Boss EX-4 Effects Expander

The EX-4 is a premium BOSS effects unit that instantly expands the range of any pedalboard, delivering a massive boost of creative firepower in one streamlined stompbox. Craft new sonic universes with up to four simultaneous effects from a vast library, accessed with a simple user interface, flexible footswitches, and a versatile array of connectivity.

Every major category is available among the 120 effect selections in the EX-4, including overdrive and distortion, modulation, delay, and reverb, as well as bass-tuned effects and unique BOSS favorites like Slow Gear and Slicer. You also get dedicated utility blocks that can be placed anywhere within an effect chain—including foot volume, two noise suppressors, send/return, and divider/mixer—plus a global EQ for overall sound shaping.

A full color 2.4-inch display provides clear viewing of the full effect signal chain, individual effect blocks, editing options, menus, and more. Quickly turn effect blocks on/off with a single press and access editing parameters with a long press. FX button colors match each effect’s display colors for fast identification.

Rugged dual-function footswitches can be custom-configured system-wide or per memory, with assignments that include effect block on/off, memory up/down, master bypass, tap tempo, and more. A newly designed color LED system surrounds the footswitches, allowing you to clearly identify current footswitch functions while performing.

Four audio jacks provide mono or stereo connectivity, with the option to use two jacks as an effect loop to place external pedals anywhere within the EX-4’s effect chain. Two footswitches or an expression pedal can be connected for more real-time control, while space-saving TRS MIDI I/O unlocks deep integration with other MIDI pedals, switching systems, and external clocking devices.