Secret Behind Guitar Tone on Metallica’s New Album According to Kirk Hammett (Spoiler: It’s Not a Wah)

As the impressions are still settling and while the discussions are still raging online, Kirk Hammett sat down with Total Guitar to discuss his guitar tone on Metallica’s “72 Seasons.” Released on April 14, we got a few early tastes of it, four to be exact, before its release. But overall, the album’s songs have a somewhat common theme and, most importantly, an old-school-oriented guitar tone.

Although the reactions to the tone are mostly positive, there’s also been some criticism aimed at it. Be that as it may, if you love the tone, Kirk revealed what he believes to be the “secret weapon” behind his guitar sound on the album. In fact, he was in disbelief that he shared this secret.

Going into more detail, he said that it was actually a replica of the legendary Schaffer Vega Diversity wireless system. In particular, we’re looking at the SoloDallas Schaffer Replica EX Tower. Kirk explained:

“It’s a type of preamp compression unit. People like Angus Young, David Gilmour, and Eddie Van Halen were able to boost the output on that transmitter, hence Angus’s amazing guitar sound.”

Solodallas EX Tower - Talk&Jam

He added:

“So the Tower is a bit of a secret weapon – I can’t believe I’m telling you about it! It’s a large part of how I got that super-dynamic lead sound. It’s really full-sounding – there’s a lot of mid, but it doesn’t sound harsh or too bold or solid.

“The harmonic distortion is amazing. I hit a note on Greeny and it literally will never quit.” 

To those who may not be familiar with this legendary contraption and its clones, the wireless system in question was developed by Ken Schaffer. Although widely adopted by rock stars, some of the components found their way into NASA for easier astronaut communication but that’s a whole different rabbit hole.

AC/DC talk about their first night with the Schaffer-Vega Diversity System

Anyhow, what also made it popular was that it altered the tone in a very specific way. And somehow, some guitar legends loved it so much that they started using it in the studio.

Going more into how this replica of the legendary wireless system is integrated in his rig, Kirk offered:

“The tone on ’72 Seasons’ is based on my live sound, which is a Fractal Axe-Fx modelled on a blend of my Fortin Meathead amp and my Dual Rectifier.”

“We took that lead sound and tweaked a little EQ, added the Tower and we’re good to go. Maybe there’s a Tube Screamer in there also, because I just love that sound.”

INCREDIBLE! The SoloDallas Guys NAIL the original vibe and sound of Hells Bells!

In an interview with Ultimate Guitar from a few years ago, Ken Schaffer discussed how he came up with Schaffer Vega Diversity System, or “SVDS” for short. Asked about it, he said:

“Around 1975, my girlfriend (Lynne Volkman) became the first female tour manager in the business for bands like the Rolling Stones, the Who, Cat Stevens, James Taylor, Linda Ronstadt, Lynyrd Skynyrd… Not bad for a girl in the mid-seventies. Usually, tour managers (male) would send for their girlfriends to join the tour every weekend. Oops… You figure it out. So, in this case it was me.”

“The 1975 Rolling Stones Tour of the Americas was the first-time commercial greed prevailed and seats were sold behind the stage at most arenas. Mick was given a wireless microphone — of course, the best money could buy at the time — to run behind the stage a couple of times each night to shake his leg for fans stuck in the booneys. And every night was a disaster.”

SoloDallas Schaffer Replica!

“The radio mic sounded horrible, at best, but more often would fade out or pick up police and taxi dispatch calls. So, I’m sitting watching, my jaw agape, thinking, “I can make a better radio than that!’ And I could. So I went back to New York and started to fiddle with circuit boards and ideas…”

“The ‘build a better microphone’ idea soon fell away: instead of building a better mousetrap I decided to focus on doing something new, something no one had ever done — to build a wireless system for guitars. There were more technical challenges to that — it was easier to transmit a voice signal than a guitar’s — so I diverted all my attention to that.”

“Actually, one of the first people to see a wireless guitar working was Gene Simmons. Gene came to the apartment one night and followed me to the roof where there was plenty of space for me to walk around playing my 3 chords. Fact is, Gene kind of missed it… I’m telling him how with this, he could run around the arena, but he didn’t catch on to that.”

Solodallas Schaffer pedals - Angus Young's secret ingredient!

“But he called from backstage in Lakeland, Florida the next Friday night after Ace was electrocuted, asking, ‘Ken, are you still making those wireless guitar things?’ It turned out his take away from his visit to my apartment was not the staging possibilities wireless could create, which he missed, but the value of wireless as an insurance policy — to keep from getting electrocuted! (A secondary benefit, to me, I admit) As Gene explained, ‘We’re not a band, we’re a brand.'”

“So, he ordered a dozen units. Kiss would be rehearsing in an aircraft hangar at Stewart Air Force Base in Westchester — I got to fly the equipment up in my Piper and taxied right under the stage. I wish I had pictures of that!”

“Though Kiss was the first to order SVDS, they weren’t the first to use it. That was Electric Light Orchestra. ELO was rehearsing, not in an aircraft hangar, but in a blimp hanger, north of London. So, I flew some prototype units over there… Because they were the first units ever, I remained in the hangar for almost a week, like in the middle of a cold empty hanger on top of a sleeping bag… If I ever hear ‘Mr. Radio’ again, I’ll go for therapy.”

Photo: Carlos Rodríguez/Andes (Kirk Hammett 2016)


  • 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.