Turnable database with TimeLine

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?

Halcro
Agree it would be nice to have consistency in the test methods.

HF Dover
Phase lag is a result of drag, not a cause of it.

Peterayer,
I wasn't including you amongst those who have said that a very high-mass platter on a string or thread-drive turntable would be immune to stylus drag as you have admitted the fact......
Dertonearm and Dover I believe in the past (amongst many others previous to the advent of the Timeline)....have made such claims.
Yet I have shown on my video of the Raven AC-2....the comparison when the stylus is NOT in the groove and I think that that gives a further comparison to both the motor, belt/string/thread and platter abilities of a belt-drive turntable......or ANY type of turntable.
Your comments (and Syntax's) about only being concerned by the performance when the stylus is tracking the record....is misleading.
I have recordings that have extremely modulated grooves and I have records which have very benignly modulated grooves.
I can adjust the motor controller to handle one or the other.....but unless the speed is manipulated for each and every record you play.......there will inevitable be a difference in the Timeline between different recordings.
This is why seeing the Timeline 'without load' in comparison to 'under load' is valuable.