A very tidy boxed example of the MXR Custom Audio Electronics MC401 Boost/Line Driver.

The MC401 Boost/Line Driver from MXR is a potent volume pusher, taking your guitar's signal up by a significant notch! With up to 20dB of boost on tap, this powerful pedal raises the overall output of your rig, serving as the perfect driver for solos.

However, it's not just a one-trick-pony. While it may only boast one control, the MC401 also adds some crisp top-end to your tone as well as more mid-range punch. This offers a sound with far more definition and brilliance, which can help to compensate for the signal loss caused by large and complex rigs.

Place this pedal in your effects loop and you'll achieve a pure, unbridled kick of extra volume. However, this unit can also shine when used in conjunction with overdrive or distortion pedals, and when placed before them you can achieve a more saturated and harmonically-rich tone. Whichever way you decide to route the MC401, you'll always find it useful!