Boss OS-2

The Boss OS-2 is an extremely versatile pedal, great for experimenting with different sounds. However, if you're just looking for a quality overdriven tube sound, this might not be your pedal - with such a wide range of sounds it doesn't necessarily excel in any one of them.

The selling-point of this pedal is probably the "color" knob, which goes from overdrive (all the way to the left) to distortion (all the way right). In combination with its "tone" knob, you can essentially dial in anything from a warm, round, bright overdrive to a thinner, darker, almost fuzz-like distortion. The "drive" knob will allow you to manipulate the amount of gain in both cases.

The Boss OS-2 was the first overdrive/distortion pedal I owned, and after 6 or 7 years I still find uses for it and will likely never get rid of it. I have even used it as a clean boost/compressor for humbucker pickups into clean amps.

That said, in none of its settings does the pedal have the dynamics and the well-roundedness of classic tube-like overdrives. Notably, it seems to be a bit lacking in bottom-end and can sound a bit screechy unless played into very clean amps with lots of headroom. Though again, there are youtube tutorials for fairly simple modifications you can make that seem to solve this problem.

As usual with boss pedals, its housing is sturdy and well built.

All in all, a great pedal I would recommend to almost anyone.

The Boss OS-2 gives both overdrive and distortion effects in one single pedal. A large range of sounds and levels of saturation can be achieved with just a few tweaks.

Four knobs are available:
Volume, to control the output volume (this had to be adjusted at the end to ensure maintaining a similar volume with the effect turned on and off).
Tone works like a Low-pass filter, allowing adjustment of the high frequencies.
Drive controls the amount of drive for both the overdrive and distortion.
Color allows you to adjust the blending of the 2 effects: at extreme left, only the overdrive will be active, at extreme right, only the distortion, and right in the middle the two will be equivalent.

I use this effect with a Fender Stratocaster with no Humbuckers. I prefer the distortion part of the pedal, which is quite rich in harmonies for this price. The overdrive sounds ok when blended with disto but it's a bit cheap on it's own. Also, I couldn't manage to get a crunchy sound with it, even with Drive very low the overdrive kicks in pretty quickly, but it might be because of my configuration (I play on a bass amp Orange Crush). Globally the effect sounds quite standard, don't expect to be surprised by it's "personality".

On the robustness side, nothing to say, it's Boss and it's tough! The battery case is easy to access (under the foot switch) and needs no screwdriver to open. Besides the pedal is delivered with a battery already in. And of course, there's a socket for an AC adaptor.

To conclude, this Boss OS-2 is a very handy and affordable solution if your playing requires a wide range of saturation and you don't want to carry too many gears. But you might want to color the sound with other effects if you want something less ordinary. I would fully recommend it as a side-effect for it's large range of tweaking but less on it's own.