Turnable database with TimeLine

Actusreus,

If a turntable slows down for a very brief moment due to the stylus drag and the Timeline registers it by shifting the laser spot but then remains constant, how relevant is that drag save for the very brief moment of the stylus settling in the grooves and the turntable adjusting its speed?

I have never witnessed what you describe.
Stylus drag is constant (but variable if you know what I mean)....so that when it slows down the speed of a turntable platter......that speed is changed for the duration.
It doesn't 'spring back' to accurate speed after the initial 'shock'....although with some direct drive turntables using speed-error correction.....this might be a possibility.
I just haven't seen evidence of it using the Timeline?

Tonywinsc,

The problem is you can't know if the drift is due to speed being something other than 33 1/3 exactly or if speed is actually changing during play.

This sounds like such a logical proposition....that no-one seems to argue against it and many have repeated it......
I suggest that it is impossible (without complex computer management).....to design an AC or DC synchronous motor to turn at multiple varying speeds which can line up a laser at an exact point every revolution at both 33.33rpm and 45rpm.
And as none of the motors in any of the turntables we know of.....have such sophisticated (and devious) computer algorithms inbuilt....this argument is simply childish?

Agree with Tonywinsc. I think the KAB measurement makes more sense for average speed and constancy of speed.

I disagree. The Timeline measures the speed accuracy AND constancy with each rotation of the platter. How much more do you want or need? I understand Tonywinsc's point as a matter of theoretical discussion and extreme obsession, but if constant speed with each rotation of the platter is not enough for a person, I suggest that he needs to find another hobby altogether or perhaps listen to digital only.

I would argue with Tony on different grounds. I think you CAN know if drift is due to "speed being something other than 33.33 exactly or if it is changing during play." At least you can know it to the accuracy of the frequency of the laser flashes on the Timeline. (Since I don't have one in my possession, I cannot describe it exactly.) I think it has more than one laser, at least two and maybe four. (Again, "I think" the early version had fewer lasers.) Let's say that the worst case scenario is it has one laser, which means that there will be a flash of light every ~1.8 seconds. Assuming the astuteness of the observer is not a limitation, that means one could detect whether speed has varied during the 1.8 second interval between flashes. If speed is just inaccurate but is not subject to stylus drag, then the drift of the laser spot will be a constant amount in one direction or the other. (Halcro just gave an example of that with the Raven.) If speed is being now and then momentarily retarded due to stylus drag (or other cause), then the laser spot movement will be irregular or regularly irregular or irregularly regular, within the limits of detection determined by the frequency of the laser flashes, which would be every 1.8 seconds divided by the number of lasers flashing per revolution.

There are two subjects here: 1) How well do the differing turntables hold speed to exactly 33 1/3 rpm? 2) What is the effect on platter speed during heavy groove modulation?
Subject 1 is being answered with the Timeline device testing. And the Timeline device is being used appropriately for these measurements. This is a perfectly valid and interesting exercise.
Subject 2 is also a valid and interesting point. The Timeline device, however is not the appropriate tool in this case. A fine tachometer is required. I find this subject interesting and especially if it were possible to compare the results of speed control with a heavily modulated record on all three basic drive types- belt, direct and idler.

Halcro,

I just watched your video of the Raven, and I must say I am puzzled by the speed changes. What's causing it? Assuming the VTF is stable, as it should be, why would the turntable speed up as the tonearm tracks toward the spindle?

I thought, this is a Database with Timeline and not a Database of "Turntable Owners Mystery Collection"?
To write somerhing useful for readers, the Kuzma "Reference" runs also with wrong Speed (too fast)....the search goes on :-)

Lewm, I also thought that there is a new version of the TimeLine with more lasers around the perimeter of the device. However, I just spoke to a dealer today who confirmed with Roy Sutherland himself, that there is only one TimeLine version and that the device has not be changed since its introduction. There is only one laser on the device. It flashes at some interval to create six equally spaced dashes around the room. This description is consistent with the unit that I borrowed to make my videos. Apparently, I had the original and only version.

I have tried a digital tachometer and found that I could not get repeatable readings even while I held the device against the edge of a table and pointed the beam toward the reflective tape. It varied by an amount much greater than my KAB and the Timeline indicated, so it must be defective or I was not using it correctly. I will try it again.

Actusreus.
Assuming
1)the stylus drag is constant throughout the LP
2) the TT slows due to stylus drag,
3) speed control is open loop ( maybe)
Then it will naturally increase in speed as it tracks towards the centre grooves.
This is a torque moment effect. On the outer grooves, the drag is acting on a larger radius so it requires more torque from the motor to counteract this.

Peterayer,
Your Dealer is wrong....

good morning Henry,
so you got one of the very early Timelines that flashes once per 1.8 seconds (33) ?
there were only a hand full of those that went out before the software was changed.
if so, let me know and i will get you a new chip.
Ron

As it turns out.....mine DOES have the new chip and flashes 6 times :-)

Actusreus,
I'm not sure I understand your question?
The turntable is not speeding up as the tonearm tracks toward the spindle....
I sense that many people without 'hands-on' experience with the Timeline may have difficulty understanding how it functions?
If the turntable is rotating at exactly the correct speed (33rpm or 45rpm).....the laser will 'hit' the wall at exactly the same spot every revolution.
Putting the Bluetak marker on the wall makes it easier to gauge the position of the 'hits' accurately.
If the turntable is running faster than 33.33rpm......the laser will hit the wall slightly further to the RIGHT of the marker every revolution so that the position will move further to the right at every revolution.
If the turntable is running slower than 33.33rpm (as is the case with the Raven)....the laser will hit the wall slightly further to the LEFT of the marker at every revolution and will move further to the left at every revolution.
With the Raven...you can see that the laser is moving approx 1mm to the left with every revolution....and it is consistent.
This probably equates to a speed of 33.31rpm instead of 33.33rpm.
When the arm is lifted at the end....you can see that the laser hits the wall mark at exactly the same spot at every revolution.
This indicates that the turntable is maintaining 33.33rpm without load.

I tried using my Fieldpiece digital tachometer again last night. I tried three l locations and placed the device on a stationary platform. In each test, the device read 33.XXX but the XXX had slightly different values at each location. These speed readings did not change when I introduced stylus drag. In fact, once the 33.439 or 33.352 was fixed I could not seem to get it to change value without turning the unit off and resetting it to zero. Nor could I get it to ever repeat a reading. Both the TimeLine and the KAB show the effects of stylus drag on my turntable. Perhaps the tachometer is just not sensitive enough to tiny changes.

But Syntax, is the Kuzma constantly too fast by a fixed amount while playing LPs, that is, regardless of stylus drag? If so, that is a fault remediable by an appropriate motor controller and not a black mark against the Kuzma.

Tony, I just cannot agree that a tachometer, no matter how good, is potentially superior to the Timeline for detecting micro-variations in speed, unless it would run off the rotation of the platter by a direct and perfectly non-compliant mechanical linkage, with no "belt creep". And then you'd have to stand there and watch it or run a recorder off of its output. In fact, Denon produced such a figure for use in their ad copy for the DP80; they show a very low level wiggle in an otherwise straight line, representing 33.33 rpm on the Y-axis, with time on the X-axis. But I doubt that the data come from a tach read-out. I don't recall how they derived it.

Peter and Henry, So if the single laser flashes six times per revolution, that would be about every 0.3 seconds. That's pretty near an instantaneous read-out. I wonder how it compares to the response time of a very good servo correction system. Maybe Richard knows.

Hi Halcro,
May I ask, did you manage to adjust the speed from a steady 33.31 to 33.33 under load?

Kind regards,

Actusreus.
Re my last post and tracking progressively towards the center grooves.
For clarity, I should have said it progressively becomes less slow as the torque demand decreases.

Lew
The servos we use at my work can have response times in the micro sec range. The limiting factor is the frequency response of the actuator they are controlling, so in practice, slower than this would suggest.
The goldmund feedback is very fast as observed on the scope current draw plot. Much faster than 0.3 sec . As I posted earlier, it was responding note by note. A startling observation.
Other TT manufacturers would, I suspect taylor the response time to suit their design philosophy.

01-16-14: Richardkrebs
The goldmund feedback is very fast as observed on the scope current draw plot. Much faster than 0.3 sec . As I posted earlier, it was responding note by note. A startling observation.

I'm very keen to try this test on my Final Audio. Could you please explain, if I use Mahler's 2nd for the test, which instrument should I listen to for the "note by note" ? Tympani ? Violin ? 1st or 2nd ?...
Could you explain what scope you used and how you calculated your reported result of less than 0.3sec for the servo response.

Since you keep referring to the Goldmund Studio, could you explain the reasons you went about modifying the power supply - what were the deficiencies that you could hear that prompted you to modify the power supply. Goldmund claim in their brochures that they used a new motor with built in regulator and Quartz controlled speed with response times fast enough to be immune from power line variations and to use an unregulated power supply.

Could you also explain what differences you could hear when you sold the Goldmund to purchase your SP10mk3. I recall that you told me at the time that the SP10mk3 was the only Direct Drive TT that you could not hear cogging or servo correction derived artifices. You told me at the time that the SP10mk2 and Goldmund did not have enough torque and thats why we could hear timing problems.

Halcro, I just shared what Ron Sutherland told my dealer yesterday. I had been under the impression that there was an early version with one strobe and a new version with six strobes. That must be incorrect. So you must be saying that all versions have just one strobe. The difference is that the newer version flashes 6 times per 1.8 seconds and the earliest units only flashed once per 1.8 seconds. Is that correct? That must be why there are six dashes spread out around the room at every rotation. Thanks for clarifying this for me.

Dover,
Less than 0.3 seconds servo response came from observing current draw modulation in the kHz range, in sync with the music being played. The test was done with the system muted and live to check if it was some sort of acoustical feedback phenomenon.
There is only one possible cause of this.....
The platters speed was being modulated note by note. The controller / motor assembly was responding to this and " attempting" to stabilise the speed. This shows a controller frequency response in the kHz range. A speed that is not unusual in the industrial field.

Suggest a better test piece for you would be " Final Fantasy" by Nobuo Uematsu.

Lew,

To write somerhing useful for readers, the Kuzma "Reference" runs also with wrong Speed (too fast)....the search goes on :-)

I wouldn't worry what Syntax writes......
For years...he has maligned the TW Acustic Raven turntables on every audio Forum he could find....
With overtones of arrogant superiority.....his subjective diatribes may have left many owners of these fine turntables feeling insecure....especially in the face of his proclaimed superiority for the Micro Seiki RX-5000?
With the advent of the Timeline....we finally have an OBJECTIVE scientific measure of the speed accuracy and consistency of any turntable.
And still over the last two years.......Syntax has proclaimed that not one...out of a dozen Raven AC turntables he had tested....could pass the Timeline Test...whilst his RX-5000 was "burning holes in the wall" with its Timeline accuracy?
The first time we see visual proof of the Timeline with my Raven AC-2 and his Micro Seiki RX-5000....you can see the Raven keeping absolutely consistent timing under load albeit at 33.31rpm (an error of .06% which is better than any turntable's printed specification)....and keeping dead-on 33.33rpm spinning freely.
Yet the laser mark with the RX-5000 can be seen to drift forwards of the letter K in the word FRUHBECK...then backwards to the C and then even further back under the letter E before appearing suddenly under the letter K again.
This cycle keeps repeating throughout the video (which is shorter than all the other videos posted).....and there is no filming with the cartridge 'up' so that comparisons can be made about the effects of stylus drag as is done on all my videos?
This objective evidence demonstrates a very poor performance from the Micro Seiki RX-5000 IMHO....and I would recommend to all those with Raven turntables who ever again see malicious subjective comments posted against these fine turntables....to simply post the two comparative videos shown on this Thread.

And those who may own Kuzma Reference turntables......notice that no visual evidence has been filed in support of these 'cheap' words from Syntax?
He prefers that you simply 'believe him'?

Hi Moonglum,
As the Raven motor controller has 'stepped' increments of speed control....the 'under-load' speed can only be adjusted to be +/- 0.06%....a superb specification incidentally.
It is a fluke that the 'exact' speed is achieved without load....
Other Raven owners with belts under tighter of looser tension....may fluke an 'exact' speed under load....but this will be slightly higher whilst spinning freely.

Peterayer,
As Ron Sutherland explained it to me......you are only using ONE laser flash hitting the wall every 1.8 seconds.
With the first few models sold.......locating that single flash on the wall where you want it.....was quite difficult and time consuming.
With a choice of one of six flashes.....that 'positioning' problem has been made easier.

Hi Lewm,
How can micro variations in speed due to groove modulations be measureed with a laser light that flashes just once every 1.8 seconds? The answer is that it cannot. The Timline gives you average speed- that's it. Don't try to read into it anymore than that. Sure, you can see the difference in average speed for an unloaded platter vs. a platter with stylus load; but you cannot measure the micro variations in speed with an averaging device. It must be an instantaneous device like a tachometer. The Timeline is a nice little package that has laboratory grade accuracy for a realatively low cost. A Tachometer with equivalent precision will cost significantly more, I'm sure. The danger is mis-using the data from an averaging device. For exmaple, the speed error for variable stylus drag is cumulative. So the longer you play the record and measure speed, the more the average, in percent, will deviate from 33 1/3. (If the stylus drag is constant, then the error will not accumulate- ie. the average speed will remain a constant delta in percent from 33 1/3). See, things can get murky real fast when working with averages. You can infer stylus drag is causing variations in platter speed with the Timeline, but actual measurements are not possible.
Back to my car analogy: Try driving and maintaining speed with the Average Speed readout on your car's trip computer. Once you have accumulated a couple of miles on the average speed computer, the speed reading will not change much even if you go very slow or 120 mph. The police officer is using an instantaneous speed readout device. Good luck convincing him not to ticket you because your average speed was below the limit. (If that does work, let me know how you did it!)

Tony, According to others, the laser flashes 6 times per revolution. That means you can get a read-out every 0.3 seconds. So you are indeed "averaging" the speed, but it is over a very small increment of time. Your talk of a "tachometer" is specious. Tell me what you have in mind more precisely, because when you use that term I envision a device that must be mechanically linked to the platter. Any such device will be subject to errors caused by tolerances in the mechanical linkage. There is always slop in any mechanical linkage. Also, any mechanical linkage cannot help but also have an effect on the performance of the turntable, the Heisenberg principle. If you chop up time into increasingly tiny aliquots, you approach a continuous read-out. By the same token, the readout can never be truly "instantaneous", nor can that of a tachometer. The Timeline does not get there either, but it gets very close. Which is why I asked aloud about the time required for servo responses in a high quality dd turntable. The comparison to a car computer is pointless, not a good analogy at all, IMO.

The odd thing is that I don't own a Timeline and never plan to own one. I choose my tt's based on how they sound and if they can hold speed with a KAB strobe. If the "33" on the strobe disc does not wiggle, much less move at all, I am happy enough. Then I listen.

I'm not sure it has been confirmed that the newer Timeline devices have 6 flashes per rev. At least the ones everyone is using seems to have just one flash per rev. Regarding tachometers: most today and even the one in your car uses either optical or hall effect sensing devices. They are not mechanically linked. The accuracy is dependent upon the precision of the encoder ring. Good data capture for micro variations in speed would need to be in the 40kHz range (two times max frequency response of a record), at least. That is several orders of magnitude beyond even 0.3 seconds.

Lew, the Kuzma was (or is) too fast anyway, be it with needle in the groove or not...and Halcro, well he is a guy who ignores everything he does not want to hear and when you read 2 sentences from him which makes sense, you can bet your car he got it from former member Dertonarm. and this "I don't like Raven nonsense..."...not my problem when he (and others from the Fanboy section) is not able to analyze the own stuff properly. And his Seiki nonsense, compared to that is any Raven a time jump back to stone age...
Wouldn't it be a better idea to spend $400 for a Timeline, and choose a turntable which passes the speed test or is it better to keep the own mediocre unit because it can't be sold properly?
I would buy a better table, but this is of course my opinion :-)

01-17-14: Lewm
Tony, According to others, the laser flashes 6 times per revolution. That means you can get a read-out every 0.3 seconds. So you are indeed "averaging" the speed, but it is over a very small increment of time....

Another example, the new Airforce One Turntable from TechDas has 1x contact per revolution with the own motor controller. This seems to be enough to hold the platter speed no matter what is going on. I never checked it but I read from an owner who did the Sutherline Test and it was ok. Personally I believe it because when the Japanese do something serious, they don't make a fault like this.
When timeline has 6 flashes per revolution, it isn't that bad, or?

Since the timeline is equipped with only a single laser, it can only produce one reference point per revolution that can be measured against any subsequent revolution. If you want to increase the sample rate, you would need 6 separate lasers flashing once every 0.03 seconds; not a single laser flashing 6x per revolution.

Tony and Brf, I hate to be wrong, but I see your point(s). I saw Brf's point in my own mind, shortly after my last post. Most servo-controlled DD turntables have some sort of platter speed sensor, optical or otherwise. One could probably tap into the output of that data stream to get a continuous read-out of speed stability. That may be what Denon did in order to produce the figure shown in their ad copy for the DP80, which I described above.

Henry, I don't think Syntax's post about the Kuzma was so provocative. As I noted, the fact that the Kuzma was a little fast (or slow; I cannot recall) is not so important as whether it was stable in speed, because a decent motor controller could probably bring it back to exact constant speed, if the error was also constant. But he never responded to my question in that regard. I am not a "Kuzma guy", but I would imagine they have a recommended motor controller for their better models, such as the Reference.

If you want to see the effect of stylus drag, you could ask Ron to make a timeline with 6 different lasers firing once every 0.3 seconds. Take a video camera and record one reference spot on the wall. When playing back the footage, increase the playback speed and you should see how much the speed varies.

The biggest argument against using the timeline is that only measures average speed per revolution. The trick is to increase the sample rate to more than once per revolution.

I have just learned that the TimeLine flashes 8 times per 1.8 seconds or 8 times per one revolution. That is why there are eight laser dashes around the room at all times. I had thought it was six. So yes, if you are looking at one dash near the turntable being tested, that one dash is flashed once per revolution as there is only one laser.

Mr. Sutherland could clarify and confirm this if he joined the discussion.

The other criticism that some have raised is the weight of the unit itself. For a low torque motor, if the TimeLine weighs a different amount from the owners clamp, that might effect the speed results. Less critical for a high torque DD motor that could deal with the added or less weight.

I'd like to see more videos added to the database.

Halcro, nice job with the timeline video. I doubt it will shout up the audio Nazis but who cares. Anyone with a brain can see past the internet bully thing.

Certainly any one overstating what the Timeline "proves" discredits themselves.

Tony, your input to the speed stability threads has been very helpful. Its a nice contrast to some of the pseudoscience b/s that some throw around in this forum.

I am not a fan of servo controlled speed. The speed is wrong a lot of the time!

A properly designed turntable should run at a constant speed!

If there is stylus drag (that audibly effects sonics) , then increase the speed slightly.

I like the VPI SDS - regenerated AC - a variable Quartz crystal controlled frequency in steps of 0.01 Hz - after startup reduces voltage for lower noise - modified sine wave for smoother motor rotation.

It made a "huge" sonic difference on my TNT III, when the speed was set with strobe disc.

All the VPI Classic turntables need the SDS, even though it was originally made for the TNT line.

Well it's nice to know that my previous posting about Tonywinsc claims goes unread or misunderstood.....so I'll repeat it once more before I'm out of here.
The analogy to a car's engine is totally spurious for this is DESIGNED to increase and decrease speed.
Any AC or DC synchronous motor is designed to maintain constant speed.
The Timeline flashes exactly once every 1.8 seconds which co-incides exactly with one revolution of the platter if spinning exactly at 33.33rpm.
If we watch it for 100 revolutions and that 'flash' is hitting the mark at exactly the same point every single time.....we can logically conclude that its speed is constant....UNLESS it can be proven otherwise?
And Tonywinsc has not once...proven otherwise?
It is not possible for a synchronous motor to speed up and down in between the 1.8 second interval yet CONSTANTLY hit the same mark every revolution.

For any scientists who may be reading this Thread and shaking his head in disbelief.....my apologies to you.
And to Ron Sutherland....forgive them for they know not what they speaketh...

Lew,

Henry, I don't think Syntax's post about the Kuzma was so provocative.

Of course it was......
Syntax was apparently observing the Kuzma turntable with the Timeline in action yet he didn't use his iPhone to film this and upload to YouTube (as we know he can do)....which is the point of the Thread.
Instead....he spreads malicious rumours by 'words' only?
But this is his preferred modus operandi as can be seen over the years of 'Raven baiting'?
Thankfully we now have a video of his 'famed' RX-5000 displaying for all to see....an abject and inferior speed maintenance performance.
This video has finally put to rest any desires I might have had to actually obtain a Micro RX-5000.
Be prepared for this damning video of his to mysteriously be removed from YouTube in the near future......?

Studying the video of Syntax's RX-5000 turntable with the Timeline.....I was trying to analyse the reasons for such a poor performance?
Mainly because I had seen nothing like it with any other turntable...belt-drive or direct drive?
How could the Timeline laser move backwards at every revolution and by the third or forth one.....jerk erratically forward to where it originally started?
And suddenly I understood.....here was a perfect visualisation of motor cogging.
This Micro Seiki motor was cogging its head off......spitting and spatting like some rat attached to electrodes?
No wonder Thuchan threw out his Micro motor and replaced it with the VPI one for his RX-5000....and sold off his SX-8000II with Micro motor?
Thuchan has discerning ears and can hear the comparisons to his EMT927 and Continuum Criterion.

And was I the only one to hear the 'sound' on Syntax's video?
I know it's compressed and running through an iPhone mic......but so are mine?
And what about the 'scraping' noise that appears half way through?
As Syntax is want to say....."one man's mountain is another man's valley"....

Syntax said...

Another example, the new Airforce One Turntable from TechDas has 1x contact per revolution with the own motor controller. This seems to be enough to hold the platter speed no matter what is going on. I never checked it but I read from an owner who did the Sutherline Test and it was ok. Personally I believe it because when the Japanese do something serious, they don't make a fault like this.
When timeline has 6 flashes per revolution, it isn't that bad, or?

wow, you are not critical of the AF1 ? As far as speed control, it helps when you use a built in tachometer that monitors and speed adjusts based on record drag. Record drag can vary record to record as I am sure you know...

Halcro, I just rewatched Syntax's video of his RX-5000. To be fair, I think the frame speed of his video camera is interfering with the laser flash increments. I think that is why some laser flashes are not even seen and why the dash appears to change in length. This occurs with my iPhone video as well, but to a lesser degree. I don't know the f/s spec. for the iPhone.

I think the scratching/rubbing sound to which your refer is his breathing. Inhale, exhale etc.

This thread is supposed to be a database for Timeline results and if each submitted video is criticize to the extent that you criticize Syntax's video, few members will be encouraged to add to the database. One of the problems I see with this format is that it is hard to find the videos if the links are added somewhere down the thread, but I don't see how this can be changed now.

Hi Halcro, let me explain something about motors here without the added detail of charts and graphs. A motor runs at a constant speed to the casual observer; but if you take a much closer look you would see that the motor armature actually speeds up and slows down as it passes by the individual poles. Cogging is an accentuated aspect of this motor property. A flywheel is added to the armature to smooth out this periodic motion. This is a property of any motor type. Now, with the exception of DD turntables, the motor is just one part of the platter drivetrain. If the pulley on the motor shaft, or the idler as the case may be, is not perfectly centered then the pulley will add a periodic motion. The roundness of the pulley and of the platter where the belt or idler rides as well as the eccentricity of the platter contributes to this periodic motion. So just like a record that has an off center hole moves back and forth during play, the motor pulley and platter are doing this too; but hopefully at an almost undetectable amount. Therefore, the motion of the platter- any platter is not perfectly constant during a single rotation. Being periodic, meaning that it slows down and speeds up, it can still hit the 1.8 second mark every time because the average speed is 33 1/3. You can see an eccentric record moving back and forth during rotation causing the tangential speed at the stylus to vary. The record is still spinning at exactly 33 1/3; but if it is off by a good amount then the WOW can be heard at every peak of rotation. That goes back to my motor analogy- you can speed up and slow down your car between mile markers and still have the correct average speed.

One other thing: Look at the specs of most turntables. The WOW & Flutter measurements of most high end tables all seem to be around +/-0.02% to +/-0.04%. Most of these very nice turntables here are showing excellent speed settings to within 0.00X%. It's clear that many companies have come very close to perfection with regard to speed control. WOW & Flutter numbers do not seem to vary much among competitive tables which is I believe due to limits of machining tolerances. WOW & Flutter being the periodic motion of the platter that I described.

Thanks Halcro. As a fellow Raven user I appreciate your feedback. I have a strobe disc that allows active adjustment while playing so I'll add a small amount of compensation.
Best regards,

I was reading over some email exchanges that Mark Kelly and have had, and some things were discussed that are useful to know when it comes to motors.

An interesting point is that a dead quiet, high torque motor might be an awful choice in a turntable application.

A motor is not necessarily better just because it has a lot of torque for its size. Some manufacturers increase stator iron, so they can improve torque numbers, but cogging is often dramatically increased as a result. One very famous maker uses such a motor, probably because of its low cost. I suspect it might pass the Timeline test, regardless. Still, that doesn't mean the product is as good as most consumers are led to believe, although an astute listener can hear it.

Can one obtain a cogless motor? Yes, but the form factor is too small to use in a turntable. There are three-phase motors in some computer drives that exhibit virtually zero cogging. Unfortunately, the technology hasn't been applied to motors of a suitable size for our use.

Fortunately, good motors are to be found, or made. Continuum uses a custom motor that cogs very little, for example. I use another that suits the purpose very well, and some other manufacturers use motors that are excellent for their designs. With some makes there is no rhyme or reason, however. They just copy someone else without knowing why. I am convinced that happens.

My point is that knowing about the specific motor is useful when making these Timeline comparisons because what you see isn't always what you actually get.

Don, You (sadly) wrote:
"I am not a fan of servo controlled speed. The speed is wrong a lot of the time!
A properly designed turntable should run at a constant speed!
If there is stylus drag (that audibly effects sonics) , then increase the speed slightly." (DUH!!)

That is more of a rant than a rational statement. It reflects your complete misunderstanding of the problems associated with maintaining constant platter speed despite frictional forces (stylus drag) that are constantly changing in magnitude. I take it your experience with direct-drive turntables, if you've had any, has been a negative one. In reaction, you are creating a hypothesis based on no data and a paucity of knowledge. You may fairly say that you dislike this or that direct-drive turntable, but do not presume that your subjective opinions are necessarily applicable to all such turntables. Nor do you have any data that would lead you to understand why you did not like whatever you've heard.

About the SDS (and similar motor contollers) I agree with you. Any belt-drive tt motor that does not have a built-in motor controller circuit of some sort will benefit greatly from the addition of a motor controller designed to maximize the performance of the particular motor type. For example, a 3-phase AC motor is quite a different animal from the induction type motors used on early Garrards and Lenco. The SDS (and the Walker Audio Precision Motor Controller) work on a wide variety of motor types, but for the same reason neither is optimized for any one type.

Someone else brought this up, and it puzzles me too: Why the heck does the Timeline laser flash 8 (or 6) times per revolution, when we are only observing a single flashpoint at a time? What is the advantage? I had hoped incorrectly that the "extra" flash events were used to enhance the sensitivity of the instrument. (As I stated, if 6 flashes could be used to cut down the time interval between observations from about 1.8 sec to 0.3 sec, then the sensitivity begins to approach that of a continuous read-out, to make Tony more happy with it. But as others, including Tony, point out, this is not happening.)

Since the mass of the Timeline is concentrated over the bearing, giving the motor lots of mechanical advantage in moving it, and since the Timeline that I had use of is very reasonable in mass, less in fact than many record weights, it's hard to imagine that its mass would alter the results detectably. If the motor cannot handle THAT much drag, it probably cannot handle stylus drag either.

Tony, This is an example of playing a very eccentric record:
http://www.youtube.com/watch?v=H_GG65tMxOs

You see the saddle swaying to and fro smoothly due to eccentricity. If you look closely enough (sorry my stone-aged video quality, well I´m not into videos really lol) you may notice the stylus stays perfectly stationary relative to the cartridge body. So the "wow" is practically caused only by the eccentricity of the record. The music sounds still very enjoyable. In this case the Salvation direct rim motor implementation works very nicely. If we have very sophisticated analog techniques, records can sound very nice despite of platter or/and record eccentricities... and slight warps.

Maybe I am pointing out the obvious here. Our ears don't care about average speed. Our ears hear the minute variations in speed.

Tony,
Maybe it isn't as obvious to some, but I hope our posts about cogging and other aspects of a turntable's design will be helpful, though. It's a lot to expect guys who aren't that interested in the mechanics of it all to understand why what they hear in a given turntable isn't exactly right, or is decidedly different from a very similar one. Hopefully, enough of the participants here are articulate enough to explain some of the things involved in ways that the casual onlooker can understand, though.

In any case, it isn't that easy to sort out all the nuances of what should be a very simple device that has the seemingly simple task of quietly spinning around.

@Lewm

In this entire thread "NOBODY" that used the timeline and "observed" the speed changes due to stylus drag came out and said they detected "ANY audible sonic changes!'

This whole tread is about drag measurements that are "NOT AUDiBLE" on well designed "high end" turntables set up with a strobe!

"Climb it and Rotate"

My point is that knowing about the specific motor is useful when making these Timeline comparisons because what you see isn't always what you actually get.

I know this is true….and I apologise to Tonywinsc if I appeared dismissive of his valuable contributions here…..but at no time was ‘cogging’ mentioned till I did so in regards to the video showing this phenomenon with the Timeline on the Micro Seiki RX-5000 string-drive turntable. This is one of the drawbacks of using string or thread drive turntables as there is no ‘filter’ to the motor’s cogging like there is with flexible rubber belt drives.
For an inflexible thread or string drive turntable to work well….the motor needs to be virtually ‘cogless’ like that of the Caliburn as Mosin has mentioned.
I understand what Tonywinsc and Mosin are saying about motors and their characteristics……and I agree that it is a highly complex subject for those without the knowledge or interest.
HERE
is a Link to Peter Moncrief’s full article which asks….and answers….more questions than you ever knew existed about turntable motors?

However……this Thread is about a Video Database of turntables with and without stylus drag as demonstrated via the Sutherland Timeline.
Syntax’s video clearly demonstrates that severe motor ‘cogging’ can be seen on the Timeline laser whilst other videos posted…..show that any cogging which may exist in other motors….is not so graphically demonstrated?
Many of us have readily admitted that correct and/or consistent speed control of a turntable…is but one ingredient to determining its performance.
Many of us also agree that it is however….the primary fundamental ingredient to get right.
Speculating on the other ‘hidden’ qualities of a particular motor….which cannot be demonstrated via the Timeline or other objective repeatable tests….should be discussed on other more suitable Threads?

We are still hopefully awaiting the promised Timeline video for Mosin’s turntable….and perhaps Dover’s Final motor which appears more sophisticated than the Micro Seiki model and might demonstrate a ‘string-drive’ turntable which doesn’t suffer from cogging or ‘stylus drag’?

Peterayer,

To be fair, I think the frame speed of his video camera is interfering with the laser flash increments. I think that is why some laser flashes are not even seen and why the dash appears to change in length. This occurs with my iPhone video as well, but to a lesser degree. I don't know the f/s spec. for the iPhone.

We are all working within the same available technologies. All my videos are taken with the iPhone and up-loaded directly to YouTube.
If you start offering excuses for the visual evidence of a particular video.....this Database will be irrelevant?

Don.
re your post to Lew. "Nobody has used the timeline.... and detected any audible sonic changes."
Firstly. The time line shows average speed per revolution. A TT that passes the timeline test has a "consistent average" correct speed, no more than this. We cannot see what is happening at a micro time interval level, but we can infer.
I would be surprised if anyone could detect the adjustment of this average speed back to say 33 1/3 if the TT in question showed slowing due to stylus drag. We are talking small changes in absolute frequency with this adjustment. The owners of these TT's cannot however adjust the TT's dynamic speed stability since this is intrinsic in how the TT was built and designed. This includes its power supply and controller. Of course there will be no audible changes since these owners are making no changes to the TT build, design itself.

However there is, I believe, at least one person posting here who has direct experience with the audible effects of an improvement in resistance to stylus drag and dynamic speed stability.

That poster is........you.
You reported a "huge" improvement in the VPI when using the SDS controller.
This device makes the motor run more consistently. What you heard was a platter rotating more accurately at a micro speed level. It is quite possible that its average speed with a load, did not change, so no difference would be seen with a Timeline. But you correctly reported the positive changes.
It would make logical sense that a motor which runs more consistently would be better able to respond to and minimise speed changes due to a dynamic load, such as that caused by stylus drag. So it would further be logical that the VPI would show greater resistance to speed sag when lowering the stylus (no load, with load) and we would likely see an improvement if this test was done with the Timeline.
So we can say that you are a champion of a design that reduces speed changes due to stylus drag.