When you need a little boost.
The MXR M-133 Micro Amplifier Pedal adds a preset amount of gain, using a single control. With a guitar, this lets you boost your signal for lead work, adjust between 2 different guitars with unmatched output (i.e., ...
This photo of Jack White's pedalboard shows he uses the MXR M-133 Micro Amp (top right of the board). He has also placed an MXR M-133 Micro Amp *inside* of a couple guitars. From [an interview in GuitarPlayer](http://images.equipboard.com/uploads/source/image/37528/CNT6jdV.png): > "I had a couple of guitars made for [the Raconteurs](http://equipboard.com/band/the-raconteurs). I designed a [Gretsch “Triple Jet”](http://equipboard.com/pros/jack-white/parsons-triple-jet-electric-guitar) by adding a third pickup to a Double Jet, and putting an MXR Micro Amp inside the guitar. You can instantly get an overdriven sound by clicking on that pickup. You can just plug into an amplifier. If it’s time to play a solo and break out a little more, just click that switch on the guitar."more
This photo of Paul Banks' pedalboard shows he uses a MXR M-133 Micro Amp Pedal (top left). About this pedal (and his Xotic Effects EP Booster) he comments: "I like my bass tone to be a little bit juicier than the straight amp sound." (original source [here](http://www.musicradar.com/news/guitars/rig-tour-interpol-618675), article dated March 31, 2015)more
At the top of Keith Murray's pedalboard in this photo, his MXR M-133 Micro Amp Pedal can be seen (turned sideways). In a [2010 interview](http://images.equipboard.com/uploads/source/image/34972/uhXGb4d.png) he confirms the signal from the Boss DD-7 feeds into the MXR Micro Amp: > Oh. Ok. After that, then it goes a Boss DD-7 delay pedal, then it goes into, uh, an MXR Micro Amp, then it goes into an MXR Micro Delay, then it goes into…more
"A pair of pedalboards with a few essential stomps helps Carrabba balance his acoustic and electric duties. His electric board holds a TC Electronic PolyTune 2 Noir, MXR Micro Amp, and a coveted sliver Klon Centaur. A Whirlwind Selector A/B box splits the signals and a Voodoo Lab Pedal Power 2+ provides the juice," reads [this](http://www.premierguitar.com/articles/22686-rig-rundown-dashboard-confessionals-chris-carrabba0 Premier Guitar rig rundown.more
http://www.premierguitar.com/ext/resources/images/content/2015_09/Rig-Rundowns/Social-Distortion/Jonny-FX-WEB.jpg Hands-down the pedal freak of the band, Wickersham travels heavy with three stompboxes—a Boss TU-2 Tuner, an MXR Micro Amp that he utilizes as a clean boost to push the amp a bit more while still retaining the guitar’s natural tonal characteristics, and a J. Rockett Audio Designs Archer that he uses as a fairly-transparent dirt box that fills his tone out and adds harmonic richness.more
When you need a little boost.
The MXR M-133 Micro Amplifier Pedal adds a preset amount of gain, using a single control. With a guitar, this lets you boost your signal for lead work, adjust between 2 different guitars with unmatched output (i.e., humbucker to single coils), or it can supply a permanent boost in a long effects chain where signal drop-off is a problem. Power: Single 9-volt battery or Dunlop ECB-003 AC Adapter - Controls: Footswitch toggles amp on/bypass (red LED indicates on) Gain knob adjusts total output volume when the Micro Amp is engaged.
It's worth noting that the Micro Amp is mainly useful in the context of playing live, specifically with a tube amplifier. It's not likely to add much to your solo practice or writing sessions (although if you practice or write at a fairly loud volume, you may find that stomping on this guy when you arrive at a song's solo section fattens your sound a lot, which can be very inspiring) and when used in conjunction with a solid state or hybrid amp, you're unlikely to really be able to take advantage of the M-133's ability to add searing gain to an already-saturated amp sound.
Therefore, please bear in mind that "live performance" is the perspective from which the rest of this review is written, as I have never bothered to use this pedal in a recording context--since two different guitar signals recorded on different tracks can be blended to taste during mixdown, with levels raised or lowered accordingly.
MXR/Dunlop initially marketed the Micro Amp as a mere volume boost, and it definitely does a great job as such. As mentioned earlier, activating on the pedal as you play introduces a boost that is as subtle or extreme as you want it to be; as an added bonus, I can attest that I've never noticed any coloration to my guitar tone when using the M-133. Other boost pedals often introduce a midrange "hump" that I, personally, usually don't mind. But it's nice to know I can use the MXR unit to get more of my sound, unadulterated.
A secondary function, per the manufacturer, is to slam the front end of a tube amplifier with extra volume to create even more saturated gain sounds than an amp is capable of producing on its own. Again, the M-133 Micro Amp excels at this, too.
Recently, MXR/Dunlop has been touting the pedal as a quick fix for guitarists who switch back and forth between, say, a Fender Stratocaster and a Gibson Les Paul during the course of a performance. Anyone who has utilized two instruments with different pickup configurations during the course of a single show is going to be... Read More
If you need a clean boost for solos, this is the one to buy! Unless you feel the need to have some tone sculpting as well to make your leads cut a little more and want to buy the Micro Amp+, this is perfect!
Having the single, big dial makes for easy on-stage adjustments if you find it's not quite the right volume in the moment.
As with all MXR pedals, very sturdy and reliable.
Very clean boost that doesn't colour the tone of my sound at all. Very useful for pushing through the band when volume is maxed out on my guitar and I need that little bit more volume.
Smooth, warm, and easy to use. Very helpful to give a punch in the mix to the guitar. Also if you're playing a solo it gives you a little bit of volume without adding gain, in case you put it after the gain pedals. If you put it before, this pedal makes you raise the gain of the pedal in the level you need. Also, it gonna makes you gain a lot of bit of punch in a tube amp. Simply a really great boost pedal.