Review: Boss MO-2 Multi Overtone Pedal (World Exclusive First Look)

Turn your guitar into an organ, or a 12-string, or a synth   20-Jan-13

    MP4 9:33 mins    

The Boss MO-2 Multi Overtone is here to make your guitar sound like an organ, or alternatively, an evil synth.

Out of three new Boss pedals released recently (MO-2, TE-2, DA-2) I certainly had the most fun during the Boss MO-2 review. Here's why...


It's a standard compact design from Boss, the design that has become an iconic fixture on pedal boards around the world. Four knobs, one stomp switch. The first knob is your output level, secondly you have tone, the third knob is 'detune', and finally, you have a three way selector knob which switches between three different modes.

Those modes on the Boss MO-2 Multi Overtone are simply numbered '1', '2', and '3'. The higher the number, the lower the overtones. For example, on setting 1, you could expect to hear higher frequency overtones, and on 3, you could expect to hear more sub octave overtones.

That's pretty much it as far as the interface goes. As far as what's going on inside the pedal, I should make it clear that this is NOT technically a harmonizer, the processor inside the Boss MO-2 simply listens to the pitch of the input signal, and uses EQ to 'hype' certain overtones depending on the notes you are playing.

The effect is that, on setting 1, you sound as if you are playing harmonics alongside playing the notes or chords you are fretting.


The two big factors on this pedal are the detune knob and the setting knob. By playing with the detune, you can get wildly varying sounds. I think the easiest way for me to display this is by way of saying what the detune does on each numbered setting. Of course, you could watch the Boss MO-2 Multi Overtone review video, in which I demonstrate this.

  • Setting 1) If you have the detune knob reeled back, almost completely off, then you get a beautiful '12-string' style sound. It sounds very much like something from the swinging sixties.

    Turn the detune up, and you begin to get a honky tonk sound, something which still sounds like it has come from the sixties, but resembles Jimi Hendrix more than it resembles The Byrds.


  • Setting 2) On setting 2, the BOSS MO-2 Multi Overtone pedal really begins to sound like an organ, if you have the detune knob reeled off, then it sounds like a very pleasant church organ.

    Turn the detune up, and what you get is more like the sound of a rock and roll organ. This sound is very reminiscent of the Micro Pog from Electro Harmonix.


  • Setting 3) On this setting, if you have the detune knob reeled back, then you get a badass sub octave sound. This is a cracking tone, and really gives the feeling of impending doom!

    Turn the detune knob up, and it begins to sound more like a synthesizer. Generally, this setting just sounds like Pink Floyd in their 'Dark Side of the Moon' era.

    Particularly in setting 3, you can hear that there is a fixed rate flanger in the mix somewhere, which is a nice little touch, and certainly adds to the textured tone of the Boss MO-2.


Build Quality

Most guitarists have owned a Boss pedal at one point or another, so you know that these things can be nigh-on indestructible.

Round Up

As I've said, this is my favourite out of the crop of new Boss pedals, and I don't really have a bad word to say.

I've already said a lot of good things in this review, so I'll try and find a drawback! I think that every setting on this pedal is useable, and that the Boss MO-2 will be a particularly popular pedal.

It's the sort of pedal you could use in a variety of different songs, with a variety of different genres, and it can be used on chords or single notes. So it's a bit of a winner in my books.

If I had to find a drawback, then I'd say that the Boss compact pedal units are sometimes limiting. I'd love to have two footswitches on this pedal. Being able to switch through settings in the middle of a song without having to reach down and twist the knob would be really useful.

But I can live without a dual footswitch, and it would probably compromise the fact that Boss pedals have such physically small footprints on pedal boards in comparison with some other companies.

The Boss MO-2 Multi Overtone is a really fun pedal to play around with, and I'd certainly recommend trying one out for yourself.

Pros: Good range of sounds, lots of fun, and inspires lots of riffmaking.

Cons: I'm struggling to come up with realistic negatives, but having the option of five different settings instead of three could be good fun.

Review by Richard Beech

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