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
I've got the Timeline in house.
On the Lenco, with AC supplied through the Walker Motor Controller, speed set by the KAB with an LP in play, and listening tests suggesting that rhythm and pitch are like real life, the Timeline says my Lenco is a touch fast. I will need another day to determine whether it is "regularly" fast (the error increases in a linear fashion with each revolution) or "irregularly" fast (the error is haphazard in magnitude per revolution). The first kind of error can be "fixed", if I care to do so. The second kind indicates that the Lenco is affected by stylus drag. Not so easy to fix. One red herring: the LP is sitting on a Boston Audio Mat1, which is kind of slippery; the LP itself could be sliding due to stylus drag. I hate when that happens. I hate record weights.
Halcro have you tried the timeline with your TT81?
Unfortunately I didn't have the Timeline when I had the TT-81 set-up.
Now it is too much of a hassle to remove the TT-101..... Install the TT-81....and then re-install the TT-81? Sorry :^)
One red herring: the LP is sitting on a Boston Audio Mat1, which is kind of slippery; the LP itself could be sliding due to stylus drag. I hate when that happens. I hate record weights.
Lew.......please remove the mat. Slippage can be a real problem?
Thanks Halcro, was just wondering by chance. Dang Lew that was fast, look forward to future comments you may have.

Have our monthly club meeting this week, have to ask the guys if anyone has a timeline. If not might have to break down just for kicks since I am love tools of the trad :).
I would love to know the results of using a Timeline on a massive platter, belt driven turntable like the Walker. Maybe it's a touch fast or a touch slow (which will show up as "cumulative error"), but I find it hard to believe that a 70 pound platter will be affected by even the greatest amount of stylus drag. Of course you would have to set the timeline on top or the Walker record clamp to compare apples to apples.

This makes me think. When testing your tables with the Timeline with the stylus in the groove, and you see what appears to be a slightly slow speed, how in the world do you know that it's not just the LP slipping on the platter? It seems like you would need to make sure that the record is mechanically clamped to the platter for the results to mean anything. And I'm not just talking about a little record weight. I'm talking about a several pound weight or a clamp that threads or clamps onto the platter spindle.

To put it another way... You test your TT with the Timeline on the platter with no LP and it maintains perfect speed. You then test your TT with an LP and the stylus in the groove and the Timeline says that your TT is slow, which makes you think it's due to stylus drag. That seemingly "slow" result could simply be because of the LP slipping on the platter, not the platter slowing down due to the stylus drag.