a method and apparatus for linear and nonlinear control of a hydraulic press is provided with a feedback loop allowing the operation of a variable displacement pump to be selectively controlled with respect to either hydraulic pressure moving a piston in a cylinder , or the velocity of the piston . during controlled movement of the piston , a directional valve blocks a pump compensator so that the pump operates as a fixed displacement pump to provide fast response to feedback signals . simultaneously , the directional valve connects a proportional pressure controller to a relief valve . during a period when the piston is maintained in fixed position , the directional valve is switched so that the proportional pressure controller now controls the pump compensator and the relief valve is blocked , so that energy consumption is substantially reduced . zero or low piston velocity is obtained by means of a sequence valve which blocks hydraulic supply to the piston below a designated pressure to eliminate the influence of inherent system pressure which may cause piston movement in the absence of sufficient material pressure .