Turnable database with TimeLine

Actusreus,
I'm not sure I understand your question?
The turntable is not speeding up as the tonearm tracks toward the spindle....
I sense that many people without 'hands-on' experience with the Timeline may have difficulty understanding how it functions?
If the turntable is rotating at exactly the correct speed (33rpm or 45rpm).....the laser will 'hit' the wall at exactly the same spot every revolution.
Putting the Bluetak marker on the wall makes it easier to gauge the position of the 'hits' accurately.
If the turntable is running faster than 33.33rpm......the laser will hit the wall slightly further to the RIGHT of the marker every revolution so that the position will move further to the right at every revolution.
If the turntable is running slower than 33.33rpm (as is the case with the Raven)....the laser will hit the wall slightly further to the LEFT of the marker at every revolution and will move further to the left at every revolution.
With the Raven...you can see that the laser is moving approx 1mm to the left with every revolution....and it is consistent.
This probably equates to a speed of 33.31rpm instead of 33.33rpm.
When the arm is lifted at the end....you can see that the laser hits the wall mark at exactly the same spot at every revolution.
This indicates that the turntable is maintaining 33.33rpm without load.

But Syntax, is the Kuzma constantly too fast by a fixed amount while playing LPs, that is, regardless of stylus drag? If so, that is a fault remediable by an appropriate motor controller and not a black mark against the Kuzma.

Tony, I just cannot agree that a tachometer, no matter how good, is potentially superior to the Timeline for detecting micro-variations in speed, unless it would run off the rotation of the platter by a direct and perfectly non-compliant mechanical linkage, with no "belt creep". And then you'd have to stand there and watch it or run a recorder off of its output. In fact, Denon produced such a figure for use in their ad copy for the DP80; they show a very low level wiggle in an otherwise straight line, representing 33.33 rpm on the Y-axis, with time on the X-axis. But I doubt that the data come from a tach read-out. I don't recall how they derived it.

Peter and Henry, So if the single laser flashes six times per revolution, that would be about every 0.3 seconds. That's pretty near an instantaneous read-out. I wonder how it compares to the response time of a very good servo correction system. Maybe Richard knows.

Hi Halcro,
May I ask, did you manage to adjust the speed from a steady 33.31 to 33.33 under load?

Kind regards,

Actusreus.
Re my last post and tracking progressively towards the center grooves.
For clarity, I should have said it progressively becomes less slow as the torque demand decreases.

Lew
The servos we use at my work can have response times in the micro sec range. The limiting factor is the frequency response of the actuator they are controlling, so in practice, slower than this would suggest.
The goldmund feedback is very fast as observed on the scope current draw plot. Much faster than 0.3 sec . As I posted earlier, it was responding note by note. A startling observation.
Other TT manufacturers would, I suspect taylor the response time to suit their design philosophy.

Halcro, I just shared what Ron Sutherland told my dealer yesterday. I had been under the impression that there was an early version with one strobe and a new version with six strobes. That must be incorrect. So you must be saying that all versions have just one strobe. The difference is that the newer version flashes 6 times per 1.8 seconds and the earliest units only flashed once per 1.8 seconds. Is that correct? That must be why there are six dashes spread out around the room at every rotation. Thanks for clarifying this for me.