The Big Muff is one of the most famous fuzz pedals around. And the fact it came out in 1969 isn't a joke either... The venerable Big Muff was originally designed by Electro Harmonix and there many different iterations of the circuit that have been released in the decades since. Countless companies have cloned the pedal's internals and changed it up for different gain and EQ responses — but nothing quite beats the lovely saturation of an early Electro Harmonix Big Muff Pi!
The tone knob is perhaps the most important control on most Big Muff-style pedals, as it lets you determine how woolly or buzzsaw-like your sound will be. It can take you from doomy, sub-harmonic sludge to searing high-end! Thick Big Muff fuzz tones have defined rock music in many ways, with key users including David Gilmour (Pink Floyd), Billy Corgan (The Smashing Pumpkins) and J Mascis (Dinosaur Jr.).
Can a Big Muff be considered an overdrive? Well it's definitely a fuzz, but to be honest, most Big Muff pedals have such an incredibly wide range of gain that they can easily be tamed in order to achieve tasteful OD tones — whether you decrease the pedal's gain control, or simply turn the volume pot down on your guitar.