Turn table speed variation question

SME30/12

Here is an attempt to show the SME 30/12 with the Sutherland TimeLine. The only other two videos of the TimeLine that I've seen are Halcro's Victor and the one on the Sutherland website.

Thinking about the original post and other instruments possibly used for evaluation, electronic music or electronically generated signals, comes to mind. The pitch doesn't waver on these tones unless it's done deliberately.
Depending on your musical fare, I've heard records with out of tune pianos.

Standard wow and flutter test signal is a 3150Hz tone evaluated on a wow and flutter meter. This might not be a great test for subjective evaluation unless the table needs a new belt, but electronically generated harmonics with dynamic content, might. Offhand, I can't think of a good candidate though.

BTW, my previous referral to KOB being a 1/4 tone off was off the cuff and apparently wrong. The original record is a little bit sharp.
Regards,

Thanks for the Link Peterayer.....
Not a bad performance from the SME....
This is what any 'good' belt-drive table should be able to achieve?
There is a slight drift backwards of the Timeline mark from the beginning to the end.....but you will notice that he doesn't show the result when the arm is 'lifted' from the record or when it is 'dropped' on the record?
Nor are there multiple arms lifted on and off?
In my experience.....a belt-drive needs to be adjusted for correct speed with the cartridge 'tracking'.
I have yet to see one which doesn't suffer from 'stylus drag'?

Thank you Halcro. You are indeed correct about the SME needing to be
adjusted while the stylus is tracking the LP. There is no option for a second or
third arm on my table. So my result is basically the "real world" for
my situation. There is no doubt the a well designed DD table like the Victor can
deal with a changing load like playing three tonearms together on one LP better
than the SME. But I would hardly describe the SME, or an owner, as
"suffer(ing) from 'stylus drag'." I simply adjust the speed while
playing an LP.

In this link, you will find a discussion about the accuracy of the SME in my
video:

http://forum.audiogon.com/cgi-bin/fr.pl?eanlg&1320876538&&&/Turntable-
speed-accuracy-

Speed is slightly slow by .003% or 6/1000th of one rotation out of 73 rotations
over the course of the 5 minute video. The calculations were done by Tonywinsc
on 12/27/13.

A close examination of your Victor video also shows a slight drift to the left of
the blue tack mark over the course of the 4 minute video. You can notice this by
watching the right trailing edge of the laser dash as it moves to the left. At the
beginning of the video, the blue tack is basically in the center of the laser dash,
but after four minutes, the dash is to the left of the blue tack and just barely
touching it.

This looks to be just slightly less than the 1/2" drift that the SME does,
but it is hard to tell precisely.

I have started a thread over on WhatsBestForum which asks for submissions of
similar videos to ours in an effort to create a database of turntable speed results.
So far, your Victor and my SME videos are the only two videos that I have located
on YouTube to include in the database. Perhaps others will add videos to the
thread and database. Here is a link:

http://www.whatsbestforum.com/showthread.php?13137-Turntable-
SpeedWhat-matters

I'm hoping that the thread prompts a discussion of the differences between
various drive types and the distinction between speed accuracy and speed
stability. Clearly, your Victor excels at both. Perhaps you would like to make a
video of your TW Akustics and add it to the database.

Small correction: 5.2 minutes of playing time is 173 revolutions. You dropped the "1". :)

Keep in mind that closed loop speed control systems like used in DD turntables will compensate for changes in load (such as dropping a needle on a record or raising it) and depending on the amount of torque that the motor has- the platter may hold speed even with light pressure of your finger applied to the edge. But closed loop speed control has its own design challenges.
I suspect belt drive became popular because open loop motors w/o controllers is much cheaper to execute and high mass platters do a lot to smooth out the speed variations; not to mention easier to apply isolation and dampening from vibrations. In other words- belt drive offered more bang for the buck. In the end, given the resources and proper design execution, the type of drive system becomes a moot point. I think Peter's website, if successfully populated with data from various types of turntables will reach that conclusion.