A modular hydraulic control valve assembly for use in a pilot-operated hydraulic control system comprises, in one embodiment, a control valve including a valve body defining a main flow passage from an inlet on a high pressure side of the control valve to an outlet on a low pressure side of the control valve, a valve member arranged in the flow passage and separating the high pressure side from the low pressure side, a control chamber comprising means for hydraulic actuation of the valve member by applying a control pressure to the control chamber so as to position the valve member between an open position and a closed position thereby adjusting a main flow through the main flow passage in response to the control pressure, a feed port for feeding fluid to the control chamber to increase the control pressure therein, a bleed port for bleeding fluid from the control chamber to decrease the control pressure therein, and a valve bonnet closing the control chamber. The assembly further comprises a feed check valve determining a feed flow direction, a bleed check valve determining a bleed flow direction, a distribution block including a common plenum, a control input in fluid communication with the common plenum, and a control output in fluid communication with the common plenum, wherein the distribution block further comprises a feed channel connecting the common plenum with the feed port via an adjustable feed constriction, and a bleed channel connecting the common plenum with the bleed port via an adjustable bleed constriction.