Colby Dual Tone Booster 50

Double Versatile
Colby Dual Tone Booster 50


Colby DTB50
Price: $3,800 (head); $750 (cabinet)

From 1978 through 2010, Mitch Colby helped Marshall become a preeminent name in amplifiers. He recently founded Colby Amplification, where he builds amps by hand, one at a time, and his first model, the Dual Tone Booster (dtb), was built in collaboration with Jim Weider, best known as former guitarist of the Band, and a well-known tone expert.

The Dual Tone Booster 50 head and cab is neatly attired in off-white tolex, with a brown panel and matching brown grillecloth. Though technically a two-channel amp, there are a great many more tonal options via the footswitch, which not only changes channels, but accesses two distinctly-voiced boost options. The amp has a bypassable, tube-buffered effects loop (with send- and return-level controls), a back-panel bias pot (with meter jacks), and a variable impedance selector.

Through Channel One, the dtb50’s Bright switch and Shift switch give the player options for thickening lower mids – particularly useful for a single-coil guitar. You’ll also find channel-specific Volume, Treble, Mid and Bass controls. On the top right are the master functions which control both channels in case you prefer to fly without the footswitch. The more-overdriven Channel Two has many of the same controls, and also employs a gain pot, followed by a Master Volume, Bass boost, and two Boost mini toggles.

Playing a vintage maple-board Fender Stratocaster, the amp conjures clean, Robert-Cray-style tones – quacky, but not plinky, with ample squeeze to sustain individual notes while retaining their dynamics. Flipping on the Shift switch reveals a big dose of mid-bottom – great for any single-coil player who happens to be the only guitarist in the band.

The amp’s secret weapon is its incredibly dynamic and sensitive Mid control. Turned down, mids are totally scooped, for that SRV-type sound. As the Mid is turned up, the amp starts to really bark, producing a Stones-like honk reminiscent of Get Yer Ya-Ya’s Out. Turning up the Channel One volume provides additional hair, to the point of rendering a great blues/rock-and-roll rhythm sound with enough sustain for clean lead work. This channel is impressively open- and chimey-sounding.


Channel Two had all the balls needed to play heavy rock; a heavy blues or moderate-rock player could readily utilize this channel – without boost – for both rhythm and lead work, controlling drive/distortion through only the guitar’s Volume knob(s).

A Gibson Les Paul ’59 reissue was just as satisfying; Malcolm-Young-style rhythm crunch can be had through Channel One, where the Bright switch lends a gorgeous bit of shimmer, while Channel Two offers a singing, harmonic distorted tone which again cleans up nicely by rolling down the guitar’s Volume control.

Channel Two’s dual-boost options (controllable by front-panel mini toggles or the LED-equipped footswitch) make this amp tremendously versatile. Boost 1 provides a similar tone with even more gain and compression, giving seemingly infinite sustain to both the Strat and Les Paul. Thick and creamy as the amp is in Boost 1 mode, Boost 2 provides even more low-mid and body, giving the Strat a fullness on par with the Les Paul. Both Boosts generate tones suitable for singing lead work as well as heavy rock or metal rhythms. The tonal flexibility and variety of overdriven tones produced by Channel Two and the boost options virtually eliminates the need for an outboard distortion pedal.

No matter how thick and distorted this amp’s tone – regardless of channel/boost modes – its sensitivity keeps the player in control. Chords of all types ring with substantial bloom, resulting in a round, tubular tone and beautiful, singing notes. Because it sounds great at any volume, the dtb50 makes a great amp for the studio as well as live venues of all sizes (for the really serious, Colby does offer a 100-watt version). The dtb50 offers tonal excellence, versatility, and superior construction.

This article originally appeared in VG February 2013 issue. All copyrights are by the author and Vintage Guitar magazine. Unauthorized replication or use is strictly prohibited.

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