Fashioned in a form factor which aims to reproduce—and perhaps replace—a traditional pedalboard, the Line 6 M13 is a stompbox modeler intended for use with electric guitars. It allows you to arrange a whole host of effects, many of them modeled off of classic pedals from the analog age, into 48 individual scenes, which you can switch up on the spot between songs. You can think of it as 48 different pedalboards with four stompboxes apiece; as such, the unit is quite handy for a touring guitar player, giving you over 15 distortions, more than 20 reverbs, and a panoply of delays, modulation effects, and filters.
The pedalboard gives you the ability to use four individual models at any one time, with six knobs and three footswitches for each effect. An LCD screen at the top of each section gives you a visible readout of each modeled effect, and furthermore, correlates in color with the applicable footswitches for easier view on a dark stage.
The unit also features a 28-second looper with controls for Undo/Redo, Record/Overdub, Play/Stop, and more. For all of the delay, modulation, and filter effects, you can utilize tap tempo to get their various parameters in lock-step and sync. The M13 offers a plethora of connectivity options, giving you two inputs for expression pedals, stereo inputs, stereo outputs, and a set of stereo send/return jacks. All of these connection points are 1/4" terminations, but there is also a MIDI I/O, allowing you to back your scenes up on a computer.