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When Jim Marshall died on Thursday, at 88, the rock world lost the man whose breakthroughs in amplifier design made possible the thunderous guitar sound of hard rock, changing the course of pop-music history.

Taking a Fender bass amp as a model, Mr. Marshall, a former drummer and owner of a music store in London, invented the Marshall stack in the 1960s. It combined a separate and powerful amp head that connected to enclosed speaker cabinets with four footwide speakers. Over the years, he changed the circuitry to give his amplifiers more power, a clearer treble, a fatter bass. They sounded great when the guitar distorted, and they were louder than anything else out there. Guitarists like Jimi Hendrix, Eric Clapton and Jimmy Page popularized them, and walls of Marshalls came to symbolize hard rock.

Kirk Hammett, the 49-year-old lead guitarist for Metallica, was in high school when he got his first Marshall, and he played Marshall amps in concert until the early 2000s. He has a large collection of Marshall amps and still uses them in the studio to get certain sounds. In a telephone interview, he talked about what Marshall amps mean to him. Here are excerpts, edited and condensed:

When I got my first Marshall amp, it was so empowering. No one ever forgets their first Marshall amp if you’re a guitar player pursuing a big powerful sound. I mean, no one ever forgets their first Marshall amp. I can remember when I was 17 years old and acquiring a Marshall head and hooking it up and plugging my guitar into it and thinking, “Ah, I’m finally here, I finally got that sound that I’ve been hearing on all my favorite albums for the last four, five, eight years.”

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It was an empowering thing. When I first hit those chords, it felt much bigger than I was, physically. Seriously. It was bigger than I was physically, but I was in control of it underneath my fingertips. I hate to use these terms, but it felt like a sonic weapon in my hands.

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A Marshall amp had a clarity, a punch, a low end and had a type of distortion that wasn’t around before Jim Marshall invented it. There were amps that were similar. The Fender Bassman, which was a bass amp that guitar players discovered was really great, because it was big sounding and full, and it had a lot of volume. Rumor has it that Jim Marshall took that template of the Bassman head and made it bigger and better and more loud.

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After I plugged into it for the first time, in my mind there was a whole range of possibilities. The tonal variations and tonal possibilities became endless to me. Up until just recently, I have always dragged a whole fleet of Marshalls into the studio with me. I’m known as a Randall, Mesa Boogie amp man, but I’ve always had a Marshall in the mix whenever I recorded because it works well with blues rock, heavy metal, punk. It’s just a necessary ingredient, just like salt and pepper.

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At that point in time, I was influenced by ’60s guitar players. Eric Clapton, Jeff Beck, Jimmy Page, Jimi Hendrix. And a lot of the ’70s guys, particularly Ronnie Montrose, Pat Travers, the guys in Thin Lizzy, Michael Schenker from UFO – they all used Marshall amps. And I would stare at the album covers, or publicity pictures in magazines, and I would stare as much at the equipment as at the musicians themselves. One thing that got me is how cool it looked to see Marshall cabinets stacked on top of each other. After a while the term having a wall of Marshalls was just equated to having a massive tsunami of sound, and it became a symbol of aggressive music. Having a Marshall stack and a Les Paul was at one point the ultimate combination.

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I would say I have north of 30 Marshall amps. For a while, I was collecting Marshall amps because I wanted to try every Marshall amp from every year, and I stopped after a while because there was a storage issue.