Used in the studio for "Lithium", as stated by Nevermind producer Butch Vig in at least three interviews. Nirvana discusses the pedal in this December 10, 1993 MTV interview at 19:01 (a transcription can be found on the fansite Live Nirvana). The version is unknown, but it was likely a V3 or V6 due to Cobain's love of Mudhoney (he sports an official Mudhoney V6 Big Muff t-shirt in at least seven photos: here, here and here, here and here (both from April 19, 1990), here, and here, plus this April 17, 1990 show) and Vig's sonic comparison to his Russian Big Muff, which uses transistors and thusly makes an op-amp version unlikely.

MTV, December 10, 1993

[Kurt Loder] I know I saw you guys at Roseland, I think what I saw is right, the stuff you're using on stage for like little stomp boxes are just little stomp-boxes, right? They're not $300 great big...

[Kurt Cobain] Oh, no, they're old early ‘70s Electro-Harmonix effects boxes.

[Loder] Wow, how do you keep that stuff going?

[Cobain] Batteries.

[Dave Grohl] Earnie Bailey.

[Cobain] Yeah, our guitar friend - this guy who fixes - he can fix anything, a blender or a guitar... He's great. He’s just um…

[Krist Novoselic] He's into old technology.

[Cobain] They're kind of hard to find. Yeah. Those things are kinda hard to find and I guess they're becoming collector's items now.

[Loder] I think there's a store in New York that collects that stuff.

[Cobain] Hm hmm.

[Grohl] And probably sells it for exorbitant prices.

[Novoselic] He knows like, like they use this capacitor, they use this transistor, because they use this poor-grade cheap transistor at the time, that's what gave it that sound like, if you used a modern transistor it wouldn't sound as cool.

[Loder] True.

[Cobain] If you were to use the same schematic but used contemporary electronics you wouldn't get the same sound, you know what I mean?

[Michael Alex] The Soviet Union [unintelligible] Electro-Harmonix was buying them [unintelligible]

[Novoselic] It's a Red Army pedal, they make ‘em out of tanks. Tanks! And you go, koough! and you like, crank on it... koough!

[Alex] Yeah! [unintelligible] That's the technology that made that.

[Cobain] [unintelligible] old tank parts.

[Loder] Really?

[Cobain] Yeah!

[Loder] Oh, Jesus... [laughs]

[Pat Smear] They’re not the same, they’re not the same.

[Loder] Really?

[Novoselic] They're cheap metal, it's about that thick.

[Cobain] It's so heavy, the distortion box, it's just...

[Alex] [unintelligible] Soviet parts?

[Smear] No.

[Alex] Still?

[Smear] No, they’re not the same.

[Alex] They got a Big Muff.

[Smear] No, they're not as good.

[Novoselic] That's a Big Muff, it's a total tank! Tank materials, that's what they're made out of, it's like kay! you stomp on it and the metal around it is like total thick and like that olive, drab... like, Soviet olive green color. It's just like, wow, amazing...

Guitar World, August 1997, "Nirvana: Super Fuzz Big Muff - The definitive guide to Kurt Cobain’s grungy assortment of pawn shop prizes, turbo- charged stomp boxes and blown woofers." (first published online in abridged form on February 21, 2008, later unabridged on February 17, 2021)

But even though Vig wasn’t the biggest fan of effect pedals, he allowed Cobain to use a few on the album, especially since the guitarist felt that the DS-1 was the main factor in his tone. Cobain also used the Small Clone liberally. “That’s making the watery guitar sound you hear on the pre-chorus build-up of ‘Smells Like Teen Spirit’ and also ‘Come as You Are,’ ” says Vig. “We used an Electro- Harmonix Big Muff fuzz box through a Fender Bassman on ‘Lithium’ to get that thumpier, darker sound.”

Classic Rock Albums: Nirvana - Nevermind by Charles R. Cross & Jim Berkenstadt (1998)

To achieve the thumping, darker sound on "Lithium," the band employed an Electro-Harmonix Big Muff fuzz box through a Fender Bassman amplifier. “As I recall,” says Vig, “we used a U87 microphone on that. We wanted something that was not so bright, a heavier sound.” The U87 was a microphone that the producer usually reserved for capturing low-frequency instruments like bass guitar. Two tracks were devoted to Krist’s bass part. An additional three tracks recorded Kurt's guitar, all gauged to beef up the sound.

Guitar.com, December 10, 2020, "Butch Vig shares the guitar recording secrets of Nirvana, The Smashing Pumpkins, Foo Fighters and more"

“I think when we did Nevermind, Kurt had a Mesa/Boogie, and I rented a Vox AC30 because, as I said, I love the clear tones on those. I also rented a Fender Bassman. We had one at Smart Studios that we used all the time. One of the engineers called Doug Wilson had modified it. I don’t know what he did, but it was the fattest, crunchiest, thickest guitar tone. So I rented one in LA when we did Nevermind, and although it didn’t sound quite the same, we used that on Lithium and for some of the really heavy tones as the main guitar amp.

“And we only used a couple of pedals. Kurt had a Big Muff. And I think I had a Russian Big Muff, which is, you know, very close. And he had a RAT. And then he had a Small Clone, which is sort of the watery effect on Teen Spirit in the verses. Come As You Are as well. But that was it; a pretty simple setup, really.”

In a July 27, 2007 Two Plus Two forum reply, Steve Albini recalled a Big Muff appearing during the recording of In Utero, although no indication was made of whether or not it was actually used. He affirmed the Big Muff’s presence in a May 30, 2020 Reddit AMA reply.

Two Plus Two, “Ask a music scene micro celebrity”, July 27, 2007 reply to damntang

damntang

Hi Steve,

Can you remember what gear kurt Cobain used when recording In Utero, I'm particularly interested in his pedals.

Cheers,

D.T.

electric

Boss DS3 and ubiquitous Big Muff Pi also a Sans Amp

Fender Quad Reverb broken, but one working tube sounded pretty great

Reddit, “steve albini AMA here is the thread” by u/steve_albini (May 30, 2020), reply to u/rock-phillistine

rock-phillistine 4. Once you mentioned he used a Sansamp, a Boss DS-2 and a Big Muff for distortion. Recently his guitar tech said he shipped two homemade fuzzes as well. Do you remember if he actually used the Big Muff or the homemade fuzzes? If so, for which tracks?

steve_albini - I only saw Kurt use regular commercial effects pedals, the ones you mentioned, and a box I brought with me that was a kind of ring modulator/overdrive called Pedal X made by a friend of mine. That might be what his tech (Ernie?) was referring to.

Contrary to rumour, Cobain was never sighted with a Big Muff on stage. In a September 13, 2021 Instagram message replying to Equipboard user eyeseeofficial, Nirvana tech Earnie Bailey reported never having seen it himself.

Which Muff Kurt used on Nevermind is one of the great mysteries and probably the question I see most. Wish I would have asked when the chance was there.

In my time, I never saw on[e] used on the stage. Krist once gave me an early triangle knob circuit board, minus the pots & enclosure. No backstory on it though and I doubt he’d remember it.

If I presented a series of pics of all the Muffs, Krist would be the most likely to remember, but Dave too as he was more of a guitar guy than people realized.

Citing Bailey via a “Personal communication with Caio Leme” in 2020, Live Nirvana reports that “a green Russian unit was among equipment that Krist once brought over to Earnie's house.”

An Electro-Harmonix Big Muff Pi can be seen in this picture of John Frusciante's pedalboard. Electro-Harmonix also confirms the use of the Big Muff Pi.

In addition to the English Muff'n, John has also toured and recorded with the Micro Synthesizer, Big Muff Pi (both USA and Russian), POG, Metal Muff, HOG, Holy Grail, and Deluxe Electric Mistress. That said, I'm sure you fru-heads are still going to email and tell me what I left out.

All I used in the White Stripes for seven years was an Electro-Harmonix Big Muff and the Whammy. So you might be hearing me building up to the note with the pedal.

Premier Guitar:

I only used to have two in the White Stripes: a Big Muff and a Whammy pedal. That’s all I had! It’s kind of crazy to have all of these. But in 20 years of making recordings, you have all these different tones for different solos and songs.

In Guitar World's “100 Greatest Classic Rock Guitar Songs of All Time!” article, Big Muff distortion is credited for Gilmour's distinctive sound on Comfortably Numb.

"Here's a short experimental video by Radiohead's Thom Yorke -- look carefully, and you'll spot his Frequency Analyzer, Stereo Polychorus, and Big Muff Pi."

A photo of Flea's pedalboard shows he at one point used the Electro-Harmonix Big Muff Pi distortion pedal. More recent variations of his board don't include this pedal, however.

Listed among the pedals Matt used on Simulation Theory in this January 1, 2019 Premier Guitar interview.

Effects

Chase Bliss Warped Vinyl HiFi

Chicago Iron Tycobrahe Pedalflanger

DigiTech Whammy 5

Electro-Harmonix Big Muff

Eventide Space Reverb

JHS Pedals VCR Ryan Adams Signature Volume/Chorus/Reverb

JHS Pedals Colour Box Preamp

MXR Dyna Comp Mini Compressor

“My old man showed me how to play barre chords, and that's when things started getting really heavy,” remembered Dimebag of his early years playing. But I think the turning point came when I discovered an Electro-Harmonix Big Muff Fuzz. Feedback! Distortion! Dude, that was all she wrote.”

Trent Reznor is confirmed to use the Electro-Harmonix Big Muff Pi, as evidenced by its inclusion in the Fragility Tour program's partial list of equipment used to record "The Fragile," according to nin.wiki.

According to this article found on groundguitar.com, it mentions that Jerry Cantrell used a Electro Harmonix Big Muff Pi pedal on his solo album, “Boggy Depot."

You can see him play the NYC reissue Big Muff in 2000.

TalkBass user funkytoe, who knew Burton personally, recalled a Big Muff with a pi symbol in multiple TalkBass threads.

"Cliff Burton's gear" Comment #31, January 17, 2008

If you want to know what gear Cliff used, you need to be specific about time.

In the later days with Metallica, he had moved on to Aria basses and mesa or ampeg amps.

Around the "Kill em All" time, Cliff was still using his burgundy (oxblood) Rickenbacker 4001. It had a Gibson EB pickup at the neck and a hot Dimarzio pickup at the bridge. He called the Dimarzio his "secret weapon." Cliff's guitar tech at that time was Chuck Martin at ABC Music in Castro Valley, California. He might be able to give you more specifics about exactly what Cliff used pickup-wise.

Cliff's amp was a Sunn Colliseum Lead head with various cabs. The one I remember most was this big 2 x 18 cab. I don't think Cliff used 10 inch speakers prior to the time he switched to Mesa.

I remember 3 effect pedals. (1) EH Big Muff Pi. I distinctly remember the Pi symbol on that pedal; (2) EH Bass Balls and (3) Morley Power Wah Fuzz. He may also have had a power wah boost, but I am certain he was playing with a Power Wah Fuzz in his Trauma/early Metallica period.

Hope that helps your quest for tone.

"Cliff Burton's gear", Comment #79, December 23, 2008

FC Bass said:

BTW: I bought a Morley PWF a while ago, with the big muff after the Morley you have instant Cliff sounds :bassist: awesome! (Much better than the PWB)

Absolutely correct. Chrome Morley Power Wah Fuzz followed by EH Big Muff PI is what Cliff used in his Trauma/Early Metallica days and is the key to his sound (apart from his hands, attack, etc.)

"Cliff Burtons Rickenbacker", Comment #3, April 23, 2009

For the Maxwell tapes, Cliff played his Ric though Jim Martin's Morely Power Wah Fuzz, an Electro Harmonix Bass Balls and a EH Big Muff PI. I know this because I have been to Maxwell with both Jim and Dave on many occasions and have my own memories of Cliff's gear in this regard.

"Burton's tone with this head", Comment #6, September 1, 2010

Before Cliff hooked up with Metallica and finally got the label money to buy tube amps, he played solid state Sunn heads and cabs. His tone was nearly identical to his later tone with Metallica.

Cliff's tone was not in his amp. It was in his hands (and to some extent his pedals) and the aggressive way he played.

If you want Cliff's tone, you are better off getting an old Tel Ray Morely pedal (either a Power Wah Volume or Power Wah Fuzz), a vintage Electro Harmonix Big Muff Pi and Bass Balls. Those pedals and some practice will get you closer to Cliff's tone than any new bass head - guaranteed!

Bonus information: Equipboard user marijan_barac had a conversation with funkytoe, which made up the original content of this submission. What he wrote is preserved in its entirety below:

Guy who knew him personally as a friend and had seen his gear many times claims he remembers a distinctive PI symbol on the pedal. Also here is part of the conversation with him in which he cites Big Muff as Cliff's pedal: 'Yes I knew Cliff and saw his equipment many times over the years. Two of the first pedals I remember him getting were a Morley Power Wah Fuzz and an Electro-Harmonix bass balls. He used the Bass Balls briefly, but it did not get dirty enough for him. He tried a lot of Boss distortion pedals, but ended up choosing a Big Muff Pi. Cliff used that set up for quite a while with both his Randall and Sunn heads, at least up until the time he joined Trauma. After he switched to Mesa Boogie heads, he decided he liked the natural grind from the head better than the Fuzz sound from the Morley Power Wah Fuzz. So, he traded that for a Morley Power Wah Boost to help overdrive the front end of the Mesa head. In all the time Iknew him, he always had a Morley pedal on his Board. He also started experimenting with other pedals to replace the Big Muff Pi during the Metallica years. I remember a Tube Screamer for a while. Then he had a combination of a Tube Screamer and a Boss CS-1 Compression Sustainer going into the Morely Power Wah Boost. That is the last set up i remember him using. A Tube Screamer with a CS-1 and a Morley Power Wah Boost into a Mesa tube head.'

The DS-1 Distortion was Boss' only distortion pedal in the late 1970s, having been released in 1978. Based on this fact and the information above, Burton's Big Muff was either a V3, a V4 or a V5.

"Cliff Burton's Pedals Timeline.", Comment #1, April 23, 2009

Its probable that Cliff used a Morley Wah Boost and Big Muff With a CS-1 on his first gigs as seen here:

Within the linked photos, the 'flat chicken-head' knobs, pedal decals & silver, rectangular casing of the Big Muff can be made out, the much shorter length of the box in the second photo very much looking to be a generative upscaling error.