A harvester head comprising a feeding device and a control circuit, the control circuit comprising: - a first motor and a second motor (18, 20) which are configured to drive the feeding device which is configured to feed a tree trunk through the harvester head, wherein the second motor is coupled in series with the first motor; - a third motor and a fourth motor (19, 21) which are configured to drive the feeding device, wherein the fourth motor is coupled in series with the third motor, and wherein the third and fourth motors are coupled in parallel with the first and second motors (18, 20); - a first valve assembly which is configured to control the rotation of the motors (18, 19, 20, 21) by means of pressurized pressure medium, wherein the first valve assembly is further configured to supply pressurized pressure medium to the motors and to receive pressure medium from the motors, and wherein the first valve assembly is also configured to start and stop the rotation of the motors and to change the direction of rotation of the motors; and - a second valve assembly; characterized in that the second valve assembly is configured to - either (i), when the motors have been stopped by means of the first valve assembly, supply pressurized pressure medium to a space between the first motor and the second motor from a line that is connected to a pressure line supplying pressurized pressure medium; - or (ii), when the motors have been started by means of the first valve assembly, convey pressure medium to a space between the first motor and the second motor from a space between the third motor and the fourth motor; - or (iii) operate according to both options (i) and (ii). - a first motor and a second motor (18, 20) which are configured to drive the feeding device which is configured to feed a tree trunk through the harvester head, wherein the second motor is coupled in series with the first motor; - a third motor and a fourth motor (19, 21) which are configured to drive the feeding device, wherein the fourth motor is coupled in series with the third motor, and wherein the third and fourth motors are coupled in parallel with the first and second motors (18, 20); - a first valve assembly which is configured to control the rotation of the motors (18, 19, 20, 21) by means of pressurized pressure medium, wherein the first valve assembly is further configured to supply pressurized pressure medium to the motors and to receive pressure medium from the motors, and wherein the first valve assembly is also configured to start and stop the rotation of the motors and to change the direction of rotation of the motors; and - a second valve assembly; characterized in that the second valve assembly is configured to - either (i), when the motors have been stopped by means of the first valve assembly, supply pressurized pressure medium to a space between the first motor and the second motor from a line that is connected to a pressure line supplying pressurized pressure medium; - or (ii), when the motors have been started by means of the first valve assembly, convey pressure medium to a space between the first motor and the second motor from a space between the third motor and the fourth motor; - or (iii) operate according to both options (i) and (ii).