Just out of interest guys have I got this right? Function of certain components of a common source amplifier: Capacitors at input and output: They are coupling capacitors and simply block the DC voltage, but allow the AC voltage through. Gate Resistance: Is the purpose of this to limit the amount of current reaching the gate of the JFET?? Source resistance: This reduces the gain of the circuit, which thereby reduces distortion. Drain resistance: Limits the maximum voltage gain? I think that the source and capacitor explanations are right, but I'm not that sure about the Gate and Drain resistors.