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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 
128x128halcro

Showing 5 responses by halcro

halcro's avatar
halcro OP
2,664 posts
 
Glad you found it interesting @jtimothya....
The Timeline actually emits a tiny circular red laser flash but because it's revolving as it does it, the projection onto a nearby wall becomes an elongated dash.
The more obliquely and further away the wall is situated....determines the length of the dash.
Look at the dash when it's projected on the nearby Copperhead tonearm...🤗
halcro's avatar
halcro OP
2,664 posts
 
My Ariston and Linn TT's don't suffer from stylus drag.
Indeed they do....🤗
Words, opinions and 'hope' aren't going to cut it on this Thread....
Only a Youtube Video with Timeline and multiple cartridges (as above) or the multiple raising and lowering of a single cartridge will be acceptable as proof 🧐

halcro's avatar
halcro OP
2,664 posts
 
Non-compliant or very low compliance belt and placing the motor drive as close as possible to the circumference of the platter are the best ways to minimize belt creep.
There is no evidence that 'belt-creep' is responsible for 'Stylus Drag'.
A compliant rubber belt was instrumental in the world-wide acceptance and domination of belt-drive turntables over idlers:-
  1. It isolated the motor noise from the platter
  2. It smoothed out the 'cogging' effects of the motors used
I've tried various non-compliant threads as a replacement for the rubber belt on my Raven AC-2 and they have done nothing to ameliorate the effects of 'Stylus Drag'.
halcro's avatar
halcro OP
2,664 posts
 
Not off Topic JT...😃
I read that Peter Moncrieff article 10 years ago....in fact it has a permanent place on my Desktop.
I even wrote to Peter (RIP) to ask him where I could find Part II of the article....but he never got around to finishing it 😥
As you say....
It thoroughly lays out the issues with belt drive and other drive systems 
So thoroughly (and understandable) in fact....that it should be required reading for every 'wannabe' turntable designer and every 'practicing' turntable designer who I'm sure, have little in-depth knowledge of the science and physics espoused in that article 🤯
halcro's avatar
halcro OP
2,664 posts
 
Hi Richard,
I hoped you would see this Thread...😃
the thing which startles is how quickly the platter slows down. All due to the drag induced by a tiny diamond thrashing about in a plastic groove. 
I first saw this demonstrated on a Transrotor FatBob Turntable which has an even heavier platter than the Raven, and the 'slowdown' was even more dramatic and faster.
I like you....was similarly 'startled' 🤯

I agree totally with your 'conundrum' about which record to choose to set speed with the stylus playing...?
Apart from massed symphonic performances with both highly and lightly  modulated passages....I think that Rodman's insightful and practical habit will work well.
RAVEN AC-2 TT vs TIMELINE

The question is.....how audible is this phenomenon in the 'real world'?
I can still happily listen to the Raven in my system although I can hear the differences in presentation on the Victors with complex orchestral works.
The Raven has a slightly more 'relaxed' sound and whilst we know from reading Peter Moncrieff's treatise.....the effects of 'Stylus Drag' are 'distortions' of the musical waveform.....there are many many more distortions (from cartridges, tonearms, headshells, turntables, speakers etc) that probably have greater consequences.

Whilst all this sounds 'gloomy' for those outside the vinyl/analogue 'True-Believers Brethren'.....none of it stops vinyl from sounding infinitely better than digital 😝👍
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