Unleash Your Bass

Introducing the B2 FOUR Amp and Effects Emulator, powered with Zoom’s Multi-Layer IR technology and 6 iconic DI models. Now you can craft the perfect low-end tone.


B2 Four Effects and Amp Emulator
angled photo of the B2 Four with stage lighting

Packed With Effects

Build patches from 104 effects, including models of famous boutique effects and preamps. Mix and match up to 5 effects and amps simultaneously to build your own custom patches.


Bassist Dimitry Gorodetsky performing live

Built For Live Performance

When you need to plug directly into the house PA, the lightweight and portable B2 FOUR has you covered. It features six DI models that recreate the tone of world-class direct boxes:

Tube 1 for rich harmonics and thick low frequencies.

Tube 2 for a clear attack and tight low frequencies.

Tube 3 for a clear and glossy sound.

Solid State 1 for moderate compression and sharp tones.

Solid State 2 for a clear tone and little distortion.

Solid State 3 for elevated mids and low treble to replicate the Motown sound

Dimitry Gorodetsky | Bassist | Los Angeles, CA

bassist’s rig set-up

Rich Amp and Cabinet Models

Zoom’s innovative Multi-Layer IR technology recreates the tonal characteristics of playing through classic amps and cabinets. These impulse responses were captured from cabinets at 3 different levels and are activated based on the volume of your bass. (Patent Pending)

Hear Zoom’s Original Amp Models >



Busby Smith | Bassist | NYC

close-up of foot selecting a setting on the B2 Four

Historic Bass Sounds

Preloaded with 250 presets, these patches are designed to give bassists the ability to recreate the sound of popular songs from the 50’s to today.

Busby Smith using the cross-key navigation on the B2 Four

Navigate and Create

The 4 rotary encoders allow for quick adjustments to effects parameters as well as output settings. The cross key navigation buttons help you control the pedal with ease.


bassist using the looper to create

Loop and Groove

Jam and rehearse with the B2 FOUR. The 60-second looper allows you to build grooves, while the 68 rhythm patterns from the on-board drum machine are the perfect companion for practice.

Manny Laine | Drummer | NYC

view of the back on the B2 Four

Input & Output Options

A balanced output helps you connect directly to a PA or interface while the stereo outputs can connect to an amp. The instrument input has a switch to change the impedance from 1M to 10M ohms, giving you a cleaner tone for upright basses equipped with piezo pickups.

Using the B2 Four as an audio interface

Audio Interface

The B2 Four can be used as a 2-in/ 2-out audio interface by connecting to a computer or smartphone with your favorite effects and amp models. 

Using Guitar Lab and an iPhone to control your sound on the B2 Four

Its Own App

With a constantly expanding library of patches and effects, bassists can continue to expand their sound with the "Handy Guitar Lab for B2 FOUR" app (for iOS), available to purchase on the Apple App Store.


Amp Models

Sun CB

Features clean bass and bright high frequencies.


A solid-state combo amp perfect for jazz, featuring a round low-mid range with a calm overall tone.


busby smith

New Preamp Models

Clear Drive

This original ZOOM Clear DRV preamp uses a linear phase filter in the distortion path. As a result, phase interference is eliminated during dry mixing, providing a clear drive.

Super Low Preamp

A ZOOM original preamp for super low sound. Using “missing fundamental” acoustic science, SpLoPre is equipped with a bass enhancer which emphasizes the low end of every note. With a Lo EQ and a negative one octave sound, a super low-end tone is produced.

Djent Preamp

An original ZOOM preamp recommended for Djent sounds. This preamp combines an undistorted low-end with a strongly distorted high-end to provide a crisp, intense distortion even with a down-tuned 5-string bass.

1073 Preamp

A thick, warm sound of a vintage mic preamp with transformer distortion.

Solid Preamp

Modeled after a console’s solid state mic preamp, the SolidPre delivers tight sounding harmonics with the ultra-low frequencies cut out.

using the pedal

New Effects

Bass Analog Octave

ZOOM's original octaver uses an algorithm based on the operating principle of analog octavers.

Bass Standard Synth

ZOOM’s original bass synthesizer sound with adjustable filtering detail.

Bass Synth Talk

This effect produces a synthesizer sound similar to a talking modulator.


Busby Smith