The secrets behind Tony Iommi's classic Black Sabbath guitar tone

Tony Iommi of Black Sabbath
(Image credit: Brill/ullstein bild via Getty Images)

Tony Iommi's "Monkey" 1964 Gibson SG Special is, of course, an integral element of the sound that spearheaded heavy metal on Black Sabbath's pioneering early works - and it's something we've grilled the riff-master about at length.

But no study of Iommi’s seminal early sound would be complete without making mention of his amp and effects setup, which is simple but pivotal to its menacing sonic presence. Simon Fraser-Clark of Laney talks us through the rig that changed the world...

“The original Laney LA100 BL amps Tony was using in 1967 were super-simple: very, very unsophisticated," he reveals. "Single channel, very little gain, with a quartet of EL34s in the power section. You had to dime it all the way across and get everything up to ‘10’. 

"There’s a really weird thing as well: the first amps that were built used Partridge box-frame transformers. And there is this thing that happens when you saturate the output section - there’s a weird undertone that is there. It’s almost sounds like an octave below, but it’s not an octave below. 

"When we were working on recreating those amps, Tony sent me a load of guitar tracks, just solo’d stems from the album - and I thought they were multi-tracked. But he said, ‘No, it’s not multi-tracked,’ so I was listening to just one guitar. 

"But there was this sub-undertone, which as soon as you notice it’s there it becomes really obvious. When you bend it doesn’t track properly - it gives you this weird oscillation that then catches up to the note. It’s kind of like a ghost tone. 

Tony said, ‘Why does yours sound better than mine?’ And the guy said, ‘Well, my brother modified it.’ So Tony said, ‘Well, would he modify mine?’ So he did

“The fact everything had to be turned up loud with those amps was why Tony also used a Dallas Arbiter Rangemaster with them in the front-end, purely to hit that amp harder to make it break up. Before Tony formed Sabbath he was playing in a band up north with another guitar player, who also had a Dallas Arbiter Rangemaster. 

It sounded better than Tony’s. So Tony said, ‘Why does yours sound better than mine?’ And the guy said, ‘Well, my brother modified it.’  So Tony said, ‘Well, would he modify mine?’ So he did. 

"Tony came back, the band broke up, he formed Sabbath. So, an LA100 BL, modified Dallas Rangemaster… that was his sound until in 1982, they employed a new tech who went through Tony’s gear, built him a new pedalboard, everything. Old stuff? Thrown away. 

“Problem was, Tony had never opened the back of the Dallas Arbiter Rangemaster in order to see what the mod was. So no-one knew. So when we built the new LA 100 amps for Tony, he said we’ll need the pedal as well. So we said, ‘What do you mean you’ll need a pedal as well?’ And we said, ‘What do you want?’ And he said, ‘I want one like my old Rangemaster.’ 

"So, again, we bought up some old Rangemasters to try out, but because we didn’t know what the mod was, we had to basically mod something, send it to him and say, ‘Is it that?’ and he’d be like ‘No.’ But we carried on listening and testing until eventually we said, ‘Hang on, how about that?’ and it was like, ‘Yeah, that’s it.’ And he said, ‘All right, I’ll have one.’ And it was sat in his rack. 

"But that was like 18 months of R&D time in a box, so then we thought, ‘We don’t make pedals - let’s make some pedals.’ So that’s where the TI Boost came from, where we were 50 years old so we decided we’d reissue 50 sets of Tommy’s original amp, his original speaker and the original pedal."

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Jamie Dickson

Jamie Dickson is Editor-in-Chief of Guitarist magazine, Britain's best-selling and longest-running monthly for guitar players. He started his career at the Daily Telegraph in London, where his first assignment was interviewing blue-eyed soul legend Robert Palmer, going on to become a full-time author on music, writing for benchmark references such as 1001 Albums You Must Hear Before You Die and Dorling Kindersley's How To Play Guitar Step By Step. He joined Guitarist in 2011 and since then it has been his privilege to interview everyone from B.B. King to St. Vincent for Guitarist's readers, while sharing insights into scores of historic guitars, from Rory Gallagher's '61 Strat to the first Martin D-28 ever made.