Pro-Ject Strobe it

Strobe it displays stripes arranged in a circular pattern, which correspond to the desired speed and mains frequency. Please remember the ring that matches the speed and mains frequency (in Europe, 33 1/3 RPM corresponds to 50 Hz and 45 RPM to 50 Hz). Place Strobe it on the turntable and then start the turntable. The tonearm will remain in its starting position. Now, direct a mains-powered light source at the Strobe it that is rotating on the turntable. The stripes of the previously noted ring should now appear to be standing still. If they seem to drift slightly forward or backward, the speed is either too high or too low.