Apparatus for attenuating the amplitude of a time-variant property of a fluid stream which comprises an enclosed volume, wherein the enclosed volume includes a mixing zone having an inlet and three or more outlets; piping means for introducing an inlet fluid stream into the inlet of the mixing zone; and piping means for withdrawing from the mixing zone three or more individual fluid portions through the three or more outlets and combining the three or more individual fluid portions into an outlet fluid stream. The distance between at least one pair of adjacent outlets may be different than the distance between another pair of adjacent outlets, and the distance between adjacent outlets may decrease as the distance of each outlet from the inlet increases.