Ease of Use — 8
Operating the Multi Overtone isn't exactly plug and play, but it's pretty darn simple once you take a minute to understand the lay of the land. Controls are Balance, Tone, Detune, and a 3-way Mode knob. Balance ranges from completely direct to totally effected. Tone controls the overall brightness level. Detune controls the depth of the effect from subtle to richly warbling (it doesn't control depth-it controls pitch). Mode selects the type of effect that adds overtones (not exactly. Mode selects the frequency range of overtones generated by the MO-2). Higher values produce a deeper effect. The Multi Overtone offers stereo output for extra spaciousness.
Sound — 8
The MO-2 is a distinctly digital sounding effect that utilizes Roland's Multi-Dimensional Processing, or MDP technology. Multiple processors bring together its blend of effects. I tried it out using a Godin Montreal Premier semi-hollowbody with dual humbuckers through a 1983 Fender Super Champ.
In mode 1, the Multi Overtone accentuated the octave above whatever I played. Chords took on a bright chorus-y sound, and when I ran some major single note melodies, it almost sounded like someone was playing along on an Irish whistle.
In mode 2, I still heard the overtone an octave above, but the focus was on the actual note I was playing, so there was more of a middle range with upper octave benefits kind of tone. With the Balance knob cranked to emphasize the effect and some serious distortion added for good measure, I achieved a stabbing lead tone with the octave note riding above a la Jack White.
In mode 3, I still heard the octave above and the note I was playing, but the emphasis was on the note an octave below. I followed a sample setting from the owner's manual. With the Balance knob at 2 o'clock, the Tone knob at 10 o'clock, and the Detune control at 4 o'clock, the Multi Overdrive produced an organ-like tone. When I played with the Detune knob, it was the sonic equivalent of an organist adjusting the levers and bringing in or out the desired amount of Leslie speaker rotation. For fun, I kicked on the Adaptive Distortion pedal set for a crunch tone, and all in the sudden the sound went from church to Deep Purple! (True - they play well together)
Reliability & Durability — 9
It's a typical Boss compact pedal that runs on either an AC adapter or a 9-volt battery, and I always appreciate how Boss makes access to the battery compartment super easy via a thumbscrew. No screwdriver or removal of a back plate required. The Check light indicates when the battery runs low. The controls all felt secure, and I feel secure saying that the Multi Overtone seemed built to last just like all Boss stompboxes. Who doesn't own a Boss pedal that's been functioning fine since you first started playing?
Overall Impression — 8
I dig how Boss has clearly made a concentrated effort to conjure new effects with its innovative MDP series of compact pedals, and the MO-2 Multi Overtone is a fine example of moving forward rather than rehashing the same old standards. It was fun figuring out exactly what the Multi Overtone was designed to do in a general sense, and even more fun to push its boundaries to yield wildly varied and endlessly interesting results. I would have never dreamed that the same pedal that could practically turn my guitar into an organ would also be capable of producing wild Whammy-like octave effects, but that's exactly the kind of sonic adventure I discovered when I started tweaking the resourceful MO-2 Multi Overtone pedal.
The MO-2's $159 street price is a bit more costly than some of Boss' other compact pedals, but not nearly as expensive as some similar style pedals on the market. The Multi Overtone's true value lies in its huge range of sounds and applications - onstage or in the studio - from rich rhythm tones to vibrant lead sounds.