The output voltage of an AE sensor is usually very small (in millivolt or less), a preamplifier and/or post-amplifier is needed to enlarge the signal before it feeds into an AE system or other signal processing equipment.

As applications and testing conditions vary along with customers needs, the applicable amplifier is also different. PAC manufacturers various amplifiers to accommodate different needs such as general amplifier, in-line amplifier, charge amplifier, intrinsically-safe preamplifier, wide temperature preamplifier, post-amplifier, etc.