Natural Sound

[microstrip]

Hi Rando, I simply posted those videos to demonstrate that some tables, and particularly this 40 year old vintage table, can hold a pretty stable and accurate speed. I've seen well regarded contemporary tables not able to do so. I once started a thread asking people to post publicly results of other tables using the Sutherland TimeLine. The thread died quickly as no one took up the challenge. A WBF member from Germany suggests taking the TimeLine for testing contenders if one is in the market for a new turntable. I think it is an interesting idea. I've heard reports of dealers not allowing clients to bring that device into their shops.

Do you think that Lamm dealers would allow consumers to measure the distortion of the Lamm amplifiers at low frequencies in a comparison with other solid state amplifiers before listening in their shop?

You systematically failed to define what you mean precisely by "stable speed", trying to debate technical matters in a vague and ambiguous language, avoiding quantification. You do not tell us what you think is the needed accuracy. Why should people use instruments if they do not know how to interpret the results clearly?

One friend let me put it on his table and the results were terrible. He was using the VPI motor controller. He concluded the TimeLine is flawed. He theorized that the weight of the unit placed on the spindle of his turntable changed the performance of the table, or that the strobe is inaccurate. This is one reason I wanted to show both the TimeLine and the RR tachometer working concurrently to confirm accuracy of both devices and that the speed does not change when the Timeline is placed on the spindle and removed, at least not on the Micro Seiki.

I think speed is a primary criteria for a turntable, and it is indeed audible at some measure of accuracy and consistency. Tim commented about this regarding his Grand Prix Monaco 2.0. What degree of accuracy and consistency or how "thin of adjustments are necessary" or audible is a debatable subject as others have pointed out.

What do you exactly mean by the results were terrible? Was it a faulty unit or simply a poor turntable?

IMHO if we want to propose, support, disseminate or compare any kind of objective measurement in public we must master it and be able to discuss it.

BTW, IMHO LP eccentricity is far more critical than accuracy to 5 digits. Yet only a few turntables compensate for it.

 

[PeterA]

Do you think that Lamm dealers would allow consumers to measure the distortion of the Lamm amplifiers at low frequencies in a comparison with other solid state amplifiers before listening in their shop?

I have no idea, Fransisco. However, I do not think amplifier distortion relates to sound quality quite the same way that inaccurate and unstable turntable speed relates to sound quality.

You systematically failed to define what you mean precisely by "stable speed", trying to debate technical matters in a vague and ambiguous language, avoiding quantification. You do not tell us what you think is the needed accuracy. Why should people use instruments if they do not know how to interpret the results clearly?

I wrote that my 40 year old Micro Seiki turntable can hold a "pretty stable and accurate speed". By the two videos, that is clearly defined by +/- 0.002 RPM. So it follows that I think 33.331 -33.335 is both pretty accurate and pretty stable. I see no ambiguity with that nor an avoidance of quantification.

Regarding "the needed accuracy", I can hear the difference of +/- 0.2 RPM because, at least with this table in this system, I could hear that 33.1 RPM was slow and that 33.5 RPM was fast. I do not know what my threshold is for detecting speed inaccuracy or instability beyond that. I have not experimented much. How much distortion in an amplifier or speaker does there need to be before it is distracting? I suspect it is different for everyone. Does it seem as though I do not know how to interpret the results of the Road Runner tachometer?

What do you exactly mean by the results were terrible? Was it a faulty unit or simply a poor turntable?

IMHO if we want to propose, support, disseminate or compare any kind of objective measurement in public we must master it and be able to discuss it.

BTW, IMHO LP eccentricity is far more critical than accuracy to 5 digits. Yet only a few turntables compensate for it.

The results were terrible because the TimeLine dash moved to the right meaning fast about 12" per revolution. The owner immediately removed the device from his turntable and called it flawed. The unit was fine. His turntable speed was either inaccurate or it simply was affected by the placement of the device on the spindle. I do not know.

I do not understand what you mean by being able to "master" the these two devices. I can use them and read them and report on the results. The videos show this clearly. I can also use a simple strobe disk but I can not tell you what speed some degree of drift correlates to. It is either fast or slow or faster or slower. I simply use these tools to set the turntable speed to either 33.33 or to 45.0. I find it easier than to set the speed by ear.

You should start a thread about LP eccentricity. I would like to learn more about the topic.

 

[tima]

BTW, IMHO LP eccentricity is far more critical than accuracy to 5 digits. Yet only a few turntables compensate for it.

Does your Air Force One Premium compensate for record eccentricity?

 

[the sound of Tao]

I have no idea, Fransisco. However, I do not think amplifier distortion relates to sound quality quite the same way that inaccurate and unstable turntable speed relates to sound quality…

… You should start a thread about LP eccentricity. I would like to learn more about the topic.

Peter I believe this is very much the same as audiophile eccentricity… sometimes they are also a bit warped… the records that is.

 

[microstrip]

Does your Air Force One Premium compensate for record eccentricity?

Fortunately no, as well as 99.99% of the turntables! This only suggests that our threshold for speed variation is lower than five digits. As it was referred in the GrandPrix web pages, measurements carried with an LP were much less sensitive and accurate that their own techniques, due to LP imperfections.

 

[tima]

Fortunately no, as well as 99.99% of the turntables!

Fortunately no ? So you do not want eccentricity correction. I wonder why you brought it up?

This only suggests that our threshold for speed variation is lower than five digits.

What is the referrerant of 'This'?

Are you trying to say that stable accuracy matters less because LPs are not perfect?

 

[microstrip]

I have no idea, Fransisco. However, I do not think amplifier distortion relates to sound quality quite the same way that inaccurate and unstable turntable speed relates to sound quality.

Exactly my point. These "things" do not correlate easily with sound quality and ranking. Why should a dealer let people bring to their space something that will be erroneous interpreted?

I wrote that my 40 year old Micro Seiki turntable can hold a "pretty stable and accurate speed". By the two videos, that is clearly defined by +/- 0.002 RPM. So it follows that I think 33.331 -33.335 is both pretty accurate and pretty stable. I see no ambiguity with that nor an avoidance of quantification.

Regarding "the needed accuracy", I can hear the difference of +/- 0.2 RPM because, at least with this table in this system, I could hear that 33.1 RPM was slow and that 33.5 RPM was fast. I do not know what my threshold is for detecting speed inaccuracy or instability beyond that. I have not experimented much. How much distortion in an amplifier or speaker does there need to be before it is distracting? I suspect it is different for everyone. Does it seem as though I do not know how to interpret the results of the Road Runner tachometer?

OK, thanks your only number for threshold for accuracy seems to around +/- 0.6% . Even .1% would be easily detected by any crude strobe disk. But IMHO stable is still a vague, meaningless and erroneously used concept.

The results were terrible because the TimeLine dash moved to the right meaning fast about 12" per revolution. The owner immediately removed the device from his turntable and called it flawed. The unit was fine. His turntable speed was either inaccurate or it simply was affected by the placement of the device on the spindle. I do not know.

This terrible figure suggests around 1% inaccuracy . As I said a simple strobe would have detected it. Or perhaps just your ears ...

I do not understand what you mean by being able to "master" the these two devices. I can use them and read them and report on the results. The videos show this clearly. I can also use a simple strobe disk but I can not tell you what speed some degree of drift correlates to. It is either fast or slow or faster or slower. I simply use these tools to set the turntable speed to either 33.33 or to 45.0. I find it easier than to set the speed by ear.

Well we have many web page telling us how to calculate the speed from the strobe variation. Or even mobile phone applications that do it for us - I have seen a guy using it in a show some years ago!

You should start a thread about LP eccentricity. I would like to learn more about the topic.

We discussed it in WBF sometime ago. I will search for it. Or if interested just google the famous Nakamichi Dragon CT turntable. I once read about some professional software application that analyzes digitized analog coming from LP and tape for speed variations along the recording and corrects them. The graphic display of existing problems in typical LPs was terrible, as you say! Fortunately our ears are very forgiving, as proved by Kind of Blue.

 

[microstrip]

Fortunately no ? So you do not want eccentricity correction. I wonder why you brought it up?

If our ears are not sensitive to typical LP eccentricity I am sure that they are not sensitive to speed accuracy variations of the forth figure.

What is the referrerant of 'This'?

Are you trying to say that stable accuracy matters less because LPs are not perfect?

No, but I am telling again and again than mixing stability and accuracy in a single concept only brings confusion and precludes any useful discussion. The longtime turntable speed parameters are speed accuracy and wow and flutter.

BTW, people addressing stability of periodic signals usually refer to the Allan Deviation, but it is not adequate to turntables. "The Allan variance is intended to estimate stability due to noise processes and not that of systematic errors or imperfections such as frequency drift or temperature effects. The Allan variance and Allan deviation describe frequency stability, i.e. the stability in frequency."

 

[Phoenix Engineering]

You systematically failed to define what you mean precisely by "stable speed", trying to debate technical matters in a vague and ambiguous language, avoiding quantification. You do not tell us what you think is the needed accuracy. Why should people use instruments if they do not know how to interpret the results clearly?

IMHO if we want to propose, support, disseminate or compare any kind of objective measurement in public we must master it and be able to discuss it.

So how do you quantify speed instability with a strobe disc? The spots or lines move, but what is a "good" reading and what constitutes "bad"? What is the "needed" level of accuracy using a strobe disc? Perhaps you could enlighten us on how to interpret the results of looking at a disc clearly? How long does it take to master this technique? Do you know the accuracy of the light source used to illuminate the moving lines? Do you know the accuracy of the printing process on the disc? Is the disc clamped securely to the platter or does it move?

You are falling into one of the more common logical fallacies: Appeal to ignorance.

A digital tachometer works essentially the same way as a strobe disc, but is more accurate and precise. Why do you have such a difficult time understanding this? Is it the price? $300 for the tach vs $100 for a quality disc and a stable crystal controlled light source does not seem exorbitant, especially for this industry/hobby (I don't consider using ambient light a very reliable source).

No, but I am telling again and again than mixing stability and accuracy in a single concept only brings confusion and precludes any useful discussion. The longtime turntable speed parameters are speed accuracy and wow and flutter.

You seem to be guilty of this as well. You are asking people what level of speed in accuracy (absolute pitch error) they can detect audibly then claiming that a simple strobe disc can do the same thing. As Peter noted, absolute pitch sensitivity will vary from person to person, so I doubt you could quantify it any better with a strobe disc than with a tachometer. But absolute speed accuracy is only one parameter.

A digital tachometer with resolution to 3 places right of the decimal will detect anomalies that can be caused by belt contamination, bearing problems, poor motor control, inaccurate drive frequency, etc., that a strobe disc cannot. This is not the same as W&F, which tends to be symmetric and the tachometer cannot measure speed errors that cancel to zero within the measurement period. Can the average (or even experienced) listener detect these types of errors audibly without an instrument? Probably not. Can they hear an improvement in SQ after these anomalies are corrected? It surely depends on a number of factors, but most indications (feedback from actual users) affirm that it will improve the listening experience. You do not need to quantify errors anymore than you do with a strobe: The lower the error, the better, above a certain level of "noise" (±0.002 RPM seems typical, YMMV).

If you use a DVM to troubleshoot a voltage regulator circuit, do you need special instructions to do this? If the voltage reads correct except for the last digit toggling, most people would conclude the regulator is working properly or at least adequately. If the voltage has higher fluctuations (1st or 2nd digit right of the decimal), one would assume there is something wrong, would they not? If the voltage is stable, but the reading is higher or lower than expected, does that indicate a problem? How much higher or lower? If the voltage is adjustable, do you try to correct it? How close to absolute accuracy is acceptable?

 

[ddk]

Exactly my point. These "things" do not correlate easily with sound quality and ranking. Why should a dealer let people bring to their space something that will be erroneous interpreted?

As a dealer I allow people to bring whatever instrument people want, I don't care. People have brought test recordings, db meters, cables, cartridges, etc. to sessions here. Fact is if they can't understand what they're hearing what they bring along won’t matter.

OK, thanks your only number for threshold for accuracy seems to around +/- 0.6% . Even .1% would be easily detected by any crude strobe disk. But IMHO stable is still a vague, meaningless and erroneously used concept.

This terrible figure suggests around 1% inaccuracy . As I said a simple strobe would have detected it. Or perhaps just your ears ...

Well we have many web page telling us how to calculate the speed from the strobe variation. Or even mobile phone applications that do it for us - I have seen a guy using it in a show some years ago!

And so what? People shouldn’t use the accurate tool they want because IYO a crude strobe is enough? How do you know if the strobe is working properly, you can’t tell by eye. I have several battery operated respected strobes and they all give slightly different readings and different again from the mains operating one. Try using your phone while the record is playing!

The RR is a wonderful accurate and easy to use tachometer with a clear display that can see anytime you want. It’s ideal for a consumer’s needs to properly set the operating speed and confirm consistency with a glance or diagnose in the moment if something happens, you can’t do that with a strobe and a strobe disc, specially if it has to go over the platter.

We discussed it in WBF sometime ago. I will search for it. Or if interested just google the famous Nakamichi Dragon CT turntable.

It’s one of the worst sounding high end turntables of that era. Gadgetry doesn’t translate into good sound!

I once read about some professional software application that analyzes digitized analog coming from LP and tape for speed variations along the recording and corrects them. The graphic display of existing problems in typical LPs was terrible, as you say! Fortunately our ears are very forgiving, as proved by Kind of Blue.

Claims are made all the time about miracles of software you should verify to see how much of it is true. Also what type of digitized copy do you end up hearing? Tone and timbre quality? In theory and on paper everything works but the real world has it’s own standards!

For many audiophiles including myself the point of a high end audio system is pleasure and it has to deliver it with minimum fault and maximum realism in real world context.

david

 

[Lagonda]

Do you think that Lamm dealers would allow consumers to measure the distortion of the Lamm amplifiers at low frequencies in a comparison with other solid state amplifiers before listening in their shop?

You systematically failed to define what you mean precisely by "stable speed", trying to debate technical matters in a vague and ambiguous language, avoiding quantification. You do not tell us what you think is the needed accuracy. Why should people use instruments if they do not know how to interpret the results clearly?



What do you exactly mean by the results were terrible? Was it a faulty unit or simply a poor turntable?

IMHO if we want to propose, support, disseminate or compare any kind of objective measurement in public we must master it and be able to discuss it.

BTW, IMHO LP eccentricity is far more critical than accuracy to 5 digits. Yet only a few turntables compensate for it.

LP eccentricities only matter with very badly centered holes, in general you don't hear that big a difference before and after auto-centering the record. I owned a Nakamichi TT 15 years.

 

[microstrip]

So how do you quantify speed instability with a strobe disc? The spots or lines move, but what is a "good" reading and what constitutes "bad"? What is the "needed" level of accuracy using a strobe disc? Perhaps you could enlighten us on how to interpret the results of looking at a disc clearly? How long does it take to master this technique? Do you know the accuracy of the light source used to illuminate the moving lines? Do you know the accuracy of the printing process on the disc? Is the disc clamped securely to the platter or does it move?

You are falling into one of the more common logical fallacies: Appeal to ignorance.

A digital tachometer works essentially the same way as a strobe disc, but is more accurate and precise. Why do you have such a difficult time understanding this? Is it the price? $300 for the tach vs $100 for a quality disc and a stable crystal controlled light source does not seem exorbitant, especially for this industry/hobby (I don't consider using ambient light a very reliable source).



You seem to be guilty of this as well. You are asking people what level of speed in accuracy (absolute pitch error) they can detect audibly then claiming that a simple strobe disc can do the same thing. As Peter noted, absolute pitch sensitivity will vary from person to person, so I doubt you could quantify it any better with a strobe disc than with a tachometer. But absolute speed accuracy is only one parameter.

A digital tachometer with resolution to 3 places right of the decimal will detect anomalies that can be caused by belt contamination, bearing problems, poor motor control, inaccurate drive frequency, etc., that a strobe disc cannot. This is not the same as W&F, which tends to be symmetric and the tachometer cannot measure speed errors that cancel to zero within the measurement period. Can the average (or even experienced) listener detect these types of errors audibly without an instrument? Probably not. Can they hear an improvement in SQ after these anomalies are corrected? It surely depends on a number of factors, but most indications (feedback from actual users) affirm that it will improve the listening experience. You do not need to quantify errors anymore than you do with a strobe: The lower the error, the better, above a certain level of "noise" (±0.002 RPM seems typical, YMMV).

If you use a DVM to troubleshoot a voltage regulator circuit, do you need special instructions to do this? If the voltage reads correct except for the last digit toggling, most people would conclude the regulator is working properly or at least adequately. If the voltage has higher fluctuations (1st or 2nd digit right of the decimal), one would assume there is something wrong, would they not? If the voltage is stable, but the reading is higher or lower than expected, does that indicate a problem? How much higher or lower? If the voltage is adjustable, do you try to correct it? How close to absolute accuracy is acceptable?

Unfortunately you did not read the first posts about the subject in Peter thread and are missing the main point and focusing on the accessory. My points were simple, as you ignore them you are asking interesting questions that are however just side points and I have already answered to them in my several answers to Peter. The debate was general on the TimeLine and RoadRunner and on the speed accuracy we need to have top playback of vinyl.

And yes, a 5 digit digital tachometer can detect many anomalies. Simply it was not what was being debated and Peter was addressing.

BTW, you systematically changed and misrepresented my points - too many times to allow a proper answer.

 

[microstrip]

LP eccentricities only matter with very badly centered holes, in general you don't hear that big a difference before and after auto-centering the record. I owned a Nakamichi TT 15 years.

Yes, I remember it, some other people also reported it in audio blogs . I am astonished how poor are our ears in detecting speed stability with a period around half a second.

 

[Lagonda]

Yes, I remember it, some other people also reported it in audio blogs . I am astonished how poor are our ears in detecting speed stability with a period around half a second.

On badly centered records, it reduced bass rumble, but it looked very cool and scientific going trough the different steps of adjustments.

 

[microstrip]

As a dealer I allow people to bring whatever instrument people want, I don't care. People have brought test recordings, db meters, cables, cartridges, etc. to sessions here. Fact is if they can't understand what they're hearing what they bring along won’t matter.

And so what? People shouldn’t use the accurate tool they want because IYO a crude strobe is enough? How do you know if the strobe is working properly, you can’t tell by eye. I have several battery operated respected strobes and they all give slightly different readings and different again from the mains operating one. Try using your phone while the record is playing!

People can use what they want - even a strobe. The fact that they show differences only prove that they are very sensitive.

The RR is a wonderful accurate and easy to use tachometer with a clear display that can see anytime you want. It’s ideal for a consumer’s needs to properly set the operating speed and confirm consistency with a glance or diagnose in the moment if something happens, you can’t do that with a strobe and a strobe disc, specially if it has to go over the platter.

Yes, it is surely more convenient than a strobe. I am astonished how humanity managed to survive for tens of year listening to vinyl without such instrument.

It’s one of the worst sounding high end turntables of that era. Gadgetry doesn’t translate into good sound!

Claims are made all the time about miracles of software you should verify to see how much of it is true. Also what type of digitized copy do you end up hearing? Tone and timbre quality? In theory and on paper everything works but the real world has it’s own standards!

For many audiophiles including myself the point of a high end audio system is pleasure and it has to deliver it with minimum fault and maximum realism in real world context.

david

Nice to see we share the same view on high end audio objectives. But I like mostly modern recordings ...

 

[microstrip]

On badly centered records, it reduced bass rumble, but it looked very cool and scientific going trough the different steps of adjustments.

Fortunately pivot tonearms manage to visually disguise eccentricity - linear tracking arms and probably the Dragon CT are ruthless in this aspect. As far as I remember around .1 mm eccentricity was fairly common. Do you remember any typical statistics?

 

[Phoenix Engineering]

Unfortunately you did not read the first posts about the subject in Peter thread and are missing the main point and focusing on the accessory. My points were simple, as you ignore them you are asking interesting questions that are however just side points and I have already answered to them in my several answers to Peter. The debate was general on the TimeLine and RoadRunner and on the speed accuracy we need to have top playback of vinyl.

And yes, a 5 digit digital tachometer can detect many anomalies. Simply it was not what was being debated and Peter was addressing.

BTW, you systematically changed and misrepresented my points - too many times to allow a proper answer.

I did read the first posts and do understand the main point. Your points were simple and I addressed them directly. I didn't systematically change or misrepresent your points, I quoted them verbatim. You were disparaging the use of anything other than a strobe disc as a "gadget" with little or no utility. I disagree with your assessment. If you can't or are unwilling to respond to the debate, then maybe it's time to admit you were wrong.

As far as what level of accuracy and stability is needed for top playback of vinyl, it's a fool's errand to attempt to quantify it, even for individuals, let alone the listening public in general. Reducing speed errors and instability to lowest level that is audible or what could be considered "noise" should be the goal. In order to achieve that goal, it is helpful to have instruments that can reliably quantify the measurement, something a strobe disc cannot do. Trying to put a number on what absolute level is audible is meaningless. If that was your point, then I agree.

I'll defer to Peter with regards to what he was addressing and what he felt was relevant or useful in making improvements to his system.

 

[Phoenix Engineering]

I am astonished how humanity managed to survive for tens of year listening to vinyl without such instrument.

A wee bit ** of sarcasm professor? Touché!


** I think even Sheldon Cooper would've caught that one...

 

[microstrip]

I did read the first posts and do understand the main point. Your points were simple and I addressed them directly. I didn't systematically change or misrepresent your points, I quoted them verbatim. You were disparaging the use of anything other than a strobe disc as a "gadget" with little or no utility. I disagree with your assessment. If you can't or are unwilling to respond to the debate, then maybe it's time to admit you were wrong.

You fail to understand the origin of the discussion - the use of the RoarRunner or TimeLine to quantify the effect of stylus dragging and correlate it with sound quality of turntables. We were not addressing its use to check their current status of performance. As you know the TimeLine only presents qualitative raw data we must analyze.

As far as what level of accuracy and stability is needed for top playback of vinyl, it's a fool's errand to attempt to quantify it, even for individuals, let alone the listening public in general. Reducing speed errors and instability to lowest level that is audible or what could be considered "noise" should be the goal. In order to achieve that goal, it is helpful to have instruments that can reliably quantify the measurement, something a strobe disc cannot do. Trying to put a number on what absolute level is audible is meaningless. If that was your point, then I agree.

I'll defer to Peter with regards to what he was addressing and what he felt was relevant or useful in making improvements to his system.

No, IMHO we should be able to put a number in the needed accuracy threshold. Otherwise consumers will always correlate more accurate with better sounding. My main point has been that the accuracy of mains is better than what we need in turntables speed accuracy. Mains accuracy is well studied and can be checked online in Europe. see https://www.mainsfrequency.com/ . IMHO we should simply set the speed with a good strobe disk - SME and Oracle supply very good ones.

BTW, my turntable has a four digit tachometer and I do not hide it with black tape!

 

[Lagonda]

Fortunately pivot tonearms manage to visually disguise eccentricity - linear tracking arms and probably the Dragon CT are ruthless in this aspect. As far as I remember around .1 mm eccentricity was fairly common. Do you remember any typical statistics?

It would just correct, without giving a readout of how much the hole was of center. Sometime two measurements and one correction, others it needed a second correction, before it was "happy" !