A spectrum modifying method and the like wherein the efficiencies of the signal estimation and prediction can be improved and the spectrum can be more efficiently encoded. Images are captured of the package and are read to identify data on labels or on the package itself. The digital controller stores a target value of a hydraulic system operating parameter and is configured to formulate a pulse width modulated control signal based on the target value. An accumulator conveyor, traveling at a substantially similar speed or a designated variable speed as the first conveyor or conveyors, is aligned in the same plane as, is adjacent to, and may mate with the first conveyor at a predetermined location for contiguous movement in the same direction as the first conveyor at this predetermined location. A driver circuit can be coupled to receive an output from the first bias stack that provides a level shifted output having a second voltage swing that is less than the first voltage swing.