Intellijel Quadrax User manual
Quadrax Manual
Quadrax
(Including Optional Qx Expander)
4-Channel CV-Controllable Function Generator
With Cycling, Pulse Burst Generation and Morphing LFO
Manual Revision: 2019.11.05
Quadrax Manual
Table of Contents
Table of Contents 1
Compliance 3
Installation 4
Installing Your Module 5
Connecting the Optional Qx Expander Module 6
Overview 7
Quadrax Front Panel 8
Controls 8
Inputs and Outputs 14
Channel Mode Options 15
AD Mode 15
AHR Mode 15
CYCLE Mode 16
BURST Mode 16
LFO Mode 17
Channel Link Options 18
No Link 18
Trigger Link 18
End Of Rise Link 19
End of Fall Link 19
Multiple Triggers 20
Burst Mode 21
LFO Mode 23
Multiple Beat Synchronized LFOs 25
LFO Waveshapes and Morphing 26
Page 1
Quadrax Manual
Making CV Assignments 27
Enter/Exit CV Assignment Mode 27
Programming the CV Matrix 28
The possible destinations (per channel) are (from top button to bottom): 28
Clearing CV Assignments 31
Using the Optional Qx Module 32
EOR/EOF for AD Mode 32
EOR/EOF for AHR Mode 33
EOR/EOF for CYCLE Mode 33
EOR/EOF for BURST Mode 34
EOR/EOF for LFO Mode 34
Firmware Version Display 35
Firmware Change Log 36
Technical Specifications 37
Page 2
Quadrax Manual
Compliance
This device complies with Part 15 of the FCC Rules. Operation is subject to the
following two conditions: (1) this device may not cause harmful interference, and
(2) this device must accept any interference received, including interference that
may cause undesired operation.
Changes or modifications not expressly approved by Intellijel Designs, Inc. could
void the user’s authority to operate the equipment.
Any digital equipment has been tested and found to comply with the limits for a
Class A digital device, pursuant to part 15 of the FCC Rules. These limits are
designed to provide reasonable protection against harmful interference when the
equipment is operated in a commercial environment. This equipment generates,
uses, and can radiate radio frequency energy and, if not installed and used in
accordance with the instruction manual, may cause harmful interference to radio
communications.
This device meets the requirements of the following standards and directives:
EMC: 2014/30/EU
EN55032:2015 ; EN55103-2:2009 (EN55024) ; EN61000-3-2 ; EN61000-3-3
Low Voltage: 2014/35/EU
EN 60065:2002+A1:2006+A11:2008+A2:2010+A12:2011
RoHS2: 2011/65/EU
WEEE: 2012/19/EU
Page 3
Quadrax Manual
Installation
Intellijel Eurorack modules are designed to be used with a Eurorack-compatible case and power
supply. We recommend you use Intellijel cases and power supplies.
Before installing a new module in your case, you must ensure your power supply has a free power
header and sufficient available capacity to power the module:
● Sum up the specified +12V current draw for all modules, including the new one. Do the same
for the -12 V and +5V current draw. The current draw will be specified in the manufacturer's
technical specifications for each module.
● Compare each of the sums to specifications for your case’s power supply.
● Only proceed with installation if none of the values exceeds the power supply’s specifications.
Otherwise you must remove modules to free up capacity or upgrade your power supply.
You will also need to ensure your case has enough free space (hp) to fit the new module. To prevent
screws or other debris from falling into the case and shorting any electrical contacts, not leave gaps
between adjacent modules, and cover all unused areas with blank panels. Similarly, do not use open
frames or any other enclosure that exposes the backside of any module or the power distribution
board.
You can use a tool like ModularGrid to assist in your planning. Failure to adequately power your
modules may result in damage to your modules or power supply. If you are unsure, please contact us
before proceeding.
Page 4
Quadrax Manual
Installing Your Module
When installing or removing a module from your
case always turn off the power to the case and
disconnect the power cable. Failure to do so may
result in serious injury or equipment damage.
Ensure the 10-pin connector on the power cable is
connected correctly to the module before
proceeding. The red stripe on the cable must line
up with the -12V pins on the module’s power
connector. Different modules use different ways to
indicate the -12V pins. Some may be labelled with
“-12V;” a white stripe next to the -12V pins; the
words “red stripe;” or some combination of these.
Additionally, some modules may have shrouded
headers, thus preventing backward connections.
Most modules will come with the cable already connected but it is good to double check the
orientation. Be aware that some modules may have headers that serve other purposes so ensure the
power cable is connected to the right one.
The other end of the cable, with a 16-pin connector,
connects to the power bus board of your Eurorack
case. Ensure the red stripe on the cable lines up
with the -12V pins on the bus board. On Intellijel
power supplies the pins are labelled with the label
“-12V” and a thick white stripe:
If you are using another manufacturer’s power
supply, check their documentation for instructions.
Page 5
Quadrax Manual
Once connected, the cabling between the module and power supply should resemble the picture
below:
Before reconnecting power and turning
on your modular system, double check
that the ribbon cable is fully seated on
both ends and that all the pins are
correctly aligned. If the pins are
misaligned in any direction or the ribbon
is backwards you can cause damage to
your module, power supply, or other
modules.
After you have confirmed all the
connections, you can reconnect the
power cable and turn on your modular
system. You should immediately check
that all your modules have powered on and are functioning correctly. If you notice any anomalies, turn
your system off right away and check your cabling again for mistakes.
Connecting the Optional Qx Expander Module
Connect the power cable between the 10-pin Qx power connector and one 16-pin power socket on
your eurorack system’s powered bus board as described above.
Using the I2C cable supplied with your Qx
module, connect one end to the 6-pin I2C
connector on the Qx and the other end to
either of the two I2C ports on your Quadrax
module (it doesn’t matter which of Quadrax’s
two I2C ports you use). Be sure to align the
red stripe with the white line on the Qx circuit
board.
Page 6
Quadrax Manual
Overview
The Intellijel Quadrax consists of four independent, CV-controllable channels, each of which can be
configured to perform any one of the following functions:
● an AD (Attack, Decay) envelope
● an AHR (Attack, Hold, Release) envelope
● a cycling envelope (resulting in a unipolar LFO)
● a pulse burst generator
● a morphing, bipolar LFO
The envelopes all feature a continuously variable response curve, ranging from logarithmic through
linear to exponential, and each stage can be as snappy as 0.3ms to as lengthy as 20seconds.
When set to Burst mode, the channel generates a rising or falling burst of pulses, with full control over
the length of the pulse burst, the number and shape of the bursts within it, and whether the bursts
increase or decrease in amplitude over the burst.
AD, AHR, Cycling and Burst modes all feature a user-selectable maximum output level of either 5V or
10V.
LFO mode offers control over the frequency and waveshape, while providing a unique morphing
feature that creates numerous variations of the selected waveshape. LFOs can be either free-running
or beat-synchronized using the channel’s TRIG input.
Channels can be chained together to create complex multi-stage envelopes, with each channel
triggered by the previous channel’s trigger input, end-of-rise, or end-of-fall. This enables multiple
function generators to fire simultaneously, or it enables the creation of complex multi-stage envelopes
by allowing the linked function to fire either at the end of the previous function’s rise time, or at the end
of its fall time.
Four freely-assignable, step-attenuverted CV inputs are capable of modulating any or all of the
various parameters across all four channels using the built-in CV matrix, with built-in attenuversion for
each assignment.
Quadrax remembers its current state (Mode and CV assignments, channel links, etc) and retains that
state even if power is removed, meaning Quadrax will always turn on in exactly the same state as you
last left it.
Use the optional Qx module to add individual outputs for each channel’s End-of-Rise and End-of-Fall
triggers.
Page 7
Quadrax Manual
Quadrax Front Panel
Controls
1. RISE (x4) - Each channel has its own RISE
knob, whose function depends on the channel’s
mode assignment, as selected by the
MODE/DESTINATION button [6] .
●AD , AHR and CYCLE modes: This knob
controls the rise time (attack) of the
function (rising from zero to the
maximum level). Slower times will create
a fade-in effect while faster times are
used for snappy percussive sounds.
When fully counterclockwise, rise time is
about 0.3ms, slowing to about 50ms at
the ‘noon’ position. Rotating past noon
results in increasingly lethargic rise
times, up to about 20seconds when
fully clockwise.
●BURST Mode : The RISE knobs sets the
overall length of the pulse burst (and,
therefore, the rate at which the pulses
repeat).
Rotating the knob clockwise increases
the length of the pulse burst from about
0.3ms when fully counterclockwise to
around 20 seconds when fully
clockwise. Using CV extends the range
even further.
●LFO Mode : The RISE knob functions as a RATE knob for the LFO.
With nothing patched into the TRIG input, the LFO is free-running and the knob sets
the LFO rate from 0.05 Hz (20sec) when fully counterclockwise to around 3.33kHz
(0.3ms) when fully clockwise. Using CV extends the range even further.
If you patch a clock into the TRIG input, the LFO will synchronize to the clock, and the
RISE knob changes the multiplication/division of the incoming clock. At the ‘noon’
Page 8
Quadrax Manual
position, the rate equals the incoming
clock. Rotating the knob
counterclockwise divides the clock,
achieving a rate 1/64 of the clock rate
when fully counterclockwise. Rotating
the knob clockwise multiplies the clock
rate, achieving a rate 64 times faster
than the incoming clock when fully
clockwise. For more information about
LFO Mode, see LFO Mode , later.
2. FALL (x4) - Each channel has its own FALL
knob, whose function depends on the channel’s
mode assignment, as selected by the
MODE/DESTINATION button [6] .
●AD , AHR and CYCLE modes: Sets the
amount of time it takes for the function
to fall from its maximum value back to
zero. In AHR mode this will act as the
release time. In Cycle mode the total
time of RISE plus FALL sets the
frequency of the cycle.
When fully counterclockwise, fall time is
about 0.3ms, slowing to about 50ms at
the ‘noon’ position. Rotating past noon
results in increasingly lethargic fall
times, up to about 20sec when fully
clockwise.
●BURST Mode : The FALL knobs sets to the number of pulses contained within the
burst. When fully counter-clockwise, Quadrax generates one pulse per burst. When
fully clockwise, Quadrax generates 64 pulses per burst. See BURST Mode later in this
manual for more information.
Page 9
Quadrax Manual
●LFO Mode : The FALL knob becomes a
MORPH knob, and is used to create
numerous interesting and morphable
variations on the basic waveform set by
the RESPONSE CURVE knob. These
are detailed in the LFO Waveshapes
and Morphing section, later in this
manual).
3. RESPONSE CURVE (x4) - Each channel has
its own RESPONSE CURVE knob, whose
function depends on the channel’s mode
assignment, as selected by the
MODE/DESTINATION button [6] .
●AD , AHR and CYCLE modes: This knob
changes the shape of the RISE and
FALL curves.
At the ‘noon’ position, the curves are
linear, which is traditionally the shape
used to control exponential VCAs.
Rotating the knob clockwise from center
results in an increasingly exponential
shape. This is the curve found on many
classic envelope generators, and is
traditionally used to control linear VCAs.
Exponential shapes tend to have more
of a plucked character.
Rotating the knob
counterclockwise from
center results in an
increasingly logarithmic
shape.
The knob’s effect on
curvature Is illustrated to
the right.
Page 10
Quadrax Manual
●BURST Mode : This knob selects the
pulse shape and whether the pulse
amplitude increases (clockwise from
‘noon’) or decreases (counter- clockwise
from ‘noon’) over the burst length. Rising
bursts start at 0V and rise to Quadrax’s
maximum voltage. Falling bursts start at
maximum voltage and decay to 0V. For
more information, see the BURST Mode
section, later in this manual.
●LFO Mode : The RESPONSE CURVE
knob controls the LFO shape, which is
further defined by the MORPH (FALL)
knob. LFO Mode’s interaction of these
two knobs is discussed in LFO Mode ,
later in this manual.
4. LED - The brighter this LED (x4), the higher the
corresponding function generator’s amplitude. If
the LED is green , then the function is
generating a positive voltage. A red LED
indicates a negative voltage.
5. LINK/CV button - This button (x4) has two
functions, LINK and CV ASSIGN.
●LINK : The button’s primary function (as
indicated by the graphics beneath) is to
determine whether or not the prior channel triggers this channel and, if so, how.
Specifically, the LINK button on Channel2 determines if/how it’s triggered by
Channel1; Channel3’s button determines if/how its triggered by Channel2; and
Channel4’s button determines if/how it’s triggered by Channel3. Channel1’s button
determines if/how it’s triggered by Channel4. Push a channel’s LINK button repeatedly
to cycle through the various triggering options. See Channel Link Options for more
information.
●CV ASSIGN : The button’s secondary function (as indicated by the label above it) is to
assign the four CV inputs to one or more destinations for each channel. Long-press the
LINK/CV button to enter CV Assignment mode. See Making CV Assignments for more
information.
Page 11
Quadrax Manual
6. MODE/DESTINATION button - This button (x4)
has two functions: In normal operation, it
selects the channel’s MODE, while in CV
Assignment mode, it sets the DESTINATION
(and attenuversion) of the CV input.
When used as a MODE button, it sets each
channel to one of five modes. Push the MODE
button repeatedly to cycle through the various
mode options, which are:
●AD : Attack/Decay envelope, where
RISE controls the envelope’s attack time
and FALL controls the decay time. AD
envelopes complete their entire cycle
upon receiving a trigger at the
corresponding TRIG input. AD
envelopes ignore the gate time of the
incoming signal.
●AHR : Attack/Hold/Release envelope,
where RISE controls the envelope’s
attack time and FALL controls its release
time. The attack portion of the envelope
is triggered by the rising edge of a gate
signal sent to the corresponding TRIG
input. The envelope holds (sustains) its
maximum value for as long as the gate
signal is high, then triggers the release
stage when the gate signal goes low.
●CYCLE : Cycle mode behaves like a unipolar LFO, with the RISE and FALL times
determining the rate and shape of the LFO.
Page 12
Quadrax Manual
●Burst : Burst mode generates a
definable number of cyclic pulses (using
the FALL knob), spaced evenly within a
definable length of time (using the RISE
knob), whose pulse shapes and overall
amplitude curve are defined with the
RESPONSE CURVE knob. This mode is
discussed thoroughly in BURST Mode ,
later in this manual.
●LFO : LFO mode turns a channel into a
bipolar, beat-syncable LFO with multiple
basic waveshapes and some advanced
waveshape morphing capabilities. This
mode is discussed thoroughly in LFO
Mode , later in this manual.
In CV Assignment mode, this button assigns
destinations to CV inputs, and controls the
amount of attenuversion applied. The brighter
the button, the more a CV input affects a
destination, with green indicating positive
modulation and red indicating negative
modulation. The operation of the DESTINATION
button is described fully in Making CV
Assignments .
Page 13
Quadrax Manual
Inputs and Outputs
A. TRIG Inputs (x4) - Patch a trigger or gate signal
here to launch the function generator. There are
four TRIG inputs — one for each of the four
function generators.
In LFO mode, the TRIG input functions as a
clock input, and the RISE/LFO RATE knob
functions as a clock divider/multiplier, allowing
beat-synchronized LFOs. Because the TRIG
inputs have jack detection, you can have
free-running LFOs by simply leaving the TRIG
input disconnected.
B. OUTS (x4) - Outputs for each of the four
channel function generators.
Channels assigned to AD, AHR, CYCLE or
BURST modes generate a unipolar control
signal. The maximum level can be set to either
5V or 10V, and is toggled by holding down
Channel4’s MODE/DESTINATION button while
powering on the module.
You can see, during any power up, whether
Quadrax is currently set to 10V or 5V. If the
maximum output level is currently set to 10V,
the Firmware Version Display LEDs are blue upon boot. If the maximum output level is
currently set to 5V, the Firmware Version Display LEDs are green upon boot. Quadrax ships
from the factory with an output voltage of 5V.
Channels assigned to LFO mode generate a bipolar signal (-5V to +5V).
C. CV Inputs (x4) - Patch control voltages into each jack to modulate one or more user-definable
parameters for any or all of the four channels. Each CV input can control multiple destinations,
and with varying amounts of attenuversion for each. For more information, see Making CV
Assignments .
NOTE: Although the range of CV modulation is ±5V, the CV inputs accept voltages up to ±10V.
Any voltages above or below 5V are simply clipped at ±5V. Use Quadrax’s internal
attenuverters (as described in Programming the CV Matrix ) to dial down the input voltages.
Page 14
Quadrax Manual
Channel Mode Options
Each of Quadrax’s four channels can be assigned to operate in one of
five modes: Pushing the MODE button repeatedly cycles through the
various mode options.
AD Mode
When the MODE button is unlit, the
channel is a classic, 2-stage Attack/Decay
envelope, where RISE controls the
envelope’s attack time and FALL controls
the decay time. AD envelopes complete
their entire cycle upon receiving a trigger
at the corresponding TRIG input. AD
envelopes ignore the gate time of the
incoming signal.
AHR Mode
When the MODE button is red , the
channel acts as an Attack/Hold/Release
envelope, where RISE controls the
envelope’s attack time and FALL controls
its release time. The attack portion of the
envelope is triggered by the rising edge of
a gate signal sent to the corresponding
TRIG input. The envelope holds (sustains)
its maximum value for as long as the gate
signal is high, then triggers the release
stage when the gate signal goes low. If
the gate length is shorter than the rise
time, the envelope will begin to fall before
reaching its maximum value.
Page 15
Quadrax Manual
CYCLE Mode
When the MODE button is green , the
channel produces a cycling AD envelope,
which behaves like a unipolar LFO. The
frequency of the cycle is determined by
the overall sum of the RISE and FALL
times. The skewing of the cycle is
determined by the relative amounts of
RISE and FALL, while the curvature is
selected by the RESPONSE CURVE
knob.
The Cycle is free running, and does not
require a TRIG input. However, if a TRIG
input is detected, then the Cycle resets,
as shown in the graphic to the right. GATE
times are ignored.
BURST Mode
When the MODE button is yellow , the
channel operates in BURST mode. Burst
mode generates a definable number of
cyclic pulses (using the FALL knob),
spaced evenly within a definable length of
time (using the RISE knob), whose shape
and amplitude curve are defined with the
RESPONSE CURVE knob.
For more information, see Burst Mode ,
later in this manual.
Page 16
Quadrax Manual
LFO Mode
When the MODE button is magenta , the channel operates in LFO mode. In this mode, the channel
becomes a bipolar LFO, with the RISE knob controlling LFO RATE , the RESPONSE CURVE knob
selecting WAVESHAPE , and the FALL knob controlling a MORPH function that varies the waveshape.
For more information, see LFO Mode
later in this manual.
LFOs can be beat-synchronized using
the channel’s TRIG input, or they can be
free-running if the TRIG input is left
unpatched.
Clocked LFO: Send a clock to the
channel’s TRIG input and use the RATE
(RISE) knob to multiply or divide that rate
by as much as 64x in either direction.
With the RATE knob straight up (‘noon’
position), the LFO rate equals the clock
rate.
Unclocked LFO: Leave the channel’s
TRIG input unpatched and use the RATE
(RISE) knob to dial in the desired
free-running rate. LFO frequency can be
set from 0.05 Hz (20sec) when fully
counterclockwise to around 3.33kHz
(0.30ms) when fully clockwise. Using
CV extends the range even further.
Page 17
Quadrax Manual
Channel Link Options
Though it’s perfectly acceptable to think of Quadrax as four completely independent
function generators, the module features several ways to link these channels
together. Use the LINK button (together with the TRIG inputs) to fire off multiple
functions with a single trigger, or to create complex envelope shapes and rhythms using multiple
triggers. Pushing the LINK button repeatedly cycles through the various channel link options.
No Link
When the LINK button is unlit, channel triggering is completely independent of the channel that
precedes it, and is controlled entirely by its own TRIG input.
Trigger Link
When the LINK button is red , channel triggering is normalled to the previous envelope’s TRIG input.
This lets you trigger two entirely different functions with a single trigger, which is useful (for example)
when you want a keyboard or sequencer to trigger multiple envelopes with a single note event (such
as one envelope for your VCA and a second envelope for your filter).
Page 18
Quadrax Manual
End Of Rise Link
When the LINK button is green , the channel is triggered when the previous channel’s function
completes its RISE time.
While the meaning of “End of Rise” (EOR) is obvious for envelope-based functions (such as AD, AHR
and CYCLE), it may be less obvious how a channel is triggered by the EOR of a BURST or LFO
channel. BURST mode triggers an EOR at the beginning of every pulse within the burst. LFO mode
triggers an EOR every time the LFO completes half its cycle. For a complete description of exactly
when EOR and EOF are triggered for each of Quadrax’s five modes, see Using the Optional Qx
Module , later in this chapter.
End of Fall Link
When the LINK button is yellow , the channel is triggered when the previous channel’s function
completes its FALL time.
While the meaning of “End of Fall” (EOF) is obvious for envelope-based functions (such as AD, AHR
and CYCLE), it may be less obvious how a channel is triggered by the EOF of a BURST or LFO
channel. BURST mode triggers an EOF at the end of every burst length. LFO mode triggers an EOF
every time the LFO completes a full cycle. For a complete description of exactly when EOR and EOF
are triggered for each of Quadrax’s five modes, see Using the Optional Qx Module , later in this
chapter.
Page 19
Other manuals for Quadrax
1
Table of contents
Other Intellijel Recording Equipment manuals
Intellijel
Intellijel Metropolis User manual
Intellijel
Intellijel Scales User manual
Intellijel
Intellijel Steppy 1U User manual
Intellijel
Intellijel Shifty User manual
Intellijel
Intellijel Passive LPG 1U User manual
Intellijel
Intellijel Palette 104 User manual
Intellijel
Intellijel Sealegs User manual
Intellijel
Intellijel XFADE 1U User manual
Intellijel
Intellijel Steppy 3U User manual
Intellijel
Intellijel MIDI 1U User manual
Intellijel
Intellijel Audio I/O v3 2023 User manual
Intellijel
Intellijel Tangrams User manual
Intellijel
Intellijel CYLONYX Rainmaker User manual
Intellijel
Intellijel Steppy 3U User manual
Intellijel
Intellijel Metropolix User manual
Intellijel
Intellijel MIDI1U User manual
Intellijel
Intellijel Planar2 User manual
