Direct drive vs belt vs rim vs idler arm

Hi Ketchup,
I'm not sure how else to say it. If you have a timeline or someone who has a timeline could do that test- measure after 20 minutes and then do a 2 hour measurement. See if the per rotation error calculates out the same or not. That would dispel my notion about too few data points.
I have a MIT powercord on my CD player. It made a difference; but I would not call it a cheap powercord. btw- seems like I saw a thread somewhere once that claimed a better powercord on their VPI controller, maybe, made a difference?

One of the downsides of having a turntable that uses an oscillator preamplifier and power amplifier to drive the motor means I have to run 2 MIT power cables/MIT Magnum MA interconnect/custom MIT speaker cable just to run the turntable. It was worse when I drove the TT with monoblocks.

I noticed that my LPs sounded cleaner after I upgraded the power cord to my Loricraft PRC 4. Just kidding. It's a mad world.

All of this serious writing about turntable speed and measuring devices had me wanting to contribute some levity to the discussion. Sorry.

Back to the topic and hand and thanks to those of you who are really thinking about this and sharing your results.

Richard,

Do you have any theories other than eccentricity as to why the results with the Feickert are inconsistent?

That's my main one....although I suspect that fluctuation of mains power could affect the sensitivity of the sine-wave generation frequency?
It appears that results are better late at night.....and without air conditioning on?.....at least chez moi :-)

Regards

My posts are not in sync as moderators are really taking their time . My last posts took something like 20hrs to come up. Seems the A'gon forum is run with a degree of paranoia that is just unbelievable...... I don't how I can take part in a meaningful discussion with such a long delay. ...... so frustrating. Anyway now that I've had my rant I think Tonywinsc hit the nail on the head when he said that our turntables are holding speed an order of magnitude better than the capability of the records. As I said the pitch waver from my supposedly well centered test record was easily heard. Even my belt drive tt while not quite as good as the dd was quite good compared to error caused by disc eccentricity . Halcro & Richardkrebs wrt worse results from tests of longer duration, could it be the stylus heating up when playing for a longer period and perhaps increasing the amount of friction which in turn might be throwing the servo out ?? Just speculating, in reality I have no idea.