4
Overview
The Woodstork is a PNP Fuzz Face with the Fulltone® ’69™ mods incorporated. It also includes a charge pump to invert
the supply voltage so that a regular 9vDC negative tip supply can be used for power.
Controls
Vol:
Output level.
Fuzz:
Fuzziness.
Bias:
Adds series resistance at the circuit input.
Cont:
Adds extra volume at the output.
T1
: Sets the bias on the collector of Q2.
Notes
Space is limited in these 1590G builds so I recommend going with T0-5 (“top hat”) style PNP transistors. These should be
soldered flush to the PCB without sockets. You should be able to use other styles of PNP transistors, as well. If using
transistors that are too large to fit on top of the PCB (so that the enclosure lid will actually close) then you can solder them
to the bottom of the PCB instead. You may need to fold them over a bit to fit in that space, though.
Smallbear has many verities of PNP transistors including matched pairs for the Fuzz Face:
http://smallbear-electronics.mybigcommerce.com/fuzz-faces-and-similar/
These often include resistor values used to bias the transistors in a Fuzz Face. I recommend using the values listed in the
BOM to build the Woodstork.
“Bias” pot: This is not a true bias control…it’s just called that because reasons. When turned down it behaves similar to
rolling the volume pot down on your guitar. People find this control useful because the Fuzz control tends to get murky
when turned down. Leaving the Fuzz mostly all the way up and turning the Bias control all the way down is a way to
reduce the total fuzz without things getting muddy.
The Cont pot (short for “Contour) does not do much in the way of tone shaping but it will add extra volume output. With
the Cont pot halfway up it is about the same output as a regular Fuzz Face. Turning it up further will give you some more
dB to work with at the Volume control.
Biasing
Biasing the Woodstork is very easy. Using your multimeter, attach the black lead to a ground point on the PCB. Touch the
red lead to the “TP” pad on the Woodstork. Now adjust the T1 trimmer until you get a reading of about -4.5vDC.
Remember, the power here is inverted so you are supplying -9v to the circuit via the charge pump and adjusting the Q2
collector for -4.5v.
