FuzzDog BadMofo User manual

Bad Mofo
Awesomely versative bass
overdrive preamp with blend
Contents of this document are ©2015 Pedal Parts Ltd.
o reproduction permitted without the express written
permission of Pedal Parts Ltd. All rights reserved.

Schematic
BOM
R1 1M
R2 220K
R3 2K2
R4 1K
R5 1M
R6 1K
R7 1K
R8 470R
R9 100K
R10 100K
R11 100K
R12 2K2 (CLR)
IC1 JRC4562*
D1-3 1 34A
D4-5 1 4148
D6-7 3mm Red LED
D8 1 4001
C1 100n
C2 220n
C3 2n2
C4 470p
C5 10n
C6 470p
C7 10u elec
C8 10u elec
C9 10u elec
C10 47u elec
DRIVE 100KB
LEVEL 100KA
TREBLE 100KB
BLE D 100KB
SWITCH 3P4T rotary
*other dual op amps
will work, such as 4558

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.
Be very careful when soldering the diodes and
LEDs. 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. Keep exposure to heat to a minimum (under
2 seconds). Best to use a socket for the chip.
The striped leg (cathode) of the diodes goes into
the square pad. Short leg of the LEDs goes into the
square pad.
The long leg (anode) of the electrolytic capacitors
go into the square pads.
The large 47u (C10) capacitor can lay flat over the
rotary switch once that’s in place. This will give you
plenty of clearance in the enclosure. You’ll still
have access to the pads for this once all the pots
etc are in place.
Snap the small metal tag off the pots so they can
be mounted flush in the box.
Align the switch so the round locator tab
on the top side is in the same postion
as the marking on the board >>>
You’ll have to snap this off to mount the switch
flush in the enclosure.
Pots mount on the back side of the board. You can
use vertical-mount pots or just wire up ‘normal’
ones. As the rotary switch is quite deep you’ll have
to line the pots up with it once its in place. Solder
the switch in before the pots. ow place your pots
in the board and align them so they’re at the same
level as the switch. In the case of the switch
supplied with the kits, the pot pin will only just
stick out of the other side of the board when at the
right hight. It’s easiest if you only solder a single
pin of the pots until you get the height right.
1 2 3
PCB Layout ©2015 Pedal Parts Ltd.
PCB
Align
+

Test the board!
NDER NO CIRC MSTANCES will troubleshooting help
be offered if you have skipped this stage. No exceptions.
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 O T. Connect IN and O T 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 it works, crack 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.
BATTERY
IN OUT
Your nice, new circuit board
INCLUDING WIRED POTS!!!!
IN 9V GND OUT

(if using a daughterboard please refer to the relevant document)
Wire it up - DC only version
his circuit is standard, Negative GND. Your power supply should be
ip Negative / Sleeve Positive. hat’s the same as your standard pedals
(Boss etc), and you can safely daisy-chain your supply to this pedal.
he BOARD GND connections don’t all have to connect to one point.
hey can be daisy-chained around the circuit, using larger connection
points (such as jack socket lugs) for multiple connections. As long as
they all connect together in some way.
L
E
D
BOARD
OUT
BOARD
9V
BOARD
GND
BOARD
GND
BOARD
GND
BOARD
INPUT
+
IN
OUT
L
E
D
BOARD
GND
BOARD
LED+

(if using a daughterboard please refer to the relevant document)
Wire it up - with battery
his circuit is standard, Negative GND. Your power supply should be
ip Negative / Sleeve Positive. hat’s the same as your standard pedals
(Boss etc), and you can safely daisy-chain your supply to this pedal.
he BOARD GND connections don’t all have to connect to one point.
hey can be daisy-chained around the circuit, using larger connection
points (such as jack socket lugs) for multiple connections. As long as
they all connect together in some way.
PedalParts.co.uk
L
E
D
BOARD
OUT
BOARD
9V
BOARD
GND
BOARD
GND
BOARD
GND
BOARD
INPUT
BATTERY
+
IN
OUT
L
E
D
BOARD
GND
BOARD
LED+
+
Just because the
FuzzDog enclosure
won’t take a battery,
there’s nothing
stopping you using a
bigger box.

Drilling template
Hammond 1590BB
SpectreVerb
Recommended drill sizes:
Pots 7mm
Jacks 10mm
Footswitch 12mm
DC Socket 12mm
Rotary 10mm
his 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.
PedalParts.co.uk
28mm
It’s a good idea to drill the holes for the pots 8mm to give
yourself some wiggle room unless you’re a drill ninja
hree different
DC socket
positions shown.
ake your pick.
BAD MOFO
27mm34mm

Plenty of room...