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
Hiho, FWIW, I use a 2nd generation PTP. As you know, it has provision for sliding the idler wheel without removing the platter; one is supposed to leave the two bolts under the platter slightly loose and tighten down only the one that is visible and accessible with the platter in place. That way, you can slide the idler by loosening only the one accessible bolt. However, I am not following that directive. I thought I was better off to get the speed as close to perfect as possible, with all bolts loose, and then to tighten down all 3 of them very firmly. From then on, I make fine adjustments to speed via the Walker Motor Controller. As you know also, the next mod was to remove the rubber bushing at the anchor point of the idler arm, so as to disallow even that small amount of play at its pivot. I have not done that, in the belief that there is some benefit to dissipating vibrational energy in the idler arm itself, by letting the arm "rattle" a little bit, so energy is not reflected back into the idler and thence into the platter. It's all a head game, because I have no data either way. I do like what I've got, however.
Lewm,
Which of the 3 tt's the Lenco L75, Technics SP10mk3, Kenwood L07D do you find the most musically satisfying. Have you ended up with same or different sounding decks, or through choice of arm/cartridge deliberately tried to dial in different strengths ? Which one assuming all are speed accurate do you feel gets the most off the record.
Dover, Cannot fairly answer any of those questions yet. I love them all in different ways, at this moment. With the Lenco, you want to root for it, because it is relatively inexpensive. If I thought I could live with only the Lenco, I could sell the others and put several thousand bucks in the bank (or elsewhere in my audio system). As Raul is fond of noting (and i agree), you cannot compare turntables when the tonearm(s) and cartridges are all different. But it would surprise me if the Lenco was the best of these three (or these four, if you include the DP80).
Lewm: " As you know also, the next mod was to remove the rubber bushing at the anchor point of the idler arm, so as to disallow even that small amount of play at its pivot. I have not done that, in the belief that there is some benefit to dissipating vibrational energy in the idler arm itself, by letting the arm "rattle" a little bit, so energy is not reflected back into the idler and thence into the platter. It's all a head game, because I have no data either way."
It is, indeed, a head game. Sometimes I wonder if we make rigid on all the linkages such as the idler arm, rubber bushing, to not allow any flexing, will the speed be even more stable and what will happen to the sound. The brilliance of the Lenco is in the use of tension: the idler arm pressing on the motor, the spring pulling the wheel towards to motor shaft, and 3 point suspension pushing up the motor towards wheel and then the platter. It's in this chain of tension of push and pull that makes the whole system work in unison. It's a complex and zen system at the same time. I wonder if making any one or all part(s) rigid will ruin this system of tension and its sound. Or it might improve it. I do not know... but it's a fun head game. :-)

To me the idea of direct drive having only one single moving part is even more zen.... and that one moving part rotates at 33.33rpm is super cool... at least it runs circle around Art Dudley's head. ;-)

______
....It's a complex and zen system at the same time.

For a lot of Audiophiles everything is more or less a fascinating wonder when a light stars to shine and something is beginning to move. A turntable needs the right speed, knowledge to make the area of the needle silent and a solution to remove the energy from the tracking. All together in the best possible way (Engineering).
The Story is simple. But not for everyone :-)