The Audio-Technica AT8537 is a power module for the AT898 or the AT899 lavalier microphones.This power module, when attached to the AT898 or AT899, provides several important functions. First, it converts the 11 - 52V DC phantom power into a smaller DC bias voltage used to power the FET impedance matching circuit inside the microphone. Also, it provides low frequency roll off, supplies battery power if phantom power is not available, converts the signal to the proper impedance and balances the output. The power module is a necessary component when using either of these mics.
