The MXR Bass Chorus Deluxe (M83) is an analog chorus and flanger pedal built for bass, part of MXR's Bass Innovations line. It runs on bucket-brigade circuitry, the classic analog approach to modulation, and its whole design centers on the problem every bass player hits with chorus: keeping the low end solid while the effect does its thing. MXR says it serves up "shimmering, liquid chorus and swooshing, metallic flanger effects while preserving the punch and fundamental of your low end"12.
The pedal reached UK shops in March 2013 at an SRP of £1793, and MusicRadar introduced it that January as an emerald green Bass Innovations pedal with "a whole host of great features inside it's classic and rugged MXR housing"3.
Chorus and flanger that keep the low end
The Bass Chorus Deluxe gives you two modulation effects in one box. The core is a chorus, and a top-mounted Flanger button with an LED indicator switches the pedal into flanger mode1. Premier Guitar's reviewer called the flanger "an awesome addition" and reported that it "functioned well at all volumes, and I ended up keeping the pedal in that mode for the rest of the show" after trying it live5.
The low-end preservation comes from two places. First, a dedicated X-Over button (also top-mounted, with an LED) decreases modulation at 100 Hz, focusing the chorus in the mid to upper ranges and preserving the fundamental notes of your bass lines15. MXR positions this as ideal for playing upper register chords and melodies while your low notes stay clean underneath1. Second, Bass and Treble controls let you cut or boost lows and highs to shape the tonal character of the effect itself1.
Controls
| Control | What it does |
|---|---|
| Intensity | Standard chorus intensity control5 |
| Rate | Standard chorus rate control5 |
| Width | Standard chorus width control5 |
| Bass | Cuts or boosts lows, shapes the effect's tonal character1 |
| Treble | Cuts or boosts highs, shapes the effect's tonal character1 |
| Flanger button | Top-mounted, with LED indicator; switches to flanger mode1 |
| X-Over button | Top-mounted, with LED indicator; decreases modulation at 100 Hz1 |
The manual also includes named sample settings, including "The Po Po", "John Francis", and "Fixation Blvd.", the last of which Premier Guitar noted recreates the spacey bass sound of The Police's "Walking on the Moon"5.
Bypass and stereo operation
Inside the pedal, a switch toggles between two bypass modes: standard true bypass, and a TRS (tip-ring-sleeve) stereo-hardware-bypass mode5. In the stereo mode, you run a TRS to TS Y-splitter cable to send the effect signal to two different amplifiers, which lets the modulation move from left to right across the two rigs for a wide stereo sound1. Vintage Guitar described the same capability at launch: the Stereo Hardwire Bypass Mode "can be used with a Y-splitter cable to send the effect signal to two amplifiers"6.
Premier Guitar's reviewer found the stereo setup practical, explaining that "the stereo mode allows a player to plug in a Y-splitter cable to divide the signal and connect to two amplifiers" for that left-to-right modulation shift5.
Power
The pedal runs on a 9-volt battery, a Dunlop ECB003 9-volt adapter, or Dunlop's DC Brick, Iso-Brick, and Mini Iso-Brick power supplies, which are sold separately1. For battery users, that means no external supply is required to get started.
What reviewers said
Premier Guitar reviewed the pedal and summed up its strengths as "Thoughtful features, easy to use, excellent flanger"5. The criticisms were just as specific: "The chorus might be too dry for some tastes, x-over switch takes away too much effect"5.
In live use, the reviewer found the chorus "seemed to have a tendency to get somewhat lost in the mix at medium to loud volumes", and the X-Over button made the effect "almost non-existent onstage"5. The studio told a different story:
"Despite some volume issues onstage, the Bass Chorus Deluxe performed quite well in the studio."
So the practical picture from the review: the flanger held up at every volume live, while the chorus worked best in the studio, where the effect could sit clearly in the mix5.
Parts and support
Dunlop sells electronic parts for the M83 for installation or repair, offered with the qualified technician in mind, and its listing carries warranty information4. The pedal sits in MXR's broader bass line alongside pedals like the MXR Bass Fuzz Deluxe, the MXR Bass Octave Deluxe, and the MXR Bass Envelope Filter, all built around the same idea of bass-specific versions of classic effects.
Videos
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Questions
What does the X-Over button do on the MXR Bass Chorus Deluxe?
The X-Over button engages a crossover mode that decreases modulation at 100 Hz. That pulls the chorus effect out of the low frequencies and focuses it in the mid to upper ranges, so the fundamental notes of your bass lines stay solid while chords and melodies up the neck get the shimmer.
Can the MXR Bass Chorus Deluxe run in stereo?
Yes. An internal switch selects a TRS Stereo Hardwire Bypass Mode, and in that mode a TRS to TS Y-splitter cable sends the effect signal to two different amplifiers, letting the modulation move from left to right. The pedal ships in true-bypass mode unless you flip that switch.
Is the MXR Bass Chorus Deluxe true bypass?
It can be. An internal switch toggles between true-bypass operation and a TRS stereo-hardware-bypass mode used for running two amps. Out of the box you choose one or the other, so set it before you wire up your pedalboard.
Is the MXR Bass Chorus Deluxe analog?
Yes. MXR describes it as powered by pure analog bucket-brigade technology, the same delay-line approach used in classic chorus designs, rather than digital processing.
What is the model number of the MXR Bass Chorus Deluxe?
The MXR Bass Chorus Deluxe is the M83, part of MXR's Bass Innovations line of bass-specific pedals. Dunlop lists it at $199.99, and Premier Guitar's review noted a $169 street price.
Sources (6)
- MXR® BASS CHORUS DELUXE, Dunlop (jimdunlop.com)
- MXR® BASS FUZZ DELUXE, Jim Dunlop (www.jimdunlop.com)
- MXR kicks off 2013 with Bass Chorus Deluxe, MusicRadar, 2013-01-09
- MXR® BASS CHORUS DELUXE, Jim Dunlop (www.jimdunlop.com)
- MXR Bass Chorus Deluxe Pedal Review, Premier Guitar, 2013-05-11
- MXR Introduces Bass Chorus Deluxe, Vintage Guitar magazine, 2013-01-16
