Gain of a simple FET circuit

Discussion in 'General Electronics Chat' started by BackyardBrains, Feb 15, 2011.

  1. BackyardBrains

    Thread Starter Member

    Aug 26, 2010
    I was given a schematic to test out as a possible amplifier for a project. Attached is a scan from an old lab notebook. It uses a simple and inexpensive FET, and a few other components. I was told that it was used as an audio amplifier and was built into a tin can. I have built it myself, and it appears to have some gain on my signal, but not very much. (I cannot measure the signal directly... just through a speaker).

    My question is: what is the theoretical gain of this circuit? Also, the POT does not appear to have any effect. Does anyone have any other comments about this schematic? I am thinking it is meant to be a pre-amplifier, and not an audio amplifier.