; for example, Hifi news test lp has a track called "Bias setting: 300Hz tone, both channels +18dB". 18 dB above what exactly?
...

The convention is that "0dB" is a maximum stylus lateral velocity of 5 cm/sec at a frequency of 1 KHz.

http://www.audiomisc.co.uk/HFN/LP1/KeepInContact.html
... and the following 4 pages. 
Title: Re: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: DVDdoug on 2017-10-09 17:24:53
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On that note, do you or anybody here know how the frequency response of cartridges is determined?
IIRC - In the olden days, the magazines would tell you what test record they used.   But, I don't recall the manufacturer's publishing the test record they use.

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If only this were easier! The "tape varies from around 10-13 'bits'" was so nice and easy to verify, too nice... dang LPs.
Tape noise is more constant, but there are still lots of variables...   Different tape speeds, track width (with pro & multi-track recorders), different tape formulations, different machine calibration, etc.    The tape heads (and overall machine) will affect performance too.



Title: Re: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: Arnold B. Krueger on 2017-10-09 19:07:34
Maybe a the cutting head from a lathe has such a spec?

One of the most comprehensive papers on a LP cutting system is: "The Westrex 3D StereoDisk System" authors: Nelson, Carl S.; Stafford, Jerome W. Affiliations: Westrex Division of Litton Industries, Hollywood, CA ; Litton Data Systems Division, Canoga Park, CA
JAES Volume 12 Issue 3 pp. 178-185; July 1964
Publication Date:July 1, 1964

Unfortunately, this paper says nothing about the nonlinear distortion of the cutter head itself. My impression is that performance of the cut LP during playback was far more interesting, but out of the scope of the paper. Attached is the frequency response of the cutter with its linearizing feedback system engaged.

I  was struck by thoughts about the futility of Luddite audiophiles who eschew feedback, but worship LPs cut with this device which obviously used feedback to great advantage.

Title: Re: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: Arnold B. Krueger on 2017-10-09 23:12:15
What sample rate and  bit depth , dithered, would create a digital recording with the same bandwidth and signal to noise ratio as vinyl

The attachment shows how bit depth can relate to noise and distortion. Based on what I've seen in the way of measurements, the LP is in the range of 11 bits.
Title: Re: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: Crysist on 2017-10-10 02:39:45
The convention is that "0dB" is a maximum stylus lateral velocity of 5 cm/sec at a frequency of 1 KHz.

http://www.audiomisc.co.uk/HFN/LP1/KeepInContact.html
... and the following 4 pages. 
Extremely useful article, thank you!! Helped answer most of my questions. Also, fitting username!

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On that note, do you or anybody here know how the frequency response of cartridges is determined?
IIRC - In the olden days, the magazines would tell you what test record they used.   But, I don't recall the manufacturer's publishing the test record they use.
Looking into it, it seems to be true from some cursory searches. Never thought it went that way!

Tape noise is more constant, but there are still lots of variables...   Different tape speeds, track width (with pro & multi-track recorders), different tape formulations, different machine calibration, etc.    The tape heads (and overall machine) will affect performance too.
But still, thankfully, quite standardized on each. I see many spec sheets include tables with different weightings, different references, and giving an associated Third Harmonic Distortion.

One of the most comprehensive papers on a LP cutting system is: "The Westrex 3D StereoDisk System" authors: Nelson, Carl S.; Stafford, Jerome W. Affiliations: Westrex Division of Litton Industries, Hollywood, CA ; Litton Data Systems Division, Canoga Park, CA
JAES Volume 12 Issue 3 pp. 178-185; July 1964
Publication Date:July 1, 1964

Unfortunately, this paper says nothing about the nonlinear distortion of the cutter head itself. My impression is that performance of the cut LP during playback was far more interesting, but out of the scope of the paper. Attached is the frequency response of the cutter with its linearizing feedback system engaged.

I  was struck by thoughts about the futility of Luddite audiophiles who eschew feedback, but worship LPs cut with this device which obviously used feedback to great advantage.
Shame about the lack of distortion info, but that curve is interesting! Probably explains some parts of "the sound" associated, at least, with records cut with this lathe. Unless any "newer" ones have gotten flatter.
Title: Re: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: Porcus on 2017-10-10 15:10:46
I'm only curious about the relationship between what is still in the original input signal into the lathe and what distortion gets added. Even if it is rolled off, a bunch of HF distortion is added, it seems.

It was a thread about content > 20 kHz recently, and I recall I found an interesting Youtube video. https://hydrogenaud.io/index.php/topic,113365.msg940556.html#msg940556 
Title: Re: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: Crysist on 2017-10-10 18:02:40
I'm only curious about the relationship between what is still in the original input signal into the lathe and what distortion gets added. Even if it is rolled off, a bunch of HF distortion is added, it seems.

It was a thread about content > 20 kHz recently, and I recall I found an interesting Youtube video. https://hydrogenaud.io/index.php/topic,113365.msg940556.html#msg940556 

Ah, I'd seen that. Unfortunately, there are ways I can think of it as being not so definitive. The cutoff is apparent, but you can also see there is distortion added. In some transients they seem to blend together on the graph, and other times we see varying amounts of a difference between the frequencies right before the cutoff and right after (a sharp drop).

Needless to say, it shows that there is definitely useful info above 20kHz, but that there is also a good amount distortion up there too. Some relationship between the two, possibly also including the level. That comment also links an interesting article! I wonder at what level the bias tone would be at...
Title: Re: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: DVDdoug on 2017-10-10 21:39:48
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Needless to say, it shows that there is definitely useful info above 20kHz
Records are for listening...   What's useful about stuff you can't hear?  ;)
Title: Re: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: Porcus on 2017-10-10 21:57:37
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Needless to say, it shows that there is definitely useful info above 20kHz
Records are for listening...   What's useful about stuff you can't hear?  ;)
The 30 kHz carrier signal on your old quadrophonic LPs could potentially have some use, if only you you had a demodulator :-o
Title: Re: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: Arnold B. Krueger on 2017-10-10 22:44:04
I'm only curious about the relationship between what is still in the original input signal into the lathe and what distortion gets added. Even if it is rolled off, a bunch of HF distortion is added, it seems.

It was a thread about content > 20 kHz recently, and I recall I found an interesting Youtube video. https://hydrogenaud.io/index.php/topic,113365.msg940556.html#msg940556

Distortion during LP playback rises with frequency for reasons relating to groove geometry. When there was a desire to exploit response > 20 KHz for quadraphonic music, actually recovering even just a pilot tone from up there was a challenge, and this is the easier part of the problem of recovering music with acceptable sound. Not only that, but the durability of this ultrasonic information was widely reported to be poor. Maybe 10 more or less playings would erase the music.
Title: Re: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: calle_jr on 2018-07-06 05:18:08
Distortion during LP playback rises with frequency for reasons relating to groove geometry. When there was a desire to exploit response > 20 KHz for quadraphonic music, actually recovering even just a pilot tone from up there was a challenge, and this is the easier part of the problem of recovering music with acceptable sound. Not only that, but the durability of this ultrasonic information was widely reported to be poor. Maybe 10 more or less playings would erase the music.
Good point. Still, it could be interesting to explore today (for other purposes than quad), in modern mc cartridge designs.
Both mechanical and electrical non linearities may appear in the 15-20kHz region, and even non linearities above 20kHz affect the modulated signal.

What sample rate and  bit depth , dithered, would create a digital recording with the same bandwidth and signal to noise ratio as vinyl
What sample rate and bit depth would create a goat with the same bandwidth and signal to noise ratio as a crocodile?
Title: Re: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: kode54 on 2018-07-07 03:24:27
Astute response, but maybe you noticed you bumped a topic from a year ago?
Title: Re: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: calle_jr on 2018-07-07 05:35:55
Astute response, but maybe you noticed you bumped a topic from a year ago?
Yes, I didn't read the thread until yesterday.
It's interesting to explore how high frequency noise affect modulated signals also 20-20k, and it seems there are a few here who might know something about that.
But maybe that should be asked in a new topic?

Anyway, that's one reason for my silly goat-crocodile note. Another is how we perceive noise, i.e perceived dynamics. Another one is what resolution means within the audioband.
I don't think I'm skilled enough to argue, but I thought somebody should point out the "issues" related to the question by OP.
Title: Re: Vinyl is equivalent to which digital bit-depth and sampling rate?
Post by: magicgoose on 2018-07-07 11:39:49
I guess it's more or less similar to some kind of ADPCM with bit depth somewhere between 6..12 bits, and the usual 44100 sample rate, plus some kind of pre-emphasis. Not like it can be compared to normal PCM, as vinyl also adds nonlinear distortion which is also very dependent on signal characteristics. Anyways, that was a strange question but if the point is to make comparison to CDDA, then it's overwhelmingly obvious that vinyl has far worse fidelity.
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