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
Dover,
I kind of like the idea of not placing lateral loads on the platter bearing....and this arrangement is working so well I don't know what there is to gain with the one motor?
What harm do you think there is if the two threads touch?
Which Empire TT are you referring to? AC or DC drive ,belt type?

The Empire is of course AC synchronous drive. But most of my experience with it is actually with our variant of the machine, which we have been doing since the mid-90s:

http://www.atma-sphere.com/Products/#Atma-208
What harm do you think there is if the two threads touch?

Increased friction and additional vibration/noise, especially when the knot of one rubs past the other thread.
Hi Dev - just curious regarding the sp10 mkII that you tested. You said

"I tried it on a "DD" SP10 MK2 and it was off"

What was the strobe doing while you tested it? I have a seen a strobe on a SP10MkII one time "waver" back and forth - it could also be heard in the music. It needed adjustment. How steady was the strobe light in this case.

Cheers
Dear Mab, L07D is not in service at this time. I am re-wiring the tonearm.