Yes, all such devices tell you is speed accuracy and consistency information. This of course is important for proper sound. But yes, the sound of the turntable depends on many factors and quality of speed is only one. When I compared the SME Model 30/12 to my friend's SP10 Mk3 in my system using the same V-12 arm and AirTight Supreme cartridge, we both preferred the sound of the SME table but the SP10 had better speed performance.
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Yes, all such devices tell you is speed accuracy and consistency information. This of course is important for proper sound. But yes, the sound of the turntable depends on many factors and quality of speed is only one. When I compared the SME Model 30/12 to my friend's SP10 Mk3 in my system using the same V-12 arm and AirTight Supreme cartridge, we both preferred the sound of the SME table but the SP10 had better speed performance.
Surely your particular anecdotal experience is interesting and relevant for you.
IMHO "Quality of speed" is just a broad meaningless qualifier. Since long the industry relied of the spectra of wow and flutter and rumble to access the objective characteristics of rotation of turntable platters - still measured in some reviews.
In a subjective hobby, most of the time limited objective data will only help creating bias listening - even hard subjectivists love measurements when they go along with their preference.
No. But in addition to the damping the stock platter has, I applied more in the form of a proper platter pad.
Thanks - I read your excellent past articles on the.SL1200G (starting here https://www.whatsbestforum.com/thre...llenge-the-state-of-the-art.38300/post-994711 Did you play with the calibration settings?
Those curious of the inside of the SL1200 G can see it at https://www.gcaudio.com/products/technics-sl-1200g-direct-drive-turntable-silver/
Apologies for the question Peter - too interesting to be forgotten and yet related to our current subject!
OK Fransisco, you have kept me busy with your many requests for data. I will let you analyze the numbers. Here is a video of platter free spin with stylus in the groove. I kept the camera on the tachometer until the reading stopped and kept it going until the platter stopped rotating. Surprisingly, the free spin time to stop with the stylus is very close to without the stylus, about 30 minutes. In fact, they are basically the same.
You can see the thread is disengaged and I got the platter up to speed with my hand. Let us know what you conclude, if anything, from the video. For convenience and easy comparison, I will repost the other free spin video with no stylus.
Video with no stylus:
Video with stylus:
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Surely your particular anecdotal experience is interesting and relevant for you.
IMHO "Quality of speed" is just a broad meaningless qualifier. Since long the industry relied of the spectra of wow and flutter and rumble to access the objective characteristics of rotation of turntable platters - still measured in some reviews.
In a subjective hobby, most of the time limited objective data will only help creating bias listening - even hard subjectivists love measurements when they go along with their preference.
Surely anecdotal experience is interesting to some. Sharing it with others on a discussion forum when it illustrates and supports a previous comment may not be of any interest to anyone or relevant to you, but I thought I would mention it just in case.
By "quality of speed" I mean both what is captured by standard measurements and also by what is heard and may not be understood or measurable. I have no way to measure wow and flutter here, nor is that my interest. I appreciate that they interest you.
In this subjective hobby, I figure limited objective data like my TimeLine results is more helpful than not. So I shared it for anyone who may be interested. Hard to self analyze about the bias it creates. What is interesting is that few others openly and willingly share similar experiments and data that I am sharing here. If you do not find it helpful or interesting, let me know. I would ask you to share something about your turntables, but I understand you are now focused only on digital with any listening you may be doing to your system. The AF1 data would be interesting to see especially for me because I have had the Micro Seiki and AS 1000 here also. The AF1 though similar in some regards sounds very different in direct comparison.
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Thanks Peter. A fast analysis of four points per case shows that measured during the first three minutes the reduction in speed is around 2.5% per minute without stylus and 4.6% per minute with stylus at acceptable speed.
We now have data that people can use if they want to make their own measurements to compare turntable bearing friction. Using the classical formulas of moment of inertia we can compute the power dissipated in the bearing versus speed using the data DDK gave us about the platter.
I only used the data from the first three minutes of videos - data at lower speeds is meaningless and will only add noise and establish confusion.
Fransisco, what do you make of the fact that the platter takes 30 minutes to stop while free spinning both with and without the needle in the groove? This would seem to say something different about stylus drag, namely that it has little influence on the total time it takes for the platter to stop spinning. It seems to contradict the behaviour early on. I understand your point that you want the data close to what is happening at the 33.333RPM speed. But we do not listen when motor is not engaged and the speed never drops below 33.331RPM when I am listening. It remains between 33.331 and 33.334 and that variation is completely inaudible to me. Could anyone hear it?
I do not see how the same free spin time to stop is not relevant when discussing bearing friction. Do you have any data on bearing friction from other turntables?
The time the platter takes to stop has no comparative meaning at all. Do you play your LPs at 20 or 10 rpm? Specially considering that after a few minutes the tachometer only shows RPM down to around 29 RPM.
I just wanted to evaluate the bearing friction in the condition of operation in a way I can compare with other bearing types. I do not have such information now, but hope to carry some measurements in the future.
My main interest now was comparing the slow down with and without stylus. As I can calculate platter drag I now have a method to calculate stylus friction. Surely data coming from a free spinning 40 kg air bearing platter is of great interest to compare with data from other articles.
Surely 5 minutes of data taken with the stylus at 50% of the LP playing time would be welcome!
That is true about comparative meaning. But then we do not listen to music from a turntable with the motor unattached either, so what are we really learning hear? We see that at close to 33.333RPM, stylus drag is real, even on a massive platter like this one. But the motor addresses that and we get very steady and accurate speed.
Based on these two videos without the motor attached, I observe this:
1. When spinning close to 33.333RPM with the needle in the groove, the platter slows down about 0.045 RPM each revolution and takes 3:13 until the tach turns off around 29 RPM.
2. When spinning close to 33.333RPM with the needle not in the groove, the platter slows down about 0.026 RPM each revolution and takes 5:30 until the tach turns off around 29 RPM.
Clearly there is measurable stylus drag when the platter is spinning faster. Also interesting is that the rate that the platter slows down per revolution is very steady in both cases during the first few minutes while the tach has a reading.
What I find fascinating however, is that the platter takes the same amount of time free spinning to stop with or without the needle in the groove. I agree this is not how we listen to music, but nor is it with motor detached. Stylus drag and free spin time might tell us something in isolation, but what really matters is the end listening result of the platter and bearing design while influenced by the motor and connection plus all the other factors in the overall design and implementation that combine to produce what we hear.
Turntables are designed to play records and however a platter is controlled it does so with a stylus in the groove. I speculate that while stylus drag may be a physical event it does not cause a sonic event. I don't know if stylus friction changes within the radius of the record but, again speculating, if it does not and remains constant then as a constant it is imperceptible in and of itself, though maybe it effects the overall character of the table? I don't know within what fraction of a second stylus drag (friction) starts. Typically the stylus is on the record before we hear music. When the stylus touches the record -- the moment drag initiates -- do you see the rpm change on the meter? My Monaco gives no indication, not even the faintest flicker of platter adjustment or correction. (It reports on the platter over 160,000 times per second.)
Yes and it’s interesting that Technics FINALLY went with a coreless, slotless motor in their TT reboot. All of the old ones were iron core motors when nearly all of their competitors had gone to much better motors long before.
Ok, that is a significant amount of reduction difference per rotation and shows even when the platter is massive the effect is not negligible.
It is not constant moment by moment…over a full rotation I imagine it more or less averages out. Strong modulation will have more drag.
What that means is to maintain speed, mass alone will never really work, and speed correction in the form of applied torque is necessary and how this is done on the micro level is probably of significance.
The question then becomes what kind of speed fluctuations are humans sensitive to? Are they sensitive to long slow fluctuations in speed or rapid accelerate decelerate motions? What is the sonic impact of tight vs. Loose control systems?
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You should start by measuring your own TT Francisco !
Well, I would think negligible is relative. If people want to really understand the significance of this, they should start looking into data from other turntables for relative importance. And as I say, all it takes is very loose thread tension to keep the speed constant meaning there’s very little influence from the motor.
As I said earlier, the big SME actually slowed down when the motor was attached when I dropped the needle. That is not the case with this turntable. The speed does not change on the tachometer when I raise and lower the needle in the groove. The operating condition with the motor attached is what we are listening to when playing records not the condition when the motor is removed from the equation.
And of course, there are other designs that have purpose breaking. I asked the question earlier if stylist drag is a kind kind of break. I did not get a response.
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GP Audio had excellent technical white papers on turntable speed and drag accessible in their site. Unfortunately it seems they were removed.
And sorry Tim, I am not interested in naïve speculation about possible stylus drag. I prefer focusing on it after we have data or reliable information.
Fortunately the feedback system of your Monaco is well designed and performs flawless - it is a technical marvel.
You should start by measuring your own TT Francisco !
My current turntable can't be measured this way - I can't remove the belt while it is playing.
People should realize that this measurement is is meaningless with DD turntables, even coreless ones - when not energised they are braked by electromagnetic counter forces.
From the baseYou should start by measuring your own TT Francisco !
Peter,
Again, I asked for data just to have a better technical knowledge about the particular bearing of your turntable. Nothing else can be inferred from it .
The mechanisms of stylus drag and vinyl /stylus friction were deeply studied and published in the 60's and 70's - companies such as Shure , Ortofon and Audio Technica had articles and papers on it. Technical magazines, such as Wireless World had studies on it - I remember having read them, surely do not remember the contents anymore.
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