MXR Custom Shop Micro Amp+

  • By Phillip Dodge @tonereport
  • January 09, 2014

The MXR Micro Amp has been a go to clean boost for many guitarists for 20 years. Now the MXR Custom Shop brings us the Micro Amp+. Beyond adding a potentially amp slamming 26dB of boost, the Micro Amp+ adds active bass and treble controls that allow you to sculpt the boost to the needs of your rig.


Unity gain is achieved with gain dial at about 7 o'clock (just a little above the lowest spot on the dial). With this output and the Bass and Treble controls at noon, it’s hard to differentiate your base tone from the tone with the pedal engaged. This is perfect thing if you’re happy with your tone and just want it louder.


If you want to accentuate (or cut) frequencies in your base tone along with boosting your volume, this is where the Micro Amp+ really starts to shine. Cut back the Bass a little if you want to dial some muddiness out of your humbuckers. Dial back the Treble if your Strat or Tele bridge pickup is too strident. Or push the Bass to give your single coils a little more meat.

Thanks to the nature of the active Bass and Treble controls, cutting both of these gives the impression of boosting the mids, while boosting the Bass and Treble serves to scoop the mids. With the gain at unity and the Bass and Treble up fully clockwise, I was able to solicit Blackface type spanky cleans out of my Vox AC15HW.

Conversely, pulling back the Bass and Treble makes for a nice “mid-rich” boost. It was too middy for the Vox but perfect into my Fender Vibro Champ. And cranking the Bass and Gain but leaving the Treble at 1 o'clock pushed the Vibro Champ into gnarly breakup bordering on fuzz. Additionally, pulling back the Bass and leaving the Treble at a noon allowed me to get a decent volume jump out of the Vibro Champ before it went into full distortion.


The Micro Amp+ is also a great stacker. Dialing the treble up to 2 o'clock allowed one of my fuzzes that's voiced nicely for rhythm work but too dark for lead to really cut through the band mix without becoming harsh.


What We Like: The sweet and natural clean boost of the Micro Amp+ is alone worth the cost of admission. The tweakability is just icing on the cake.


Concerns: None.


Tone (out of 5 stars): 5

Build Quality (out of 5 stars): 5

Value (out of 5 stars): 5


Overall Rating (out of 5 stars): 5

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