Let's Talk Hot Coals and Rangemasters


The Dallas Rangemaster Treble Booster has been used by the great and good of rock: Jimmy Page, Ritchie Blackmore, Rory Gallagher, Tony Iommi, Marc Bolan, Brian May...rumour even has it that Eric Clapton used one on several tracks of John Mayall's Bluesbreakers With Eric Clapton - or the "Beano" album.

Dallas Rangemaster Treble Booster

The original Dallas Rangemaster Treble Booster was a simple amp-top box

Released in 1966, the Treble Booster was effectively a germanium-based pre-amp in a simple box that would sit on top of your amp. Consisting of one germanium transistor (typically a Mullard OC44 or NTK275), three resistors and four capacitors, it sums up the simplicity of the era's guitar equipment, but the sound it was capable of producing...well, let's just say it made more than one guitar legend!

The idea behind the Rangemaster was to bring upper-frequency clarity to typical British amps of the day, which tended to be on the darker side. The "growl" of the pushed germanium transistor running into the first tube in an amp's pre-amp section not only adds grit and texture to the final sound, but it provides the amp with an EQ'd sound and light compression. 

The germanium transistor asymmetrically clips the signal in a relatively smooth way, which the amp's pre-amp valve then builds on by clipping the peaks on the other side of the waveform. The result is a smooth, compressed signal which works wonders when the volume is then turned up.

Read: What Are Clipping Diodes?

Treble Booster?

Interestingly, the name is a bit of a misnomer - it's not just a case of simply boosting the treble frequencies. Instead, the upper-mid and lower-treble range "feed" the pedal and dictate how much boost it produces: the more high-end signal, the more dBs of gain. There is also no cutting of the bass frequencies as you find in something like a Tubescreamer. 

The result is an extremely responsive tone with plenty of texture, zing and girth - a perfect match for an overdriving Marshall!

Introducing the Hot Coals

You can buy an original Dallas Rangemaster today for around £2,000, which us great if you want to collect a piece of history, but if you're chasing the tone itself then I strongly recommend giving the Tate FX Hot Coals a place on your pedalboard.

Since I started stocking the Tate FX Hot Coals, it's become difficult to unplug this pedal from my setup. Based on the Dallas Rangemaster, it brings just what I want to my sound: plenty of cutting mid-range and high-end clarity. It's difficult to express in words the grin this simple one-knob pedal puts on my face!

Stuart Tate of Tate FX explained to me how he uses the best components he can find: "The Hot Coals uses NOS UK military-spec germanium transistors with NOS Soviet-era Russian germanium diodes for temperature stabilisation. It's based on the classic Dallas Rangemaster Treble Booster. The switch toggles between the classic treble frequency boost and a fuller frequency boost."

So grab yourself a Marshall (other amps are available...), a Tate FX Hot Coals, your favourite guitar and 30 minutes to yourself and see if you can unplug this pedal afterwards. Our bet is that you can't!