How Tony Iommi got his electric guitar tone in Black Sabbath is the stuff of legend. It is the origin stories of origin stories.
There was the brutal machining injury to his fretting hand, requiring the use of thimbles to play again. If Django Reinhardt was an inspiration, the determination to continue came from within. Iommi sized down his electric guitar strings, mixing them with super-light banjo strings to go easier on his fingers. He would arrive at his downtuning epiphany soon enough...
Initially, Iommi played a Fender Strat. He had tracked Wicked World with one before it crapped out and he switched to the SG. Happenstance, a quirk of fate, and lo, Iommi would go on to become one of the most famous SG players.
Like most players, Iommi was an early adopter of Marshall amps. But a local amp builder by the name of Lyndon Laney made him an offer he couldn’t refuse. There began a lifelong collaboration and lifelong friendship until Laney’s passing in April 2026.
“I think I was using Marshall early on, and then Laney on the first album, but when we first wrote [Black Sabbath] songs I was using a Marshall 50-watt,” Iommi told MusicRadar in 2010. “I switched to Laney because they started up around the same time as us and they’re a Birmingham company. To be honest, they offered to give us all this gear when nobody else did. What do you say to that? ‘OK!’ So I used them.”
He had found the Gibson SG. He had found a way of playing that circumvented his injury. He now had the amp. What tied it all together was a piece of kit he was introduced to in 1968, the year before Black Sabbath formed, when he was cutting his teeth in Mythology. A drugs bust over some hashish in their practice space brought fines upon on Mythology. The band soon split.
We have to remember that this was a different time. When you went into a guitar store, there was no pedal cabinet. Okay, you might have been able to pick up a Maestro FZ-1 Fuzz-Tone, but most players faced the similar conundrum; if you wanted distortion, you got it the old-fashioned way, you turned your amp up.
But someone turned Iommi onto a unit that sat on top of your amplifier and worked some magic with it. Enter, the Dallas Rangemaster…
I don’t know what he did to it, but it was really good. I used that treble booster on all the early Sabbath albums
“When I lived in Cumberland, when we did the Mythology thing, there was a guy up there and I used to use his treble booster called a [Dallas] Rangemaster to give my sound a bit more oomph,” recalled Iommi. “A guy from another band up there said, ‘I can make that sound better for you’. So he took it off me and brought it back the next day.”
This was a febrile era for homespun guitar electronics. If something didn’t sound quite right, there was always someone who had a soldering iron, a handful of spare transistors and capacitors, and some ideas on how the circuit could be improved.
In this case, Iommi had the guitarist of Spooky Tooth, Luther Grosvenor, on hand to give him exactly what he needed. It worked gangbusters with his Laney tube amp, and better still, no one had one like it.
“I don’t know what he did to it, but it was really good,” said Iommi. “I used that treble booster on all the early Sabbath albums and put it into the Laney because it boosted the input and gave it the overdrive I was looking for, which amps in the early days didn’t have.”
Other gizmos would enter the picture. In 1970, when he tracked the solo to Paranoid under the watchful eye of producer Rodger Bain, Iommi applied a ring modulator to the solo. Iommi would become a fan of the Tychobrahe Parapedal wah pedal. His touring rig grew, and for the post-reunion Sabbath shows it is monstrous, controlled by a custom Pete Cornish routing and control unit. But this this modded Range Master was the secret sauce to Iommi’s sound.
Not everyone appreciated it. Iommi’s good friend Brian May of Queen also used the Rangemaster, having watched Rory Gallagher use one. He understood its appeal and urged Iommi to stick with it even if other people in the band and crew would complain about its eccentricities. It wasn’t unknown for the Rangemaster to have a Spinal Tap air base moment onstage.
“I used to rely on Brian a lot because I’d constantly have problems with people saying there was too much interference coming through my booster,” said Iommi, speaking to Guitar World in 2024. “I’d have to explain, ‘I know, but that’s part of my sound!’ In them days, you’d pick up bloody taxis and everything. There was no isolation. Brian would back me up and say, ‘That’s the sound – don’t change it.’
“Sometimes you’d get some boffin come along telling me, ‘I can get rid of that for you,’ and I’d say, ‘Oh, can you?’ But it would always change the sound and I didn’t want my sound to change. The only person who understood how I felt in those days was Brian, because he had the same problem. We both had a bit of noise but were ultimately getting the sound we wanted.”
Iommi used that same modded Rangemaster right up into the Heaven And Hell era, when Iommi started experimenting with Marshalls in his rig, with the late John ‘Dawk’ Stillwell working on his amps.
Stillwell famously designed Joey DeMaio of Manowar’s bass guitar, and had worked with Ronnie James Dio in his Elf days before doing jobs for Rainbow and Deep Purple.
Stillwell knew his stuff but made a grave mistake with Iommi’s rig.
In the meantime, while he was building these things, he threw my treble booster away
“I used that treble booster up until 1979 when I had a guy come in to build me some Marshalls,” said Iommi, in his 2010 MusicRadar interview. “They gave me a whole stack of Marshalls and this guy came in and rebuilt them. In the meantime, while he was building these things, he threw my treble booster away. I didn’t know until it came to the time when I was looking for it and he said, ‘Oh that? I threw it away. It was crap.’”
Iommi was devasted.
“I couldn’t believe it,” he said. “I’ve never seen it from that day on and my amps didn’t sound right without it.”
There are no shortage of treble booster clones. In 2001, Analog Man’s Mike Piera sent Iommi the company’s first Beano Boost. Iommi’s signature Laney amps have their own boost section.
But the Rangemaster behind Iommi’s Black Sabbath tone has long been consigned to landfill, and only one man knows the real secret of what went in that Dallas Rangemaster all those years ago…
