This is our FAB4312 Non-Inverting Amplifier Module. You can use any single opamp, 8-pin PDIP package like an LME49710, NE5534 or equivalent. It also features Mill-max sockets if you want to mount a 2520-style discrete opamp, like our DOA-12, DOA-17, 990C, API 2520, or compatible discrete opamp.
A trimmer is also provided to let you adjust DC offset to zero volts (0V). A 2-pin header is provided for connection of your gain control potentiometer (or selector switch, or digital potentiometer, or switched resistor ladder network). In the future, we’ll be providing FAB modules that will offer these different options for controlling the gain of your amplifier.
0.1uf bypass capacitors are positioned as close as possible to the supply rails of the chip. There is a 100pf capacitor across Rf to provide further stability even at high frequencies/and gain. A small 100R series resistor is connected at the OpAmp output to protect it in case of accidental shorting of the OpAmp outputs.
Use this FAB4312 Non-Inverting Amplifier Module with our FAB input and output modules, and along with the XLR input and XLR output modules to build your own “API-type” preamp! Then play with it by substituting different kinds of input and output transformers, opamps, etc, and see which combination of parts you prefer for your own custom mic preamp.