G.R.A.S. 40AE-26CF Feature » Microphones – Preamplifier Gain

The GRAS 26CF preamplifier provides 20 dB of gain to the microphone, providing a higher voltage output needed to drive many of the USB and higher voltage input devices (like the PXI-4472) with a signal that is of high enough level to achieve a lower noise floor than would normally be achieved with a standard 50 mV/Pa microphone.  For example, with the NI USB-4431, as standard 50 mV/Pa microphone has a noise floor of about 30 dBA.  With the 26CF preamplifier, the noise floor is reduced to less than 20 dBA by applying gain to the microphone