2. analog
  3. 151541-486

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 
128x128halcro
rodman99999
6,159 posts
 
@tablejockey - The Denon DD table(DP75), I purchased in 1980(still have it, in a closet), has a Quartz referenced/AC servo motor speed control system, that reads 1000 precisely recorded pulses, from what amounts to magnetic tape, imprinted on it’s platter’s circumference, via a tape head(like in a cassette deck or RTR). That particular tech’s been out there, for decades. I’d be using the new version of the Roadrunner/Falcon system, with my VPI, if it didn’t require a redesign of my homemade SAMA(remachining, to fit their motor). I waited too long, when the original Phoenix pieces(excellent concept) were available(then: poof, gone). That system would have worked, with my VPI motor. Not that I’ve had any speed issues anyway. Easy to adjust, via my SDS. Long as I keep the belt talced; I measure/hear no drift or pitch change, whether with my LASER tach or strobe .
rodman99999
6,159 posts
 
@tooblue :   +1
davekayc
173 posts
 
Variability adds to the beauty of the vinyl sound . Why try and make it sound digital. Every single live performance does this, except techno. Does this drag decrease with softer passages ? Increase with dynamic peaks ? Back and forth ? I dont think the magic of vinyl should be sterilized to this extent . Same as reference equipment is looking at art under  fluorescent lights. 
rodman99999
6,159 posts
 
@davekayc- There’s Physics, again. ie: The heavier the groove modulation, the greater the friction(think sandpaper coarseness). Same with stylus force/pressure, in the groove(higher pressure = higher friction coefficient). Further from the center of the record = more leverage. The fluctuations in actual speed, to me anyway, are inconsequential enough to ignore(it may bother the back of my head, but- not my ears, gratefully).
lewm
13,112 posts
 
Davey and Rodman, Wouldn't you rather leave the human-ness of live music in the hands of the actual musicians, who are also human, rather than to the super-imposed alterations in pitch and timing due to stylus drag, belt creep, and the like?  For me, I want to eliminate those mechanical problems to the greatest extent possible so that the actual treatment of the music by the actual musicians gets across to me, so much as that is possible.  The reproduction system has enough inherent problems as it is without admitting those others into the mix.
More to discover