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Re: Re: >20kHz content found in vinyl?

Reply #27
Dynagroove.

https://en.wikipedia.org/wiki/Dynagroove
Said to be abandoned in 1970.

I proved that information >20 khz could be recorded on to 33 rpm vinyl.  If memory serves me it also unfortunately proved that such information would be destroyed by the first few plays using actual needles ...
Ed Seedhouse
VA7SDH

Re: Re: >20kHz content found in vinyl?

Reply #28
I proved that information >20 khz could be recorded on to 33 rpm vinyl.
...and countless others.

If memory serves me it also unfortunately proved that such information would be destroyed by the first few plays using actual needles ...
Highly doubtful that "destroyed by the first few plays using actual needles" is necessarily the case.



Is 24-bit/192kHz good enough for your lo-fi vinyl, or do you need 32/384?

Re: Re: >20kHz content found in vinyl?

Reply #29
If memory serves me it also unfortunately proved that such information would be destroyed by the first few plays using actual needles ...
Highly doubtful that "destroyed by the first few plays using actual needles" is necessarily the case.

I've heard anecdotes of extreme record wear - signal literally wiped off a disk for very short wavelength signals such as QS-4 carriers in the 30+ kHz range. 

The possibility of damage to test LPs has to be taken into account, but actual removal of signals bewlo 20 kHz seems to be very severe, if it happens.

Re: Re: >20kHz content found in vinyl?

Reply #30
20k-30k!?!

...or are we still busy shooting arrows at the man stuffed with straw???

>20 khz [...] would be destroyed by the first few plays using actual needles
Is 24-bit/192kHz good enough for your lo-fi vinyl, or do you need 32/384?

Re: Re: >20kHz content found in vinyl?

Reply #31
20k-30k!?!

...or are we still busy shooting arrows at the man stuffed with straw???

>20 khz [...] would be destroyed by the first few plays using actual needles

The physics of the situation suggests that vinyl's durability for really small stylus contact areas seems marginal at best. I have to admit that back in the days when this mattered to me, we just didn't have the sophisticated tools for analysis that we do now.

 One of my long term projects involves assembling enough vinyl stuff to look at things again from a real-world perspective. To that end I've so far assembled a collection of about 100 LPs including more than a dozen or more est records, 5-8 turntables, a dozen or more cartridges and maybe a half dozen or more preamps.  Maybe sometime this summer some results will perculate up to this level.


Re: >20kHz content found in vinyl?

Reply #32
I've heard anecdotes of extreme record wear - signal literally wiped off a disk for very short wavelength signals such as QS-4 carriers in the 30+ kHz range. 

I dug up some stuff in the old thread:
https://hydrogenaud.io/index.php/topic,113365.msg940580.html#msg940580
http://www.positive-feedback.com/Issue2/mastering.htm

(Keeping a spinoff thread alive is a great thing - one can discuss the same hearsay all over and rebuild the straw man and ...
... edit: and the quarrel at the last half of that thread can be repeated! Yay!)
Memento: this is Hydrogenaudio. Do not assume good faith.

Re: Re: >20kHz content found in vinyl?

Reply #33
I proved that information >20 khz could be recorded on to 33 rpm vinyl.  If memory serves me it also unfortunately proved that such information would be destroyed by the first few plays using actual needles ...
It seems that some of the Quadraphonic vinyl formats were based on playing back frequencies far beyond 20kHz to operate properly.

I have never experienced such a system, but unless they were a technical sham, this does suggest that playback >20kHz is indeed possible in at least some cases.

https://en.wikipedia.org/wiki/Compatible_Discrete_4

Re: >20kHz content found in vinyl?

Reply #34
I dug up some stuff in the old thread:
https://hydrogenaud.io/index.php/topic,113365.msg940580.html#msg940580
http://www.positive-feedback.com/Issue2/mastering.htm

(Keeping a spinoff thread alive is a great thing - one can discuss the same hearsay all over and rebuild the straw man and ...
... edit: and the quarrel at the last half of that thread can be repeated! Yay!)

Looking back at some of those old threads, I see two people who claimed to routinely cut high rez audio onto vinyl offer files of the original digital recording and needle drop files of the results for us to compare. 

Did I miss something or are these offers proven to be just more hot air given that months have gone by since they were offered?

Re: >20kHz content found in vinyl?

Reply #35
That doesn't come from your record player.

That's aliasing coming from poor resampling (Windows-Resampler?). The noise may come from that too, because it is in the center where the mirroring starts. It has been resampled poorly two times (it mirrors again at 24kHz) until it reached your recording software.

Avoid the build-in resampler from Windows at all, because it scraps any recording:

- Always set record sample rate at the highest available sample rate that is natively supported by sound card (in most consumer sound cards, this is 48 or 96 kHz. Professional sound cards may go higher)
- Set Windows driver settings for recording to that sample rate
- Record a sine wave and look to the spectogram of the recording to ensure, that no distorition is happening.
- Do the recording
- Resample it to something else after recording using a good resampler, if necessary

How to fix:
The easy way: Chop the frequency crap off by using a steep lowpass filter at 20kHz
The better way: Re-record with better hardware and properly set sample rates
- I abandoned this account since I didn't find a way to delete it -

Re: >20kHz content found in vinyl?

Reply #36
That doesn't come from your record player.

That's aliasing coming from poor resampling (Windows-Resampler?). The noise may come from that too, because it is in the center where the mirroring starts. It has been resampled poorly two times (it mirrors again at 24kHz) until it reached your recording software.

Avoid the build-in resampler from Windows at all, because it scraps any recording:

- Always set record sample rate at the highest available sample rate that is natively supported by sound card (in most consumer sound cards, this is 48 or 96 kHz. Professional sound cards may go higher)
- Set Windows driver settings for recording to that sample rate
- Record a sine wave and look to the spectogram of the recording to ensure, that no distorition is happening.
- Do the recording
- Resample it to something else after recording using a good resampler, if necessary

How to fix:
The easy way: Chop the frequency crap off by using a steep lowpass filter at 20kHz
The better way: Re-record with better hardware and properly set sample rates

Who or what is this post addressed to?

Re: Re: >20kHz content found in vinyl?

Reply #37
It's certainly not distortion.
Where was it in the original soundfield?

We mastered an LP for a punk band; they were really proud of the fact that the recording was made entirely on a mono Ampex 300. I hated to tell them that it looked like they had either a ground loop or a microphonic tube somewhere; right at 23KHz was a steady tone (easy to see under the microscope in the grooves) on the master tape. Its a pretty good bet it wasn't in the original sound field, but I would not call it a distortion either, although it clearly was an artifact.

Re: Re: >20kHz content found in vinyl?

Reply #38
We mastered an LP for a punk band; they were really proud of the fact that the recording was made entirely on a mono Ampex 300. I hated to tell them that it looked like they had either a ground loop or a microphonic tube somewhere; right at 23KHz was a steady tone (easy to see under the microscope in the grooves) on the master tape. Its a pretty good bet it wasn't in the original sound field, but I would not call it a distortion either, although it clearly was an artifact.
You discovered it after the pressing?

But "hated to tell them" ... does that extra lo-finess really matter?
Memento: this is Hydrogenaudio. Do not assume good faith.

Re: Re: >20kHz content found in vinyl?

Reply #39
It's certainly not distortion.
Where was it in the original soundfield?

We mastered an LP for a punk band; they were really proud of the fact that the recording was made entirely on a mono Ampex 300. I hated to tell them that it looked like they had either a ground loop or a microphonic tube somewhere; right at 23KHz was a steady tone (easy to see under the microscope in the grooves) on the master tape. Its a pretty good bet it wasn't in the original sound field, but I would not call it a distortion either, although it clearly was an artifact.

Probable cause is either a switchmode power supply in some gear, perhaps a CRT PC monitor.

You're beating a dead horse - the presence of information > 20 KHz on LPs has been generally agreed to around here. And it has also been shown that a lot of that is observed at playback, is due to the relatively high nonlinear distortion that is inherent in the LP.

Here's a reliable technical source pointing out the details: http://archimago.blogspot.com/2017/06/musings-measurement-thoughts-on-vinyl.html  

Here is a graphic from that source, since I don't seriously expect you to follow up logically on this post based on past experience with you:

The green line shows harmonics of a pure tone that was added by a fairly typical LP high quality playback setup, and one of them is beyond 20 KHz.


Re: Re: >20kHz content found in vinyl?

Reply #40
Probable cause is either a switchmode power supply in some gear, perhaps a CRT PC monitor.

You're beating a dead horse - the presence of information > 20 KHz on LPs has been generally agreed to around here. And it has also been shown that a lot of that is observed at playback, is due to the relatively high nonlinear distortion that is inherent in the LP.

Sure, the imagined footprints of Schrödinger's long dead horse is distortion inherent in the LP, simultaneously as the horse is neighing through a power supply or perhaps a CRT monitor.

Maybe inside that box, if one bothers to opens it, there will be some finite and nonzero s/n ratio?
Memento: this is Hydrogenaudio. Do not assume good faith.

Re: Re: >20kHz content found in vinyl?

Reply #41
We mastered an LP for a punk band; they were really proud of the fact that the recording was made entirely on a mono Ampex 300. I hated to tell them that it looked like they had either a ground loop or a microphonic tube somewhere; right at 23KHz was a steady tone (easy to see under the microscope in the grooves) on the master tape. Its a pretty good bet it wasn't in the original sound field, but I would not call it a distortion either, although it clearly was an artifact.
You discovered it after the pressing?

But "hated to tell them" ... does that extra lo-finess really matter?

Nah- we found it as soon as we started doing test tracks. Their tape didn't really sound that bad, but it did have a lo-fi quality. We put a filter on the system to kill the noise, whatever was causing it; no need to heat up the cutter head unnecessarily.



Re: >20kHz content found in vinyl?

Reply #43
 Here's a classic paper on the topic. It shows the effects of wear on a test record which is great because not only does it show what wear does to a LP, it shows how the wear changes with frequency.

The little drawing in the upper left-hand corner of the attachment shows the reference - what happened when they played the record various numbers of times using a high-quality stylus (for the day) tracking at what seems to be a very high tracking force - about 3 times what most people would use with that particular cartridge. Wear was minimal.

As you go right, the tests are repeated with crappier cartridges. The second column used a production cartridge that was good for the day, but obviously was shortly to be improved on.

The third column shows what happens with a ceramic cartridge, which is what we see today in bottom buck LP playback systems, such as those sold by Crosley and the like. Basically, groove busters, and here you see where that reputation comes from - reality!

As you go down the rows, you see the effects of using less and less stylus pressure with each kind of cartridge. The bottom left hand drawing seems to show that even with the really good developmental stylus, it was not that hard to lighten up the tracking force to the point where there were signficant losses, and they were worse with increased numbers of playings. T

his is the caliber of work that one obtains from professionals developing what was in the day, the mainstream means for playing back recordings. It could be done today, but truth just isn't that important to the powers that be, it seems.

But the lesson remains true - even with modern cartridges, track too light and pay the price!

Re: Re: >20kHz content found in vinyl?

Reply #44
Published in 1961.... back when the M3D was king...

Arnold, just so you know, there have been serious improvements in the LP technology since then.  Just a FWIW sort of thing :)

I do agree that tracking is everything. In fact I'm of the opinion that the ability of the arm to properly track the cartridge without breakup is far more important than what cartridge you actually have.

Re: Re: >20kHz content found in vinyl?

Reply #45
Published in 1961.... back when the M3D was king...

Arnold, just so you know, there have been serious improvements in the LP technology since then.  Just a FWIW sort of thing :)

Your belaboring of a point that I made with the phrase "...of the day..."is noted.  I sold M3Ds and N21d stylus upgrades in an aduio store in the day when I was a teenager.  I suffered with vinyl for about another 15 years after that until the advent of vastly superior digital technology.  During that time I also earned a degree in Engineering and learned a lot about what changed, and what did not. First off, there were significant refinements, but there were no major changes.

To this day records are made from vinyl and the best stylii are tipped with diamonds. Looking at an  old Shure 1966 catalog, the N21 was specified for tracking forces from 1 to 2 1/2 grams, and today about a half a century later, minimum tracking force specifications have not changed dramatically.  There is no reason to think that the record wear sitaution has changed dramatically since the materials and operational conditions are not all that different desipte the passage of over 50 years.

Quote
I do agree that tracking is everything. In fact I'm of the opinion that the ability of the arm to properly track the cartridge without breakup is far more important than what cartridge you actually have.

Well, we can agree on that. Frequency response errors can be effectively equalized, but the ugly sound of diamond on vinyl mistracking can only be removed by replacing  the diamond and the vinyl. Fortunately, that was accomplished  after 1982, some 36 years ago.

Re: Re: >20kHz content found in vinyl?

Reply #46
There is no reason to think that the record wear sitaution has changed dramatically since the materials and operational conditions are not all that different desipte the passage of over 50 years.

Fast forward half of those fifty years, and then you have that experiment where they played a groove ten thousands of times with the same stylus trying to provoke forth wear.  (While some other styli would wear the groove significantly in a couple of minutes - you did not need any "50 years", you could buy them in the same market at the same time.)
Memento: this is Hydrogenaudio. Do not assume good faith.

Re: Re: >20kHz content found in vinyl?

Reply #47
There is no reason to think that the record wear sitaution has changed dramatically since the materials and operational conditions are not all that different desipte the passage of over 50 years.

Fast forward half of those fifty years, and then you have that experiment where they played a groove ten thousands of times with the same stylus trying to provoke forth wear.  (While some other styli would wear the groove significantly in a couple of minutes - you did not need any "50 years", you could buy them in the same market at the same time.)

Is there a comparable paper to the one I posted from for this wonderful "50 years later" performance. The one thing that is missing from the 50 year old paper is eliptical stylii. What else that is truely significant has changed?  Or, are we playing dueling anecdotes?

Re: >20kHz content found in vinyl?

Reply #48
Or, are we playing dueling anecdotes?

Yeah, and I chose the "did you bother to click any link in a post you quoted?" weapon.

I do not pretend that the periodical of AES Sweden is a scientific journal, and as they do not have their archives online, you could (if you want to) just accuse their then-president (and present treasurer) of both making up the experiment and making up the story that they put it on print back in 1992.
Nobody disputes that certain styli tax the vinyl heavily, so pointing at styli that do cause wear isn't bringing much new to the table. That a certain make could play the groove like fifty thousand times (locking groove, no cooling) without annoying artifacts show that you cannot just select [random pick-up], measure the wear and claim it generalizes, can you?
Memento: this is Hydrogenaudio. Do not assume good faith.

 

Re: >20kHz content found in vinyl?

Reply #49

To this day records are made from vinyl and the best stylii are tipped with diamonds. Looking at an  old Shure 1966 catalog, the N21 was specified for tracking forces from 1 to 2 1/2 grams, and today about a half a century later, minimum tracking force specifications have not changed dramatically.  There is no reason to think that the record wear sitaution has changed dramatically since the materials and operational conditions are not all that different desipte the passage of over 50 years.


Well, actually there is.  Tone arms have improved dramatically! I think the only vintage arm that gets any traction at all these days is the Fidelity Research FR66. Goes for a lot of cash, but as far as I can tell, really only to collectors.

There was not an arm made in the 60s that could track any cartridge correctly. Unfortunately we still see a lot of modern arms that have traditional engineering defects (one example is the bearings not being in the same plane as the LP surface) so apparently YMMV depending on how well (or not) the tone arm is up to its job. So this is that part where the ability of the arm to track the cartridge becomes paramount- mistrack, it can damage the groove almost immediately, if it doesn't, groove life is extended to the point of decades.

That, and the continuing difficulties in really getting the cartridge set up properly, are really some of  the bigger reasons digital is an actual improvement as often with digital its plug and play, unless you have a music server.


 
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