Turnable database with TimeLine

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.

01-16-14: Richardkrebs
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.

I'm very keen to try this test on my Final Audio. Could you please explain, if I use Mahler's 2nd for the test, which instrument should I listen to for the "note by note" ? Tympani ? Violin ? 1st or 2nd ?...
Could you explain what scope you used and how you calculated your reported result of less than 0.3sec for the servo response.

Since you keep referring to the Goldmund Studio, could you explain the reasons you went about modifying the power supply - what were the deficiencies that you could hear that prompted you to modify the power supply. Goldmund claim in their brochures that they used a new motor with built in regulator and Quartz controlled speed with response times fast enough to be immune from power line variations and to use an unregulated power supply.

Could you also explain what differences you could hear when you sold the Goldmund to purchase your SP10mk3. I recall that you told me at the time that the SP10mk3 was the only Direct Drive TT that you could not hear cogging or servo correction derived artifices. You told me at the time that the SP10mk2 and Goldmund did not have enough torque and thats why we could hear timing problems.

Dover,
Less than 0.3 seconds servo response came from observing current draw modulation in the kHz range, in sync with the music being played. The test was done with the system muted and live to check if it was some sort of acoustical feedback phenomenon.
There is only one possible cause of this.....
The platters speed was being modulated note by note. The controller / motor assembly was responding to this and " attempting" to stabilise the speed. This shows a controller frequency response in the kHz range. A speed that is not unusual in the industrial field.

Suggest a better test piece for you would be " Final Fantasy" by Nobuo Uematsu.