FuzzDog JenFuzz User manual

J n Fuzz
Skanky 60s fuzz tones
Contents of this document are ©2022 Pedal Parts Ltd.
No reproduction permitted without the express written
permission of Pedal Parts Ltd. All rights reserved.

Important notes
If you’r using any of our footswitch daught rboards,
DOWNLOAD THE DAUGHTERBOARD DOCUMENT
•Download and read the appropriate build document for the daughterboard
as well as this one BEFORE you start.
•DONOT solder the supplied Current Limiting Resistor (CLR) to the main
circuit board even if there is a place for it. This should be soldered to the
footswitch daughterboard.
POWER SUPPLY
Unless otherwise stated in this document this circuit is designed to be
powered with 9V DC.
COMPONENT SPECS
Unless otherwise stated in this document:
•Resistors should be 0.25W. You can use those with higher ratings but
check the physical size of them.
•Electrolytics caps should be at least 25V for 9V circuits, 35V for 18V
circuits. Again, check physical size if using higher ratings.
LAYOUT CONVENTIONS
Unless otherwise stated in this document, the following are used:
•El ctrolytic capacitors:
Long leg (anode) to square pad.
•Diod s/LEDs:
Striped leg (cathode) to square pad. Short leg to square pad for LEDs.
•ICs:
Square pad indicates pin 1.

Schematic + BOM
R1 1M
R2 10
R3 33
R4 150
R5 4 7
R6 22R
R7 1
C1 10n‡
C2 10n‡
C3 Empty
C4 1n2
C5 22u elec
C6 15n
C7 100u elec
D1-2 BAT46*
D3 1N5817
Q1-3 Low gain NPN BJT**
BIAS 22 trimmer
FUZZ 1 B
VOL 50 A***
*Original diodes are SA815. Try what you like here - they’ll make a big difference to
the feel of the fuzz.
**Aim for 200-250 for Q1, 300-350 for Q2-3. Originals used BC238B and BC239C.
We’ve designed the PCB to take both TO-18 and TO-92 packages. See page 6 for
orientation information.
**100 A works much better - honestly.
‡If you want to beef up the sound, swap C1 and C2 for larger values, such as 47n.

The power and signal pads on the PCB conform
to the FuzzDog Direct Connection format, so can
be paired with the appropriate daughterboard for
quick and easy offboard wiring. Check the
separate daughterboard document for details.
Be very careful when soldering the diodes and
transistors. They’re very sensitive to heat. You
should use some kind of heat sink (crocodile clip
or reverse action tweezers) on each leg as you
solder them. eep exposure to heat to a
minimum (under 2 seconds).
Snap the small metal tag off the pots so they can
be mounted flush in the box.
You should solder all other board-mounted
components before you solder the pots. Once
they’re in place you’ll have no access to much of
the board. Make sure your pots all line up nicely.
The best way to do that is to solder
a single pin of each pot in place then melt and
adjust if necessary before soldering in the other
two pins. If your pots don’t have protective
plastic jackets ensure you leave a decent gap
between the pot body and the PCB otherwise
you risk shorting out the circuit.
There are extra pads on trimmers to allow
different package formats to be used. Pads are
connected via PCB traces as shown above, so
just fit your trimmer into whichever holes it fits
naturally into. As long as you have one pin each
in the top, middle and bottom sections.
No jumpers are required.
There’s no set voltage to aim for to bias this up.
Adjust it until it sounds good to you.
PCB layout ©2022 Pedal Parts Ltd.

Transistor orientation
You can use transistors with any combination of pinouts.
TO-18 transistors should follow the screen print, with the emitter tab as shown.
Standard EBC transistors, such as 2N3904, 2N5088Standard EBC transistors, such as 2N3904, 2N5088Standard EBC transistors, such as 2N3904, 2N5088Standard EBC transistors, such as 2N3904, 2N5088Standard EBC transistors, such as 2N3904, 2N5088Standard EBC transistors, such as 2N3904, 2N5088
CBE transistors, such as BC238B, BC239C
E B C
E

Test the board!
Ch ck th r l vant daught rboard docum nt for mor
info b for you und rtak this stag .
UNDER NO CIRCUMSTANCES will troubl shooting h lp
b off r d if you hav skipp d this stag . No xc ptions.
Once you’ve finished the circuit it makes sense to test is before starting on the switch and LED
wiring. It’ll cut down troubleshooting time in the long run. If the circuit works at this stage, but it
doesn’t once you wire up the switch - guess what? You’ve probably made a mistake with the switch.
Solder some nice, long lengths of wire to the board connections for 9V, GND, IN and OUT. Connect
IN and OUT to the jacks as shown. Connect all the GNDs together (twist them up and add a small
amount of solder to tack it). Connect the battery + lead to the 9V wire, same method. Plug in. Go!
If you’re using a ribbon cable you can tack the wires to the ends of that. It’s a lot easier to take them
off there than it is do desolder wires from the PCB pads.
If it works, carry on and do your switch wiring. If not... aw man. At least you know the problem is
with the circuit. Find out why, get it working, THEN worry about the switch etc.
Your compl t d circuit board
including pots

Now’s the time
to refer to the
daughterboard
document for
your chosen
bypass method.
Enjoy your pedal!

This template is a rough guide only. You should ensure correct marking of your
enclosure before drilling. You use this template at your own risk.
Pedal Parts Ltd can accept no responsibility for incorrect drilling of enclosures.
FuzzDog.co.uk
Recommended drill sizes:
Pots 7mm
Jacks 10mm
Footswitch 12mm
DC Socket 12mm
Toggle switches 6mm
32mm
Drilling template
without battery
Hammond 1590B - 60 x 111 x 31mm
It’s a good idea to drill the pot and
toggle switch holes 1mm bigger i
you’re board-mounting them.
Wiggle room = good!

This template is a rough guide only. You should ensure correct marking of your
enclosure before drilling. You use this template at your own risk.
Pedal Parts Ltd can accept no responsibility for incorrect drilling of enclosures.
FuzzDog.co.uk
Recommended drill sizes:
Pots 7mm
Jacks 10mm
Footswitch 12mm
DC Socket 12mm
Toggle switches 6mm
32mm
Drilling template
with battery
Hammond 1590B - 60 x 111 x 31mm
It’s a good idea to drill the pot and
toggle switch holes 1mm bigger i
you’re board-mounting them.
Wiggle room = good!