A control circuit controls current through a voice coil motor (VCM) during retraction of a transducing head from the surface of a recordable medium. The transducing head is carried on movable member actuated by the VCM. The control circuit includes a measuring circuit for measuring a back electromotive force (back EMF) from the VCM. The control circuit also includes a driver circuit connected to terminals of the VCM for providing the VCM with a drive current having a magnitude based on the back EMF from the VCM. The control circuit further includes a chop clock to alternate between measuring the back EMF from the VCM and providing the VCM with the drive current at a random frequency within a range of frequencies around a median frequency.

 
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