Over(s)

A term associated with A/D converters. It is used to describe input signals exceeding the full scale range (0 dBFS). Over indicators vary from a simple LED to elaborate calibrated digital meters. To be of genuine value the Over indicator, however displayed, must be based on reading the true digital code associated with the input level. It is important to distinguish between O dBFS and Overs; they are not the same. O dBFS is the absolute highest voltage level that any particular A/D can convert. It produces the equivalent of a digital code consisting of all 1s. No digital level can exceed 0 dBFS. A true Overs indicator actually counts the number of times that the 0 dBFS level was exceeded and displays this number. As yet there is no standard as to how many samples exceeding 0 dBFS constitutes an Over. Everyone agrees that very brief excursions beyond 0 dBFS (producing digital clipping) cannot be heard; however no such agreement exists as to just how many samples it takes before an Over is audible.