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
1) speed accuracy to the point where its musically relevant has been pretty much solved in any TT costing over $300
2) the average stylus pressure is 1.5 gm. The drag of this on a rotating platter assembly of 2000 gms is negligible; the mass equivalent of a tricycle towed behind a truck
3) vibration isolation/damping is what counts...horizontal vibration in the plane of the stylus vibration will suck transients, detail and bass out of your playback

Direct drives are very difficult to isolate vs belt drives
Davide 256, 'the average stylus pressure is 1.5 gm.,etc.' I was always wondering about this 'drag issue' more in particular because of the 'vulnerable' stylus cantilever combo. But as a non-technical guy I was not brave enough to say something although I asked the question how this 'vulnerable thing' can cause such problems? Well I was dismissed but not convinced. I still have this 'picture' of an elephant (the platter) and the mouse (the stylus) in my mind. BTW 'my elephant' is 8 kgr.

Regards,
Davide256: "Direct drives are very difficult to isolate (vibration) vs belt drives"
Really? What if there is little or close to no vibration in direct-drives to isolate to begin with? Not sure you understand how direct-drive system works...

______
Davide256, everything you write is so obvious and logical, yet wrong as regards points one and two. Point 3 does count for a lot too, I grant you.

People who don't like direct drive generally make the same point you have made re "isolation". Usually such persons do not own and have not owned a direct drive turntable. However, if you examine the workings of the best examples, you will see that the platter is part of the motor. Thus "isolation" is really a function of the quality of the bearing, which is an issue of equal significance for BD turntables as well.