Boss has unveiled the EX-4 Effects Expander, a powerful, compact standalone multi-effects unit that frees up vital pedalboard space.
Coming out of the gate like a bigger and bolder take on the Line 6 HX One, which also boasted many effects in one, the EX-4 can run four effects simultaneously. These are drawn from a “vast onboard library” of effect options, taking in overdrive and distortion, modulation, delay, and reverb across a 120-string roster of familiar Boss pedals.
Beyond that, there are bass-tuned effects and some of Boss’ more outlandish creations. That includes the Slow Gear, introduced in the late ’70s for effortless violin-like swells, and the Slicer, which turns played parts into glitchy, percussive patterns.
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A global EQ for sound shaping is also in place. Moreover, dedicated utility blocks can be placed anywhere within an effect chain – including foot volume, two noise suppressors, send/return, and divider/mixer – as Boss looks to maximize its usefulness.
Away from what its digital innards can do, two dual-function footswitches can be configured to a player’s needs, whether for a specific preset (Boss calls them memories) or a system–wide preference. Examples include effect block on/off, memory up/down, master bypass, and tap tempo.
Boss has also gone back to the drawing board to nail a colored LED system for clearer on-the-fly feedback on what the pedal is doing.
Connectivity includes four audio jacks for mono and stereo connectivity, with two of those slots used for an effects loop for placing external pedals within the EX-4’s internal effect chain.
Its inputs give more options, too, with space for two external footswitches – like Boss’s FS-5U tap tempo, freeing up one of the unit’s footswitches – as well as an expression pedal. Low-profile TRS MIDI in/outputs also make plugging it into a wider MIDI-powered rig or switching system a doddle.
That’s a lot of features for $299.99, and an interesting prospect in an age where amp modelers and traditional pedalboards are both vying for a player’s loyalty. The Boss EX-4, then, lands in the happy medium spot between the two, and could theoretically be hooked up to a modeler as well, with the modeler treated as a single external pedal within the EX-4’s chain. Lots of possibilities.
“Modern players carefully curate their pedalboard builds, and every slot must earn its place,” Boss reasons. “Offering a large selection of classic Boss effects in a space-saving design, there’s no better utility pedal than the EX-4. It’s an essential toolbox.”
The Boss EX-4 is available now for $299.99.
See Boss for more.


