What makes an op-amp good for use in an electret microphone preamp vs other op-amps? Being JFET, current bias, voltage bias, etc?

Does an op-amp that requires a negative voltage supply work better or not (related to electret) than a op-amp that does not?

  • \$\begingroup\$ Do you plan to remove the common preinstalled fet from an electret mic capsule and to connect the voice sensitive capacitor directly to an opamp? If yes, what unwanted things you plan to avoid with the idea? \$\endgroup\$
    – user136077
    Commented Mar 24, 2022 at 9:50
  • 5
    \$\begingroup\$ Op-amps don't have a ground terminal so they don't know whether their \$ V_{EE}\$ is negative with respect to ground or not. What's important is where the inputs are relative to the two supply pins. \$\endgroup\$
    – Transistor
    Commented Mar 24, 2022 at 9:51

1 Answer 1


An LM386 set to a gain of 200 (see data sheet) will work well with many electrets to give an adequate signal output. Electrets, properly biased, provide outputs of at least a few millivolts. The LM386 will gain this signal to respectable fractions of a volt, without much distortion. This can be coupled into an audio preamp, of further gained by a capacitor coupled op amp, as needed. Hope this helps some !


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