ok, there is a difference between them, mine doesnt have as much gain, but thats a good thing for recording.
Kurt did use a big muff, on the Nevermind sessions. I think thats the only time he ever used one. Live, he never used one, he always used a Ds-1 untill he broke his, then he (to his dismay) started using a DS-2. on Live and Loud, he used the Dod Grunge pedal and then threw it out in the croud, hehe. He used a sansamp like once or twice I think. Ok ill shut up now.