Abstract: A waveform tracking clipper circuit for limiting the instantaneous amplitude of a processed vibration test signal at the input to a shaker amplifier to the instantaneous amplitude of an unprocessed vibration test signal, the unprocessed vibration test signal having been processed to develop the processed vibration test signal. Included is clamper circuitry connected to the input of the amplifier. Numerous variations are disclosed, including the use of precision rectifiers and a variety of redundancy configurations to guard against the potentially-devastating consequences of a component failure or control misadjustment.