The Boss ME-90B is a Boss multi-effects floorboard processor built for bass, an all-in-one amp modeling and effects workstation in the mold of the guitar-oriented ME-901. It carries 61 effects from the Boss bass effects library, organized into a dedicated preamp section plus six simultaneous effect categories, and its ten onboard preamp models use Boss's AIRD (Augmented Impulse Response Dynamics) technology with gain and EQ controls for fast sound shaping23.
For a player, it works like a pedalboard in one box: eight multi-function footswitches, a built-in expression pedal with a toe switch, a Blend knob for mixing in the direct bass sound, and Manual mode for pedalboard-style on/off control or Memory mode for switching complete setups34. It launched in April 2024 and remains in the Boss lineup1.
What it does: 61 bass effects and ten AIRD preamps
The ME-90B's 61 effect algorithms are tuned specifically for bass6, and they live in one of six effect categories that can run simultaneously alongside the preamp section36. The Preamp/EQ section offers ten preamp types backed by AIRD technology, including newly developed types, each with gain and EQ controls for rapid adjustment38. There is also an Acoustic type optimized for acoustic-electric and upright bass pickups, plus an EQ-only option for clean DI tones2.
One standout for reviewers was the Overtone effect. Boss describes it in MDP terms6:
"This effect uses MDP technology to add new harmonics to the sound, producing resonance and richness that was not present in the original sound"6
BassGearMag's Sean Fairchild highlighted the preamps and the Overtone effect among the unit's strengths in his 2024 review6.
The unit stores 36 ready-to-play preset memories and 36 user memories for custom setups3, and BassGearMag's spec listing counts 93 effect types in total across the categories6. A rear-panel switch optimizes the 1/4-inch audio outputs for either a bass amp or a full-range sound system3.
Controls, connections and power
| Feature | What it does |
|---|---|
| Eight multi-function footswitches | Turn effects on and off pedalboard-style, or switch memories3 |
| Expression pedal with toe switch | Real-time control of volume, wah and more4 |
| Blend knob | Mixes in the direct bass sound3 |
| Manual / Memory modes | Pedalboard-style operation or full-setup switching3 |
| Phrase looper | 38 seconds of mono loop recording6 |
| Tuner | Built-in, with ±0.1 cent detection accuracy6 |
On the connections side, it has stereo 1/4-inch outputs, a mono balanced XLR output with a ground lift switch, an effects send and return, and a 1/8-inch headphone jack37. Bass Magazine's E. E. Bradman appreciated the full output set:
"It's great to have an overall output control, stereo output, effect send and return, and a DI with switchable ground lift"7
He also called the 1/8-inch headphone jack "so nice to not have to carry a 1/4-inch adapter"7.
Power comes from four AA alkaline batteries, spec'd to last up to seven hours, or an optional PSA-S series AC adaptor367. Current draw is 195 mA6. The USB-C connector handles communication with Boss Tone Studio and audio recording and playback with music production software3, and an optional Bluetooth Audio MIDI Dual Adaptor (BT-DUAL) adds wireless editing and audio streaming from iOS or Android devices8. Boss released system program Ver.1.04 in May 2025, fixing a CTL pedal LED issue and minor bugs9.
The ME-90B is a full-size floorboard, not a compact unit: Bass Magazine puts its weight at just a smidge over seven pounds, with dimensions of 443 mm wide by 220 mm deep (17-1/2 by 8-11/16 inches)67. Boss offers optional carry bags (CB-ME80, CB-BU10)6.
Where it came from
The ME-90B is the latest in a series of Boss digital multi-effects processors for bass spanning decades, following the yellow ME-6B of the 1990s6. MusicRadar's Jonathan Horsley framed it at launch as the bass sibling of the ME-90 for electric guitar, "an all-in-one amp modelling and effects workstation"1.
What reviewers said
BassGearMag's Sean Fairchild reviewed it in June 2024 at a $399.99 price, praising its value, preamps and Overtone effect while noting Windows 11 driver troubles, and concluding:
"At just under $400 street, The BOSS ME-90B is a very easy recommendation to make"6
Bass Magazine's E. E. Bradman found the switches solid and the build rugged enough that "this pedalboard could probably take a beating on the road"7.
In Guitar World's review of the Darkglass Anagram, the deputy reviews editor compared the two directly, finding that "the Boss ME-90B can cover all of the Anagram's target applications," though its signal routing is simplified relative to the Darkglass, and calling it "a lot of bang for your buck on a budget overall"5.
Videos
Andertons Music Co
BOSSchannel
Nate Navarro
Questions
Can the Boss ME-90B run on batteries?
Yes. It runs on four AA alkaline batteries, which Boss and reviewers spec for up to seven hours of use, or on an optional PSA series AC adaptor. Four AA batteries are included in the box.
Does the ME-90B work as a USB audio interface?
Yes. Its USB-C connector carries audio recording and playback with music production software, and connects to Boss Tone Studio for editing. An optional Bluetooth Audio MIDI Dual Adaptor adds wireless editing and audio streaming from iOS and Android devices.
Can I use the ME-90B with an upright or acoustic bass?
Yes. The Preamp/EQ section includes an Acoustic type optimized for acoustic-electric and upright bass pickups, plus an EQ-only option for clean DI tones, so you can skip amp modeling entirely.
How much does the Boss ME-90B weigh?
Bass Magazine's reviewer found it weighs just a smidge over seven pounds. It measures about 17-1/2 inches wide and 8-11/16 inches deep, so it is a full-size floorboard rather than a compact stompbox.
What is the difference between the ME-90 and the ME-90B?
The ME-90 is the electric guitar version and the ME-90B is the bass version of the same all-in-one amp modeling and effects workstation. The ME-90B's 61 effect algorithms are tuned specifically for bass, and its preamp section includes bass-specific types such as an Acoustic model for upright and acoustic-electric pickups.
Does the ME-90B have a looper?
Yes. It includes a phrase looper with 38 seconds of mono recording time, alongside a built-in tuner with plus or minus 0.1 cent detection accuracy.
Sources (9)
- “Next-generation sound experience backed by decades of R&D”: Boss has big news for bassists, unveiling feature-packed ME-90B multi-fx, plus high-powered Katana-500 head and matching 1x12 cab, MusicRadar, 2024-04-18
- BOSS - ME-90B | Bass Multiple Effects, BOSS (boss.info)
- BOSS - ME-90B | Bass Multiple Effects, BOSS (boss.info)
- BOSS - ME-90B | Bass Multiple Effects, BOSS (www.boss.info)
- Darkglass Anagram review, Guitar World, 2025-07-18
- Bassic Review, BassGearMag, 2024-06-28
- Review: Boss ME-90B Multi-Effects Processor, Bass Magazine, 2025-05-28
- BOSS - ME-90B | Bass Multiple Effects, BOSS (boss.info)
- BOSS - Support - ME-90B - Updates & Drivers, BOSS (boss.info), 2025-05
