Makes things fuller, smoother and creates a tighter connection between player, guitar & amp!
The connection between player, guitar & amp can be a very complex story sometime. During my time in retail stores I have seen quite a few players that had an amazing rig: High-end guitar, amazing boutique amp, quality cables...but they always felt that they're not getting the desired tone out of their setup. Some described it as being "not connected enough" to their rig.
The MP can establish that connection! It's designed as a boost/preamp/driver that will ultimately make your amp work harder, but can prevent unwanted distortion in order to keep the tone in the cleans. Its Texture control works with the Pre gain setting and smoothens the gain structure up to the point where you'll hear a slight compression, that might be wanted depending on the situation.
The output stage of the MP has a lot of potential and is able to turn the preamp section of your amp inside out. The op amp used in the circuit is strong enough to power up a small practice amp, so there's enough beef to kick your amp into distortion or saturation, if needed. The top-end response on the MP is smoother, which makes it a great pedal to work with brighter amps or models that get brighter at higher volume levels.
The MP wouldn't be a FFX pedal if it didn't feature a HPF control. The high pass filter is going to help taming low frequencies, when your amp is already driven or distorted and you want to give it that extra kick. It can take out as much as up to 700Hz, so don't worry if you're using a very low tuning.