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
> Lewm: "The L07D is among those that use the servo feedback sparingly or gently, whichever term fits best."
I don't know enough of electronics to decipher servo circuits but I do know one DIYer in another forum tinkered with the servo on a heavily modded unit of a stock Technics SL-Q3 turntable with the following:
"I modified the negative feedback loop network to make the whole thing under-damped. As it is from the factory, it is over-damped and after doing some A/B test by switching instantly between the factory network and the new one, it is obvious the change in sound. The modded version is much more relaxed and clear and all the distortion (similar to jitter in digital) in mids and highs is gone."
Now, I wish I can do that to my Technics table...

> Lewm: "But sadly the test could not be done, because the Timeline will not fit over the L07D spindle. Apparently, L07D has a "fat" spindle like my Lenco."
Maybe you can raise the Timeline above the spindle with, say, a piece of styrofoam or a roll of electrical tape, center it and hold it with double-side tape? It's a little mickey mouse but it can be done...... that is, if you have the time and energy to entertain us. :-)

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Unoear:

No, I did not get a chance to try a Timeline with Rockport Sirius lll while it was here last year. However; Tim Sheridan, was here late last year for a visit before I shipped the Rockport to its new home...where it joined a few other Rockport TT siblings in the UK.

I can hardly believe after all the work and effort you put into obtaining the Rockport you sold it. Your post is the first I've heard about that.
For $400, the timeline needs to be built with an internal clamp so that it will fit any spindle.
Lew and others with "the big spindle" issue. Could you stack enough metal washers on the spindle to leave only the top exposed, then use that to center the Timeline? If the top of your respective spindle is slightly rounded this might work. If your spindle is machined flat across the top then I suppose you could only "approximate" centering.
Hi Albert,

Yes, having the Rockport Sirius lll here last year was really some enlightening audio fun. It is now with Mik in the UK...he is a mad about Rockports; three lll's, and two ll's. He is also a big fan of stonebody Koetsu cartridges and the Goldfinger cartridge.

Like yourself, I do like to hear and make decisions based on what is going on in our systems.

I believe that in my case with the Rockport along with your case with the NVS, we both decided that we were not able to replicate what was presented. So, mine has found a new happy home; similarly, you are trying to find a new home for your NVS and Talea.

Albert, I have fondly followed your posts and do appreciate your desire to find the differences that work.

Cheers!
Alan