To reduce the energy consumption of a vibrator.

The servo-control system for a hydraulic system 7 comprises a pump 8 driven by a motor 9, which feeds hydraulic fluid to a vibrator 1 or vibrating system comprising eccentric weights driven in rotation by at least one hydraulic motor receiving the fluid. It also comprises adaptation means for continuous adaptation of the rotation speed of the motor 9 of the hydraulic unit 7 in relation to the energy actually consumed by the vibrator 1.