Rangemaster Treble Booster

The box was a Dallas Rangemaster, and it was made to fix a very English problem. British players in the ’60s ran Vox AC30s and Marshalls, and those amps could go dark and muddy when you pushed them. The high end got lost.

Roger Mayer, who built boosters of his own, explained the fix. Those amps weren’t very detailed, he said, and “one of the secrets of getting a good guitar sound is to use equalisation before the signal hits the front-end of the amplifier. And it’s about how hard you push the first tube.”

Dallas, a London instrument firm, made the Rangemaster around 1965 or 1966. The sources don’t agree on the year, nobody knows who designed it, and nobody knows how many were built. It was a plain, folded-metal box painted battleship grey, with musical notes climbing up it. It wasn’t really a pedal. It sat on top of the amp, you flicked it on by hand, and a cable came straight out the back into the amp’s input.

Inside, there’s hardly anything: one germanium transistor, usually a Mullard OC44, a few resistors and capacitors, a Boost Set knob, a switch and a battery. That’s it.

The name is a little off. A small input capacitor decides what gets boosted, and what it lets through is mostly upper mids and lower treble. One pedal designer, Adrian Thorpe, says it should really be called a “frequency dependent booster.”

The magic is in what happens next. The old transistor starts to growl and clip when you hit the strings hard, and then the amp’s first valve clips too. The pedal designer Dan Coggins describes it as two kinds of distortion stacked up: “from the Rangemaster on one lot of peaks and then from the valve on the other lot of peaks.” That’s where the singing comes from.

Gallagher found his Rangemaster in about ’67, his nephew Daniel says, and ran it into the Normal channel of the Vox with his Stratocaster. From ’68, with the second line-up of Taste, “that’s when you really hear that combination.” He’d run the amp all the way up and work the volume from the guitar. “And the booster really made it scream.”

He stuck with that sound through his first two solo records and Live in Europe in 1972. When he added a Fender Twin around 1973, the Rangemaster stayed where it was. “The Rangemaster belonged to the Vox,” Daniel says. “You don’t see him putting it into any of the Fenders.”

Up in Cumberland, Tony Iommi borrowed one to give his sound more oomph, and a man from another band offered to make it better. “He took it off me and brought it back the next day. I don’t know what he did to it, but it was really good.” Iommi ran the modified box into a Laney. “I used that treble booster on all the early Sabbath albums.” Put on “Iron Man” and that’s the sound. It was noisy enough that Black Sabbath cancelled some gigs, because he couldn’t get his sound without it.

May recorded Queen’s first album, from June to November 1972, with the Red Special plugged into a secondhand Rangemaster plugged into an AC30. Then, sometime in 1973, a roadie left the box behind at a gig. His explanation, as May tells it: “oh I didn’t think it did very much.” Everything May played afterwards went through other boosters.

Iommi kept his longer. In 1979, by his count, a tech came in to build him some new Marshalls. Others put it at 1982. Either way, the treble booster disappeared. “He said, ‘Oh that? I threw it away. It was crap.’ I couldn’t believe it.”

The two of them understood each other. “The only person who understood how I felt in those days was Brian,” Iommi said, “because he had the same problem. We both had a bit of noise but were ultimately getting the sound we wanted.”

Gallagher’s box didn’t get lost. In February 2025, before a show at the Beacon Theatre in New York, his nephew Daniel, with his father Donal’s blessing, gave Joe Bonamassa Rory’s number one Rangemaster. It was still in fine working order.

Bonamassa’s verdict: “We plugged it in and it turned that tweed Vibrolux into Irish Tour 74.”

Fifty-odd years after a kid stayed behind at the Marquee to ask a question, the answer was still being handed on: an amp, turned up, and this little box.