A pre-compressed vibration damper is provided for inhibiting transfer of vibration to an apparatus during the evacuation thereof by a pump. The moveable side panels at least partially define a closure for the opening. Lossless compression is achieved through redundancy elimination. The device includes a resistive switch having a first terminal connected to the peaking path and a second terminal connected to a voltage reference, and a controller configured to set the resistive switch to a first resistance value when a power input of the Doherty amplifier is below a threshold and to a second resistance value when the power input of the Doherty amplifier is above the threshold. Numerous additional aspects are provided.