Voltage Regulator (also called voltage potentiometer or v-pot) is the small adjustable screw knob on Compac F. It can be turned using a small Phillips-head screwdriver. The flat part on the circular dial determines the voltage setting. These settings are analogous to clock bearings with 1 o’clock position being the lowest voltage setting and 11 o’ clock being the highest voltage setting. The voltage regultor resets at 12 ‘o clock position. Most Compac F miners are set between 3 0’clock and 6 o’clock position from the factory. You might have to increase voltage to support higher clock frequencies. It is recommended to turn the dial in 30-degree increments. Higher voltage while necessary to support overclocking, will produce more heat and reduce mining efficiency.