Measuring turntable speed

Optimize thanks for the information.  I have a Phoenix roadrunner for the speed which goes out to 33.333.  I have been interested, in the different turntables I have been building, to see if you can see the difference between a 35 lb platter vs 55 pounder.  Also different bearings I have been playing with.  

The roadrunner take one trigger per revolution then does the math.  But like you say what goes on for the 2 seconds.  

It would be nice to know how the software or machine samples the revolution and how accurate it really is.

I need to experiment more to see what make changes in the readings.  
 
Thanks again
Tom

Optimize, I know of no turntable were you can adjust wow and flutter. I know a bunch were you can adjust the speed. Thus a device measuring 3150 times a second is no more useful in adjusting speed than one measuring every revolution. It is revolutions per minute after all.

• As I said previously. If you add more mass with a ring clamp or other types. You will add more rotating mass and inheritance. That is indirectly a example to adjust the wow and flutter. (There is a reason why everyone is talking about "the nice and heavy platter" when looking at TT reviews. And look at high end shows. Those platters weight several kg. So they get greater inheritance and lower speed fluctuation. As simple as that.)
• Yes speed is one thing and fluctuation is something else as you say. I just wanted to point out what and how the industry standard are. We do not bring a knife to a gun fight (just wanted to say that there is a right tool for the job). :)
• Yes that is right: "It is revolutions per minute after all" (I do not know what you are trying to say with this.. RPM is just a speed expression. We could have chosen other units cm/s or like in tape speed that uses inches per second "ips") let us think what that means.. It means that during a whole minute the record has spun 33⅓ revolutions. BUT what happens if the platter has done 33½ instead? It only means that the record has turned an excess of ~20cm.. So in a whole minute the extra speed that the platter has it has resulted in a extra ~20cm.. rather unimportant if the TT rotates in 33.3 or 33.5 during that minute in my opinion. But you miss a thing of greater importance that is that our ears is much more sensitive to fluctuation (of the sound) than speed. So we are maybe obsessing about wrong things here. :)

Best regards.

Different belts and tension can affect wow and flutter/ speed stability.  You can watch the road runner pick that up to a certain degree.

Enjoy the ride
Tom

Good to know. Thanks!

Optimize, in this life it helps to be realistic about things. Nobody I know is going to spend $50 large on a turntable and try to add mass to the platter.
Does a heavy platter reduce wow and flutter? Given the same motor probably but with a different more powerful motor maybe not. One thing I will guarantee is you will never be able to tell the difference. So all this is purely academic. In reality people do just fine with plain A/C synchronous motors and stepped pulleys. The only good reason to have adjustable speed is to match pitch which the vast majority of us do not need. 
I do have a SOTA cosmos with all the fixins and one of the nicest things about it is you can set it and forget about it. I'm not going to add mass to the platter and risk burning out the motor and I do not care about the wow and flutter spec because I can't hear it. Don not burn your brain out mental masturbating about less than trivial issues.