MusicRadar Verdict
It's no chameleon, but it'll boost your tone with subtle colour.
Pros
- +
Variety of boost and character - clean boost to a pleasing edge.
Cons
- -
Fans of snarling tones should look elsewhere.
MusicRadar's got your back
There are loads of boost pedals around at the moment, some offering tonal adjustment as well as boost, but on the surface T-Rex's Karma Boost looks as simple as it comes, with just a single knob that can deliver 16dB at full whack.
The pedal, though, offers non-linear boost so that the character of the sound will change at different knob positions.
"At around a 10 o'clock setting there's a nice, subtle lift that works well, transparently giving a driven amp a bit extra"
With the control knob set to minimum, there's no apparent boost at all, but at around a 10 o'clock setting there's a nice, subtle lift that works well, transparently giving a driven amp a bit extra for solos.
Further advancement of the knob gives you more of this, with a pleasing edginess and presence easing in at higher settings.
That extra presence is also there when used with a clean valve amp: the Karma boost won't turn it into a snarling monster, but it will drive it into a useful degree of breakup.
A tasteful booster with the added advantage of a buffer to make up for long cable runs.
Trevor Curwen has played guitar for several decades – he's also mimed it on the UK's Top of the Pops. Much of his working life, though, has been spent behind the mixing desk, during which time he has built up a solid collection of the guitars, amps and pedals needed to cover just about any studio session. He writes pedal reviews for Guitarist and has contributed to Total Guitar, MusicRadar and Future Music among others.

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