Vintage DD turntables. Are we living dangerously?

RK,
Just as I thought. Thigpen says, "Since the advent of the belt drive turntable, wow and flutter has been purely a function of tonearm geometry, the phono cartridge compliance with the elastomeric damping, and surface irregularities in the LP."

He's measuring tables with no load (absolute speed) and comparing to W/F measurements with cantilever oscillation thrown in. Yes, the belt drive tables are often more susceptible to external forces presented by a pivoting arm. This is not to say DD/idlers are immune, but I think we've all heard what happens with low torque tables of any type, when the needle drops.

This sales pitch is misleading because he takes TT speed stability out of the picture and replaces it with arm geometry, although benefits might be true for those with low torque tables.
I haven't considered W/F as a function of arm damping, but I don't like low torque tables. The term oscillation implies an increase in magnitude, but that's interpretive.
Regards,

Thanks for that interesting excerpt Richardkrebs.
I wish he had included the graphs, charts and figures to properly support his claims....
We of course are now able to graphically demonstrate some actual performance charts and figures for various turntables under test.
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.
It is indeed revealing that Dover has never had the intestinal fortitude to post his Final Parthenon turntable performances under both the Timeline and the Feikert Speed App yet continues to boast of its abilities. I am dubious in the extreme.....😎

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.
But as far as we can visually disprove Thigpen's theories, here are the Frequency Charts for my three arms and cartridges.
WE8000/ST
FR-64S
507/II
And just to show that not all DD turntables are the same here is the
Onkyo CP-1050
I have seen some good performance charts for some belt-drive decks....but just to show you what some are capable of....
Wilson Benesch
George Warren

Halcro.

Thanks for the tests. Do you have the companion numbers for each arm?
I was interested in any consistent differences between the arms/carts, which could go some way to validating BT's ideas. There was nothing else in my request.

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.

cheers.

Sharp spikes on the raw trace...this is the servo in action.

Hmm....both belt-drive turntables must also have servos....if that's what sharp spikes indicate......🙈

Halcro
The Wilson does have speed feedback, don't know about the George.
If you look at the George's raw trace, even though it is all over the place, it is quite smooth in comparison to the others and approximates a sine wave. This would imply a different speed control architecture.

The key point is that that the traces you posted clearly show that within a single revolution, the TT-101 has significant very short duration speed changes, but it's AVERAGE over one revolution is exceptionally stable.

Cheers.