Keeley Katana

The Keeley Katana is a one-knob boost pedal from Keeley Electronics, built around dual cascaded JFET (junction field-effect transistor) stages running in Class A. Pushed in, the knob works as a plain volume control: it boosts your signal without coloring the tone. Pulled out, it switches the pedal into a second mode that adds gain and saturated, high-gain character, which Keeley describes as "not quite an overdrive"¹²³.

It is a compact pedal, housed in a 4 3/8" x 2 3/8" x 1 1/4" chassis that fits just about anywhere on a pedalboard, with true-bypass switching and Keeley's signature blue LED indicator⁴.

What the Katana does to your sound

With the volume knob pushed in, the Katana is what Pedal of the Day calls a "fat, harmonically rich boost": it raises the level of your signal while leaving the tone alone. One reviewer found that "there are very few boost pedals out there that add less to your tone while still significantly boosting your volume"⁸¹. Vintage Guitar's reviewer, testing it into a Budda Superdrive 45, reported "exceptionally clear, transparent tone" that "parlayed every nuance the Budda offered at greater volume"⁴.

Pull the knob out and the character changes. Guitar World's original review describes the pulled mode as "High Gain mode, giving your tone a little tube grit just this side of overdriven"⁵. Sweetwater's demo puts it more strongly: pulling the knob out "gives you an entire additional palette of saturated high-gain tones"⁶. Either way, the second mode is where the Katana stops being a pure volume control and starts driving the front of your amp harder.

The pedal suits two working styles. You can keep it on all the time to push an amp harder, or use it as an occasional boost to cut through the mix for a solo¹. One Pedal of the Day reviewer ran it at the beginning of his pedal chain as an always-on tone shaping tool⁸.

The push-pull volume knob

The Katana's single control is an oversized "Speed knob" mounted on the side of the enclosure rather than the top, which means you can adjust the level with your foot while playing³⁶. Rolling it forward adds what MusicRadar calls a "fat, harmonically rich boost"³.

The pull-out position does two things at once. It engages the higher-gain mode, and on the Throwback White version it also engages the pedal's voltage doubling, raising the internal supply voltage for increased headroom⁷. The volume pot sits at the output of the circuit, so it can take the level all the way down to nothing⁹.

How much boost does it give?

The reviews disagree on the exact figure, and both are worth knowing. Vintage Guitar's review states the push/pull knob "acts as a level control, giving the user up to 23 db of boost"⁴. Sweetwater's demo describes pulling the knob out as "an instant +30dB boost"², and MusicRadar likewise describes the pull-out position as "the extra +30db mode"³. The 23 dB and +30 dB figures come from different outlets reviewing the pedal at different times.

Power: 9V in, 18V inside

The Katana runs from a nine-volt input, but a charge pump circuit inside doubles that to an 18V internal rail⁵. DIY builders tracing the circuit have confirmed this, measuring 18V at the bias trimmers, and identified the charge pump IC as an ICL7660S⁹. The doubled rail is what gives the JFET stages their headroom, and it is the same "vintage doubler" approach Premier Guitar describes in its builder profile of Robert Keeley, "a circuit with an AC input and a DC output of roughly twice the peak input voltage"¹⁰.

What JFETs are in the Katana?

The original Katana circuit uses 2N5484 JFETs, with the two stages cascaded⁹. The 2N5484 is marked obsolete on the Fairchild product sheet but has been available from surplus sellers; DIY builders have also substituted the 2N5485 and reported it works well⁹. Later versions keep the original recipe: the Throwback White reissue uses "the same JFETs as the original circuits," and Pedal of the Day's 2024 review of the updated version notes it "uses the original JFETs that made the first Katana so special"¹³.

For builders experimenting with substitutes, the DIY community has ranked the options: J201s were found to work but could not bias below about 14 volts, while the 2N5484 remained the favorite, described as sounding "really rich, round and power[ful]" with a sweet spot around 9.5V⁹. The JFET stages are what give the Katana what Keeley's own press materials call their "legendary tube clarity"¹¹.

History: Robert Keeley's first design

The Katana circuit is Robert Keeley's first guitar effect design for Keeley Electronics¹. It did not start out as a Keeley product: it was originally designed for Legendary Tones, appearing as part of the two-channel Time Machine Boost, and only became an independent product under the Keeley name after the Compressor came out¹³⁹.

Keeley had built his reputation before that on modification work. As he told Guitar World, "I could take a popular pedal, say, the [Ibanez] Tube Screamer, and look at the list of complaints about it... Then I'd c[reate mods]" to address issues like more gain and less midrange¹². The Katana was his first original circuit rather than a mod, and Premier Guitar's builder profile calls it "his very first unique design," "a pedal that many players love for both the cleanness of its boost and its harmonic richness"¹⁰.

The pedal has been around for over 20 years, and the 2024 version keeps the same component values while updating the build construction with modern techniques¹. Along the way it has appeared in several finishes:

• Throwback White: a 2021 reissue in a retro white colorway, with period-accurate JFETs and an updated Boost mode, which Guitar World called "the best Katana ever"⁷
• New Light Pink: a custom shop limited edition, sold exclusively through Sweetwater²
• Arlon Prince custom finishes: custom-finish versions offered by Keeley for the Katana among other pedals¹³

A smaller Katana Mini also exists, made with cascading FETs, with the full-sized pedal's Pull Boost mode integrated into the upper ranges of its volume knob¹⁴.

Who uses it

The Stompbox Book's interview with Robert Keeley describes the Katana Clean Boost as "favored by Billy Gibbons"¹⁵. Beyond named players, the pedal has a long following among working guitarists: one Pedal of the Day reviewer used it as an always-on tone shaping tool at the front of his chain⁸, and DIY builders have reported it "works wonders on solid state amps," making one builder's Valvestate clean channel work like a "real" amp⁹.

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