The Fifth Gear is our take on a transistor OD which goes from barely-there overdrive to a distortion that toes the line of fuzz. The Fifth Gear can stand out on it's own, but also excels when pushing other pedals, or your amp, that extra bit further.
The 'gain' and 'heat' knobs are extremely interactive - with 'heat' off the 'gain' knob sets your drive level with a relatively flat EQ. Turning up 'heat' will add some midrange and a lot more grit, pushing the overdrive into a huge wall of distortion. The Fifth Gear has a passive volume roll off to tame the pedal when the other knobs are cranked.
'Heat' changes the DC bias on a resistor which causes static to be heard. This is totally normal and will not damage the pedal in any way. You can silence the static by turning down the volume before adjusting.