1. A system for providing dynamic gain over non-noise electrocardiographic data with the aid of a digital computer, comprising: a download station configured to execute code comprising: a value module configured to obtain a time series of a plurality of voltage values that comprises a digital representation of a raw electrocardiography (“ECG”) signal recorded by an ambulatory monitor recorder; a mark module configured to mark one or more segments of the ECG signal as noise, each of the segments comprising a plurality of the values, based on a difference between a maximum one and a minimum one of the values within that segment; and an analysis module configured to analyze further segments not marked as noise each of the segments comprising a plurality of the values, and to determine a gain factor for all of the values in the analyzed further segments based on the analysis.