Joranalogue ORBIT 3 User manual

ORBIT 3
DOUBLE-SCROLL CHAOS
OSCILLATOR
1
INTRODUCTION
In everyday usage, 'chaos' means 'disorder,
'randomness'. In mathematics however, chaos
has a very specific meaning. Chaos theory deals
with systems exhibiting highly irregular
behaviour, seemingly random yet completely
deterministic.
Applying this to the world of modular synths
opens up a whole new world of modulation
opportunities, introducing a natural irregularity
to otherwise purely ‘mechanical’ music, yet with
much more control and repeatability than just
simple randomness.
In chaos theory, the combination of all possible
oscillations at a specific set of parameters is
known as the ‘attractor’. Orbit 3 incorporates a
modified electronic analogue of the classic
double-scroll attractor. Since it contains some
(bi)stable regions in addition to chaotic ones, this
type is known as a ‘strange’ attractor.
The voltages at each of the module’s outputs can
be thought to describe the orbit of a particle
through 3D space around two equilibrium
points. The positions of these points, as well as
the distribution of the orbits and rate of
movement can all be adjusted under manual or
voltage control.
Not just limited to low frequency modulation
use, Orbit 3 can operate in the audio frequency
domain as well, yielding a variety of waveforms
from its three complementary output pairs.
These span a wide range, from near-sine waves
to white noise. The addition of temperature
compensation and calibrated pitch tracking
makes for an unconventional and lively, yet also
accurate audio oscillator.
And when you need a break from all that musical
chaos, simply connecting any pair of outputs to
the XY inputs of an oscilloscope will surely not
disappoint!
CONTENTS
In the Orbit 3 box, you’ll find:
Product card, stating serial number and
production batch.
16-to-10-pin Eurorack power cable.
Mounting hardware: four black M3 x 6 mm
hex screws, four black nylon washers and a
hex key.
The Orbit 3 module itself, in a protective
cotton bag.
If any of these items are missing, please contact
your dealer or [e-mail].

ORBIT 3
DOUBLE-SCROLL CHAOS
OSCILLATOR
2
CONTROLS & CONNECTIONS
1 FREQUENCY RANGE SWITCH
This switch determines over which frequency
range Orbit 3 will operate: low frequency (VCLFO)
or audio frequency (VCO).
2 FREQUENCY KNOB
Although it may not always be apparent with
highly irregular chaotic signals, there is a
constant underlying oscillation frequency. This
drives the chaos and sets the rate at which the
signals evolve. It is controlled by this knob, with a
range of 22 Hz to 22 kHz in the audio frequency
mode.
In low frequency mode, the total range is
2.4 mHz (a period of 7 minutes) to 180 Hz, with
1 Hz when the knob is centred.
3 FREQUENCY MODULATION INPUT AND
KNOB
This input is used to modulate the frequency in
an exponential fashion. It includes a polariser
knob to set the modulation depth, with 0 in the
centre, standard +1 volt per octave maximum
and −1 volt per octave minimum in audio mode.
In low mode, the sensitivity is increased to
approximately 0.6 volt per octave.
3 DISTRIBUTION KNOB
The distribution knob manipulates Orbit 3’s
internal feedback path to change the nature of
the chaos generated by ‘widening’ the orbits.
When configured with a large distribution, the
oscillator will typically orbit closer to each of the
equilibrium points and spend more time around
it before switching to the other point.
4 DISTRIBUTION MODULATION INPUT AND
KNOB
The distribution parameter can be modulated
using this input, which also includes a polariser
knob. A modulation value of +5 V results in
maximum distribution.

ORBIT 3
DOUBLE-SCROLL CHAOS
OSCILLATOR
3
5 TAME/WILD SWITCH
This switch presents another way to affect the
kind of chaotic signals that are generated. In
mild mode, the orbits take the form of two
distinct scrolls. In wild mode, changing scrolls
becomes much easier, usually resulting in more
irregular orbits.
6 EQUILIBRIUM POINT KNOBS
Rotating either of these knobs clockwise moves
the corresponding equilibrium point further
away from the origin (0 V). As such, these
parameters affect the output amplitudes as well
as the nature of the chaotic signals. Additionally,
setting both points in different positions results
in asymmetric attractors, and changing one
point affects both scrolls.
Any combination of the system parameters may
result in stable oscillation (much like a standard
VCO), bistable operation (cycling between two
different orbits) or full chaos, which is typical of
chaotic systems.
7 EQUILIBRIUM POINT MODULATION INPUTS
Both equilibrium points can be voltage
modulated using these inputs, with 0 V and +5 V
corresponding to the minimum and maximum
values for each scroll.
8 RESET INPUT
Orbit 3’s core can be instantly reset by a rising
edge on this input, much like the ‘hard sync’ on
a conventional oscillator. Depending on the
chaos parameter values, the oscillation direction
may also flip during each reset pulse, leading to
octave down effects at audio frequencies.
This input is uniquely designed to be driven
reliably even from weak, slow, bipolar signals. It
features Schmitt action, with a +2 V low and +3 V
high logic threshold.
9 CHAOS OUTPUTS
These are the outputs from the different stages
inside the chaotic oscillator’s core. They
represent a three-dimensional orbit on axes X, Y
and Z around two adjustable equilibrium points.
The output signal of each successive stage will be
phase shifted by 60°, as shown on the front panel,
although the irregular nature of chaos means
this is not always apparent. For patching
convenience, inverted outputs are included as
well, yielding a full set of 6-phase outputs.
The output amplitudes typically range between
3 and 12 Vpp, as determined by the tame/wild
switch and the distribution and scroll position
parameters.
The images on the following page illustrate the
typical figures that arise when projecting the 3D
orbits onto two dimensions, with a variety of
parameter values and in each case using only
two out of six outputs. They are based on true
output captures of the module in operation.

ORBIT 3
DOUBLE-SCROLL CHAOS
OSCILLATOR
4

ORBIT 3
DOUBLE-SCROLL CHAOS
OSCILLATOR
5
10 EQUILIBRIUM POINT OUTPUT
At each instance, this output represents the
equilibrium point that is currently being orbited.
The output voltage will alternate between +5 V
for the positive scroll, and 0 V for the negative.
The resulting signal may be used as a pseudo-
random gate stream in low frequency mode, or
as a sound source at audio frequencies.
11 VOLT PER OCTAVE TRIMMER
This trim potentiometer is used to calibrate the
module’s pitch tracking. Since it is accessible
from the front panel, calibration can be easily
performed without removing the module from
the system. Each module is individually
calibrated during production; do not adjust this
trimmer if not needed.
Should you find your Orbit 3 to be out of tune, set
it to the audio frequency range and in wild mode,
with the coarse frequency knob to about 30 % of
its range (10 o’clock), the distribution knob to 9
o’clock, and the frequency modulation and both
equilibrium point position knobs fully clockwise.
There should now be a steady, regular oscillation
on all outputs. If not, you may need to adjust the
distribution or equilibrium point knobs slightly.
Make sure Orbit 3 has been powered for at least
20 minutes at a stable ambient temperature.
Now connect the equilibrium point output to a
calibrated digital tuner.
During the tuning process, the frequency
modulation input should be continually
switched between 0 V and a precision +4 V
source, toggled automatically or by hand. Leave
all other inputs unpatched.
Using a dedicated trimming tool or standard
2.5 mm flat screwdriver, adjust the trimmer until
the interval between both states is exactly 4
octaves. For example, if 0 V corresponds to a
pitch of C1 + 23 cents, +4 V should yield C5 + 23
cents.

ORBIT 3
DOUBLE-SCROLL CHAOS
OSCILLATOR
6
PATCH IDEAS
CHAOTIC DUET
You can create two alternated, chaotically
modulated voices using Orbit 3, a gated signal
switch and a single oscillator. Patch two different
waveform outputs through the selector switch.
Set Orbit 3 in low mode and use one of the Z
chaos outputs to frequency modulate the
oscillator. Next, send the EP output to the gate
input of the switch.
The switch will cycle between the two
waveforms, each of them modulated around a
different centre pitch. Each scroll is now given its
own voice, resulting in a chaotic duet.
SAW WAVE CHAOS
There are many useful applications for feedback
patching within Orbit 3. For example, patch any
of the X outputs into the frequency modulation
input and turn the modulation amount up to the
maximum setting.
The waveforms at the Z outputs will now be saw-
like, rather than sinusoidal. Experiment with
different feedback path and output
combinations of to achieve a wide variety of
timbres.
STEPPED TONE GENERATOR
While stable points can be readily found by
experimenting with the chaos parameters in
normal operation, Orbit 3 can also be forced into
stable oscillation by patching the EP output into
the reset input.
While the oscillation frequency can still be
controlled normally, adjusting the distribution
and equilibrium point parameters will cause
stepped changes in perceived pitch when the
module is set in the audio frequency range. Use
tame mode for the best results.

ORBIT 3
DOUBLE-SCROLL CHAOS
OSCILLATOR
7
SPECIFICATIONS
Module format
Doepfer A-100 ‘Eurorack’ compatible module
3 U, 10 HP, 30 mm deep (inc. power cable)
Milled 2 mm aluminium front panel with non-
erasable graphics
Maximum current draw
+12 V: 70 mA
−12 V: 65 mA
Power protection
Reverse polarity (MOSFET)
I/O impedance
All inputs: 100 kΩ
Analogue outputs: 0 Ω (impedance comp.)
Gate output: 1 kΩ
Outer dimensions (H x W x D)
128.5 x 40.3 x 43 mm
Mass
Module: 140 g
Including packaging and accessories: 215 g
SUPPORT
As all Joranalogue Audio Design products,
Orbit 3 is designed, manufactured and tested
with the highest standards, to provide the
performance and reliability music professionals
expect.
In case your module isn’t functioning as it should,
make sure to check your Eurorack power supply
and all connections first.
If the problem persists, contact your dealer or
send an email to [e-mail].
Please mention your serial number, which can be
found on the product card or on the module’s
rear side.

With compliments to the following fine people,
who helped to make Orbit 3 a reality!
Björn Jauss Boris Uytterhaegen
Daniel Miller Frits Jacobs
Gregory Delabelle Jan D’Hooghe
Janus Coorevits Jérémy Bocquet
Jeroen De Pessemier Lieven Stockx
Marcin Staniszewski Quincas ‘Synth DiY Guy’ Moreira
Rick Van Oss Sebastiaan Tulkens
Orbit 3 User Manual
version 2021-09-13
21st Century Analogue Synthesis—Made in Belgium
© 2021
[e-mail]
https://joranalogue.com/