The Runoffgroove Buzz Box is a DIY octave-up fuzz, a circuit that pushes your guitar an octave above what you play while adding heavy fuzz distortion. It was designed by Christian at Runoffgroove and is built from two Bazz Fuss circuits in series, with the second stage using a germanium diode for clipping rather than the usual silicon1. Because it is a homebrew design rather than a commercial pedal, the way most players meet it is through the published stripboard layout and the build reports of people who have put one together.
What it does to your sound
Guitar FX Layouts describes the circuit as producing "a nasty (in a good way), explosive octave-up fuzz similar to the Scrambler and Green Ringer"1. The octave character is not from a dedicated octave circuit: layout author IvIark suggested "the octave is probably an artifact of two high gain circuits in series" and that the strength of the effect may be more luck than judgement1.
Builders' reports vary in a way worth knowing before you build:
- Travis found "not a lot of octave on single notes but it has some nasty octavey overtones on chords. Works great!"1
- Piltdown Man got "a super compressed snarling speaker punisher" but no octave1
- mirosol reported "Works and sounds really mean" and liked the way the diodes un-gate1
- Rodrigo Toscano found it "sounded better with 2n5089 but I didn't get to much sustain"1
One tweak that builders found brings the octave forward: "lowering the middle cap (to, 10-47 nF) and rolling off guitars tone knob really makes the octaving effect jump out"1.
Building one
The vero layout was posted on Guitar FX Layouts on 4 September 2012, with circuit information from Runoffgroove1. IvIark later revised the layout to put the 9V row on the bottom, which made it easier to add a filter cap and saved a column, with everything else the same1. For wiring the volume pot, the layout gives: "Output to Volume 3, Volume 2 to output, Volume 1 to ground"1.
On transistors, a commenter suggested trying MPSA18 instead of 2N5089: "Those have higher gain range, and aren't as prone to premature gating as 2N5089s are"1.
On diodes, the second stage normally uses a germanium diode where a standard Bazz Fuss uses silicon, and a builder confirmed schottky types work in its place: "Used LED as D1 and BAT41 as D2 - can confirm schottkys can replace Ge diodes in this circuit"1.
Related circuits
A commenter on the layout page noted the Scumtone green fuzz is a clone of this circuit, with 15u tantalum capacitors and the germanium diode swapped for two 4148 diodes in parallel1. The Bazz Fuss design itself also appears elsewhere; the Guyatone Buzz Box, a commercial pedal, has been described on a JHS Pedals video as "kind of like a tone bender 1.5"2. If you are exploring octave effects more broadly, see Octave & Pitch Pedals.
Videos
Speebtone Pedals
Questions
What does the Runoffgroove Buzz Box sound like?
Guitar FX Layouts describes it as a nasty, in a good way, explosive octave-up fuzz, similar in character to the Scrambler and Green Ringer. Builders who put one together report that single notes get some octave effect while chords produce strong octavey overtones, and one builder described the result as a super compressed snarling speaker punisher. The octave effect comes from two high gain circuits in series rather than a dedicated octave stage.
Can schottky diodes replace germanium diodes in the Buzz Box?
Yes. A builder on Guitar FX Layouts confirmed that schottky diodes can replace germanium diodes in this circuit, using an LED as D1 and a BAT41 as D2. The circuit's second Bazz Fuss stage normally uses a germanium diode where the usual Bazz Fuss design uses silicon, so the diode choice is a natural place to experiment.
Is there a vero or stripboard layout for the Buzz Box?
Yes. Guitar FX Layouts published a vero (stripboard) and tagboard layout for the Buzz Box in September 2012. The layout was later revised to put the 9V row on the bottom, which made it easier to add a filter cap and saved a column, with everything else unchanged.
Is the Buzz Box the same as the Scumtone green fuzz?
Not the same, but closely related. A commenter on the Guitar FX Layouts page noted that the Scumtone is a clone of this circuit, with 15u tantalum capacitors and the germanium diode swapped for two 4148 diodes in parallel. So the Scumtone green fuzz is built on the Buzz Box design with component changes.
Sources (2)
- Guitar FX Layouts: Runoffgroove Buzz Box, Guitar FX Layouts (tagboardeffects.blogspot.com), 2021-02-07
- TNB: Big Muff, Elk Fuzz, Gretsch ContoFuzz, DOD Grunge, Guyatone, Super Fuzz, Ibanez Standard Fuzz, JHS Pedals (YouTube), 2022-02-04
