A Field Effect Transistor is a specific class of transistor that uses an electric field to control the flow of electrical current. It typically consists of three terminals: the Source, the Drain, and the Gate. By applying a specific voltage to the Gate, the conductivity of the channel between the Source and the Drain is modulated, functioning effectively like a fast-acting electronic valve. In professional audio applications, the FET is revered primarily for two distinct roles. Its ultra-high input impedance makes it indispensable in the internal circuitry of capacitor microphones, where it buffers the high-impedance output of the capsule to a lower impedance suitable for transmission. Secondly, in the world of dynamic processing, FETs are utilized as voltage-controlled resistors. Their ability to change resistance almost instantaneously allows for the design of limiters with exceptionally fast attack times, such as the legendary 1176 compressor, which adds a distinct character and punch to the signal.