Review: One Control's BJF-S66 offers amazing portability with the tone, volume output and features of amps many times its size

(Image credit: One Control)

The compact guitar amplifier market has become very interesting in recent years with the rapid proliferation of small lunch box heads and versatile desktop combos. While One Control’s new BJF-S66 certainly also qualifies as a compact amp, it’s quite different than a lunch box amp (which often has somewhat low output power and limited controls) and a desktop amp (which is usually a do-it-all product with a variety of tones and effects geared more for home and studio applications). 

Instead, the BJFS66’s 'genuine big amp in a micro-sized package' design places it in a class by itself. Small enough to fit into a gig bag or carry-on luggage and powerful and versatile enough to gig with, the BJF-S66 is perfect for guitarists seeking the ultimate in portability without making any compromises.


According to One Control, designer Björn Juhl’s main inspiration for the BJF-S66 was the tone of Sixties blackface amps, known for their stellar clean and crunchy overdrive tones, pristine reverb and trippy tremolo effects. The BJF is no mere clone, however, providing individual rhythm and lead channels each with separate reverb, decay and level controls for truly independent reverb effects, a lead channel boost control, an effects loop and a ¼-inch preamp output. 

There is also a compact three-switch footswitch controller (sold separately or included as an amp/footswitch bundle) for engaging channel switching, tremolo on/off and FX loop on/off functions, or users can connect separate individual footswitches to the channel, tremolo and FX loop jacks. 

The lead and rhythm channels share the same set of treble, bass and mid EQ controls as well as a gain knob, but each channel has its own master volume control. Like a classic blackface combo, the amp also features a bright switch, while the tremolo effect provides depth and speed controls.

The BJF-S66 combines a discrete solid-state preamp with an all-analog signal path and an extremely efficient Class D power amp design. Output power depends on the ohm rating of the connected speaker cabinet, delivering a maximum output of 100 watts with a 4-ohm cabinet and a minimum of 30 watts with a 16-ohm cabinet.


Tube purists may balk at the BJF-S66’s solid-state design, but anyone with good ears and an open mind will discover that this amp sounds uncannily like a blackface amp and much more. As one might expect for a solid-state amp, the clean headroom is impressive, but the overdrive tones also deliver harmonically rich crunch, expressive touch-sensitive dynamics and impressive body and definition. 

The BJFS66’s EQ controls provide a wider range of tonal colors than a blackface amp, with peak frequencies at 70Hz (bass), 450Hz (mid) and 2kHz (treble) while the bright switch boosts 4kHz by 10dB. As a result, the amp can deliver bigger bass, fatter mids and more sparkling treble without flab, mud or shrillness.

The BJF-S66 provides a moderate amount of overdrive crunch that’s ideal for classic/roots rock, blues and country. Pedals are essential for guitarists who need heavier distortion or prefer compressed high-gain lead tones, but fortunately the amp is the perfect platform for a pedal-based rig. 

I got some of the best tones I’ve ever heard from my B.K. Butler Tube Driver and MXR Super Badass Distortion pedals, with an extra layer of clarity I’ve never gotten from a tube amp. The BJF-S66’s built-in reverb and tremolo effects are also first class, so it can save some space on your pedalboard that would be taken up by those effects.

Other than its incredibly small size and light weight, the BJF-S66 is truly a big amp with pro features. For maximum volume output you’ll want to use a 4-ohm 4x12 cabinet, but I found a 16-ohm 1x12 more than loud enough for a club gig.

STREET PRICE: $599 ($699 bundle w/footswitch); footswitch (separately), $119

• Individual rhythm and lead channels provide a wide variety of classic blackface amp tones, from sparkling clean to rich, raunchy overdrive.

• Each channel has individual reverb, decay and level controls to provide truly independent reverb effects.

THE BOTTOM LINE: Offering the ultimate small amp portability along with big amp tone, volume output and features, the One Control BJF-S66 is the perfect solution for guitarists looking to minimize their performance rigs to the smallest size.

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Chris Gill

Chris is the co-author of Eruption - Conversations with Eddie Van Halen. He is a 40-year music industry veteran who started at Boardwalk Entertainment (Joan Jett, Night Ranger) and Roland US before becoming a guitar journalist in 1991. He has interviewed more than 600 artists, written more than 1,400 product reviews and contributed to Jeff Beck’s Beck 01: Hot Rods and Rock & Roll and Eric Clapton’s Six String Stories.