The Demiurge Instruments Atom Fuzz is a fuzz pedal from a small guitar and pedal builder based in the UK. Demiurge describes it as their take on the Fuzz Face, reached by way of another Fuzz Face-inspired pedal, the Suhr Rufus. What sets it apart from a plain three-knob fuzz is the tone shaping: knobs for bass and mids sit alongside the usual level and gain, and two toggle switches add extra brightness and fatness, giving what the builder calls a much wider range of tones1.
Controls
| Control | What it does |
|---|---|
| Bass | Cuts or boosts the low end |
| Mids | Shapes the midrange |
| Level | Sets the output volume |
| Gain | Sets the amount of fuzz |
| Treble toggle | 3-way: left boosts the highs for scooped, Muff-like tones, right tames them, center is flat1 |
| Fat toggle | Two settings, each adding a subtle lower-mid push1 |
The bass and mids knobs are the heart of the pedal's flexibility. On a conventional Fuzz Face-style circuit the tone is largely fixed, so having independent low and mid controls, plus the two toggles on top, changes what the pedal can do in a mix1.
Circuit lineage
The Atom Fuzz sits in the Fuzz Face family, but not directly: Demiurge describes it as a take on the Fuzz Face via the Suhr Rufus, itself a Fuzz Face-inspired pedal1. Aion FX, which offers a DIY project version called the Atom Fuzz Drive, traces the design further back, calling the Atom a direct adaptation of the ETI Fuzztone based on the schematic from an article in ETI (Electronics Today International) magazine2.
Power and bypass
The pedal runs on 9V DC with a negative tip and is PSU only, meaning it takes no battery1. It is true bypass, so the circuit is removed from the signal path when switched off1.
The Atom Fuzz is PSU only: it cannot run on a battery, so plan a 9V DC negative-tip supply spot on your board for it1.
What reviewers said
Delicious Audio's Paolo De Gregorio, profiling the pedal in April 2022, summed up its range this way:
"With everything from classic overdrive to booming, honky, blown speaker sounds on offer"
That range comes from the tone controls doing more work than they would on a standard fuzz: the Treble toggle's scooped position pushes the pedal toward Big Muff territory, while the Fat toggle's lower-mid push moves it the other way1. For more on the wider category, see Fuzz Pedals.
Videos
Pedal Experiments
Questions
What power does the Demiurge Instruments Atom Fuzz need?
The Atom Fuzz runs on a 9V DC negative-tip power supply and is PSU only, so it takes no battery and should not be run from anything with the wrong polarity. Use a standard center-negative 9V supply like those found on most pedalboards.
Is the Atom Fuzz true bypass?
Yes. Delicious Audio lists the Atom Fuzz as true bypass, so when it is switched off your guitar signal passes through without the pedal's circuit loading it.
What does the Treble toggle do on the Atom Fuzz?
The Treble toggle is a three-way switch. The left position boosts the highs for scooped, Muff-like tones, the right position tames the highs, and the center position leaves the treble flat.
What circuit is the Atom Fuzz based on?
Demiurge Instruments describes the Atom Fuzz as their take on the Fuzz Face, reached through another Fuzz Face-inspired pedal, the Suhr Rufus. Aion FX, which sells a DIY adaptation called the Atom Fuzz Drive, traces the design to the ETI Fuzztone, a direct adaptation of the Fuzztone schematic from an ETI magazine article.
What does the Fat toggle do?
The Fat toggle has two settings, both adding a subtle push in the lower mids. It is a simple way to thicken the pedal's voice without touching the bass knob.
Sources (2)
- Demiurge Instruments Atom Fuzz, Delicious Audio, 2022-04-25
- Atom Fuzz Drive / ETI Fuzztone, Aion FX, 2020-11-16
