Think of a famous three knob overdrive and the colour red may not be what pops into your mind but what Keeley has produce here is extremely clever, they've created a a low gain mid hump overdrive which ACTUALLY sounds like the tubes are screaming!
How? Well that's actually fairly simple (as genius often is)! There is a type of transistor called a FET which on many levels behaves much the same as the glass tubes/valves we love to hear in amp and more importantly they sound much more like a tube/valve than normal transistors found in gear. What's more is this pedal has a unique touch responsiveness meaning as you play lighter and harder the pedal becomes cleaner and dirtier respectively causing the pedal to feel alive and organic in your hands.