When using 100 µm steps, it is important to minimize any vibration produced by the stepper motor. This is accomplished by reducing the motor voltage until the vibration artifact is minimized. This adjustment is achieved using the voltage adjustment control on the rear of the SF-77. Any residual artifact may be removed by subtracting 'averaged null traces'. 

Reference:   

Jie Zheng and Fred Sigworth,
Selecting Changes during Activation of Mutant Shaker Potassium Channels,
J. General Physiology, 10: 101-117 (1997)