Turnable database with TimeLine

Dinster, The whole idea of the "Timeline test", so far as it goes, is that it does indeed give you some notion of the instantaneous speed stability, as opposed to average speed accuracy, of a turntable. The time interval measured is akin to the time between laser flashes on your observational starting point. If speed deviates between flashes, such that the flash appears to move in either direction from start, it indicates that in that time interval the speed has deviated, up or down from 33.333. (I don't own a Timeline. I think there are 4 lasers built into it at 90 degree intervals around the pillar, but I could be wrong. 33.333 rpm corresponds to one rotation every ~1.8 seconds. You can figure out the rest.)

Well, I think, we all do us a favor to say, the Timeline is just "another" strobe and has its own faults (which is, of course, wrong). It is super precise, or better said, the best tool today. It measures the REAL speed when the diamond is in the groove. The force (VTF) is remarkable.
The majority of turntables run quite well when the Diamond is Not in the groove, but honestly, who is interested in THAT????
Performance is with tone, not without.
When I did the tests with adjustable motors while playing, and they run out of specs (drift) and then I made the corrections, the difference in sonics is easy to hear. Deeper soundstage, no smeared cynics and much better modulated details.
Today we have two "religions":
The unit "does something", Product A has better bass, Product B is analytic and needs this or that cartridge/Arm for compensation or endless "updates" because the designer is unable to do something right, some call it Prat
or
the "Religion" is based on software reproduction. The emotion is coming from the recording, the purest form of a sonic truth...
"Religion 1" is"keep the business alive
"Religion 2" is "done right"

Halcro,

I, for one, do not claim that a belt drive turntable with heavy platter is not subject to stylus drag. I thought I made the point quite obvious in my earlier comments. One can set the speed of the SME with no stylus in the groove. Then when the stylus is playing, the speed slows down slightly. In other words, the SME 30/12 IS susceptible to stylus drag. No one has denied this fact. I would make another video showing this with arm up and arm down, but I returned the Timeline to its owner.

I want the speed to be accurate when I listen to music with one cartridge in one tonearm playing one record. Therefore, I set the speed when the stylus is in the groove, and you see the results of that speed in my video with the TimeLine. It is 0.003% slow according to Tonywinsc who did the calculations in that other thread. The KAB is also designed to be set with music playing. In fact, Sutherland markets this as an advantage to his device, that it can be used while music is playing to check the speed.

One can also clearly see that your Victor with the three tonearms is also slightly slow because the Timeline dash does not stay centered on the blue tack. It in fact drifts to the left by about 3/8th of an inch.

There is no denying that a high torque DD table will not loose as much speed as a BD table with a rubber belt when a needle is dropped in the groove. Therefore, my recommendation is to set the speed while music is playing.

Well, the Timeline is a strobe; but I do not say that with disdain. It is just a fact. It is a very precise strobe with reported 0.0002% accuracy. As with any measurement device it must be used properly. The results must be interpreted properly as well. I know it is too late in some cases; but I propose that when using the timeline, 9 minutes minimum should be the measurement cycle. That is just short of 1000 rotations of the platter. If turntable speed accuracy is in the 0.003% range like Peter's SME deck, then that will show an error of 0.03 rotations. For example, 0.03 rotations is 10.8 degrees. If the laser line is projected out to a wall 18" away, then the drift after 1000 rotations will be 3.4". Measuring 3.4" vs. less than 0.5" will reduce the affect of measurement error and give more accurate speed measurement results.

From Jfrech's post about the Grand Prix Monaco:

"A highly accurate test procedure has demonstrated the speed error to be an extremely low .002%! Speed accuracy equals frequency accuracy, which means there is virtually no distortion on playback."

Is anyone else wondering what their highly accurate test procedure is?