Another Platter Speed queston

The Platterspeed app is based on the premise that in order to reproduce the 3150hz tone, the table must turn exactly at 33 1/3 rpm. If the table runs slow, the test tone produced will be lower than 3150hz.

Since your table reproduced a test tone greater than 3150hz, it is assumed that your table runs faster than 33 1/3rpm.

If you are concerned about the accuracy of the test tone, you could always use another 3150hz test tone from another test album/manufacture and compare the results.

Thanks Brf: Now I get it. All I have to do now is figure out how to adjust. First think I'll try is a new belt.

If there is build-up on the motor spindle due to perished belt material, it can run too fast.

I'm also going to try and clean off motor spindle with some alcohol to see if that works.

If all else fails, try to find out what type of motor you have, and then select an aftermarket motor controller that is suited to it. Not only will your platter speed be adjustable but also the constancy of the speed will likely improve, and motor noise/vibration will lessen. The net effect is surprisingly beneficial.

I think you will find a vast majority of turntables, regardless of price, are going to be off 33.3 rpm a very small amount. Most likely a small enough amount to be undetectable by the human ear. IMHO an infinitesimally small variance from the ideal 33.3 does not affect the quality of the sound. On the other hand, wow & flutter, a constant variation of the speed, does easily affect the quality of the sound.

The point is, will adjusting your overall speed by +/- .05% make you system sound better? In my opinion, probably not. So I wouldn't worry about that. I would worry about a dirty pulley inducing greater wow & flutter though.

I cleaned off the pulley and put on a new belt. Now my speed varies from 33.28 to 33.38. I guess that's good enough, no?

If it sounds good, it is good.