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Turntable speed accuracy

There is another thread (about the NVS table) which has a subordinate discussion about turntable speed accuracy and different methods of checking. Some suggest using the Timeline laser, others use a strobe disk.

I assume everyone agrees that speed accuracy is of utmost importance. What is the best way to verify results? What is the most speed-accurate drive method? And is speed accuracy really the most important consideration for proper turntable design or are there some compromises with certain drive types that make others still viable?
peterayer
aoliviero
269 posts
 
Halcro,

In my statement about AC belt driven TT's vs DC motor driven TT, I was meaning belt driven DC TT's, not a DC driven DD.

I have no experience with DD's yet. If I get a timeline will try to post some results.

Atmasphere,

Which Empire TT are you referring to? AC or DC drive ,belt type?
sarcher30
596 posts
 
(quote)Sarcher, What is the evidence that the hum is (or was) due to the motor/cartridge interaction? (/quote)

The hum occured when the tonearm was swung over the platter in both cases. With the motor off on the Classic there was no hum with the tonearm over the table. The LP12 was likely the power supply because I had to unplug it to make the hum go away with the arm over the platter. I have solved the hum issue on the Classic by using an outboard Teres motor.
sarcher30
596 posts
 
Hiho, The motor was grounded. I am not the only one with a hum problem on their Classic. There is a thread about it on this forum.
halcro's avatar
halcro
2,664 posts
 
And finally, all this chat is still overlooking what I thought was the real issue: speed variation due to stylus drag. None of the above mentioned observations really tell us anything about that. Unless sensitivity to stylus drag is gross, the Timeline may not reveal it.
Lew.......have you not tested the Timeline with and without 'stylus drag' yourself?
I assume all the comments on the Timeline tests are 'with' the stylus playing as demonstrated with 1,2,&3 styli engaged on my YouTube video?
I can assure you that the Timeline is the ONLY device currently available......capable of graphically demonstrating the most marginal of drifts due to stylus drag.
lewm
13,507 posts
 
Henry, I've done it both ways with the Lenco and Mk3. The DP80 has no cartridge mounted at the moment, so could not do it with "stylus drag" factor. Likewise, I don't have 3 tonearms on any one tt, so could not repeat that show either.

If the tt is not slowing due to stylus, based on Timeline, then one would also not expect to see it with the KAB, so I am in no position to argue your point that only the Timeline can reveal it. Nor do I doubt you, absent any experience of my own.
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