# Faust: Delay

## Unit Delay

A unit sample delay can be used with the ' operator. This very basic operation is used in standard building blocks like integrators or digital filters.

## Integer Delay

The integer delay can be controlled during processing. This example uses a horizontal slider for controlling the delay. Original and delayed signal are sent to the left and right output for testing the effect.

Load the example in the Faust online IDE for a quick start:

import("stdfaust.lib");

// get the sample rate
SR    = fconstant(int fSamplingFreq, <math.h>);
delay = hslider("Delay[samples]",0, 0, 10000, 1);

sig = os.lf_saw(1);

process =  sig <: _,(_ , delay : @);


## Fractional Delay

Integer delays can only shift the signal by multiples of the inverse sampling frequency. Fractional delays can also shift the signal by non-integer values. The Faust delay library contains multiple implementations.