Effects units can give you an amazing amount of control over your sound. Of these devices, volume and expression effects pedals are among the most fundamental. While a volume pedal seems like a simple thing at first glance, many performers would agree that it's a seriously effective tool to have on your pedalboard. A volume pedal is part of the 'dynamics' family of effects. It works by changing the amplitude of a signal, which changes its volume by extension. This function makes it easy to adjust your volume quickly and smoothly with a simple foot motion. The pedal can also work as a booster, giving the signal a kick to help push it through a long effects chain. You can pump up an intense solo, or even make your own manual fade effects for dynamic live mixing.
To add even more effects to your sound, you might use an expression pedal. These use a similar rocker design to volume pedals, and some are actually dual-mode pedals that can work as one or the other. Expression pedals work together with multi-effects units, amplifiers or synths to provide adjustment or generate additional effects. This gives you control over aspects such as wah-wah frequency or the timing of delays and modulation effects. Along with the volume and expression rocker pedals, you'll also find some overdrive stompboxes amongst the selection here. With these, you can have pre-set tones, from subtle grit to serious distortion, that turn on and off in an instant.
Custom electronics can even give an overdrive pedal its own signature tone, such as the specialty channels on Jetter Gear's Jetdrive and Gold Standard pedals. Your own signature sound, naturally, is going to come from the unique combination of effects pedals that you incorporate on your pedalboard. Don't let the simplicity of volume and expression pedals fool you—they help put you in control of some of the most powerful characteristics of your sound.