The two-stage or multi-stage electro-hydraulic servo-valve (EHSV) is provided with one stage that works as pilot stage and another stage that works as output stage, where the latter stage has a valve block and a pilot valve sleeve with a lateral area. The lateral area or an area of the pilot valve sleeve is provided with a flow channel for transferring control-flow or volume flow. One of the flow channels is formed by a groove arranged in the surface of the pilot valve sleeve. The flow channels has different dimensions and are essentially arranged symmetric to each other on the surface area. An independent claim is included for an actuator, particularly for driving one or more flaps of an aircraft.
