Fuzzboxes you can make
A vintage circuit that would give you a tone like Jimi Hendrix and
Jorma Kaukonen: What would you pay for such a circuit? $200? $300? $1,000?
Now you can build this circuit yourself. Use common, but top-quality parts, and pay $100
or less. The "or less" depends solely on your junkbox and your skill.
Real McCoy. Analog fuzz sounds different because it is different.
When you want an analog effect, don't make do with a digital fake. Go with a real
fuzzbox: Then you're back to simple construction and sweet sound.
But the cost! Not to worry. The price can be much less than the cost of a
factory unit or even a kit.
Benefits. This version of the Dallas Arbiter fuzzbox offers many advantages over other
versions. Modern, silicon transistors make the unit more reliable than the original
germanium devices. The parts are easy to find, and we help with sources. Our Troubleshooting & Mods page helps you to adjust the tone
to your need. The effect circuit fits onto a little piece of perfboard. We explain perfboard
construction, because it differs from other methods. Why perfboard? Because it's inexpensive. Because
it's the best way to achieve an effect that's both reliable and serviceable. Consider these perfboard
- Only perfboard projects can adapt to many shapes of devices, such as axial and radial-mount
- Only perfboard projects allow for frequent mods without the risk of damaging foils.
- Only perfboard projects involve you in the circuit design. Building this perfboard project helps
you to build and understand other projects. As you build, you're not just assembling. You're
thinking about relationships between parts.
I built this fuzzbox for my nephew Jonathan who had then just joined a garage band.
(His brother Jason was the drummer.)
NPN swap & input resistor. My circuit uses NPN transistors instead of the PNP devices
in the original Fuzz Face. The NPN swap is an easy and worthwhile change to make.
More general-purpose NPN devices than PNP devices will work in this circuit. Besides,
most people relate better to NPN operation than to PNP operation. There's no big secret to
the conversion. You flip the battery and then you reverse all other polarized devices.
Done. I've also added one resistor to the classic design. The one-megohm
pulldown resistor at the base of transistor Q1 reduces noise.
Depend on silicon. The transistors are silicon. I've heard that "silicon
transistors have too much gain for this circuit." This statement is illogical. Thousands
of different silicon devices exist. Among them are low-gain parts. Besides, the device
doesn't necessarily determine gain. The circuit has a great effect on gain. Later, I'll
explain more about the circuit.
To avoid gain problems, I hand-picked two
transistors from my stock of old devices. (These devices come from Dayton Hamvention. My old stock consists of
mostly "pull-outs" from old equipment.) According to my homemade beta meter, the
transistors that I chose had gains around 100. The original germanium devices had these
gains: Q1, 70. Q2, 120. On gain, I'd say that I'm in the ballpark.
You can use many general-purpose, small signal transistor types: 2N2222A, PN2222A, 2N3904, 2N4401,
2N5089, BC108, BC109C or many others. Though these transistors have gains of around 200, circuit adjustments can tame the angry silicon beasts. When I last
checked, you could buy several fuzzbox-compatible transistors at
Just a few compatible transistors
MPSA06 (Gain of about 100.)
Price is right! 34¢ each, including shipping (in 11-2015)
2N2222A, PN2222A, PN3846, 2N3904, 2N4124, 2N4400, 2N5772, MPS3704, MPSA20
(Gain of about 200)
10 to 20¢ each
||Battery, 9-volt, alkaline or long-life transistor type
||Capacitor, 2.2 μF, electrolytic
||Capacitor, 20 μF, electrolytic
||Capacitor, 0.1 μF, poly film
||Jack, input, stereo 1/4-inch phone
||Jack, output, mono 1/4-inch phone
||NPN, small-signal transistor: 2N2222A, 2N3904, PN2222A,
2N4401, etc. or hand-picked device
||Resistor, 1M, 1/4-watt, 5%*
||Resistor, 33K, 1/4-watt, 5%*
||Resistor, 330Ω, 1/4-watt, 5%*
||Resistor, 100K, 1/4-watt, 5%*
||Resistor, 8.2K, 1/4-watt, 5%*
||Switch, DPDT, toggle pushbutton (Carling®;
||Pot, "Fuzz," 1K, miniature, linear taper
||Pot, "Volume," 500K, miniature, audio taper
||Case, cast aluminum. Knobs, small, set-screw type; for quarter-inch pots. Paint.
Decal, printable. Wire, stranded hookup type.
Wire, solid bus
Studs, perfboard type. Hardware, 6-32.
Clamp, metal battery.
Pen, lacquer marker.
*RESISTOR TYPE. For the "original sound," use carbon composition or carbon film
resistors. For low-noise applications, use metal-film resistors.