The FatMetal Pro is designed for players who wanted a warmer metal tone that works better with brighter guitars and amps, but also is less aimed at palm-muted metal, and works better for tremolo-picking Black metal, and darker sludge and doom metal tones. All features are identical to the TightMetal Pro, but the tone has been tweaked to extend the low range of the Tight and Tone controls, and the Black Gain switch boosts the gain in an appropriate way to get the thicker, buzzier gain required for those genres. The Thrash switch converts the basic tone into a heavier, more mid-scooped tone for classic vintage metal tones. The noise gate has also been retweaked to make it smoother, and to sound better with the reduced highs of the FatMetal to allow it to work better for solos but it’s internally adjustable if you want the TightMetal CHOMP gate, just crank it! Amptweaker pedals are known for effects loops, and this one has 3: a universal loop, another active with the boost, and our popular SideTrak loop which activates when the pedal is OFF, to automatically shut off clean effects. It can be used to add a compressor, chorus or chain of effects that only works when you play clean, or to switch to another distortion pedal to use for an alternate rhythm sound…all without having to hit more than one switch it’s like having a built-in A/B box. A green LED alternates with the normal red one to indicate that the loop is active when the pedal is bypassed. Another cool SideTrak trick is that if you only plug in the SideTrak Send, and don’t plug in the Return, then that Sent dry signal can be sent to another amp meaning you could have the FatMetal Pro going through a 412 halfstack while sending the clean tone to a Twin or some other clean amp. All this ability comes from two simple jacks on the side of the pedal!