Transient response and the stabilization of feedback amplifiers

ANY VACUUM-tube or transistor amplifier is continuously subjected to random current and voltage disturbances of varying peak amplitude and waveshape. Thermal noise is a common example of such excitation. The importance of this interfering effect, as far as the circuit designer is concerned, depends to a large extent upon the relative magnitudes of the desired signals for which the amplifier is designed as compared to the strength of the response produced by the system to the random excitation.