Abstract: An unbalanced vibrator for compacting concrete components during their manufacture has a vibrating table, unbalance shafts arranged on the vibrating table, and electronic motors allocated to the unbalance shafts in order to drive them, wherein the electronic motors have a device for the control and/or regulation of the rotational speed and/or the relative phase position of the unbalance shafts. The unbalanced vibrators of this type should be adjustable in an extremely rapid manner, in order to shorten manufacturing processes. For this purpose the electronic motors are designed as servo-motors and are provided with a device having sine-cosine transmitters, which determine the angular position and rotational speed of the unbalance shafts, such that the entire regulation/control can occur in a fully digitalized manner.