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LI0010 – 1 October 2015
Introduction
The G.R.A.S. 14AA Electrostatic Actuator Amplifier is a high gain, high voltage amplifier. The
output AC signal can be superimposed on either a 200 VDC or a 800 VDC signal. With the
200 V DC polarization voltage a standard measurement microphone as for example G.R.A.S.
40AF 1/2” Ext. Polarized Free-field Microphone, High Sensitivity can be used as a precision
sound source for high frequency signal generation.
The 800 VDC polarization voltage can be used with the G.R.A.S. RA0014 1/2’’ and RA0015
1’’ Electrostatic Actuator for frequency response calibration to accurately measure the frequency
response of microphones.
The input signal to the 14AA is supplied via a standard BNC connector and can be any signal up
to 1V RMS. The input signal is amplified 40 dB (100 times) in the 14AA for a maximum output
signal of 100 V RMS. The 14AA has three output connectors: AC output, AC + 200 VDC output
and AC + 800 VDC output.
Fig. 1.
Electrostatic Actuator Amplifier 14AA
