Expand your pedalboard capabilities without altering the core rig you rely on with the Boss EX-4 Effects Expander.
Designed for guitarists and bassists who want to explore fresh sonic textures, this versatile processor packs 120 premium effects, utility blocks, and professional routing options into a compact footprint.
Whether you need rich spatial delays, classic modulation, or flexible signal management for live shows and studio sessions, it gives you the creative tools to build professional tones quickly.
Expanded Range and Multi-Effect Versatility
The BOSS EX-4 delivers a vast library of historic Boss algorithms, covering everything from overdrive and distortion to modulation, delays, and reverbs, alongside specialized bass-tuned effects and classics like Slicer and Slow Gear. You can run up to four effects simultaneously, incorporating multiple instances of the same effect type alongside dedicated utility blocks including foot volume, dual noise suppressors, a send/return loop, and a global EQ for complete tonal shaping.
Building professional sounds is fast thanks to the Gear Suite feature, which provides professionally tuned parameters accessible with a simple turn of a knob. The unit features 128 user memories alongside 128 presets, giving you ample space to save custom sounds for every song in your setlist. Integrated manual and memory modes let you switch instantly between traditional stompbox-style control and preset-based setups.
Intuitive Interface and Real-Time Control
Navigating complex routing configurations is straightforward via the 2.4-inch colour graphic display, which provides a clear view of your signal chain and parameters. Dedicated effect buttons let you toggle blocks on or off with a single press or access deep editing menus with a long press, while dynamic illumination matches the display's effect colours.
Performance control is handled by rugged dual-function footswitches surrounded by customisable colour LEDs. You can assign them to control effect blocks, memory banks, tap tempo, master bypass, or deeper parameter adjustments. For extended capabilities, you can connect external footswitches or an expression pedal, while space-saving TRS MIDI jacks allow seamless integration with wider pedalboard switchers and external clock sources.
BOSS EX-4 Effects Expander Specifications
- Effect Type - multi-effects processor.
- Instrument - guitar and bass.
- Effects Library - 120 effect types.
- Maximum Number of Effects - four concurrent effects plus six utility blocks including divider/mixer, send/return, foot volume, dual noise suppressors, and global EQ.
- Memories - 128 user memories and 128 preset memories.
- Sampling Frequency - 48 kHz.
- AD Conversion - 24 bits plus AF method.
- DA Conversion - 32 bits.
- Processing - 32-bit floating point.
- Inputs - mono INPUT L/MONO jack and INPUT R (RETURN) jack, 1/4-inch phone type.
- Outputs - mono OUTPUT L/MONO jack and OUTPUT R (SEND) jack, 1/4-inch phone type.
- Input Impedance - 1 M ohm.
- Output Impedance - 1 k ohm.
- Recommended Load Impedance - 10 k ohms or greater.
- Control and MIDI Connectors - CTL1,2/EXP jack (1/4-inch TRS phone type), MIDI IN jack, and MIDI OUT jack (miniature phone type).
- USB Port - USB Type-C.
- Power Supply - AC adaptor (PSA-S series) included.
- Current Draw - 300 mA.
- Accessories - startup guide, leaflet, AC adaptor (PSA-S series), and four rubber feet.
Weight and Dimensions for Boss EX-4
- Dimensions (cm) = 11.7 L x 13.8 W x 6.5 D
- Weight (Kg) = 0.80
The Boss EX-4 is a dependable choice for gigging musicians and studio producers looking to add a deep well of sound-shaping tools to an existing setup without crowding valuable pedalboard space.