neutral labs NERMAL User manual

NERMAL v1.1
by neutral labs
Build Guide
Congratulations on your decision to build a Nermal module! Nermal is a
fairly easy build with a moderate component count, but please go
through this guide at least quickly to make sure you’re not missing
anything.
Important!
DO NOT EMPTY ANY OF THE COMPONENT BAGS NOW! The components are grouped
into the bags so that all of them can be identified without having to
look up resistor ring codes. Rather leave everything inside the bags
and take out what you need while soldering.

Component List
This list of components is for reference. The part IDs are also
indicated on labels on each of the bags, which is why it’s a good idea
to keep the parts in the bags or empty the bags onto separate piles.
Part
Count
Type
C1, C2, C14-C16
5
electrolytic 10 µF
C3, C11
2
electrolytic 1 µF
C4, C6, C8-C10
5
electrolytic 0.1 µF
C5
1
electrolytic 47 µF
C7
1
electrolytic 4.7 µF
C12
1
electrolytic bipolar 1 µF
C13
1
electrolytic 2.2 µF
D1-D8, D11, D12
10
BAT85 Schottky diode
D9
1
LED 3 mm orange
D10
1
1N4148 signal diode
R1-R3, R9, R10, R16, R20, R25
8
10 kΩ
R4, R32
2
2.2 kΩ
R5-R8
4
220 kΩ
R11
1
47 Ω
R12-R14
3
100 Ω
R15, R29, R33, R34
4
1 kΩ
R17, R30
2
100 kΩ
R18
1
4.7 kΩ
R19, R27
2
220 Ω
R21, R31
2
47 kΩ

R22
1
470 Ω
R23, R24, R26, R28
4
1 MΩ
SW1-SW5
5
SPDT switch
J1
1
Eurorack 10-pin power header
J2-J6
5
ThonkiConn mono 3.5 mm switching jack
RV1-RV3
3
10 kΩlinear potentiometer
U1
1
L7805 voltage regulator
U2
1
MCP6004 quad op-amp
U3
1
TL072 dual op-amp
U4
1
NE555P precision timer
OK1-OK3
3
H11F1M bilateral analog FET optocoupler
Step-by-step instructions
Solder all the resistors first.
Polarity doesn’t matter for them,
so you can orient them in
whichever way you choose.
In case you haven’t noticed: You
do NOT have to read ring codes or
use a multimeter to determine the
resistor values. Each bag contains
unique sets of resistors, so you
will not find e.g. two sets of 4
resistors in the same bag. The
information on the bag labels is
enough to be able to tell the
resistor value.
Some of the resistors in your kit
may be white, green or blue
instead of beige as shown here.
Don’t worry, they all work pretty
much the same.

Now on to most of the diodes,
except the LED (D9), which goes on
the other side and will be added
later.
There are 2 types of diodes used:
1N4148 (a single one) and BAT85.
Pay attention to the polarity: The
black line on each diode must
match the white line on the PCB.
In case of reversed polarity, you
may damage your module when
plugging it in!
Next, solder in the IC sockets.
They all have a little notch on
one side which should match the
notch of the white outline on the
PCB. (It’s not harmful if you put
one in the other way around by
accident, as long as you make sure
the IC is facing the right way
when you plug it in later.)
An easy way to solder those
sockets is to set all of them into
the PCB holes, lay the front panel
or a piece of cardboard on top and
flip the whole thing over. Now
solder one pin of each of them and
you can freely move the PCB to
solder the rest of the pins.

Add the 2x5 pin power header in
the top left and the capacitors.
You can solder the small (0.1 µF)
capacitors first, so they won’t
fall out after fitting the larger
ones and flipping the board for
soldering. Or just fit them all at
once and bend their legs slightly.
Polarity matters for almost all of
the capacitors except for C12,
which is a bipolar electrolytic
one. It does have one short and
one long leg, but the orientation
doesn’t matter. However, make sure
not to confuse C12 with any of the
other 1 µF capacitors!
The long legs go on the plus side
as indicated on the PCB.
Now for the easiest part: Plug the
ICs into their sockets.
They all have a little dot on them
which should match the little
notch on the IC socket (and the
notch in the white outline on the
PCB).
Bend their legs slightly inward if
you have trouble fitting them in.
Make sure not to confuse the
NE555P with the TL072, as both
have 8 legs.
The H11F1M in your kit may not be
white, but black instead. Don’t
worry, they work the same.

Now as the last component on this
side, solder in the L7805. Make
sure it’s correctly oriented: The
heat sink (metal) side should
match the double line of the white
outline on the PCB.
The recommended way to do it is
not to insert the legs into the
PCB holes too far, but just a bit,
solder them in and then bend the
legs at a 90 degree angle as shown
in the picture. This will lower
the depth of the completed module,
so it looks more tidy. But it
shouldn’t be necessary as most
Eurorack cases offer far more
depth.
After bending make sure it doesn’t
touch the surface of the MCP6004!
Now flip the PCB over.
Solder in D9 (the LED) after
pushing it in all the way, long
leg on the side marked with a plus
sign on the PCB.
Remove the washers from the pots
and the outer nuts and washers
from all the switches. Leave the
lower nuts on the switches and
lightly tighten them.
Fit all the remaining components
on the PCB without soldering yet.
Now put on the front panel. Add
and lightly tighten the washers of
the 3 pots to hold the panel in
place. Carefully flip everything
back over and solder.

Now plug in and test your module.
Refer to the manual if needed.
If something’s not right, it may
be best to unplug the module from
Eurorack power immediately so as
not to damage the PSU.
Most problems can easily be fixed
by reheating all solder joints so
the solder can reflow. Also
visually inspect joints and see if
you can spot accidental solder
bridges.
When everything is working
correctly, you can add the
remaining washers and tighten
them. If using a wrench or pliers,
be careful not to scratch the
front panel surface.
As the final step, put the knobs
on the pot shafts.
If you need help troubleshooting or want to share photos, audio and/or
video of your creations (please do), send a message to
[email protected]