The big box RAT has been reissued as the "vintage RAT" and it sounds pretty spot on. They even use the LM308 chip. So why would you want build one? Because rat clones are fast becoming the new it pedal of the boutique world. A little clipping modification here...Change a capacitor value there...And presto! BYOC have an all new "original" pedal. The BYOC Mouse has a 6-way rotary switch that allows you to choose from all the must have clipping combinations. Positions 4, 5, and 6 on the rotary switch even relocate the clipping devices to a more tubescreamer-like position in the circuit which turn the pedal into an amazing sounding overdrive.