The Wattson Classic Electronics EFY-6 is a fuzz pedal with an octave effect, built around the circuit of the Shin-ei FY-6 Super Fuzz, the 1968 pedal whose design Shin-ei today describes as "a reproduction of the original 1968 Shin-ei branded FY-6 Super Fuzz"12. Guitar FX Layouts, in its technical analysis of the pedal, sums it up as "Basically, it's an FY-6 with some extra bells and whistles in a \"pedal board friendly\" enclosure"3. Premier Guitar's review roundup likewise lists it as a "Wattson FY-6 Shin-Ei Super-Fuzz clone"4.
What it does to your sound
The FY-6 Super Fuzz design is known for its pronounced upper-octave overtones, and the EFY-6 keeps that character while letting you shape it. Delicious Audio's buying guide describes Wattson's version as going "more in-depth with knobs to control the tone and how pronounced the upper" octave is2. Guitar FX Layouts' builder, after laying out the circuit, reported that "it sounds like a much fatter superfuzz. the octave pot acts a bit like a mild volume knob"3.
"In between you can adjust for however much chord smashing synthy overtones you want."
The controls
Where the original FY-6 unit is "controlled by the Balance/Expander knobs and the slider switch (Tone 1 & 2)"5, Wattson renamed and expanded the layout:
| Control | What it does |
|---|---|
| Gain | Renamed from the original "Balance" knob; the rename reflects what the control actually does in the circuit3 |
| Fuzz | Renamed from the original "Expander" knob3 |
| Octave | Adjusts the amplitude of half of the cycles coming out of the differential amp. All the way down gives no octave step up; all the way up sounds like an original FY-63 |
| Tone | A cross-fade knob between the mid-scoop filter and the voltage divider that used to be connected to a switch labeled "Tone"3 |
The renames are deliberate: as Guitar FX Layouts puts it, "the \"Balance\" knob has been renamed \"Gain\", as these more clearly describe what these controls do"3.
Transistors and the octave trimmer
A builder report on Guitar FX Layouts, dated April 2017, gives the transistor complement: "Q4-Q5 are 2N3904 matched at HFE 197, the rest are 2N2222"3. The same report places the octave sweet spot about dead center on the trimmer, which is useful reference for anyone servicing or calibrating one.
For comparison, Shin-ei's own current FY-6 units are built with "NOS carbon comp resistors as well as the highest quality original design Matsushita/Panasonic transistors"5, so the EFY-6's 2N3904 and 2N2222 parts are a different, more commonly available choice than the original-design transistors Shin-ei specifies.
Who has used it
Guitar FX Layouts notes that "the guys of SUNN O))) have been known to use this pedal"3, which sits comfortably with the pedal's fat, octave-heavy fuzz character.
Why it is hard to find
The EFY-6 is a rare pedal. Guitar FX Layouts reports that "while they were around they made very few of these"3. Wattson Classic Electronics is no longer making them, so the pedal surfaces mainly on the used market, and players looking for the same territory today often compare it with Shin-ei's own current FY-6 reissues3.
Videos
Prymaxe
Peter Taylor
joeakajoe1
Questions
What is the Wattson Classic Electronics EFY-6 based on?
The EFY-6 is based on the Shin-ei FY-6 Super Fuzz, the 1968 octave fuzz. Guitar FX Layouts describes it as basically an FY-6 with extra features in a pedalboard-friendly enclosure, and Delicious Audio calls it Wattson's boutique take on the Super Fuzz, with added knobs for tone and the level of the upper octave.
What does the Octave knob do on the EFY-6?
According to Guitar FX Layouts, the Octave knob adjusts the amplitude of half of the cycles coming out of the differential amp. Turned all the way down there is no octave step up at all; turned all the way up the pedal sounds like an original FY-6. In between you can dial in as much of the chord-smashing, synth-like overtone as you want.
Which transistors does the EFY-6 use?
A builder report on Guitar FX Layouts says Q4 and Q5 are 2N3904 transistors matched at HFE 197, and the rest of the circuit uses 2N2222 transistors. The same report places the octave sweet spot about dead centre on the trimmer.
Did SUNN O))) use the EFY-6?
Guitar FX Layouts notes that the guys of SUNN O))) have been known to use this pedal, which fits the pedal's fat, octave-heavy fuzz character.
Why is the EFY-6 hard to find?
Guitar FX Layouts reports that while Wattson Classic Electronics was around, the maker produced very few of these pedals. Combined with the maker no longer being active, that small production run is why the EFY-6 turns up rarely on the used market.
Sources (5)
- Shin-ei Honey V8 8ctavarius, shin-ei.com
- 20 Of The Best Super Fuzz Clones And Evolutions In 2023, Delicious Audio, 2022-10-11
- Guitar FX Layouts: Wattson Classic Electrons EFY-6, Guitar FX Layouts (tagboardeffects.blogspot.com), 2016-11-27
- The Fuzz Boxes That Fuel PG Staff’s Meanest Musical Moments, Premier Guitar, 2025-05-12
- Astron FY-6 Super Fuzz, shin-ei.com
