Vintage DD turntables. Are we living dangerously?

Halcro -

10-23-15: Halcro
..Dover still resorts to imagined 'monsters' from his antipodal 'sleep of reason' as witnessed by
4.The timeline only measures the arrival of a single point on the platter at the same place at each time. It does not measure what happens in between.
He strangely ignores the Feikert Frequency Response Charts posted which demonstrate a 'real-time' ANALOGUE print-out over a 30 second time interval....an interval comprising 16 revolutions of the platter....which disproves his (and your) theory of malevolent speed behaviour BETWEEN the Timeline recording interval.

That is not correct - point 2 in my post you refer to highlights that the Feickert test record can be prone to error - evidenced by the fact that the weighted averaging process is supposed to account for eccentricities in the record ( see Feickert for confirmation ).

10-23-15: Halcro
As for your idea of testing the various arm/cartridge combinations on my TT-101...I don't believe the Feikert Speed App is accurate enough for this contest. In fact....if you conduct three 30 second test measurements with the identical table/arm/cartridge (without touching the set-up)...you will receive three sightly different results.

Indeed, you have confirmed that the Feickert is not accurate enough to quantify the micro changes in speed between the test intervals.

I would also remind you that in your earlier testing you indicated that you got different results if you rotated the record a quarter turn.

10-24-15: Richardkrebs
As for Dover's and my comments about what is happening "between" each pulse of the time line. I was hoping that this topic was in the 'agree to differ basket', but since it has been raised....you only need look at the traces you have just posted. Sharp spikes on the raw trace... this is a servo in action! Rapid acceleration/deceleration of the platter. Yet the platters average speed is 33 1/3. The smoothed ( green) trace filters these spikes, so it tells only part of the story.

In Fremers testing thus far he highlights the vastly different shapes of the raw trace between the Caliburn and the Onedof even though they measure similarly, indicating differences in micro timing vs macro timing.
I would also expect for example differences in the shape of the traces according to motor type - AC motors tend to self correct sinusoidally, whereas DC motors tend to correct trapezoidally.

An important point is that we can only do true comparisons where the testing instruments, protocols, and environment are constant. In other words comparing your results to Fremers is not scientifically valid. There will be differences in the test records, there are errors integral in the iPhone/computer apps that vary depending on model, and many other variables.

Dover,
All you and Richardkrebs do is disparage every scientific test method we have available for turntables without ever offering an alternative.
If you have nothing to offer to help analyse a turntable's performance in an objective manner, perhaps you should both just ignore these discussions...

So show me all the speed changes in this raw trace frequency chart Richardkrebs?

Halcro.

The TT-101 is a machine, a thing, nothing more. It, like all machines, is far from perfection. My objective comments, made as a result of properly interrogating all of the Feikert test data you provided, are in no way a reflection on its owner.
The same cannot be said for your attempt to censor me by suggesting I "ignore these discussions" because I posted facts that you find uncomfortable.

Dover,
"Speed is never absolute. It is always measured from a point of reference. The planet is rotating, the measured speed on your platter is relative to the rotation of the planet - it cannot be absolute."

We're talking rotational speed not land/air/sea speed. It's as absolute as the timing of a minute.
Regards,