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
Ummm..., Dev, I think you took what I wrote and ran away with it. You can't have it both ways; either a turntable is given to you with the possibility to adjust its speed and therefore correct for any inaccuracy, or not. In the latter case, the turntable had darn well be speed-stable under all conditions, because there is nothing you can do about it. I take it as a virtue that the Lenco mechanism provides an easy way to adjust speed over a very wide range.

By the way, I meant to convey that I was too lazy to do a fine adjustment of the idler wheel, to get my Lenco back to exact speed, so I did it with the Walker motor controller. Since the needed correction was tiny, it was not an issue to do it with the Walker, and I had been meaning to re-insert it in the system in any case, to isolate the Lenco motor so as to block EMI from getting into the AC feeding my preamp.

Then, too, there are two different issues: speed adjustability and stability with no load vs speed stability under the actual condition of playing an LP. That latter property has more to do with torque, compliance in the drive system, platter mass, presence of a servo feedback loop (really only a property of DD turntables), etc. I've been saying this over and over. I guess if you don't like the Lenco, that's cool, but I think you are criticizing it for the wrong reasons. Have you ever heard an LP being played on one? They impart great clarity and drive for a fraction of the cost of other tt's that sound as good (unless you buy a dolled-up version). Isn't that why we are here? I recommend that you listen to a "street version", if possible, before you dismiss the idea.

Henry, You wrote, "well trained ears are our best tools". Did you read my story about listening to my Lenco when it was going too slow, where I heard it as a slowing of tempo and my friend heard it as a flattening of pitch. Two pairs of "well-trained" ears that heard the same music in different ways.
Lew,
You both 'heard' it :^)
I think our descriptive language pertaining to audio......is subjective and ill-defined by convention?
I also have doubts that others here......really understand what people mean when they attempt to describe their impressions? :^)
Sorry......I missed your Lenco story. Is there a link?
Here is a link: Go back up the thread two or three posts of mine, and you will find it. Anyway, there is no need, because I just summed up the story. The oddity is that he claims to be unable to sing a single note but to have a perfect sense of pitch. OTOH, I sing jazz informally and sometimes formally but sensed the tempo error, not the pitch error.

A lot of good jazz singers sing on the low edge of the note, if you know what I mean. (I refer here to real professionals, not me. If I do it, it is a mistake.) It imparts a blue-sy feel. (Examples might be Betty Carter, Chris Connor, Kurt Elling.) Perhaps that is why I was not hearing the pitch error. Kind of like tuning an orchestra to 438Hz instead of 440Hz.
Hi Lewm,

thanks for the reply back and clarification. I have nothing against Lenco tables and was actually looking at buying one as mentioned prior, really just conversation and learning.

That being said at the same time I was shocked when I had asked this seller what I felt was a pretty basic question and the reply back was they are not spot on.

Your reply in general has left me wondering, if you can set-up the speed as you suggest then why in the heck would you be using what you are? there must be a reason.
Dev, As I wrote, I used the Walker because (1) the exact final speed adjustment using only the Lenco idler wheel requires a bit of fiddling. (For example, you have to remove the platter to loosen the adjustment screws, the way I have rebuilt mine, then replace the platter to set the speed, then remove the platter to tighten down the adjustment screws, then replace the platter again, etc.) And, (2) there are some unrelated benefits of using a motor controller; namely it isolates the tt motor from the AC line. Thus any EMI emanating from the motor cannot get back to contaminate AC feeding my phono stage, etc. Is that clear enough? Nothing mysterious.

Also, I already own the Walker, so why not use it? The Walker is useless with any of my other tt's, which are all direct-drive.