A perfect amplifier produces a signal of greater amplitude at its output, but of the same shape as the input signal. If the output signal does not have the same shape as the input signal, we say that there is distortion. This means that the audio system (the amplifier in this case) induces non-linearities.
– A so-called linear audio system reproduces the signal accurately (faithfully).
– A non-linear audio system transmits the signal but in an altered way.
Here is a square wave followed by a sinusoidal wave.
Here is the manipulation of this same signal as it travels through a non-linear component. The signal at the output has changed shape.
The distortion that an amplifier can generate is caused by the nature of the electrical and electronic components (tubes, transistors, power supply) that this same amplifier uses to increase the level of the sound signal. And the harmonic distortion caused by the amplification of the electrical signal using a tube or a transistor gives very different results.
Saturation, or more precisely tape saturation, occurs when the intensity of the sound signal (input voltage) is too high (hot) during recording. The original characteristics of the sound signal are then changed.
This is something that can be deliberately caused for aesthetic reasons. Because this
manipulation is a form of distortion that many sound mixers appreciate,
especially on instruments such as drums, bass and even vocals.
During sound mixing, adding imperfections or non-linearity to the sound signal (of an instrument for example) allows modifying its timbral content and to give it a unique sound identity.
Here are some plugins to color and distort your instruments:
Brainworx - Black Box Analog Design HG-2
Modify the timbral characteristics of your instruments, without compromise, with this plugin that combines different pentode and triode tubes while keeping a modern touch of brilliance with the AIR AMOUNT CONTROL.
More recently, Brainworx released a MS version (Mid/Sides) of the HG-2, which, beyond allowing the management of the signal separately for the mid and the sides, brings us even more saturation options and a wider variety of colors with its new filter section.
Fabfilter - Saturn 2
Gathers 28 distortion types and stands out by the possibility to process the signal in multiband mode (apply different distortions on different frequency bands). It also allows adding differents modulations (LFO, Envelope, XY pad…) to pretty much any of the plugin’s parameters and even to other modulators to create unique timbral manipulations.
Waves - NLS
Non-Linear Summer from Waves includes three console emulations inside the same plugin. Add the subtle color of the nonlinearities of these legendary consoles to your virtual tracks.