The Pro Co FAT RAT expands on the legendary RAT formula with enhanced versatility, increased headroom, and multiple clipping options that make it one of the most flexible distortion pedals in the RAT family. Whether you're chasing classic RAT grind, smooth amp-like overdrive, or thick low-end saturation, the FAT RAT delivers a wide range of inspiring tones.

A switchable clipping section allows you to choose between the traditional silicon clipping of the classic RAT and a unique MOSFET/germanium clipping mode. The MOSFET setting introduces a smoother, more natural response with a subtle midrange scoop, giving the pedal a more amp-like character across its entire gain range.

The FAT RAT also features a dedicated Fat switch that boosts bass frequencies while gently rolling off highs, making it an excellent choice for bass guitar, extended-range instruments, lower tunings, or players seeking a fuller overdrive tone. Running the pedal at either 9V or 18V provides additional flexibility, with 18V operation offering increased headroom, improved clarity, and a more dynamic feel.

For tone enthusiasts, the socketed op-amp design allows easy, solder-free experimentation with compatible chips, including the highly sought-after LM308.

Features

• Switchable silicon and MOSFET/germanium clipping modes
• Classic RAT distortion with expanded tonal flexibility
• Fat switch for enhanced low end and smoother highs
• Socketed op-amp design for easy chip swapping
• Ships with OP07DP op-amp installed
• Operates on 9V or 18V for increased headroom and dynamics
• Large CTS potentiometers for smooth, precise control adjustments
• Distortion, Filter, and Volume controls
• 100% analog signal path
• Rugged steel enclosure built for years of reliable use
• Heavy-duty footswitch, knobs, and jacks
• Military-spec glass-epoxy circuit board
• Tool-free battery compartment (battery not included)
• Standard 2.1mm barrel power jack
• On/off LED indicator
• Five-year limited warranty

From classic RAT aggression to smooth, amp-like overdrive and bass-friendly distortion, the FAT RAT delivers an expanded feature set while preserving the unmistakable character that has made RAT pedals a staple for generations of players.