Eventide

A chorus pedal is a modulation effect. The original signal is split and run through a short delay and then combined with the original signal. The delayed part of the signal can then be modulated to create movement to create a thicker tone. A classic effect used on elctric, acoustic and bass guitars.

The harmoniser can be as simple as adding one note an octave above or below as in the octaver through to adding the major or minor third and beyond.

Multi effects units combine all the common effects and some uncommon ones into one box usually with a range of switches allowing you for example to create different patches allowing you to go from a clean sound with chorus straight into a high gain lead patch with delay with the press of a button. Infinite sounds in a compact package, the swiss army knife of guitar effects.

Reverb pedals modify the signal in such a way that you can replicate playing in different sonic spaces. Delay pedals allow you to repeat your sound at pre-determined intervals after you've played it. Both effects whether used independently or together can add warmth and depth to your tone. Reverb and delay pedals are collectively known as time-based effects and are typically positioned at the end of your signal chain.