Need to adjust the speed every time I turn on turntable


Need to adjust the speed every time I turn on turntable.This is a belt driven Oracle Delphi II with Origin Live motor and Origin Live Control Board and Origin Live Power Supply.  I am guessing it can be the belt, motor, control board and /or power supply.   How do I determine what is not working?
dcaudio
phoenixengr

Thank you for that insight around speed fluctuations, phoenixengr! 

In the later 90's, I had a full blown SOTA Star Sapphire with vacuum hold-down / electronic flywheel (line conditioner) - paired with a Fidelity Research fx64 arm with mid-priced Grados.  The speed would hold only through a 3-4 hour listening session no matter what I tried, including swapping out for a new motor with an engineer friend.   In the end, I simply lived with the issue.  Two decades later, it's still comforting to know that something can be done. 

During that experience, my rig was situated on a jouncy upstairs room, presenting a real challenge in isolating the turntable from footfalls, etc.  I tried bladders, masonry (never have had any luck with that,) tiptoes, sorbothane, etc...but, the "cure" in that application was a sandbox with super dry play-sand from hardware store and a carefully leveled maple plinth atop the sand under the SOTA.  Maybe this may help others. 

Happy listening and More Peace, Pinthrift   
A long time ago when I began to notice speed fluctuations on my VPI TT I cured it with a clean-out and lubrication of the bearing and a lubrication of the motor.  So that might be an issue,

But phoenixengr, who apparently now licenses his inventions to SOTA, solved the problem forever initially for me and other VPI owners with his Falcon/Eagle/Roadrunner.  Now sold together with a advanced design motor by SOTA.  If they make it in a way that is compatible with your TT you might look into it.  It's clearly the way to go for many reasons including better SQ, and it's quite low-cost for what you get.. 
Just wanted to point out that many of the posts seem to confuse long term speed stability with instantaneous speed stability.  A turntable may measure out perfectly for speed over longer time intervals yet still create momentary episodes of pitch instability due to short interval speed errors.  There's a difference.
A dirty belt/belt tension is the number one cause of this in my experience, also check to make sure pulley isnt slipping on motor shaft and be sure to clean pulley grooves

Bruce