Editing Amplifier figures of merit (section)

== Linearity{{anchor|linearity}} ==
An ideal amplifier would be a totally linear device, but real amplifiers are only linear within limits.

When the signal drive to the amplifier is increased, the output also increases until a point is reached where some part of the amplifier becomes saturated and cannot produce any more output; this is called clipping, and results in [[distortion]].

In most amplifiers a reduction in gain takes place before hard clipping occurs; the result is a ''compression'' effect, which (if the amplifier is an audio amplifier) sounds much less unpleasant to the ear. For these amplifiers, the 1&nbsp;dB compression point is defined as the input power (or output power) where the gain is 1&nbsp;dB less than the small signal gain. Sometimes this non linearity is deliberately designed in to reduce the audible unpleasantness of hard clipping under overload.

Ill effects of non-linearity can be reduced with negative feedback.

[[Linearization]] is an emergent field, and there are many techniques, such as [[Feed forward (control)|feed forward]], [[predistortion]], postdistortion, in order to avoid the undesired effects of the non-linearities.