aion DEIMOS User manual

DEIMOS GERMANIUM FUZZ 1
PROJECT NAME
DEIMOS
BASED ON
EFFECT TYPE
PROJECT SUMMARY
DOCUMENT VERSION
Tone Bender Mk. II Professional
The second (and most famous) version of the legendary fuzz pedals from Macaris in London that
changed the music world forever.
Germanium fuzz 1.0.1 (2022-07-01)
BUILD DIFFICULTY
This documentation is for the kit version of the project. If you purchased the PCB by itself, please
use the PCB-only version of the documentation instead. The circuit is the same, but the instructions
are completely different due to the specialized parts and assembly methods used in the kit.
IMPORTANT NOTE
Intermediate
LEVEL
GERMANIUM FUZZ
FUZZ
9V
MODE
II 1.5
DEIMOS

DEIMOS GERMANIUM FUZZ 2
TABLE OF CONTENTS
1Project Overview
2Table of Contents
3Introduction
4Packing List
5Packing List (Cont.)
6Tools Needed
7Component Identification
8Hardware Identification
9PCB Assembly Overview
10 Resistors
11 Diodes
12 Socket & IC
13 Trimmers
14 Capacitors (Non-Polarized)
15 Wire Headers
16 Capacitors (Polarized)
17 Germanium Transistors: Introduction
18 Germanium Transistors
19 Footswitch PCB
20 Input/Output PCB
21 Enclosure Layout: Panel Mounts
22 Enclosure Layout: Panel Mounts (Cont.)
23 Enclosure Layout: Main & Footswitch PCBs
24 Enclosure Layout: Input/Output PCB
25 Final Assembly & Biasing
26 Final Assembly (Cont.)
27 Schematic
28 Full Parts List
29 Troubleshooting Information
30 Support & Resale Terms
31 Legal Information & Document Revisions

DEIMOS GERMANIUM FUZZ 3
INTRODUCTION
If this is your first pedal, welcome to the hobby and thank you for choosing Aion FX. You’ve just joined
a community of over 40,000 people around the world with a passion for building homemade noise
machines using obsolete electronics technologies, and we’re glad to have you!
If you’ve done this before, it’s great to see you again and we’re confident you’ll find this build experience
an enjoyable one.
Aion FX kits are designed to empower anyone to build a high-quality pedal, no matter the skill level.
The pedalbuilding hobby has traditionally had a steep learning curve, but don’t be overwhelmed—we’ve
done all the hard work for you. All you need to do is follow these instructions and you’ll be on your way
to transforming your tone.
There are a few things to go over before you get started.
• You’re going to have to get your hands dirty—there’s no way around it. Nothing here comes
preassembled, and you’ll have to learn the skills to put it all together. This document will walk you
through everything you need, but be prepared to learn a few things along the way.
• This will take time. Plan on about two hours start to finish. It may take even longer if it’s your first
time building. Don’t rush it. If you find yourself getting frustrated or overwhelmed, take a break
and come back in a couple of hours or the next day.
• No direct technical support is offered. There are several DIY forums and Facebook groups with
thousands of members who enjoy troubleshooting and teaching. But please be sensitive to the
fact that the staff at Aion FX is minimal, and every minute spent helping individuals in private is
time that can’t be spent on new project development.
• There is no implied guarantee of a final product. Aion FX provides the ingredients and the recipe,
but you are responsible for putting everything together to make it work. We’ve tried to make the
process as clear and accessible as possible, but it must be expressly stated that purchasing the kit
is not a guarantee that you will end up with a working pedal.
It’s recommended to read through all of the instructions before you start, particularly if you’ve never
built a pedal before. If you familiarize yourself with the entire process ahead of time and you know what
the goal looks like, each step will make more sense.
Now, on to the fun stuff!

DEIMOS GERMANIUM FUZZ 4
PACKING LIST
This is a list of all the parts that are included with the kit, grouped by value. For a list of all the parts
based on their PCB part numbers, please see page 28.
If you find that any parts are missing or damaged, please fill out the Missing Parts form.
Film Capacitors
NAME QTY
10n (0.01) 2
100n (0.1) 1
Electrolytic Capacitors
NAME QTY
4.7uF 3
10uF 1
47uF 1
100uF 1
MLCC Capacitors
NAME QTY
100n (marked “104”) 1
470n (marked “474”) 1
Diodes
NAME QTY
1N5817 1
1N4742A 1
Resistors
NAME QTY
100R 1
470R 1
4k7 1
8k2 1
10k 1
47k 1
100k 2
2M2 1
ICs
NAME QTY
TC1044SCPA or LT1054CP 1
8-pin socket 1
Transistors
NAME QTY
Transistors, germanium, matched for
Tone Bender Mk. II
3
Trimmers
NAME QTY
10k trimmer 1
100k trimmer 1

DEIMOS GERMANIUM FUZZ 5
PACKING LIST (CONT.)
Potentiometers
NAME QTY
1kC 1
100kA 1
Dust cover 2
Knob 2
Mounting nut, potentiometer, 0.44" 2
Lock washer, potentiometer, 0.5" 2
Outer washer, potentiometer, 0.475" 2
Other
NAME QTY
LED bezel 1
LED, blue 1
9V battery snap 1
DC jack 1
Input/output jack 2
Mounting nut, jack, 0.54" 4
Outer washer, jack, 0.6" 2
Lock washer, jack, 0.5" (thin) 2
Enclosure 1
Enclosure screws 4
PCB, main circuit 1
PCB, footswitch 1
PCB, input/output/DC 1
Switches
NAME QTY
Toggle switch, DPDT on-on 1
Mounting nut, toggle switch, 0.36" 1
Lock washer, toggle switch, 0.4" 1
Dress nut, toggle switch, 0.375" 1
Stomp switch, 3PDT 1
Mounting nut, stomp switch, 0.6" 2
Lock washer, stomp switch, 0.6" 1
Dress nut, stomp switch, 0.77" 1
Wiring
NAME QTY
3-strand wire assembly, 70mm 2
4-strand wire assembly, 108mm 1
3-pin wire assembly header 2
4-pin wire assembly header 1

DEIMOS GERMANIUM FUZZ 6
TOOLS NEEDED
SOLDERING IRON
Temperature-adjustable is
recommended. The optimum
soldering temperature is 700-725º
F (371-385º C) for leaded solder, or
750º F (400º C) for lead-free.
WIRE SNIPPERS
Also called nippers or wire cutters.
The Hakko CHP-170 is the best you
can get for less than $10.
SCREWDRIVER (PHILLIPS)
Used for the enclosure screws. Get a
powered driver if you’ll be building a
lot of pedals!
SOLDER
Preferably 63/37 or 60/40 leaded
solder. Lead-free is more difficult to
use, so if that’s the only type you can
get, it’s best to watch tutorials that
are specific to lead-free solder.
NEEDLE-NOSE PLIERS
These are used for bending leads on
components and other general uses.
Use the smaller type with a tip that’s
approximately 0.05” (1.25mm) wide.
FLAT SCREWDRIVER (SMALL)
This is used for tightening the set
screws on the knobs. The tip should
be no more than 0.1” (2.5mm) wide.
DIGITAL MULTIMETER (DMM)
Most cheap ones in the $10-30 range
are fine for what we’re doing. Make
sure it has audible continuity testing
(i.e. it beeps at the lowest resistance)
and transistor hFE measurement.
FLAT-NOSE PLIERS
Many general-purpose uses, but par-
ticularly tightening the nuts of pots,
switches and jacks. Quicker than
changing out sockets on a ratchet.
RUBBER BAND
Yes, a plain old rubber band. This is
used to tighten the dress nut to avoid
scratching or denting it (which can
happen with metal tools).

DEIMOS GERMANIUM FUZZ 7
COMPONENT IDENTIFICATION
If you’ve never built a pedal before, you’ll need to know what all the components are. These are shown
actual size. (Not all of these types of components may be part of this kit.)
RESISTOR TRIMMER POTENTIOMETER
FILM CAPACITOR
SILICON DIODE
ZENER DIODE
LED
DC JACKWIRE ASSEMBLY HEADER
LED BEZEL
WIRE ASSEMBLY
ELECTROLYTIC CAPACITOR
GERMANIUM DIODE
OP-AMP / IC
TANTALUM CAPACITOR
SCHOTTKY DIODE
IC SOCKET TRANSFORMER
MLCC
RECTIFIER DIODE
TRANSISTOR OR JFET
Not polarized. Color may
vary by brand and type.
Not polarized. MLCC stands for
“multi-layer ceramic capacitor.”
Some Schottky diodes
also look like this.
These are very fragile, so be
careful when handling them.
Polarized. The positive side
is marked.
Polarized. The negative side
is marked.
Charge pumps and delay chips
also look like this. They may
have more than 8 legs.

DEIMOS GERMANIUM FUZZ 8
HARDWARE IDENTIFICATION
The hardware comes unassembled, so you’ll need to sort & identify each of the pieces. The diagrams
below are actual size, so you can set them against the printed page to identify them if needed.
I/O JACK
TOGGLE SWITCH
POTENTIOMETER
(SINGLE)
FOOTSWITCH
POTENTIOMETER
(DUAL)
MOUNTING NUT
MOUNTING NUT
MOUNTING NUT
MOUNTING NUT
DRESS NUT
OUTER WASHER
DRESS NUT
OUTER WASHER KNOB
LOCK WASHER
LOCK WASHER
LOCK WASHER
LOCK WASHER
DIAMETER: 0.54” / 13.7mm
DIAMETER: 0.36” / 9.1mm
DIAMETER: 0.44” / 11.2mm DIAMETER: 0.5” / 12.7mm
DIAMETER: 0.6” / 15.2mm
DIAMETER: 0.375” / 9.5mm
DIAMETER: 0.475” / 12mm
DIAMETER: 0.5” / 12.7mm
DIAMETER: 0.4” / 10.1mm
DIAMETER: 0.6” / 15.2mmDIAMETER: 0.77” / 19.6mmDIAMETER: 0.6” / 15.2mm

DEIMOS GERMANIUM FUZZ 9
PCB ASSEMBLY OVERVIEW
Now it’s time to start building!
The first thing you need to do is snap apart the PCBs
into 3 separate boards (if needed) and break off the
tabs from each using needle-nose or flat-head pliers.
You should be left with the PCBs shown to the right.
The general principle for PCB population is that you
want to work in layers from shortest components
(i.e. lowest-profile) to tallest so that when the PCB is
upside-down, everything is making contact with the
work surface and is held in place.
Generally speaking, you should populate the
components in this order:
1. Resistors
2. Diodes
3. IC sockets
4. Trimmers
5. MLCC capacitors
6. Film capacitors
7. Electrolytic capacitors
8. Germanium transistors

DEIMOS GERMANIUM FUZZ 10
RESISTORS
PART VALUE
R1 100k
R2 10k
R3 47k
R4 8k2
R5 470R
PART VALUE
R6 100k
R7 100R
RPD 2M2
LEDR 4k7
Using the parts list above, populate the resistors by pushing them through the holes and bending the
leads outward at an angle to hold them in place. Resistors are not polarized, so they will work in any
direction. Turn the board upside-down to keep the components held in place while you solder.
You’ll use this same technique for most of the other components as well.
If it gets too crowded, just flip the board and solder everything you’ve done so far, then cut the leads
using the wire snippers to make room for more.
If this is your first time soldering, watch tutorial videos on YouTube and make sure you get it down
before you begin. You don’t want to practice or experiment on this board!

DEIMOS GERMANIUM FUZZ 11
DIODES
PART VALUE
D1 1N5817
Z1 1N4742A
Next, you’ll populate the diodes—only one on each board, so this step is pretty simple. The 1N5817 is
black with a silver stripe, while the 1N4742A is orange with a black stripe.
Diodes are polarized, so make sure to identify the polarity band (which indicates the “cathode”, or
negative side) and match the band to the footprint on the PCB.

DEIMOS GERMANIUM FUZZ 12
SOCKET & IC
Next up is the IC socket. You can’t bend the leads of a socket like you can with the other components, so
it won’t stay in on its own until it is soldered.
Again, it’s much easier to do this with gravity holding it in place for you, so you’ll want do the socket
before you do any of the taller components.
Installing the IC
Don’t insert the IC into the socket just yet. We will do this in a later step, after we’ve finished soldering
the tallest components (the polarized capacitors). This information is just listed here for reference.
The legs of the IC are bent outward slightly during manufacturing, so they’ll need to be bent back inward
before they can be inserted into the sockets.
It’s easiest to do this by laying the IC legs against the table and bending the body itself so all four legs on
the side are straightened out at once. Then, flip it and do the other side.
ICs may have two different orientation marks: either a dot in the upper-left or a half-circle notch in the
middle of the top side. Some ICs have both marks. This shows which way the IC should be rotated when
inserting it into a socket (the socket also has a half-circle notch).
PART VALUE
IC1 TC1044SCPA
or LT1054CP

DEIMOS GERMANIUM FUZZ 13
TRIMMERS
The bias trimmers come next. The two trimmers have different values, so you’ll first need to identify
them by the code on the side of the case. The text is laser-etched rather than printed, so if you have a
hard time making it out, you can hold it at an angle to a light source and it should be much easier to see.
The 100k trimmer for Q2 BIAS is marked P 104, while the 10k trimmer for Q3 BIAS is P 103.
The two trimmers can be soldered like normal components, by bending the legs outward as shown:
These trimmers are used to bias the germanium transistors. We will adjust them at the end once the
pedal is fully assembled.
PART VALUE
Q2 BIAS 100k (104)
Q3 BIAS 10k (103)

DEIMOS GERMANIUM FUZZ 14
CAPACITORS (NON-POLARIZED)
After the trimmers come the box film and MLCC capacitors. These are all several different heights, but
there aren’t as many, so just do them all at once. Bend the leads at an angle to hold them in place.
MLCCs and box capacitors are not polarized and will work in any direction. To keep things neat, though,
it’s best to put them all facing the same way so the values can easily be read.
Note: C1 and C6 (box film capacitors) may be either blue or red. The blue ones have the value printed on
the top, while the red capacitors have the value on the side. The text on the side of the blue capacitors is
not related to the value and can be ignored.
PART VALUE
C1 10n (0.01)
C3 100n (0.1)
C6 10n (0.01)
PART VALUE
C10 470n MLCC
C11 100n MLCC

DEIMOS GERMANIUM FUZZ 15
WIRE HEADERS
Install the two 3-pin headers (wire connectors) as shown above. These have a polarity pin, so as long
as they are pressed all the way down, there’s only one possible way to install them. They do fit pretty
tightly in the holes, though, so press firmly.
There’s also a 4-pin header on the I/O board that we will do in a later step.

DEIMOS GERMANIUM FUZZ 16
CAPACITORS (POLARIZED)
Populate the electrolytic capacitors. They are polarized (i.e. they will only work in one direction), so note
the vertical mark that indicates the negative side. The longer leg is positive and fits in the square pad.
At this point, we only have the transistors left to do, so now is a good time to go back and insert the IC
into the socket (page 12).
PART VALUE
C2 4.7uF
C4 4.7uF
C5 4.7uF
C7 100uF
C8 10uF
C9 47uF

DEIMOS GERMANIUM FUZZ 17
GERMANIUM TRANSISTORS: INTRODUCTION
Next are the germanium transistors. These are very different than modern electronic
components, so they need an introduction before we cover how to install them.
Silicon vs. germanium
Compared to silicon, germanium transistors are imprecise and inconsistent, even among the
same part number. As a result, when classic fuzz circuits use germanium transistors, it’s not the
part number that’s important, but the specifications of the individual device. Two transistors of
different part numbers with identical gain and leakage will sound exactly the same. Conversely,
not all transistors of the same part number will work in a particular circuit.
Because of this, be aware that this kit may include any of several different part numbers. In this
document we will refer to them as Q1-Q3, not by specific part numbers such as AC125.
Matching
The transistors included in the Deimos kit have been measured and matched for best performance in
the Tone Bender circuit. There are three bags labeled Q1, Q2 and Q3.
It is extremely important that the transistors are not removed from the bags until it’s time to
install them, and only one at a time, to avoid inadvertently mixing them up. They are not visually
distinguishable from each other, and outside of the bags there is no way to tell which is which. The pedal
won’t sound right if the transistors are used in the wrong positions.
Temperature sensitivity
Germanium is a delicate semiconductor material and very sensitive to overheating. If the transistor is
overheated, it could be permanently damaged. It’s recommended to mount the transistors so they are
elevated above the PCB by about 3/8” (9.5mm) to allow some of the heat to dissipate before it reaches
the body of the transistor. If it takes longer than two seconds for the solder to form a good joint, move to
a different component and let the transistor cool a bit before trying again.
Old-stock precautions
Germanium transistors are not manufactured today except for some expensive industry-specific
applications, so nearly all of the germanium transistors used in guitar pedals are old-stock. The
transistors in this kit are 40 to 50 years old, sometimes even older.
While age has nothing to do with performance of the device itself, the leads may be corroded and solder
may not adhere well unless they are cleaned first. If you notice any corrosion on the leads, use medium-
grit sandpaper or a fine metal file to remove it, and ensure the leads are shiny before soldering.

DEIMOS GERMANIUM FUZZ 18
GERMANIUM TRANSISTORS
Now that we’ve covered the basics of germanium transistors, it’s time to install them. Remove Q1 from
the bag. As mentioned on the previous page, it’s important to leave the other transistors in their bags
and only remove them when it’s time to solder so they don’t get mixed up.
First, note the emitter tab. The diagram to the right shows the transistor
from the side, so the third leg is hidden behind the first.
Bend the legs down at a right angle as shown in the next diagram. The outer
legs should be bent around 0.25” to 0.3” from the body, and the center leg
(base pin) should be 0.15” to 0.2”.
Now, mount it to the PCB at a right angle with the top of the transistor
pointed toward the bottom of the PCB, as shown in the PCB graphic at the
top of this page. It will overlap some of the resistors. The third diagram
shows a side view.
Make sure there’s some clearance above the resistors. The resistors are
electrically insulated, so it’s not going to cause any problems if the metal
body of the transistor makes contact, but it’s best to keep them apart.
Before soldering, double-check the orientation against the PCB diagram above and ensure the emitter
tab is on the left. The transistors are rare, old, and expensive, and if they’re soldered incorrectly then
they could be easily damaged when removing them.
If everything looks good, go ahead and solder the legs in place. Be quick and make sure the transistor
casing doesn’t get too hot or the transistor could be damaged.
Once Q1 is finished, go back and repeat the same steps with Q2, and again with Q3.
Q2 and Q3 will partially overlap the biasing trimmers on the right-hand side of the board. These two
transistors should be elevated slightly more than Q1 to allow for easier access to the trimmers.
PART VALUE
Q1 Germanium
Q2 Germanium
Q3 Germanium
EMITTER TAB
EMITTER TAB

DEIMOS GERMANIUM FUZZ 19
FOOTSWITCH PCB
Next, it’s time to finish up the footswitch board. You should have done most of the on-board components
on this board in a previous step, but if not, go back and do those.
There will be one longer assembly with 4 wires and two shorter ones with 3 wires. The longer one goes
in the middle and the shorter ones go on the left and right sides. The wire assemblies should then be
soldered to the footswitch board as shown.
Once all three wire assemblies are soldered, set the footswitch PCB aside. We’ll solder the actual
footswitch and LED in a later step.
PARTS
3-strand wire assembly (2)
4-strand wire assembly
STEP 3
Then, solder the wires from the top.
This is the trickiest part of the whole
build. You want to solder the pads
without touching the iron to the
wires themselves and risking burning
through the insulation. It helps to
use a sharp or narrow tip on the
soldering iron.
STEP 2
Next, bend the wires back upward
and fit the ends of the wires into the
solder pads.
On the top side of the PCB, bend the
exposed wires backward so it holds
the wire in place. Pull the header
back up through the slot partway.
STEP 1
First, thread the wire through the
strain-relief slots, with the blue
side facing outward and the PCB’s
previously-installed components
facing up.
For now, pull it through as far as it
can go.
BLUE
MARKING

DEIMOS GERMANIUM FUZZ 20
INPUT/OUTPUT PCB
Almost done! Get the two input/output jacks, the DC jack and the wire header and snap them in place.
The PCB is designed for them to fit securely, so you can do them all at once before flipping and soldering.
After you’ve soldered everything, make sure to snip the leads on the I/O jacks as close as possible to
the PCB. There’s not a lot of clearance between the bottom of this board and the top of the main PCB
once everything is in place, and you don’t want the pins to short against anything on accident.
Next, we’ll hook up the 9V battery connector. This is optional. Not everyone uses batteries. But, if you
do, this pedal should last a long time on a single 9V so you won’t need to change it very often.
PARTS
Input & output jacks
DC jack
Wire header
9V battery snap
STEP 1
Thread the battery snap leads through the strain-
relief hole twice so it forms a single loop.
STEP 2
Bend the exposed wires back down and solder them
into the pads. Red is positive (+), black is negative (-).
After soldering, pull it tight.
For even more strain relief, you can thread the snap
through the loop to form a knot. (not shown)