BOSS EX-4 Effects Expander Multi-Effects Pedal - Black

Turn a carefully curated pedalboard into a virtually limitless effects rig with the BOSS EX-4, a compact effects expander packing 120 effects, four simultaneous effect blocks and advanced routing into a remarkably small footprint. Its extensive library spans drive, modulation, delay and reverb alongside bass-optimized effects and distinctive BOSS favorites like Slow Gear and Slicer, giving players instant access to sounds that might otherwise require a much larger collection of pedals. Manual and Memory modes support both stompbox-style operation and preset-based control, while a vivid 2.4" color display, dedicated FX buttons and Gear Suite make building and editing sounds fast and intuitive. Flexible mono/stereo I/O and an integrated effects loop let the EX-4 work naturally alongside existing pedals, with series, parallel and wet/dry routing opening even deeper configuration options. Add assignable footswitches, external control and MIDI, and the EX-4 becomes a powerful way to dramatically expand what an existing pedalboard can do without demanding significantly more space.

120 BOSS Effects With Four Simultaneous Effect Blocks

The EX-4 puts 120 BOSS effects at your disposal, covering every major category from overdrive and distortion to modulation, delay and reverb. Bass-optimized effects broaden its usefulness beyond guitar, while distinctive BOSS sounds such as Slow Gear and Slicer provide creative options that might otherwise require dedicated specialty pedals. Up to four effects can run simultaneously, and unlike architectures that restrict each block to a specific category, the EX-4 supports multiple instances of the same effect for setups such as stacked drives or layered delays. Additional utility blocks include Foot Volume, two Noise Suppressors, Divider/Mixer, Send/Return and a three-band Global EQ, giving players the tools to build complete, polished signal chains within a compact pedalboard footprint.

Gear Suite and Color-Coded Controls Make Sound Building Fast

Despite its deep effects library, the EX-4 is designed to keep sound creation immediate. Gear Suite provides ready-to-play effect setups and lets players save favorite parameter configurations for individual effect types, making it easy to establish useful starting points without rebuilding familiar sounds from scratch. A 2.4" color display clearly presents the complete signal chain, individual blocks, editing parameters and menus, while dedicated FX1–FX4 buttons provide quick access to each effect. Color coding between the display, FX buttons and footswitch LEDs makes functions easy to identify at a glance. Manual mode supports direct, stompbox-style control, while Memory mode provides preset-based operation with 128 factory presets and 128 user memories for storing custom sounds.

Flexible Routing Integrates the EX-4 With Your Existing Rig

The EX-4 goes beyond conventional serial effects chains with flexible routing that allows its four effect blocks to be reordered and configured in series, parallel or wet/dry structures. An integrated Send/Return block brings external pedals into that architecture, allowing favorite stompboxes to remain part of the rig while taking advantage of the EX-4's broader routing capabilities. The Send/Return can also support four-cable-method setups for integrating effects around an amplifier's preamp section. Divider and Mixer functions provide additional control over more complex signal paths, while compatible configurations can preserve delay and reverb trails during memory changes for smoother transitions between sounds.

Assignable Footswitches and MIDI Expand Real-Time Control

Two rugged multifunction footswitches give the EX-4 flexible performance control, with split color LEDs clearly indicating their current assignments onstage. Functions can be configured system-wide or independently for individual memories, including effect block switching, memory changes, master bypass, tap tempo and other operations. Up to eight parameters can be assigned to built-in and external control switches per preset, opening deeper possibilities for changing multiple aspects of a sound in real time. A TRS control input supports up to two external footswitches or an expression pedal, while compact TRS MIDI In and Out connections allow the EX-4 to integrate with MIDI-equipped pedals, switching systems, external clocks and more sophisticated performance rigs.

Massive Pedalboard Flexibility in a Compact BOSS Footprint

The BOSS EX-4 gives players a practical way to dramatically expand the range of a carefully assembled pedalboard without filling it with effects that may only be needed occasionally. Its 120-effect library can cover everything from everyday drive and modulation to specialized textures, while four simultaneous blocks and advanced routing provide enough flexibility to build sophisticated combinations around the pedals already at the heart of a rig. Manual and Memory operation make the EX-4 equally comfortable for traditional stompbox control or preset-driven performances, with MIDI and external control ready for more elaborate setups. Measuring just 4.63" wide by 5.44" deep and weighing 1 lb. 13 oz., the EX-4 packs an enormous amount of BOSS effects power and utility into a remarkably pedalboard-friendly format.