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Vintage DD turntables. Are we living dangerously?

I have just acquired a 32 year old JVC/Victor TT-101 DD turntable after having its lesser brother, the TT-81 for the last year.
TT-101
This is one of the great DD designs made at a time when the giant Japanese electronics companies like Technics, Denon, JVC/Victor and Pioneer could pour millions of dollars into 'flagship' models to 'enhance' their lower range models which often sold in the millions.
Because of their complexity however.......if they malfunction.....parts are 'unobtanium'....and they often cannot be repaired.
halcro
halcro's avatar
halcro OP
2,664 posts
 
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......🙈
richardkrebs
427 posts
 
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.
halcro's avatar
halcro OP
2,664 posts
 
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.
richardkrebs
427 posts
 
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.
dover
2,351 posts
 
Fleib,
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.

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