In one illustrative example disclosed, a
magnetic storage device includes at least one magnetic disk; a magnetic head which includes first and second read sensors; a suspension which supports the magnetic head relative to the magnetic disk; and read circuitry which includes a
preamplifier. The
preamplifier has a first input port coupled to the first read sensor; a second input port coupled to the second read sensor; a first bias source coupled to the first input port for actively current /
voltage biasing the first read sensor; a second bias source coupled to the second input port for zero biasing the second read sensor; and a
subtractor having first and second inputs coupled to the first and the second input ports, respectively. The first input of the
subtractor is provided with a first
signal which includes a read sensor
data signal and an interference
signal, whereas the second input of the
subtractor is provided with a second
signal which includes the interference signal but not the read sensor
data signal. Thus, an output of the subtractor provides a read sensor signal without the interference signal.