Vintage DD turntables. Are we living dangerously?

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.

the TT-101 has significant very short duration speed changes,

No.....the Wilson Benesch has "significant very short duration speed changes"and the George Warren has "significant very short duration speed changes" and the VPI Direct has "significant very short duration speed changes" and the Continuum Caliburn has "significant very short duration speed changes'.
The TT-101 has less speed change than any turntable so far shown.
If you can show results for any turntable with LESS speed changes than that of the TT-101.....please do so.

Halcro
Look at the raw trace for the WE8000.
Start at the first lower min freq, just above 3130 hz. Other than the max at around 3164hz, count every sharp change in direction until immediately before the next min of around 3130 hz again.
I count 14. The platter changes speed 14 times during that single revolution.

Cheers.