A dynamic threshold detector for a servo writer/detector in a magnetic
storage system with a magnetic medium comprises a detector that receives
data from the magnetic medium and that selects one of a first condition
and a second condition based on at least one of an amplitude, a sign and
bit transitions of the data. A threshold selector selects a first set of
thresholds when the first condition is selected by the detector and a
second set of thresholds when the second condition is selected by the
detector. The data includes pairs of numbers with a first number and a a
second number each having one of a positive sign and a negative sign and
wherein the detector selects the first condition when the signs of the
pairs are the same and the second condition when the signs of the pairs
are different.