Karma Guitar Amplifiers MTN-Bass

The MTN-bass is a spin-off of the popular MTN-10 (improved Mostortion) for lead/rhythm guitar, with eight adjustments to make it bass-friendly (and to work within that frequency range). The possibilities of this amp-like drive/distortion pedal are beyond distortion, however. With the gain low (less than 12-o’clock), there is a distinct energy not achieved with a typical bass gear, even those amps (or a bass/guitar amp/cab combo) that are dual in nature, which is what most modern bassist desire. In essence, the MTN-Bass offers an attack that is so clear that it surfaces proudly in any mix, removing any muffle or mud. Most bassists and studio mastering know what I’m referring to, as a heavy kick drum with bass sometimes can produce a big bottom end that saturates a track, viz., it can be difficult to discern what the bassist is playing. This is the first thing that impressed me with the MTN-Bass pedal, in that it elevates a regular tone into that which I find more confrontational with notes pouncing forward.



As the Drive increases with this true bypass pedal, there is greater distortion (although that depends on the guitar and amp setting, which I’ll address soon). Now, this distortion is very smooth. I’ve tried other bass drives, including the one built in the Orange Bass Butler (which I find a bit rough or grainy if you push it past 1-o’clock). With the MTN-Bass’ drive up full, there is more saturation, yet it maintains a velvety complexity very different from a typical ‘breaking up’ effect. In essence, the MTN-Bass increases subtle harmonic richness through its touch sensitive dynamics, but while keeping control of the drive’s quality.
The headroom is massive, to say the least. Be prepared to turn your amp down as you will drown out other musicians! If you pay attention to the demo included in this review, you will notice that the MTN-Bass’ volume control never goes past 9-o’clock, since I kept the amp’s output consistent for the demo. To increase that volume even slightly necessitates a corresponding decrease in amp output. Of course, such a boost may be desired when pushing for a solo or a more forceful and hard-hitting segment of a song.

The EQ offers tweaking for bass, midrange and treble. This highly-flexible, wide-ranging tone control is superb, in that the degree of possible sounds are massive, from utterly deep and brooding, for stoner rock, to punchy klang for more modern metal styles. It also should be noted that the MTN-Bass has tremendous bottom end response, although very tight and not mushy. This may require a slight reduction in bass via the amp or guitar if you want to keep the heaviness consistent whether the pedal is on or off.
To get the most from the distortion, to make it really pop, activation the bridge pickup (for a higher end tone) and using a pick is most effective. However, for those players who know how to snap the strings and thump with the thumb, the distortion can be heard very well without a pick. From there you can adjust the EQ for taste, whether going for a mid-scoop, greater midrange and treble, etc. From the ‘classic’ pithy sound of Jaco Pastorius to the much-revered drive of Lemmy, the MTN-Bass can deliver the goods.

Developed by Karma Guitar Amplification, the MTN-Bass is all about quality, and beyond its sonic palette. Made in the USA (with as many parts sourced therein), it has a premium quality plated through pcb, a CA3260 IC chip (as in the original) and a custom powder coated and silk-screen chassis. Fairly new to the market, any bassist serious about tone and wanting to stand out in the band (or merely for more enjoyable home playing) definitely should investigate the MTN-Bass.