The Keeley Retro Super Germanium Phat Mod is a limited-edition overdrive pedal from Keeley's Custom Shop that layers old-school fuzz tones over an amp-like germanium overdrive. At heart it is the Keeley Phat Mod Germanium overdrive, but the Custom Shop team tinkered with the secondary gain stage so the dynamics are more pronounced, and the result takes the core sound in a fuzzier direction than the pedal it came from12.
Keeley announced it as "a custom shop overdrive that blasts our Super Phat Mod into the stratosphere," describing it as "a fuzz, a drive, and a cranked amp all in one"3. It is discontinued: Guitar Pedal X lists it as a 2019 release, discontinued, at $179 when new4.
What it does: fuzz over a germanium overdrive
The circuit is based on Keeley's germanium amplifier design, which gives it amp-like qualities rather than the pure clipping character of a dedicated fuzz15. Keeley started with the drive from the Super Phat Mod Germanium, then added an additional germanium amplifier gain stage in front of the amp tone-stack3. In practice, that means the pedal can run as a warm, amp-like drive at lower settings and lean into fuzz as the gain comes up. Guitar Pedal X's reviewer put it simply: "It does take the core sound in a slightly more Fuzzy direction - which is really cool!"4
Keeley also pitched it as a team player, saying that any fan of the Phat Mod knows it "performs perfectly in low AND high gain applications"3.
The controls
The layout is deliberately simple: three knobs and one toggle1.
| Control | What it does |
|---|---|
| Level | Sets the output volume1 |
| Tone | Shapes the EQ of the drive1 |
| Nitro | Gain control feeding the germanium stages1 |
| Flat/Phat toggle | Mini toggle; Phat engages an added bass boost, Flat leaves the low end alone12 |
On That Pedal Show, the presenters described the toggle as "flat and fat. Fat is, um, an added bass boost," and Guitar.com likewise reported that the "Phat" switch "gives your bass frequencies an added boost"52.
How it differs from the regular Super Phat Mod
The Keeley Super Phat Mod itself is Keeley's take on a famous mod, which Robert Keeley described as "our famous mod now perfected with amazing sounding JFETs that emulate old tube amps"6. The Germanium Super Phat Mod that followed was hand-built and available from September 201778, and a Germanium Anniversary Edition added a couple of visual changes over the regular one8.
The Retro Super Germanium Phat Mod goes further: it keeps the germanium amplifier stage at its core but adds the extra gain stage in front of the tone-stack, pushing it toward fuzz13. It also stands apart visually. The retro-inspired artwork was created by Phillip Ortiz, applied over a textured, deep blue powder coat using UV LED printing, which Gearnews reported is supposedly pretty hard wearing1. On That Pedal Show, the presenters called it "the coolest graphics possibly ever seen on a pedal"2.
The Retro Super Germanium Phat Mod was sold in limited quantities from launch1, and a 2020 overdrive buying guide already listed it as rare/limited9. It is now discontinued, so it is a used-market pedal.
What reviewers made of it
The main published demo comes from That Pedal Show in October 2018. The presenters found the pedal needed a moment to settle in: "When we first turned it on, I thought, 'Oh god, this is a bit thin.' And then you just find that little sweet spot," after which they described a really lovely overall sound2. They also demonstrated that it cleans up on the guitar's volume control, a behavior they attributed to germanium-equipped circuits2.
Videos
Keeley Electronics
Mike Hermans
Guitar Bonedo
Questions
Is the Keeley Retro Super Germanium Phat Mod discontinued?
Yes. Guitar Pedal X lists it as discontinued, released in 2019 at $179 when new. It was sold in limited quantities from the start, and a 2020 buying guide already described it as rare, so finding one today means the used market.
What does the Phat switch do on the Keeley Phat Mod?
The mini toggle chooses between Flat and Phat. Phat is an added bass boost, giving your low frequencies extra weight, while Flat leaves the low end alone. On That Pedal Show, the presenters described it simply as an added bass boost.
What does the Nitro knob do?
The Nitro knob is the Retro Super Germanium Phat Mod's gain control, sitting alongside Level and Tone in a three-knob layout. It feeds the germanium gain stages, letting you dial from amp-like drive into fuzzier territory.
Who made the artwork on the Retro Super Germanium Phat Mod?
The retro-inspired artwork was created by Phillip Ortiz. It is applied over a textured, deep blue powder coat using UV LED printing, which Gearnews reported is supposedly pretty hard wearing.
Does the Germanium Phat Mod clean up with the guitar volume?
Yes. On That Pedal Show, the presenters demonstrated the pedal cleaning up on the guitar's volume control, a behavior they attributed to germanium-equipped circuits. Roll the volume back and the drive backs off.
How is the Retro edition different from the regular Super Phat Mod?
The Retro edition keeps the germanium Super Phat Mod drive at its core but adds an extra germanium amplifier gain stage in front of the amp tone-stack, pushing the sound in a fuzzier direction. It also carries special retro artwork over a deep blue powder coat.
Sources (9)
- Keeley Retro Super Germanium Phat Mod, gearnews.com, 2018-08-10
- Keeley RS Phat Mod, JHS Unicorn V2, Dano Pride Of Texas, Thorpy Fat General, That Pedal Show, 2018-10-16
- Keeley Launches New Super Germanium Overdrive Pedal, Premier Guitar, 2018-08-09
- Guitar Pedal X, Guitar Pedal X, 2024-01-26
- Keeley launches new germanium fuzz/overdrive stompbox, Guitar.com, 2018-08-10
- Keeley Launches Germanium Super Phat Mod Overdrive, Premier Guitar, 2017-09-07
- Keeley Electronics drops Germanium Super Phat Mod, MusicRadar, 2017-09-20
- Keeley Super Phat Mod Germanium Anniversary Edition, Delicious Audio, 2017-10-04
- Guitar Pedal X, guitarpedalx.com, 2020-11-05
