A valve-actuator for a hydraulic valve includes a valve chamber, ports spaced mutually and opening into the chamber, a spool axially located in the chamber for opening and closing hydraulic connections between at least two of the ports as the spool moves axially in the chamber. An actuator includes a housing having mutually spaced surfaces, and a piezoelectric element located in the housing between the surfaces, the element expanding and contracting in response to an electric signal applied to the element. A temperature compensation and motion damping circuit comprising feedback resistors and a thermistor. The spool moves axially in the chamber in response to expansion and contraction of the element.