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Stylus-Drag..Fact or Fiction?

Most audiophiles can't seem to believe that a tiny stylus tracking the record groove on a heavy platter could possibly 'slow-down' the rotating speed of a turntable.
I must admit that proving this 'visually' or scientifically has been somewhat difficult until Sutherland brought out the Timeline.
The Timeline sits over the spindle of the rotating disc and flashes a laser signal at precisely the correct timing for either 33.33rpm or 45rpm.
By projecting these 'flashes' onto a nearby wall (with a marker attached)....one can visualise in real-time, whether the platter is 'speed-perfect' (hitting the mark at every revolution), losing speed (moving to the left of the mark) or gaining speed (moving to the right of the mark).

RAVEN BELT-DRIVE TT vs TIMELINE 
Watch here how the laser hits the mark each revolution until the stylus hits the groove and it instantly starts losing speed (moving to the left).
You can track its movement once it leaves the wall by seeing it on the Copperhead Tonearm.
Watch how it then speeds up when the tonearms are removed one by one....and then again, loses speed as the arms are dropped.

RAVEN BELT-DRIVE TT vs TIMELINE
Watch here how the laser is 'spot-on' each revolution with a single stylus in the groove and then loses speed as each additional stylus is added.
Then observe how....with NO styli in the groove.....the speed increases with each revolution (laser moves to the right) until it 'hits' the mark and then continues moving to the right until it has passed the mark.

Here is the 35 year-old Direct Drive Victor TT-81 turntable (with Bi-Directional Servo Control) undergoing the same examination:-
VICTOR TT-81 DD TT vs TIMELINE 
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phoenixengr's avatar
phoenixengr
94 posts
 
Unfortunately, I haven’t had the chance to "look under the hood" on very many of them, but based on my limited exposure:

Belt drive: American Sounds AS2000. David Karmeli not only understands high end audio, he gets the physics and engineering part right as well. His design philosophy may be unique in the industry. Full disclosure: I had a hand in  designing the motor control for this table, based on the Eagle PSU and RR tach.

Direct Drive: I’ve not auditioned the new Technics tables and I don’t have a lot of technical info on them, but from what I can gather, they are doing some really sophisticated things in motor control and they have the engineering HP to do things right. It wouldn’t surprise me at all if they were doing FOC.

I’m basing my observations more on an engineering perspective than an audiophile one. YMMV.
atmasphere's avatar
atmasphere
11,942 posts
 
Anyway, who do you send the masters to for pressing?
@mijostyn I've found that if the mastering is done correctly most pressing plants can do a pretty good job. But QRP stands out as the best (their pressings have noise floors that easily rival Redbook), RTI is excellent and oddly enough we've had very good results from United. One of our projects was pressed in Holland, not sure which plant but all the US plants were 3-6 months behind at the time.
lewm
13,287 posts
 
The point I tried to make earlier and which seems to have been ignored by some who might favor turntables with laissez-faire speed control is that yes, live human musicians will inevitably vary tempo during the course of a performance of a given piece of music and given conductors will pace different classical pieces differently, but that's the crux of the matter.  You/I want the turntable to make no alterations of tempo that might obscure the human factor inherent to the pleasure of listening.  The turntable should ideally do no editorializing, in other words.  Plus there is the fact that inconstancy of turntable speed affects pitch, whereas human errors in timing produce only changes in tempo. No turntable or drive system is absolutely perfect in this respect, but that should be the goal.  In my opinion, of course.
cd318
2,636 posts
 
@lewm too modest. That should be clear to anyone (wherever their vested interests may lie).
richardkrebs
422 posts
 
Hi  phoenixengr. VPI have made interesting choices in the controller and motor. You would think that Thingap would make a motor with low speed/power windings ( higher resistance  ) making for finer speed control from the Elmo.
All that said, the TT gets great press, so the package seems to work very well indeed. 
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