BJF Custom Trebler Booster

BJFe Custom Treble Booster

Not more treble. The right treble.

The BJFe Custom Treble Booster combines two classic Björn Juhl ideas in one uniquely flexible pedal: the upper-frequency magic of the Little Red Trebler and the boost circuit of the Red Rooster Booster, here expanded with Master Volume and a specially designed 2-band EQ.

The result is much more than a conventional treble booster. It is a highly tunable analogue front end designed to control how the guitar interacts with an amplifier, overdrive circuit, modeler or digital system.

As with many BJF designs, the concept starts with the player rather than the circuit: what does the guitar actually need in order to feel clearer, more responsive and easier to play?

Little Red Trebler – “Angelic Treble”

The Treble Booster side is based on Björn Juhl’s Little Red Trebler and features a single Amount control.

Its purpose is to add what Björn describes as “angelic treble” – the airy, musical sense of brilliance at the very top of a great guitar sound.

The idea is not simply to add more treble. In fact, Björn’s thinking starts from the opposite direction: which upper frequencies actually make a guitar sound better, and which ones merely make it sound harsh, unnatural or fatiguing?

A traditional electric guitar rig is naturally bandwidth-limited. Guitar speakers, amplifiers and classic recording chains do not reproduce every frequency equally, and those limitations are an important part of the sound we associate with electric guitar.

The Little Red Trebler concept is about finding the useful part of the upper-frequency information – adding sparkle, air and definition that helps notes come alive without simply making the entire sound brighter or sharper.

Turn up the Amount control and you can introduce anything from a subtle sense of air and articulation to a much more obvious treble-booster character.

Red Rooster Booster – Expanded

The other side of the pedal is based on the Red Rooster Booster, but this custom version adds considerably more control with Gain, Master Volume and a 2-band EQ.

The important part is that this is not a conventional bass and treble EQ. The controls have been designed around where they sit in the signal path and what is musically useful when boosting a guitar.

Bass – Before the Boost

The Bass control sits before the boost stage.

This is important because excessive low-frequency energy entering an overdriven circuit can quickly make chords and individual notes lose definition. Low guitar frequencies generate harmonics extending into the midrange, and when too much low end is pushed into distortion those harmonics can begin to obscure the information already present there.

Rather than using an aggressive bass cut, BJF employs an unusually gentle passive filter. The idea is not to make the guitar thin – it is to find the exact point where the low end remains powerful but stops getting in the way.

This means the Bass control can make surprisingly subtle adjustments. For example, if the low E string feels disproportionately powerful compared with the rest of the guitar, the control can be used to bring it into better balance without radically changing the overall character of the instrument.

When pushing an amplifier, you can also trim just enough bass before the boost to make the resulting overdrive tighter, clearer and more articulate.

Gain & Master Volume

The Gain control determines how hard the Red Rooster-based boost circuit is driven.

At lower settings it can provide a natural enhancement in level, response and playing feel. Turn it up and the circuit can push the following amplifier or pedal harder, adding harmonic content and making the guitar feel more immediate under the fingers.

The addition of a dedicated Master Volume gives you independent control over the final output level.

This means gain and output no longer have to be the same thing. You can drive the booster harder for its tonal character while controlling the level sent to the next device, or use it as a powerful clean boost when required.

Treble – After the Boost

The Treble control sits after the boost stage and, again, it does not behave like a conventional tone control.

It uses a deliberately gentle shelving filter. With the control fully open, it is essentially out of the way. As you turn it back, it creates a subtle step between the upper midrange and treble rather than simply rolling off everything above a fixed frequency.

This lets you remove just enough upper-frequency energy to tame an amplifier that is already bright, smooth the edge from a heavily boosted signal, or shave away unwanted harshness while preserving articulation.

The filter is intentionally gentle. Dramatic filters can create equally dramatic changes in both frequency and phase response. BJF’s approach is to use the smallest amount of filtering necessary to achieve the musical result.

A Treble Booster You Can Tune

Put all of this together and the BJFe Custom Treble Booster can be configured to behave remarkably like a classic treble booster – but without forcing you to accept all of the compromises of a fixed traditional circuit.

You can trim the bass before the boost, decide how hard the boost is driven, set the final output level, carefully shape the treble after the boost, and then introduce the “angelic treble” of the Little Red Trebler exactly where you want it.

Want the attack and urgency of a classic treble booster into an already cooking amplifier? It can do that.

Want a fuller boost with just enough bass removed to keep the amplifier from becoming loose? It can do that too.

Or use the controls more subtly and the pedal becomes something entirely different: a precision tool for balancing the guitar before it reaches the rest of your rig.

Especially Useful Before Digital Gear

This philosophy becomes particularly interesting in front of modern digital modelers, effects processors and audio interfaces.

Digital equipment can accommodate and reproduce an extremely wide frequency and dynamic range. But maximum bandwidth is not necessarily the same thing as the most musical electric-guitar sound.

A traditional guitar amplifier and speaker naturally shape the signal. They limit bandwidth, alter dynamics and remove information that we often do not even realise we do not want – until we hear the guitar through a much wider-bandwidth system.

Placed before a digital device, the BJFe Custom Treble Booster can therefore function as a sophisticated analogue front end.

The Bass control can prevent unnecessary low-frequency energy from dominating the input. Gain determines how the signal responds and how hard the circuit is driven. Master Volume establishes the appropriate output level. Treble can tame unwanted upper-frequency content, while the Little Red Trebler section introduces the musical brilliance and articulation you actually want.

Instead of trying to repair the guitar sound with EQ after conversion, you can shape the behaviour of the signal before it enters the digital domain.

Designed From the Outside In

Perhaps the most interesting thing about the BJFe Custom Treble Booster is the philosophy behind it.

Many circuits begin with familiar electronic building blocks: add a bass control, add a treble control, choose familiar filter networks and then determine their ranges.

Björn Juhl approaches the problem differently.

What should happen when the guitarist turns this control?

What part of the signal actually causes the problem?

Where in the circuit should that adjustment happen?

And how much adjustment is actually musically useful?

Only then is the electronic solution designed.

That is why some of the controls on this pedal may initially seem subtle. They are not intended to create spectacular EQ curves on a graph. They are intended to let you find the point where the guitar suddenly feels balanced, defined and right.

Sometimes the difference between an inspiring guitar sound and one that feels slightly wrong is much smaller than we think.

Not More Treble. The Right Treble.

The BJFe Custom Treble Booster brings together the Little Red Trebler and Red Rooster Booster concepts and takes them considerably further.

It can be a classic-style treble booster. It can be a powerful analogue boost. It can tighten an amplifier before distortion, smooth an overly bright rig, balance the response of the guitar, or act as an analogue front end before a modern digital system.

Most importantly, every control has been placed and voiced according to what it actually does when you play guitar.

Little Red Trebler sparkle. Red Rooster boost. Master Volume. Precision 2-band EQ. One uniquely flexible BJF custom design.