FuzzDog HellGazer II User manual

HellGazer II
Twin circuits to destroy your
delicate sensibilities
Contents of this document are ©2021 Pedal Parts Ltd.
No reproduction permitted without the express written
permission of Pedal Parts Ltd. All rights reserved.

Important notes
I you’re using any o our ootswitch daughterboards,
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:
•Electrolytic capacitors:
Long leg (anode) to square pad.
•Diodes/LEDs:
Striped leg (cathode) to square pad. Short leg to square pad for LEDs.
•ICs:
Square pad indicates pin 1.

Schematic + BO
R1 82R
R2 1K
R3 2 2
R4 10K
R5 3 3
R6 10K
R7 10K
R8 2 2
R9 10K
R10 2 2
R11 10K
R12 100K
R13 100K
R14 100K
R15 82R
R16 47100K*
CLR-S 2K2**
CLR-TP 2K2**
C1 47u elec
C2 100n
C3 100n
C4 100n
C5 100n
C6 100n
C7 100n
C8 22n
C9 1n
C10 100n
C11 100n
C12 1n
C13 100n
C14 47u elec
D1 1N4001
Q1-3 PSA18
Q4 2N2907
Q5-6 PSA18
Q7-8 2N2222
S -GAIN 100KA
S -VOL 100KA
TP-TX 500KA
TP-VOL 100KA
SWITCHES ALL ONON
*Only include R9 if you’re including the gain switch in the TP circuit.
It gets a bit whacky if you go up to 100K, 47K is not so mad.
**These resistors are only required if you’re including the order switcher and
channel indicator LEDS (D1 and D2). If not using the order switcher leave them out.
There are notes later about jumpers for unusued toggle switches.

PCB layout ©2021 Pedal Parts Ltd.
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.
We supply daughterboards with LED above the
footswitch with this kit.
Be very careful when soldering the diode,
transistors 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). The same
goes for the IC if you aren’t using a socket.
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. ake sure your pots all line up nicely.
Same goes for the toggle switches. It’s best to
use the enclosure as a guide when placing the
pots and switches to ensure they all sit correctly.
Order Switch
If you’re including the order switcher then it’s
going to be fiddly get get everything lined up to
mount in the enclosure. You’ll have to place with
the pots with the pins only just going through the
PCB so they sit somewhere near the height of
the larger toggle with it’s nut. We’ll supply extra
washers to sit on the pots on the inside of the
enclosure to make it work. You’ll have to adjust
the inner nuts of the smaller toggles to line up
with the 4PDT.

Toggle Switches
If you aren’t using some of the toggle switches
you need to place jumpers instead.
ORDER SWITCHER
Place jumpers from the centre pads to the lower pads as shown in red above. This will give you the
standard format of right hand fuzz circuit (Soda) into left hand drive circuit (Ripper). If you’re really
strange you can reverse that order by connecting the centre pads to the upper pads instead. Don’t!
SODA CHAOS
Remove the chaos option by jumpering pads above marked A.
SODA OCTAVE
To keep it standard (no octave), jumpers B and C. To have permanent octave-up, jumper D and E.
RIPPER GAIN
To keep it standard use 10K in R9, leave out R16, jumper F above.
RIPPER NOISE
To omit this simply leave out the toggle switch.No jumper required.
ABC F
DE

JOINING THE BOARDS
Connect the two footswitch daughterboards to the main PCB with wires or ribbon cables. Ensure the
pads correspond, i.e. don’t get the switch boards upside down!
Don’t forget the current limiting resistors (CLRs) for the LEDs. The fit vertically in the two pads marked
CLR on the daughterboards, same side as the footswitches.

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
Drillin template
Hammond 1590BB
It’s a ood idea to drill the pot and
to le switch holes 1mm bi er if
you’re board-mountin them.
Wi le room = ood!
Recommended drill sizes:
Pots 7mm
Jacks 10mm
Footswitch 12mm
DC Socket 12mm
To le switches 6mm
20mm
20mm10mm
26mm
60mm
11mm