ANTUMBRA ATN8 User manual

ANTUMBRA
ATN8
MANUAL

TABLE OF CONTENTS
01. INSTALLATION 4
02. JACK LIGHTS 5
03. FRONT 6
04. OVERVIEW 7
05. ATTENUATORS 8
06. MIXING 9
07. OFFSET 10

00. THANK YOU!
Thank you for purchasing the Antumbra ATN8 module!
In this documentation you can find information about the
installation and use of the module.

01. INSTALLATION
POWER CABLE HEADER: Red stripe should be on the
right, next to the white marker!
When you turn ATN8 around, you should see the module as
it is on the left illustration. Plug in the power cable to the
power cable header pins, but BE CAREFUL with the orien-
tation of the cable! The RED STRIPE should be towards the
RIGHT of the module, indicated by the white line next to
the header pins. By doing otherwise you can potentially
harm the module or even your whole system! Power off
your Eurorack system and connect the other end of the
cable to the power source, here also pay attention to the
PSU manufacturer’s instructions!
TL074
TL074
TL074
TL074
TL074
TL074
TL074
TL074
TL074TL074
181
181 181 181
102
102
102
102
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102
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102
102 102 102 102 102 102 102
103104 104
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104 104 104
104 104 104
104 104
104104104104104104104
104 104
104 104 104 104
104

02. JACK LIGHTS
On the back there is a jumper for enabling the jack lights.
Note that by enabling them the module draws additional
current from the +12V rail.
Jack lights jumper
TL074
TL074
TL074
TL074
TL074
TL074
TL074
TL074
TL074TL074
181
181 181 181
102
102
102
102
102
102
102
102
102
102 102 102 102 102 102 102
103104 104
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104 104
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104 104
104 104 104 104
104

03. FRONT
1 Voltage switch for channels 5-8
2 Voltage switch for channels 1-4
3 Status LED for the channel
4 Unipolar/Bipolar switch for each channel
5 Attenuator for each channel
6 Input for each channel (+/-12V)
7 Output for each channel (+/-12V)
5
2 1
6 7
4
3

04. OVERVIEW
ATN8 is an eight channel attenuator with inverting, mix-
ing and offset capabilities. The 8 channels are laid out
horizontally, each with a switch to change between uni-
polar and bipolar modes, a status LED that reflects what’s
happening on the output (green is positive voltage, red is
negative), an input and an output jack. The outputs are
normalized for each subsequent channel so that it can be
used for offset or mixing.
When there’s no patch cable present on an input, it’s nor-
malized to a fixed voltage selected on the top by the two
switches either to +5V or +10V.

05. ATTENUATORS
Each channel is equipped with a switch to change how the
potentiometer functions. In unipolar mode the potenti-
ometer goes the full range, fully counter-clockwise the
output is 0V, fully clockwise it matches the input level.
In bipolar mode 0V is at 12 o’clock, turning the potenti-
ometer clockwise it increases the output level. Turning it
counter-clockwise from 12 it inverts and increases the
level.
UNIPOLAR
BIPOLAR

06. MIXING
Mixing is achieved by normalization, meaning that if you
leave the output jacks unplugged, the last output jack
that you patch in will contain the mix of all the previous
channels (level set by the attenuators). A patch cable in
the output jack breaks the normalization and on the next
channel you can start a new mixing chain.
INPUT 1
INPUT 1
INPUT 1
INPUT 2
INPUT 2
INPUT 2
INPUT 3
INPUT 3
MIX OF CH 1-3
MIX OF CH 4-5
MIX OF CH 6-8

07. OFFSET
If there is no cable patched in an input, the channel uses
a preset voltage, changed by the top switches. There are
two options:
. is 5V
.. is 10V
The 8 channels are split into two groups for the preset
voltage, each set independently by their corresponding
switches. The groups are marked by an outlined and a
filled circle above the input jacks and next to the switch-
es. If a channel is set to bipolar mode, the output will be
+/-5V or +/-10V.
Combining offset with mixing, you can offset an incoming
signal with an input left unpatched.
GROUP A
GROUP B
A B
INPUT 1 INPUT 1 WITH
OFFSET

ATN8 is designed by David Szebenyi under Antumbra.
www.antumbra.eu
Manual by David Szebenyi (www.aman.hu)
2021 • All rights reserved!