a reproducing unit that performs a reproducing process on a magnetic recording medium that includes a servo area where servo data used for detecting a position of a magnetic head on the magnetic recording medium is recorded, and a writable data area, arranged side by side with the servo area in the track direction, on which user data is written by the magnetic head, the servo area including a preamble area where a preamble recording pattern that represents data used for providing a clock synchronization of the servo data is formed by a plurality of magnetic sections, and a burst area where data used for detecting a relative position of the magnetic head with respect to a track center position of the servo data is recorded and on which a single burst recording pattern which is a layout pattern that tilts to the preamble recording pattern with a predetermined tilt angle is formed by a plurality of magnetic sections,

the reproducing unit including

a phase detection unit that detects a phase difference of a burst reproduced signal of the burst area from a reproduced signal of the preamble area, based upon sample values at respective points in the preamble area, which are sampled by using a synchronous clock determined by a reproduced signal processing of the preamble area and a plurality of predetermined coefficients, as phase difference information corresponding to a plurality of phase differences, the phase detection unit including

a filter circuit to which the sample values at the respective points are inputted and which outputs output values obtained by multiplying each of the inputted sample values by a plurality of different coefficients and adding resulting values; and

an integrator that integrates the output values output from the filter circuit for respective divided gate intervals into which a burst gate interval corresponding to a reproducing process interval for the burst area is divided, and outputs resulting values as the phase difference information,

wherein the filter circuit calculates the output values by multiplying the sample value by one of the coefficients in a manner so as to sequentially cycle the coefficients each time the sample value at each of the points is inputted and outputs the calculated output values; and

a position detection unit that detects position deviation information indicating a relative distance of the magnetic head from the track center position based upon the phase difference information.