Back in April we reviewed four pedals from Mooer’s Micro Series of miniature guitar pedals. This is the second installation and this time it’s all about distortion. We’ve got four more pedals on hand from the fantastic series of pedals covering a wide range of distortion styles including the Flex Boost (Boost Effect), Rumble Drive (Overdrive Effect), Grey Faze (Vintage Fuzz Effect), and Solo (Distortion Effect tailored for solos). It blows my mind how many different flavors of distorted tone you can choose from these days, and these four stompboxes represent just a few of these flavors – presenting no conflict of interest!

Flex Boost:

The boost is an effect that typically works to enhance that of another drive stage in your effects chain or amp. There are clean boosts but this is a little different. It has controls for Bass and Treble as well as Gain. Where I feel like this pedal truly shines is when it is put in front of a meatier distortion. So if you put this pedal in front of, say, the Rumble Drive (that I’ll be talking about next) it does a great job of enhancing and intensifying the effect which is perfect for solos or A/B sections of songs. The point is that it is typically used as an enhancer rather than a stand alone pedal. The exception is when it is used in front a lovely tube amp. It then can be used to drive your amp’s channel as if you were automating the amp’s controls to get different tones, but instantly. Great for playing 60′s rock and other genres that rely less on modern effects. The straight forward design and key yet simple feature set, coupled with the extra small footprint, make this one of my favorite boosters to date.

Rumble Drive: 

Unlike the aforementioned Flex Boost, the Rumble Drive does stand alone quite nicely. It’s a very well rounded and meaty overdrive effect reminding me of a TS-style overdrive with extras. The controls on board are Voice, Tone, and Gain. The Voice control is something we don’t see everyday as it adjusts the shape of the distorted signal. Overall, the tone is pretty wide and round in the fully CW position but as you turn it CCW it becomes thinner and more fuzz-like. The Tone control simply rolls off highs. I was very impressed with how well the pedal responded to the dynamics of the performance, and in doing so, makes for a wonderful rhythm guitar distortion tone.

Grey Faze:

Who doesn’t love the fuzz tones of 60′s rock? The Grey Faze is plain and simply Mooer’s take on an original Dallas-Arbiter Fuzz Face from the 1960′s. It uses a Germanium transistor and has controls for Fuzz and Volume. I didn’t have an original to compare it to, but if my memory serves me well, it’s in the ballpark for sure. The more you crank that Fuzz knob the more intense the effect becomes from Hendrix to Sabbath.


The Solo is a distortion designed to shine. Mooer’s goal was to create a distortion meant for guitar solos. With controls for Level, Tone and Gain you’d think that this was just an ordinary distortion. Where this pedal really stands out is with the 3-way switch that allows you to choose between Natural, Tight and Classic. Natural provides for an organic timbre with great dynamic response, Tight provides for a modern mid-rangey tone with tight bottom end, and Classic coaxes a vintage tone with a detailed presence. In practice, I found this pedal to not only sound good for soloing, but to be just a real good all around distortion tone that sounded good across different guitars, amps and applications. I would say that this pedal is the most well rounded of the bunch and could be a candidate for your “deserted island” distortion.

I am still very impressed as to what Mooer has been able to squeeze into these little boxes. They sound good, they don’t take up a lot of space, they look cool. They are the BOSS of a new, more space conscious, era. - Gus Green