The Ace Tone Fuzz Master FM-2 is a Japanese fuzz pedal from the late 1960s, first appearing in around 1967 according to Guitar.com's Josh Gardner, who calls it "a notable early example" of its kind1. It belongs to the same circuit family as the Univox Super-Fuzz: the aggressive two-stage octave fuzz sound that later pedals have kept returning to.
Circuit: a Super-Fuzz variant
The FM-2 sits squarely in the Super-Fuzz lineage. Guitar.com's review states plainly that "the FM-2 is a very similar circuit to the Super-Fuzz"1, and Guitar Pedal X's Stefan Karlsson goes a step further, describing it as "in essence just another re-badged Shin-ei / Univox Super-Fuzz"3. Delicious Audio's Brent P. Gladless frames it the same way: "It's basically a Super Fuzz variant, that same aggressive octave grind, but harder to find and usually crusty with age"2.
The independent circuit analysis at Guitar FX Layouts draws a slightly finer line. In a discussion of the Univox Super Fuzz layout, the site's readers suggest: "Try building the Ace Tone FM-2 - it's a Superfuzz variant - similar in many respects, but not a clone"4. So the honest summary for a player comparing the two: same family, same octave grind, but not an identical circuit.
Controls
The original keeps things simple. As Delicious Audio notes, "The original had a footswitch to toggle between two fixed tone settings"2. There are no knobs to turn: the player chooses between two preset voices with their feet.
Related pedals
Ace Tone also made a successor, the Ace Tone FM-3 Fuzz Master, which carries the Fuzz Master name forward. Modern builders have revisited the Super-Fuzz design the FM-2 belongs to, including EarthQuaker Devices' Fuzz Master General, which reviewers discuss alongside the Ace Tone original123.
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Questions
Is the Ace Tone FM-2 the same as the Univox Super-Fuzz?
Not exactly. Reviewers describe the FM-2 as a very similar circuit to the Super-Fuzz, and Guitar Pedal X calls it in essence another re-badged Shin-ei / Univox Super-Fuzz. The technical analysis site Guitar FX Layouts treats it as a Superfuzz variant, similar in many respects but not a clone, so the two pedals share a circuit family while differing in detail.
When did the Ace Tone Fuzz Master FM-2 come out?
Guitar.com dates the FM-2 to around 1967, which makes it a notably early example of the octave fuzz design it belongs to. Originals are hard to find and, as Delicious Audio puts it, usually crusty with age.
Sources (4)
- Earthquaker Devices Fuzz Master General review, Guitar.com, 2025-09-10
- Earthquaker Devices Fuzz Master General, Delicious Audio, 2026-07-28
- Guitar Pedal X, Guitar Pedal X, 2025-08-07
- Guitar FX Layouts: Univox Super Fuzz, Guitar FX Layouts (tagboardeffects.blogspot.com), 2014-10-20
