turntable speed control

phoenixengr

Thanks for dropping in, pretty much sums it up.

I was looking at buying an SDS for my Prime, but after reading this and comparing the price ($525 for the Eagle vs $1399 for the SDS) it seems like a no brainer.

If the motor on the sds system is always turning the same speed the platter will not go faster because the bearing is warm. That's a load of hooey. And I think the affects of belt creep are also greatly exaggerated. You could always go to tape, silk, or thread if you are concerned about that. To me a a constant stable speed is always better than a changing one. 

The best belt would be a endless rubberized steel cable style belt like the old micro seikis. Quiet and they can't stretch. Micro did things right

To me a a constant stable speed is always better than a changing one.

Agreed.  But constant motor speed does not equal constant platter speed, it's basic physics.  Belt creep does exist and it is measurable.  With an elastic drive belt, it cannot be cured, but the effects can be mitigated by holding the platter speed constant as we do.

By your own assertion, a constantly changing speed could affect the audio.  A table driven by the SDS will have constantly changing platter speed for the first 30-45 minutes;  it will either be off-speed (slow) initially then correct after 40 mins, or correct speed when cold, then off-speed (fast) after that. 

With  the Eagle PSU and  tachometer feed back, the platter speed will always be constant, therefore, it will sound correct both when started and after the table warms up.

Thanks for helping make my point.