A cutting machine includes a main body in which a rotary blade is included, a base over which a workpiece is to be placed, and a guide fence mountable to the base. A digital gain control circuit controls both the digital amplifier and at least one analog amplifier to produce a smooth linear and continuous gain, wherein perturbations in the digital control of gain are smoothed by a signal applied to gain control circuit by a gain step correction circuit. At least one shoulder on the valve bonnet engages the elastic seal to deform the elastic region to place the sealing surface of the seal in contact with at least one of the valve bonnet or the valve cage to form a fluid seal.