I have a Luxman PD-277 direct-drive turntable and have seen the strobe slow down very slightly when the stylus is dropped. The effect is more noticeable at the outer edge of the record.
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
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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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 systemsSo 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 🤯 |
The belt v direct drive battle has swung to and fro over many decades but is the tide finally about to turn for good in the favour of the latter? @cd318 The tide has turned. Read Moncrieff's article part 1 article on the Rockport Sirius III http://www.iar-80.com/page12.html It thoroughly lays out the issues with belt drive and other drive systems with a view from several years back. Those issues still hold today. Then to get a perspective on where modern direct drive is today, read Roy Gregory's review of the Monaco 2.0 turntable.http://www.theaudiobeat.com/equipment/grand_prix_monaco_20.htm or a different take here:http://www.theaudiobeat.com/blog/grand_prix_monaco_20.htm The stable speed accuracy of this table is stunning. While stylus drag cannot be denied (physics), there are ways to deal with it. apologies to H for going off topic... |
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:-
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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 🧐 |
I always thought the Phoenix Engineering setup made sense. Why hi end manufacturers don't incorporate a real time speed monitoring/ adjusting setup is odd. https://sotaturntables.com/products/total-eclipse-package/ Measure speed while playing, adjust when neessary. Pretty simple concept, yet not incorporated in the most advanced tables? |
The belt v direct drive battle has swung to and fro over many decades but is the tide finally about to turn for good in the favour of the latter? Should anyone in 2019 really leave the vital matter of turntable speed control precision depending upon a rubber belt? A rubber belt who’s main purpose seems to be an attempt to dampen and isolate motor vibrations at the cost of significantly measurable imprecision. |
the time constant of the timeline is so long in relation to the music it can only show general speed and your experiments seem to show that stylus drag does indeed slow the platter. It is interesting that the TT-81 seems to correct for this "automatically" and seems to suggest that speed on other tables should be set with the stylus in the groove. I think the more true tell as to how much of an issue this is would be to use a much higher sample rate to see how the music dynamically effects the speed. As an aside, I have a 301 and a TT-81 and all i use the TT-81 for is as a test deck to measure cartridges since I much prefer the sound of the 301. |
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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...🤗 |