An amplifier is an electrical device that increases signals.
The FET amplifier is used in weak signal amplifiers
The efficiency is the measure of how much of the power source is usefully applied to the amplifiers input.
What does mean "pickup"?
Trasduttore
Raccoglitore
Camioncino
What is the negative feedback?
Technique to avoid distortion by comparing the gain of the amplifier to the output.
A technique to avoid distortion by fed back a portion of the output signal and compare it with the input signal.
A technique to avoid gain-excess by fed back a portion of the output signal and compare it with the input signal.