The effect of track-edge amplitude asymmetry on position-error signal, PES,
of spin-valve GMR heads was investigated. Cross-track profiles of both amp
litude and amplitude asymmetry are showed along with the PES line of the he
ad. The results indicated that amplitude-asymmetry effect from servo burst
is finite but not significant enough to alter PES sensitivity, or the slope
of PES line, However, it is shown experimentally that the PES linearity is
functionally correlated with asymmetry of the servo bursts, which substant
iates the track-edge effect of spin-valve heads.