Metallica’s Guitar Tech Explains Why Band Switched from Amps to Digital Modelers

Chad Zaemisch, the guitar tech for Metallica, recently reflected on how the band switched from conventional guitar amps to digital modelers. In an interview with RJM Music Technology Inc, Chad was asked whether he does all the rig building or if he just does the maintenance of guitar setups for James Hetfield and Kirk Hammett. He replied (transcribed by Killer Guitar Rigs):

“We had just put our racks together, and we went from the typical analog guitar amps and cabinets — we had these giant, huge isolation cabinet boxes and stuff that we used to have mics in there, and that’s what I inherited.”

“So I came in, and this stuff is all plugged in like this, like, ‘Okay, just maintain it. That’s great.'”

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Some years ago, Metallica switched over to Fractal Audio’s Axe-Fx modelers. Obviously, this caused a lot of commotion among the online (and offline) guitar community. Going into more details, Chad explained how this switch happened:

“But when we switched to more of a digital setup with the Axe-Fx, and we had to rethink a bunch of stuff, I got a lot more familiar with this stuff.”

As Chad added, it all started with Metallica’s famous trip to Antarctica in 2013, famously known as “Freeze ‘Em All.” He continued:

“Matt Picone [of Fractal Audio] came out and helped us to transition into this stuff because we actually had to go play a show in Antarctica. That’s why we couldn’t bring any amps, all the people at the show that we brought with us on the ship wore headphones, there was an environmental issue too, where you can’t disturb the wildlife.”

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The show took place in a dome with about 120 people in attendance. “We were all set up in there, but we had to figure out how to get all our gear,” said Zaemisch. The tech also explained that the huge amp racks and conventional cabinets weren’t the most logistics-friendly option at that point. And that’s how they decided to go with Axe-Fx units.

Zaemisch then continued:

“We did all seven continents that year — I think we’re in the Guinness Book for that — within a 12-month period. So yeah, that caused us to rethink how we were going to do things.”

Metallica - Freeze 'Em All: Live in Antarctica (FULL CONCERT) [HD]

“And I gotta actually give James a lot of credit because it was a big deal to give up your typical analog amps. We got an old-school band, and it’s all about the loud amps, and James was really like, ‘Do we continue to use these?'”

Reflecting on the benefits of digital modelers, he offered:

“All this stuff is cheaper to ship around, it’s more reliable, and all the rigs now sound exactly the same, rather than analog amps being finicky. It made a lot of sense. I was all for it because anytime I can plug my computer into my equipment and manipulate it.”

“I’m all for it because it was starting to get boring, just taking strings off, putting strings on for bands, and plugging a couple of things in it. You gotta be really creative when doing that. So, once we got into that, then yeah, we started from scratch and built up presets.”

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“Then you move to the next better thing that comes out, improvements and things. So yeah, we’re all pretty well, we help each other, but we do it ourselves just to get good sounds.”

“And it was actually nice because, for me, I went from inheriting what the guitar rig was sounding like and just maintaining it to now being responsible for what it sounds like, having more invested in it.”

So, are digital modelers better? Well, here’s what he had to say about that:

“Is it better? When it sounds good, and people will tell you it sounds good, it’s because of the work you did directly. So yeah, we do it all. And then if there’s a problem, we can help each other. If there’s something new that has to happen, we know exactly where to go in, and fix it, or change it, or how to create the new stuff.”

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During the interview, Chad was also asked whether bands these days use conventional amps more than modelers or whether it’s vice-versa. He replied:

“A lot more modelers. It’s still probably, maybe, 60/40 with 60% being modelers. It’s just so much more economical for the bands. And like I said, repeatability. If you have analog amps, if you have one that overheats, does whatever, you go to the backup and it sounds different.”

As Chad explains, it simply comes down to things being much easier and consistent with digital stuff:

“It’s just the way it is, the way it’s always been, and the way it’s always going to be. So, especially with the advent of everybody wearing in-ears, now that you have the sound right here in your head and if it’s different than what you’re used to, it’s like, ‘Whoa, what happened?’ It’s really difficult to get around that.”

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“Then you send all the audio guys running to change it and fix the sound, and it’s like, ‘Well, it still sounds different, I know its tone.’ So to be able to go to backups, and go to a different rig and do all that stuff, you just take your USB stick, right? And I take all my files, stick it in the other machines, and they sound exactly the same.”

“And it’s a lot less work for the techs, too, because we went from having Big Mick — the front-of-house guy early on — and we would go from festival to festival, from A rig to the B rig, and the speakers would be different, [as] we wouldn’t carry those.”

“And he would always have us chasing sounds and, ‘Ah, turn this up’ and tweaking the amps for half an hour, 45 minutes. And it got to where when we’re using the Axe-Fx, he knew exactly how it was going to sound and what it was supposed to sound like, and what the PA was supposed to do with it and be able to reproduce it. So he started, ‘Hold on, let me fix the PA.'”

Metallica: Live At MetLife Stadium, East Rutherford, NJ - August 6, 2023 (Full Show With HQ Audio)

“So instead of sending us running around in circles tweaking analog stuff, it became like, ‘Hold on, let me fix the PA,’ and then he tweaks how the PA is responding and whatever else, and, ‘Okay, yep, got it sounds great.’ And it’s just so, so much easier.”

Photo: Raph_PH (Metallica – The O2 – Tuesday 24th October 2017 MetallicaO2241017-3 (37955387006) (cropped))

  • David Slavkovic

    David always planned for music to be nothing more than a hobby. However, after a short career as an agricultural engineer he ended up news editor at KillerGuitarRigs, senior editor at, as well as a freelance contributor to online magazines such as GuitaristNextdoor and brands like Sam Ash.

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