Optimum sound quality can only be reached with the exact turntable rotational speed.
 
With the Speed Light exact adjustment of the turntable speed is possible by keeping the light source independent from fluctuations in the mains frequency and voltage, which would otherwise give distorted results.
A quartz oscillator within the Speed Light generates an accurate 300 Hz light source making precise speed adjustment easy when used in conjunction with the clearaudio Stroboscopic Test Record.