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
From Peterayer
As this is a thread about turntable speed accuracy, I'm curios to know if Albert or anyone has tested the NVS with a TimeLIne?

From Dev
So when using the TimeLine on the NVS what are the results?

From Halcro
Albert and Lew,
You don't specifically mention it......but I assume the SP10-3 maintained its speed with and without the cartridge tracking the groove?

Also Albert......you don't specifically mention if the NVS passed the Timeline test with equal aplomb?

So far, only the Technics MK3 passed of all the tables I've checked. The laser is absolutely steady state on precisely the same spot without LP.

Repeat again, cartridge in the groove and heavily modulated material (Massive Attack, Heligoland) and still on the same spot. In fact, the MK3 can play the same LP (either 33 or 45) two or three times, all the way through, picking up the arm and re cuing to the beginning multiple times. Same spot on the wall in the end.

We used Scotch painters tape on the wall to be sure we don't mistake where the laser is supposed to be.

The NVS did not pass the test. However, neither has any other table so far. Either the MK3 is highly accurate, or whatever it's errors, it's in precise conjunction and sync with the Timeline.

Halcro mentioned rim drive. I've posted my opinion before on this, apologies in advance to those that have read it. Each design has strengths, perhaps a diagram should be made up so you could view what each contributes to the sound.

Mind you, this is opinion ! I do not have scientific data. It's much like my support for aftermarket power cables here at Audiogon in 1999. I got in trouble for that too :^), although that seems to be more flame proof as time goes on.

OK, what we want in a turntable:

(1) Enough torque that it ABSOLUTELY rocks through the material without even a microscopic slow down.

(2) Consistent speed, preferably perfect but not a deal killer if "slightly" and consistently fast or slow.

(3) Freedom from speed error. Wow and Flutter. This stuff matters a lot, we pick this up.

(4) Last and obvious, freedom from all noise, both mechanical and electrical.

Probably other things or variations of these but you get the idea.

What each design does:

BELT DRIVE: Typically poor on #1, some are good on #2, varies on #3 by brand and condition of parts. Typically great on #4 due to separation of motor from platter, although some can have noisy bearings.

RIM or IDLER DRIVE: Many are excellent on #1, typically good on #2, varies on #3 (some not so hot), dependant on model and parts condition. Typically less than ideal on #4, motor in direct contact which is difficult to keep absolutely silent.

DIRECT DRIVE: Varies on #1 depending on power of motor and design of system, from near perfection to bland. Typically excellent on #2. Typically good on #3 with some models approaching perfection. Good to near perfect on #4 depending on model and condition.

What I've discovered about myself and from long term listening is I fall distinctly into the "high torque" consistent speed category. That means my favorite sound is a high torque direct drive with idler right behind. A low torque direct drive is next and belt drive last.

Of course my comments are easy targets. For instance, a well tuned Micro Seiki has more torque than other typical belt drives.

Error number two, some direct drives have electronic noise leaking through their platters which make them sound "cold" or what some describe as jitter. Electronic noise can be really bad as it "flashes" the cartridge.

My statements are GENERALITIES that are ripe for picking, it's complicated but this is a very rough start and only a simplistic attempt to explain why turntable designs "tend" to sound a certain way.

I know all the holes that can be poked in this, discussion of arms, set up and such. I'm just saying that these rough rules for turntables are like clumping horn speakers, cone speakers and electrostatics into categories to explain why they behave a certain way.
Albert, Thanks for the specifics on the TimeLine tests. That Mk 3 must be something and perhaps "best of DD breed". I'd love to hear it someday. Pity it's no longer made.

I witnessed a TimeLine demo on a DD table last weekend. The owner held an envelope 12" from the laser and yes, the spot did not move during the 30 second test. When I asked him what the result would be if he let the laser hit the wall six feet behind the table, he admitted it would not maintain its fixed position. Now that table does have speed adjustments for fine tuning, and I presume better results could be attained, though we did not spend the time. I appreciate and respect the thoroughness with which you seem to be doing your evaluations.

The remainder of your post is thorough and well reasoned, it seems to me. Thank you for summarizing the issues to clearly. It's very helpful.
Thanks Albert,
A thoroughly lucid and objective opinion........from a subjective point of view.....which is all we can really have after all?
Right Nandric? :^)
Hi Albert,

thanks for the responce inrelation to the NVS using the TimeLine.

It's great you are providing other info. too but as you mention it's your take, prefference and obviously VERY subjective.

I have heard two SP10 MK3's to date now in my own set-up and over all preffered specific belt drive tables, "all belt drives aren't buit equal" in comparison but that's for another thread.
While I was visiting Syntax last month, he checked the speed stability of his machine. The laser from the Timeline was spot-on and did not waiver...his well-tuned Micro Seiki RX-5000/RY-5500 was simply steady and consistent.

Albert, you may have already mentioned the reason, if so, I apologize for bringingtip the question again...why do you think that the NVS was not up to task? Since you are not having issues with your fabulously-modified Technics Mk 3, great; why do think you maybe having instability with the NVS? It appears that is not an issue with the quality of the mains being presented to the motor controller; otherwise, I guess that Technics Mk
3 would also have an issue...what do you think could be the issue with the NVS?

Cheers!
Alan