Keeley Electronics Super Phat Mod

  • By Eric Tischler @tonereport
  • January 14, 2017

Robert Keeley made his name modding pedals, and one of his most beloved upgrades was to the Boss Blues Driver.  Keeley’s “phat” mod added some low end to the mostly full-range Blues Driver and, despite the Boss pedal’s reputation as a “transparent” overdrive, the restored beef was deemed a welcome addition. The Super Phat Mod is Keeley’s in-house take on the Blues Driver; it follows the original pedal’s topology but, notably, upgrades some of the components.  Interestingly, the result is somewhat similar to Keeley’s Oxblood: he’s turned a supposedly transparent low-gain fave into an addictive rock monster.

The Super Phat Mod has controls for Level, Tone and Drive, and a toggle switch for “Flat” or “Phat.”  The Tone control is a little more nasal than the Blues Driver’s, but the difference, while discernible, is small.  As you turn it clockwise, the Tone control adds some very aggressive upper mids, and accentuates the low end as you turn it counter clockwise.  The Phat setting suggests Flat is misnamed; to my ears, Phat added back low end that was otherwise cut in Flat, and the Super Phat Mod’s bass cut in Flat mode is a little more noticeable than the Blues Driver’s.

Using a low-output Tele, I started in Phat mode, rolled the Tone control back a hair and heard my basic clean tone with just a hint of dirt. Advancing Drive to 9:00 and moving Tone to noon gave me a very hairy overdrive with attitude—think The Replacements.  With Drive at 2:00 and Tone rolled back to approximately 11:00 I was into early Aerosmith territory—past that, the low end was a little too woofy.

I rolled Drive back to 1:00 and discovered a Tweed-y snarl with an Ampeg-y roundness, and concluded that, in addition to restoring low end, Phat adds compression and pushes the signal more. It’s really most useful at low-gain settings, when the Drive isn’t working hard, or for lending weight to single notes. Drive compresses the signal, accentuating the upper mids but also bringing out attack in the low end, ultimately adding both cut and more muscle.

As I turned to plug in a variety of humbuckers and more powerful single coils, I switched the Super Phat to Flat mode. With the higher output pickups, the Super Phat Mod sounded wiry rather than weedy. As I eased Drive up to noon, I became more and more enamored of the pedal’s distortion and, by the time I had Volume, Tone and Drive at 12:30 I couldn’t turn back. The roar was intoxicating. And kinda British. The nasal attack of the Blues Driver’s tone stack was now a brash, Vox-y clarion call. The slightly anemic character of the Flat mode became the lean, compressed attack of a JCM800 but with a more powerful push that was HiWatt-y in its authority. I couldn’t stop playing power chords. My arm would hover—mid-windmill—as I’d wait for the notes to slowly resolve, each one audible within the halo of harmonics.  Interestingly, this setting was equally fulfilling in both bridge and neck positions.

On his site, Keeley talks about looking for chips that provided the right “grain” for this pedal’s drive character, and I totally get it.  While the voicing itself manages the enviable trick of being both focused and powerful, the character of the overdrive is so lively and complex that it was genuinely thrilling to me—it popped out of my speakers and lingered in the room.  Forget internal charge pumps, forget germanium diodes: the Super Phat Mod has your new secret sauce and, apparently, its Toshiba FETs. Robert, I hope you had the good sense to goop ’em!

What We Like: Thrilling, amp-like distortion that manages to suggest unruly rock ‘n’ roll while maintaining articulation and responding to picking dynamics.

Concerns: Truly “transparent” voicings at lower-gain settings were a little dull to my ears, but the solution was simple: I turned the Super Phat Mod up.

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  1. Matthew

    Hey guys, is this better than the Keeley Oxblood? The only review I could find was this I actually commented on one of your klone shooutouts asking for feedback about this pedal. But in terms of overdrive transparency, is the Super Phat Mod better? Looking forward to what you have to say, thanks!

  2. Eric T

    Hi Matthew,

    I like both pedals for higher gain applications. The Oxblood’s midrange is more focused—almost cocked wah-y. I talk about it in my review of the Keeley Tone Workstation. -E