Whereas metal guitarists' overdriven sound generally comes from a combination of overdriven amplifiers and distortion pedals, grunge guitarists typically got all of their "dirty" sound from overdrive and fuzz pedals, with the amp just used to make the sound louder. Grunge guitarists tended to use the Fender Twin Reverb and the Fender Champion 100 combo amps (Cobain used both of these amps). The use of pedals by grunge guitarists was a move away from the expensive, studio-grade rackmount effects units used in other rock genres. The positive way that grunge bands viewed stompbox pedals can be seen in Mudhoney's use of the name of two overdrive pedals, the Univox Super-Fuzz and the Big Muff, in the title of their "debut EP "Superfuzz Bigmuff"". In the song "Mudride", the band's guitars were said to have "growled malevolently" through its "Cro-magnon slog".