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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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Showing 9 responses by rodman99999

rodman99999
6,033 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).
rodman99999
6,033 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
6,033 posts
 
@tooblue :   +1
rodman99999
6,033 posts
 
Earlier; geoffkait asked, "Is this where low effective mass of the tonearm comes in?" Since 1980; I’ve been using low mass Magnepan arms and high compliance cartridges. Among the reasons I went that way, is the lower VTF at which many higher compliance carts can faithfully track. That translates into lower friction coefficient / less stylus drag. Currently; I’m using a high compliance Soundsmith cartridge, at just a hair over 1G. I’ve no doubt; that helps. I still miss my Sonus Gold-Blue!
rodman99999
6,033 posts
 
@lewm- I’ve never, in the last(slightly over) four decades of listening to vinyl, experienced any loss of fidelity, to, "super-imposed alterations in pitch and timing due to stylus drag, belt creep, and the like." In the years prior; some had to be addressed(cheaper tables). I have perfect pitch. ie: I’ve always been able to accurately tune my guitar, without a tuning aid, etc. Thought that was normal, until a fellow musician pointed out it wasn’t. Were there anything, in any of those later analogue systems, that caused an actual, audible problem(wow, flutter, pitch anomalies); I’d have been the first to notice and would have corrected it. The reason I gave tooblue a +1, is my following the same speed adjustment procedure(done w/stylus in the groove). If you can hear the result of stylus drag, with a correctly adjusted table; that’s patently amazing. Belt creep/slippage is an equipment malfunction, that needs to be addressed, if present. Don’t have it, here. Thanks(for your concern).
rodman99999
6,033 posts
 
@uberwaltz- Yeah; they were kinda special and now, pretty much unobtainium(popular and rare does that). Had I known then: I woulda/shoulda/coulda had mine retipped and kept it. That’s one of very few components, that I’ve sold and wish I hadn’t. Perhaps: thinking about selling his Sonus, pushed that member, "off the face....."? Still, I’ve had some very nice, high compliance MCs, since. My Soundsmith is no slouch, either. They’ve all helped me to address/minimize stylus drag, at the source(to me: better than Band-Aids). 
rodman99999
6,033 posts
 
"Any aspect of reproduced music related to time - depth, soundstage, transients, dynamics, tonality, etc. - is better or worse thanks to timing in the creation of the original signal. And no amount of downstream electronic wonderfulness can ’fix’ that signal if the turntable rotation is not accurate. These are not just technical considerations, but tangibly audible results."
Without those aspects, to me; there can be no simulacrum of any musical event and simple boredom, the result(again: to me).   Of course: ALL aspects of reproducing(or creating) music well, are dependent on accuracy, regarding time/timing.
rodman99999
6,033 posts
 
In my experience, the biggest change in speed of BD tables is caused by the warming of the belt and bearing oil viscosity; it is not uncommon to see speed drift of 0.2~0.3 RPM over a 45 minute playing time which is audible to those with pitch sensitive hearing and if corrected all at once, audible to just about everyone.
That’s why I’ve always turned my SDS on first and had my BD TT spinning, while the system’s electronics/tubes warm up, B+ stabilizes, etc, for about an hour.  Then there’s that 0W-20 Mobile 1, in the VPI’s bearing.  I figure; every little bit helps!
rodman99999
6,033 posts
 
’Very interesting thread. As I read through these responses, I have to wonder if the original recording mechanism, the record lathe that cuts the master from which the molds are made, is equally subject to modulation induced speed variations. ’
@pickindoug- Phoenixengr addressed that exact issue, just four posts before yours.
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