According to one embodiment, a disk device including a head, a disk, and a controller is provided. The disk includes at least one band. When a target track is written while being partially overlapped with a track adjacent to the target track in each of the at least one band, the controller writes a plurality of tracks in the band such that a track pitch on the head side of the band is larger than the other track pitches in at least a part of a circumferential position range.

A module including first and second variable inductances. The first variable inductance is electrically connected to a pair of nodes in a first half-circuit. One of the nodes in the first half-circuit is a first connection terminal. The second variable inductance is electrically connected to a pair of nodes in a second half-circuit. One of the nodes in the second half-circuit is a second connection terminal. The first half-circuit receives a flow of current in response to the second half-circuit supplying the current to the load in a flow direction from a load through the first connection terminal. The second half-circuit is configured to receive the flow of the current in response to the first half-circuit supplying the current to the load in a direction opposite to the flow direction from the load through the second connection terminal.

According to one embodiment, a disk device including a head, a disk, and a controller is provided. The disk includes at least one band. When a target track is written while being partially overlapped with a track adjacent to the target track in each of the at least one band, the controller writes a plurality of tracks in the band such that a track pitch on the head side of the band is larger than the other track pitches in at least a part of a circumferential position range.