Use the Gain Adjustment Knob on a D3 Pro mic to adjust the gain. The gain adjustment knob on the D3 Pro is a step-less gain dial. It allows the user to change the microphone gain by up to +20dB above the base level. The circular know has been subdivided with markings going from 0 to 10. Each division on the dial is equivalent to a change of 2dB. However, being a step-less or analog control, it is possible to dial-in any gain increase from 0 to +20dB rather than being restricted to preset steps within that range.