Abstract: A broadband vibration sensor apparatus includes a single housing having at least two vibration sensors disposed in signal communication with a machine contact surface of the housing and a machine on which the housing is mounted. One of the sensors is a piezoelectric element capable of detecting high frequency vibrations and the other sensor is an accelerometer capable of detecting low frequency vibrations. A low impedance transducer is mounted in the housing to convert the output of the piezoelectric element to a low impedance output. An amplifier is connected to the output of the low impedance modified first sensor and the output of the second sensor for amplifying both outputs. A single cable connects the housing to an amplifier housing. Select jumpers are provided for converting the amplifier between a one input, two or four channel amplifier and a two input, two channel amplifier.