A method of detecting edges of a preamplifier signal including identifying a first portion of the signal wherein each part thereof has an instantaneous slope having a first polarity, identifying a second portion immediately following the first portion wherein each part thereof has an instantaneous slope having a second opposite polarity, and identifying a third portion immediately following the second portion wherein each part thereof has an instantaneous slope having the first polarity. The method further includes determining a first difference between the magnitudes associated with an end point and a beginning point of the second segment, determining a second difference between the magnitude associated with an end point of the third segment and the magnitude associated with a beginning point of the first segment, and detecting an edge if: (i) the first difference exceeds a threshold, and (ii) the second difference exceeds a fraction of the threshold.