Abstract: A system and method for calibrating amplifier gain and a comparator threshold for use in verification of magnetic media integrity in a magnetic data storage device. Commercially available read data processors are used which have an amplifier with controllable gain and a comparator with an internal indirectly-controllable threshold. An on-board voltage reference is provided for gain calibration. The calibrated gain is used to provide signals with known peak values for calibrating the comparator threshold. In one embodiment, the numeric control value for the threshold is reduced from a calibrated peak value to a specified fraction for media verification. In a second embodiment, the gain is reduced to the industry specified fraction and the threshold is calibrated to match peak signal magnitudes at the reduced gain. The gain is then returned to the calibrated level for media verification.