AnalogMagik Tutorial No. 2:
How to set proper turntable Speed, and measure Wow & Flutter
Accurate Turntable Speed
The starting point for any turntable cartridge setup and calibration is to have the proper turntable speed because an incorrect speed will affect all other setup parameters.
The most popular tool for setting turntable speed is to use a strobe disk. A strobe disk has is easy to use, but accuracy is based upon visual observations and the result will only be a close approximation. Secondly, when the cantilever is landed on the record, the dragging force of the cartridge stylus on the LP, albeit small, will slow the platter down.
The most accurate method of measuring is to use a test tone signal. This brings us to AnalogMagik's speed test function. The Analog Magik test LP contains a 3150Hz Test Tone on both a 33 1/3 rpm and 45 rpm Test LP. Because the test tone is recorded at exactly 3150 Hz at 33 1/3 rpm or 45 rpm, only an accurate speed will play back the test tone at exactly 3150Hz.
To achieve the proper turntable speed, simply play back the test tone on the 33 1/3 TEST LP, adjust the turntable speed until it registers exactly 3150 Hz on the laptop screen. Repeat the same procedure using the 45 rpm TEST LP.
The AnalogMagik software will also perform a WOW & FLUTTER calculation on the speed of the turntable. In layman's term's, WOW & FLUTTER is basically speed variations which your turntable is experiencing. The AnalogMagik WOW & FLUTTER calculation is based upon the Audio Engineering Society's standards which require the sampling of a minimum of approx. 30 seconds of test signals, therefore the WOW & FLUTTER test will talk approx. 30 seconds to complete.
Users can experiment with a variety of adjustments to minimize speed variations. For example, on belt driven tables, adjust belt tension or motor distance until the WOW & FLUTTER number is minimized. For idler wheels, the pressure exerted onto the platter can sometimes be adjusted.