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Klavis Twin waves user manual V1.7 Page 1 of 19
Twin waves VCDO
Voltage-controlled Dual Oscillator - User manual
Introduction
The driving idea behind the Twin waves Voltage-controlled Dual Oscillator/LFO module is to offer
two interesting oscillators in a skiff-friendly and compact size. To achieve that challenge, we built
the product’s architecture on the concept of pre-defined algorithms, where the most useful
configurations and their matching parameters are ready to use.
Out 2Out 1
FM/AM
V.Oct 1
Param 2
Sync/Clk
Coarse
Twin waves
Parameter
Fine/
Level
DUAL OSCILLATOR
1
Param 1
V.Oct 2
Algo
Osc 2
Sync
LFO/AM
Qtz/Clk
Klavis
Features at a glance
Two oscillators independently set as VCO or LFO
Features in VCO mode:
o V/Oct tracking over 10 octaves
o Through zero and linear FM
o Sub-octave output
o Hard & soft synchronization
o VCA control and CV algorithm selection
o Quantizer with various scales
o Algorithm-based synthesis to choose among:
Wave shaping
Phase modulation
Phase positioning of multiple waves
5 stacked oscillators in tunable unison
Self-sync with phantom oscillator
Additive synthesis (7 waves)
Variable bit reduction (bit-crushing)
Ring modulator with its own 2
nd
oscillator
Noise with LPF, BPF, or resonant VCFs
Features in LFO mode:
o Simultaneous signal and trigger outputs
o External wave synchronization
o Clock controlled rate with multiplier and divider
o CV and knob control of output level
o Algorithm based wave engine with a selection of:
Wave shaping
Phase modulation
Random levels and vectors (also Brownian)
Randomly spaced triggers and waves
Display with contextual icons and instant reminder help text
LEDs indicating potentiometer vs. value matching, switch
settings and output levels
Automatically saved settings for instant recall at power on
Firmware update via a simple audio file
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Table of Contents
INTRODUCTION ...................................................................................................................................................... 1
FEATURES AT A GLANCE ........................................................................................................................................... 1
INSTALLATION AND SECURITY ............................................................................................................................ 4
PURPOSE .............................................................................................................................................................. 4
INSTALLATION ....................................................................................................................................................... 4
FIRMWARE UPDATE .............................................................................................................................................. 5
PROCEDURE .......................................................................................................................................................... 5
FINDING YOUR WAY AROUND THE PANEL ......................................................................................................... 6
HOW DOES THE CONTROLS SHARING WORK? .............................................................................................................. 6
SHARING OF THE SYNC/CLK JACK .............................................................................................................................. 6
CONTROLS OVERVIEW .......................................................................................................................................... 7
VCO & LFO .......................................................................................................................................................... 7
LOCKING THE POTENTIOMETERS ............................................................................................................................... 7
LFO ..................................................................................................................................................................... 7
VCO .................................................................................................................................................................... 7
PARAMETER AND ALGO .......................................................................................................................................... 7
THE DISPLAY AND CONTEXTUAL HELP ........................................................................................................................ 7
AUTOSAVE ............................................................................................................................................................ 7
VCO ......................................................................................................................................................................... 8
OVERALL PRESENTATION ......................................................................................................................................... 8
VCO ALGORITHMS TABLE ........................................................................................................................................ 9
V/OCT INPUT JACKS .............................................................................................................................................. 10
FM/AM JACK ...................................................................................................................................................... 10
SYNCHRONIZATION – SYNC BUTTON ........................................................................................................................ 11
QUANTIZER – QTZ/CLK BUTTON .............................................................................................................................. 12
THE [SQUARE] 1 JACK ............................................................................................................................................ 13
LFO ........................................................................................................................................................................ 14
OVERALL PRESENTATION ....................................................................................................................................... 14
LFO ALGORITHMS TABLE ...................................................................................................................................... 14
V/OCT INPUT JACKS ............................................................................................................................................... 15
CLOCK & SYNC – SYNC/CLK JACK ............................................................................................................................ 15
INTERNAL/EXTERNAL CLOCKING – QTZ/CLK BUTTON .................................................................................................. 15
SYNCHRONIZATION – SYNC BUTTON ....................................................................................................................... 16
FM/AM JACK & LEVEL KNOB ................................................................................................................................ 16
THE [SQUARE] 1 JACK ........................................................................................................................................... 16
SUMMARY OF BUTTONS USE .............................................................................................................................. 16
SINGLE BUTTON USE ............................................................................................................................................. 16
DUAL BUTTON USE ............................................................................................................................................... 16
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SUMMARY OF LED INDICATIONS ........................................................................................................................ 17
VCO MODE .......................................................................................................................................................... 17
LFO MODE ........................................................................................................................................................... 17
POTENTIOMETER LEDS .......................................................................................................................................... 17
OUTPUT LEDS ...................................................................................................................................................... 17
TROUBLESHOOTING ............................................................................................................................................ 18
FACTORY RESET ................................................................................................................................................... 18
THE POTENTIOMETERS DO NOT RESPOND ................................................................................................................ 18
NO SOUND OUT OF VCO1 ...................................................................................................................................... 18
NO SIGNAL IN LFO MODE ...................................................................................................................................... 18
LFO IS STUCK ...................................................................................................................................................... 18
VCO TRACKING IS ODD.......................................................................................................................................... 18
SPECIFICATIONS ................................................................................................................................................... 19
MECHANICAL....................................................................................................................................................... 19
SUPPLY ............................................................................................................................................................... 19
INPUT/OUTPUT .................................................................................................................................................... 19
SIGNALS ............................................................................................................................................................. 19
PACKING LIST ...................................................................................................................................................... 19
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Installation and security
Purpose
This module is meant for installation in a Eurorack-compliant chassis.
It adheres to Eurorack mechanical and electrical specifications.
Do not attempt using this module in other mechanical or electrical contexts.
Installation
Supply current requirements
Before the installation, disconnect the mains power supply from your modular system. Some
power supplies are not safely isolated; there is a risk of injury!
See in the specifications if this module requires 5V from the supply rails. If 5V is needed and your
rack is not providing 5V, do not attempt connection! You can add our NoDrain supply adapter.
Check that the current consumption requirements of this module, when added to your installed
set of modules do not exceed the available current from your supply. This is done by adding up
the current draw of all modules (mA) separately for each of 5V, 12V and -12V rails. If any of these 3
sums exceeds the available current of your supply for that voltage, do not connect the module to
your system; you need a stronger power supply.
Supply cable connection
The provided supply flat cable can only be inserted in the appropriate orientation at the back of
the module, so there is no risk of error on that end. However, you should pay attention to the
orientation of the cable in the socket of the supply PCB inside your chassis. Cheap sockets
without shrouding may allow you to plug in the connector the wrong way!
Such inversion may bring trouble as it shorts the supply rails which in turn may destroy some
sensitive module in your rack!
The red stripe on the cable should match a stripe printed on the supply board. The stripe also
indicates the -12V side. In case there is no stripe, a -12V (minus 12) marking is a safe indication of
the orientation.
Double check that the connectors are fully inserted and correctly oriented before switching on
the power supply. In case of an anomaly, switch off the power supply immediately and check
everything again.
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Firmware update
Always ensure that you have the latest firmware installed before using the module.
To know the current firmware revision of your module, press simultaneously the Osc2 and Sync
buttons; the display starts scrolling: “TW-REV x.xx - CAL OK”. Press any button to stop the
scrolling. If that procedure doesn’t show the version, you have an early version of the firmware.
The product can be updated by playing an audio file such as “TwinWaves_1.00.wav”.
Procedure
Connect a mono or stereo cable between your audio playing device headphone output
and the Twin waves FM/AM input.
Prepare to play the audio file
Set the play level at two thirds
While pressing the Osc2 and Sync buttons, switch on your modular case supply, or press
these two buttons immediately after switching on (within the first half-second).
The green and blue LEDs are flashing
Start playing the audio file
If everything goes fine
The green LED is steady ON while the blue is flashing
After a couple of seconds, the display starts filling up with dots
When the display is full,
o a message confirms the success of the update
o both blue LEDs plus the green one are flashing
Press the encoder to restart the module
If the sound level is too low
The red LED is steady ON; the two blue LEDs are flashing
Stop audio playback
Slightly increase the audio playback level
Press the encoder button; the green LED is flashing
Start audio playback from the beginning
If there is an error during the playback
It is possible that the sound setting was too loud to begin with. There is no LED feedback in such
case. Diminish the sound level drastically and restart the procedure.
Playback error can also be due to various parasitic sound causes:
Touching the cable
Using sound-generating features of your phone or computer
Some power saving feature that affects the audio playback
Surrounding noisy modules, bad electrical grounding or modular supply noise
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Finding your way around the panel
The module contains two oscillators: on the left drawing, the controls of the first oscillator and
on the right, those of the second one. All jacks but the Sync/Clk are dedicated to one of the
oscillators while all buttons, knobs, display and LEDs are somehow shared, in fact, virtually
duplicated. (There is a however a setting to allocate the V.Oct inputs with added flexibility)
Out 2Out 1
FM/AM
V.Oct 1
Param 2
Sync/Clk
Coarse
Twin waves
Parameter
Fine/
Level
DUAL OSCILLATOR
1
Param 1
V.Oct 2
Algo
Osc 2
Sync
LFO
Qtz/Clk
Out 2
Param 2
Sync/Clk
Coarse
Twin waves
Parameter
Fine/
Level
DUAL OSCILLATOR
V.Oct 2
Algo
Sync
LFO
Qtz/Clk
Out 1
FM/AM
V.Oct 1 Sync/Clk
Coarse
Twin waves
Parameter
Fine/
Level
DUAL OSCILLATOR
1
Param 1
Algo
Sync
LFO
Qtz/Clk
A
B
Section 1 controls and jacks Section 2 controls and jacks
Klavis Klavis Klavis
How does the controls sharing work?
The Osc2 button (A) with the blue LED determines which oscillator/section is currently selected.
When switching back and forth between the two sections, it is likely that the potentiometer
positions will not reflect the actual setting they control. This is why next to each pot there’s a
white LED (B) that goes on as soon the pot hits the actual value. Any time the white LED is on,
the pot cursor matches the value it controls. A pot only acts on the setting when its LED is on.
By design, the display and LEDs always reflect their section settings.
Sharing of the Sync/Clk jack
This jack feeds both sections and fulfills two roles in each. This sharing is solved by independently
allowing the jack to play a role in each section. Details are covered in Sync and Clock chapters.
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Controls overview
VCO & LFO
Each section of the Twin waves can do more than a typical VCO or LFO. We use the VCO and LFO
terms as generic names to categorize the functions into Audio generation and Modulation
generation. In this manual we use the VCO and LFO terms even when dealing with features which
are neither VCO nor LFO, such as filtered noise (VCO) or random vectors (LFO).
Locking the potentiometers
By pressing simultaneously the two lower buttons (Qtz & Sync), the potentiomer settings of the
current section can be locked/unlocked. Locking is indicated by regular flashes of the pots LEDs.
LFO
The LFO button, when lit tells that the selected section is in LFO mode:
The Qtz/Clk button gives access to clock settings
The Sync button is always about synchronization in both VCO and LFO modes
The Fine/Level knob is here Level, and controls the amplitude of the LFO
The FM/AM jack is controlling the Amplitude of the LFO 1 signal, AM thus!
VCO
When the LFO LED is off, you are in VCO mode:
The Qtz/Clk button gives access to the pitch quantizer settings
The Sync button is always about synchronization in both VCO and LFO modes
The FM/AM jack offers several control options to choose from, which are detailed later
Parameter and Algo
By default, the encoder controls the parameter related to the current algorithm. For example,
when selecting the Square/Pulse algorithm, the associated parameter is PWM (Pulse Width
Modulation). You can change that setting with the encoder and via the parameter jack.
To select another algorithm, briefly press the encoder. The Algo LED is now flashing. Turning he
encoder shows the various algorithm icons in the display. Most icons are straightforward; when
in doubt, there’s contextual help right on the module’s display.
The display and contextual help
At any time, a long press on the encoder tells you in scrolling text what you are currently
selecting or controlling. This help is available in every context so that you’ll never be lost.
While the text is scrolling you can turn the encoder to roll the text back or move it forward.
Press the encoder or any button to exit scrolling.
Autosave
Current settings are automatically saved to be restored during the next power-up. Settings
should not be changed within ten seconds of switching off.
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VCO
Overall presentation
In VCO mode, it is possible to activate a melodic quantizer, specific for the section, and to accept
an external sync.
The oscillator 1 has two additional capabilities:
an input jack that can be set into various control options: 2 FM modes, VCA, Quantizer
base note setting, or Algorithm selection
a sub-octave square output
The sound generation is selected from a list of algorithms belonging to one of the following
categories:
Single wave algorithms
Here are the typical waves found in analog oscillators, such as triangle, sine, square and pulse.
However, they can be dynamically changed in shape or phase ratio.
We have variations of true additive synthesis where sines are consecutively added to each other
for bright waves that have the purity of FM synthesis and remind of drawbar organs.
Multi-oscillator algorithms
These are realized within a single section. In other words each oscillator section will generate
more than one oscillator wave at once. The two sections in the Twin waves are totally
independent in this regard, so both can simultaneously use a multiple oscillator algorithm if
wished.
Examples of such algorithms are the Quad-saw where 4 waves act as a single one by locking their
pitch relation but adjusting their phase relation, or the Unison where 5 stacked oscillators can be
detuned.
Self-sync algorithms
Syncing is a typical patch that requires two oscillators. In Twin waves, each section can generate
the necessary pair of oscillators. Self-sync brings screaming leads and rumbling basses that need
no distortion to sound aggressive.
Ring modulator algorithm
A ring modulator is normally not a VCO feature and requires a pair of sound sources to do its
magic. Here, in a single algorithm, we provide the two necessary VCOs, each creating a pure sine.
Then jointly feeding a ring modulator, they create a whole range of metallic, robotic and bell
sounds.
Bit crushing algorithms
Bit crushing (also improperly called decimation) is a process applied on a sound. This process is
about resampling a sound with a lower bit resolution. We have improved the usual binary-valuesonly approach by allowing for integer values. This offers a much smoother change in the effect
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depth. For the best effect, these algorithms use waves that present soft slopes such as saw or
sine which are then broken down into staircases of variable step size. This creates a harmonically
rich sound. The dynamic control of the process allows a gradual change from the original wave
up to a buzzing pulse sound.
Noise algorithms
These algorithms are not based on oscillators. We start with a perfect white noise that will go
through various filters, such as low-pass, variable-width band-pass and resonant. The filters
cutoff frequency is controlled by the Coarse knob combined with the V.Oct (also FM for Osc 1)
jacks. Their resonance or bandwidth is controlled by the parameter and its CV.
Since the filter tracks the V.Oct input, the Quantizer is available.
Sync is obviously not available with the noise algorithms.
VCO algorithms table
Icon
Algorithm
Configuration
Parameter
Parameter effect
Sine
1 osc
Phase mod
Wave Symmetry
Sqr/pulse
1 osc
PWM
Square to pulse waveshaping
SawTri
1 osc
Wave shape
Triangle to saw waveshaping
Quad saw
4-saw osc
Phase spread
Phase spreading of 4 saw waves
Additive even
7-sine osc
Harmonics
Harmonics content
Additive odd
7-sine osc
Harmonics
Harmonics content
Additive all
7-sine osc
Harmonics
Harmonics content
Unison square
3x square osc
Spread
Detuning of the 3 oscillators
Unison saw
5x saw osc
Spread
Detuning of the 5 oscillators
Bit-crushed saw
1 osc + BR
Bit resolution
Sample levels (integers 3 to 24)
Bit-crushed sine
1 osc + BR
Bit resolution
Sample levels (integers 3 to 24)
Self-sync sqr
1+1 osc
Carrier Frq
Frequency of slave oscillator
Self-sync pulse
1+1 osc
Carrier Frq
Frequency of slave oscillator
Self-sync saw
1+1 osc
Carrier Frq
Frequency of slave oscillator
Self-sync tri
1+1 osc
Carrier Frq
Frequency of slave oscillator
Self-sync sine
1+1 osc
Carrier Frq
Frequency of slave oscillator
Ring modulator
1+1 osc +RM
Carrier Frq
Frequency of secondary oscillator
Noise low-pass
Noise + LPF
Resonance
Filter resonance
Noise bandpass
Noise + BPF
Band width
Filter Bandwidth
Noise resonator
Noise + APRF
Filter gain
Quality factor
Any combination of algorithm is possible between the two oscillators.
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V/Oct input jacks
These are meant to bring a control voltage that determines the pitch of the oscillator and
respond to 1 volt per octave, thus 1/12 volt per semitone. With noise algorithms, the voltage
controls the cutoff frequency of the associated filter.
When both sections are in VCO mode, a long press on the Osc2 button brings the V.Oct
configuration options. Setting is changed with the encoder.
Accordingly, the Osc2 LED will blink none, once, or twice per 2 seconds.
0. Separate – This is the default mode where each V.Oct jack controls its related oscillator
without interference with the other.
1. Added – The voltages brought at each V.Oct input are summed up before controlling
both oscillators in parallel. The tuning, as all other settings remain completely
independent.
2. Offset – V.Oct1 controls both oscillators in parallel. V.Oct2 adds up to the voltage sent to
oscillator 2.
When at least one oscillator is set to LFO, the V.Oct jacks go into separate mode. If later returned
to VCO+VCO configuration, the previous V.Oct setting is restored.
FM/AM jack
A long press on the LFO/AM button shows the current role of the FM/AM jack.
Rotate the encoder to select one of the 5 jack roles, and then press it to apply the change.
Accordingly, the LFO/AM LED will blink none, once, twice or 3 times per 2 seconds.
0. BZX (FM) – a sophisticated frequency modulation of Osc1 which is at the same time:
Bipolar – the modulation behavior is mirrored between positive or negative
modulations; in other words, the wave direction is reversed twice over the full
positive + negative modulation span.
Through-zero – the oscillator slows down to a stop before time reversal of the
wave and increase of the frequency.
Symmetrically crossing the zero frequency point – the maximum frequency of the
reversed wave at full modulation is strictly identical to the one when modulation
is zero, whatever the initial frequency.
The zero points are set halfway of each modulation range, positive and negative.
1. FM – a moderate linear bipolar control voltage is added to the pitch of Osc1.
2. VCA – amplitude control of Osc1. Without control voltage, there is no sound !
3. QTZ base note – the voltage will define the base note of the oscillator 1 Quantizer.
See Quantizer base note on the following page.
1. Algo – this is a meta-control: a bipolar voltage selects an algorithm away from the one
currently set manually. Note that the parameter manual setting for all algorithms is now
derived from the starting algorithm setting.
The LFO/AM LED stays off; the Algo LED is flashing once every two seconds.
The BZX-FM mode is inoperative with Unison, Self-Sync and Noise algorithms.
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Synchronization – Sync button
Besides offering self-sync capability, both Twin waves’ oscillators can be synced in the usual way,
meaning slave-synchronized to an external master oscillator.
Pressing the sync button opens the sync setting menu. Turning the encoder allows you to apply
or not the sync signal from the sync jack, and in most algorithms, to choose between soft sync
and hard sync.
Pressing again the sync button or the encoder will validate your selection. When steady on, the
Sync LED tells that some sync is active.
Keep in mind that the sync jack being shared by the two oscillators you have to enable/disable its
use in the adequate section.
Since you have a pair of oscillators in Twin waves, you can connect the output of the second
oscillator to sync the first one via a patch cable in the sync jack.
Just for fun, note that even the Self-sync algorithms allow being re-synced by an additional
oscillator for a sonic result which is, how to say, hmmm, judge by yourself!
Self-Sync slave tracking
When using any of the Self-sync algorithms, a pair of oscillators is involved. By default the pitch of
the slave oscillator is relative to the one of the master oscillator (their pitch moves jointly with
V/Oct input and pitch settings of the section).
A long press on the Sync button allows changing the setting of the slave oscillator between
relative and absolute. In absolute mode, the Sync LED pulses once every two seconds.
Notes about the soft-sync
Soft sync is available in the sine and triangle self-sync algorithms as well as with external sync.
In both cases, the sync signal is time-reversing the wave direction, exactly like doing thru-zero FM
using a square wave as the modulation signal. Note that the frequency of the resulting wave is
maintained over the direction change.
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Quantizer – Qtz/Clk button
Each section has an independent pitch quantizer. To edit its settings, press briefly the Qtz/Clk
button. The encoder allows you selecting a quantize mode or scale. Pressing the Qtz/Clk button
again or the encoder validates your choice.
The Qtz/Clk LED is steady on when any quantizing is enabled.
There is one quantizer setting per section; it applies to all algorithms of that section.
Quantize name
Icon
Details
Base note span
Quarter tones
¼
Divides the octave in equal 24 steps
n.a.
Semitones
½
Divides the octave in 12 equal steps
n.a.
Diatonic
Di
c, d, e, f, g, a, b
12
Major
M
c, e, g
12
Minor
m
c, d#, g
12
Natural Minor
nm
c, d, d#, f, g, g#, a#
12
Pentatonic
Pe
c, d, e, g, a
12
Spanish
Sp
c, c#, e, f, g, g#, a#
12
Gamelan
Ga
c, c#, d#, g, g#
12
In Sen
IS
c, c#, f, g, a#
12
Hirajoshi
Hi
c, d#, f, g, g#
12
Blues
BL
c, d#, f, f#, g, a#
12
Chinese
Ch
c, e, f#, g, b
12
Hungarian
Hu
c, d, d#, f#, g, g#, b
12
Octatonic
8n
c, c#, d#, e, f#, g, a, a#
3
Hexatonic
Hx
c, d, e, f#, g#, a#
2
Thirds
3”
c, e, g#
4
Fifths
5”
Fifth to fifth; does not repeat over octaves!
7
Octaves
Oc
Oc
12
Just intonation
Ji
1/1, 9/8, 5/4, 4/3, 3/2, 5/3, 15/8 ratios
12
19 tones
19
Divides the octave in 19 equal steps
n.a.
A long press on the encoder allows you seeing the full name of the mode/scale selected.
The Pentatonic scale covers both major and minor variations because Pentatonic Minor is the
same as Major when the tonic starts 3 semitones lower. So, retuning the base note and if
necessary, the oscillator pitch, will do the trick.
Quantizer base note
This setting is to make the Twin Waves Quantizer match the degree of a voltage source
(sequencer, keyboard, …) that generates its V/Oct CV according to predefined notes.
Suppose a keyboard that gives 1.25V when playing C1; if you apply a quantizer that expects
voltage for C being 1V, the notes allowed by the quantizer scale will not match the ones on the
keyboard’s keys.
Once a quantizer is active, it is possible to set its base note. The base note determines which
voltage level will be the start point of the scale selected. In other words, the base note setting
transposes the scale that checks the incoming volts; it does not transpose the oscillator.
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If the base note for the scale is zero Volts, setting the base note 6 semitones higher will put it at
0.5V (1 V x 6/12). Now to accept a voltage that should be a C, you need 0.5V. Then to actually hear
a C, you must tune the coarse and fine pots as needed.
A long press on the Qtz/Clk button displays the base note setting. It can be edited with the
encoder in the usual way.
The base note can also be changed dynamically by setting the FM/AM jack to base note mode and
feeding it with a voltage. In such use, the base note voltage complies with 1 V/Oct.
Root note and Base Note for the musically inclined techie
In the quantizer, the root note is always indicated as a C. Moving it to another degree is done by
turning the coarse knob. This transpose happens after the quantize operation.
While the Base Note setting can give some transpose side effects, it is different in that it tunes
the root note on the voltage input side of the quantizer, before the quantize operation occurs.
This is why Base Note had to have another name than Root note.
If you don’t know what to do with Base Note, it is most likely because you don’t need touching it.
The need arises when melodic CV generators do not play what they should when passed through
a Twin Waves quantizer. This is because the scale of the CV generator is already defined as a set
of voltages whose “Root note/voltage” is higher/lower than the one the Twin Waves expects at
its V/Oct input.
The [square] 1 jack
This output provides a square wave at half the frequency of out1. It can be used to be audio
mixed but also conveniently provides a clean wave for synchronizing a slave oscillator.
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LFO
Overall presentation
In LFO mode, the oscillator can be resynchronized (restarting of wave phase without affecting
the cycle duration) or fully clock-synchronized (the rate is defined by external clocking).
The oscillator 1 offers two additional features:
The amplitude of the output signal can be voltage controlled (AM)
Trigger pulses are available on the [square] 1 output in addition to the main wave output
The LFO signals generated belong to one of the two following categories:
Cyclic signal algorithms
The most known usage of an LFO is to generate repeated waves. The triangle, square and sine
offered here can all be modulated in shape or phase ratio, replacing many fixed waves.
Moreover, these waves can be synchronized, which means phase-restarted by an external
triggering.
Another regularly timed signal is made of random level steps generated with a sample-and-hold
circuit clocked by an LFO and fed with noise; a function usually labelled S/H or S&H.
Less common is the vector generation. At each step, the current level defined randomly will
progressively reach the next level also defined randomly. The end result is some kind of noise too
slow to be heard but very interesting when modulating otherwise static sounds.
Aperiodic signal algorithms
The Twin waves’ LFOs offer algorithms where the duration between events is irregular. This is
what is called aperiodic signals.
The parameter knob and jack control the degree of timing randomness, from perfectly cyclic to
widely irregular.
The aforementioned vectors and S/H algorithms each exist in their aperiodic variation.
LFO algorithms table
Icon
Algorithm
Parameter
Parameter effect
Saw/triangle
Slope
Wave shaping between triangle and saw
Square/pulse
PWM
Wave shaping between square and pulse
Sine
Phase mod
Wave symmetry
Brownian S/H
Random level
maximum deviation
Randomness delta between 0 to 100%
Randomly timed S/H
Time randomness
Spacing regularity, cyclic to random
(Levels are always 100% random)
Brownian vectors
Random level
maximum deviation
Randomness delta between 0 to 100%
Randomly timed vectors
Time randomness
Spacing regularity, cyclic to random
(Levels are always 100% random)
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V/Oct input jacks
These are meant to bring a control voltage that determines the frequency of the LFO and
respond to V/2F, thus doubling/dividing the speed for every additional volt up/down. With
external clock, the V/Oct input controls the div/mult ratio (see further).
In LFO mode, the V.Oct inputs always drive their related section.
Clock & Sync – Sync/Clk jack
The LFO can be controlled by signals entering the Sync/Clk jack. The synchronization and external
clocking functions are exclusive; only one of these can be active within a given section. With LFOs
in both sections, it is allowed having one of them with its Sync active, while the other is set to
external clocking. Both will obey to the same external signal.
Internal/external clocking – Qtz/Clk button
The default use of an LFO is to be the master of its rate. The rate is controlled by the Coarse
knob. Alternatively, the Twin waves LFO can be synchronized to an external clock or any periodic
trigger/gate signal. Moreover, it is possible to define a ratio between that external cyclic signal
and the actual rate of the LFO.
Briefly pressing the Qtz/Clk button enters the LFO clock settings. The options are: internal clock
(ic) and external clock (xc). These are selected and validated by the encoder.
When external is selected, the Qtz/Clk LED will be on. Now, instead of setting the rate, the Coarse
pot allows selecting the multiply or divide ratio applied to the incoming clock.
The rate is defined by the time elapsed between consecutive incoming clock ticks.
Clocks ticks spaced several minutes apart can lead to cycles of several hours when divided by 64.
Voltages brought to the V/Oct jack are added to the Coarse knob setting to determine the
division/multiplication ratio applied.
Multiplication and division ratios
16x
/1.5
12x
/2
9x
/3
8x
/4
6x
/6
4x
/8
3x
/9
2x
/12
1.5x
/16
1x
/32 /48
/64
When activating external clocking, the Sync function within the same section is unavailable.
Page 16
Klavis Twin waves user manual V1.7 Page 16 of 19
Synchronization – Sync button
With sync active, every trigger/gate signal brought to the Sync/Clk jack will instantly start a new
LFO cycle.
Pressing the sync button opens the sync setting menu. Turning the encoder allows you to apply
or not the sync signal from the sync jack. With cyclic algorithms, you can choose between rising
edges, falling edges, or both. Random algorithms only allow rising edge synchronization.
Pressing again the sync button or the encoder will validate your choice. The Sync/Clk LED is
steady on when synchronization is enabled.
When activating Sync, external clocking in the same section is not available.
Keep in mind that the sync jack being shared by the two oscillators you have to enable/disable its
use in the adequate section.
FM/AM jack & Level knob
The CV in at this jack adds up with the setting of the (Fine/) Level knob to control the amplitude
of LFO 1. Negative voltages can close down a level set up with the knob.
LFO 2 has only knob control.
The [square] 1 jack
This jack issues a short trigger pulse at the beginning of every wave cycle. It can be used to clock
external devices. It is particularly useful when using the random timing algorithms.
Summary of buttons use
Single button use
Button
Short press
Long press
Osc 2
Toggles the panel between Osc 1 & 2
V/Oct jacks mode editing
LFO/AM
Toggles between VCO & LFO modes
FM/AM jack usage editing
Qtz/Clk
Quantizer settings when VCO
Clock settings when LFO
Quantizer base note selection
when quantizer is active
Sync
Sync settings
Relative/Absolute setting with
Self-Sync algorithms
Dual button use
Combo
Function
Osc 2 + Sync
Display the firmware revision and calibration status
Qtz/Clk + Sync
Lock/unlock the tuning pots in the current VCO
Dual button - before powering on
Combo
Function
Osc 2 + Sync
Prepare for firmware update
LFO/AM + Qtz/Clk
Reset to factory default settings
Page 17
Klavis Twin waves user manual V1.7 Page 17 of 19
Summary of LED indications
Depending on a function being on or off, pulses might be inverted (black blips).
VCO mode
When LFO/AM red LED is (mostly) off
LED
Off
On
Blink
Pulse
Double
pulse
Triple pulse
Osc2
Blue
VCO 1
selected
VCO 2
selected,
Editing
V/Oct jacks
V/Oct =
Added
V/Oct =
Offset
LFO/AM
Red
VCO,
FM jack
= BZX
See LFO
mode
Editing FM
jack
FM jack =
Lin FM
FM jack =
AM (VCA)
FM jack =
Qtz base note
Qtz/Clk
Yel Qtz = on
Editing Qtz
Sync
Green
Ext sync
= on
Editing Sync
algos
Slave osc is
absolute
Algo
Blue
Select Algo
FM jack =
Algo
LFO mode
When LFO/AM red LED is (mostly) on
LED
Off
On
Blink
Pulse
Osc2
Blue
LFO 1 selected
LFO 2 selected
LFO/AM
Red
See VCO mode
LFO, FM jack = AM
Cycle start
Qtz/Clk
Yel Ext clock = on
Editing clock
Sync
Green
Ext sync = on
Editing sync
Algo
Blue
Select Algo
Potentiometer LEDs
LED
Off
On
Pulse
Pot LEDs
White
Knob <> setting
Knob = setting
Knobs locked
Output LEDs
Output white LEDs follow the shape of the signal, where LED off = max negative, and full on =
max positive. Beware that this indication is independent from the actual amplitude of the signal
coming out of the jack!
The Sqr1 blue LED follows the signal coming out: off = -5V, on = +5V
Page 18
Klavis Twin waves user manual V1.7 Page 18 of 19
Troubleshooting
Here is a shortlist of unexpected behaviors due to particular settings.
Remember that when in doubt of any setting, a long press on the encoder will scroll a help text.
Factory reset
In case you’re completely lost with the settings or want to start with fresh out-of-box settings,
there is a factory default reset function. Hold the LFO and Qtz buttons before powering up. Once
you see the scrolling message, you can release the buttons.
The potentiometers do not respond
Pot locking is engaged. See chapter: Locking the potentiometers
Beware that locking the tuning pots is a separate setting for each section!
No sound out of VCO1
The FM/AM jack is configured for VCA and there’s no voltage coming in.
See chapter: FM/AM jack.
No signal in LFO mode
The out level is closed; turn the Fine/Level pot up with the pot’s white LED being on
There is a negative voltage on the FM/AM jack
LFO is stuck
The Qtz/Clk LED is on; the LFO expects an external clock which is missing or so much divided that
it seems stopped.
See chapter: Internal/external clocking – Qtz/Clk button
VCO tracking is odd
VCOs play according to strange transpose relation. V/Oct setting is put to added or offset.
See chapter: V/Oct input jacks
You have engaged some unusual quantizer scale.
See chapter: Quantizer – Qtz/Clk button
Page 19
Klavis Twin waves user manual V1.7 Page 19 of 19
Specifications
Mechanical
Dimensions
mm
inches
Eurorack compliance
Height
128.40
5.06
3HE
Width
40.00
1.57
8HP
Depth behind panel (with supply cable inserted)
37.40
1.47
Weight 100 grams/3.53 oz
Supply
The supply socket is protected against reverse insertion.
Supply rail
Current draw
+12V
46 mA
-12V
18 mA
+5V
0 mA
Input/output
All inputs and outputs can withstand signals between -12V and +12V without harm.
Jack
Effective voltage range received or generated
V.Oct 1 & 2
-4V to +6V
All other jacks
-5V to +5V
Signals
Parameter
Values
Fundamental frequency range in VCO mode
10Hz to 10KHz = over 10 octaves
Output1 and 2 signal frequency range (incl. harmonics)
DC to 20KHz
LFO frequency range (internal / external clocking)
2 minutes to 2KHz / several days to 2KHz
Input and output conversion
16-bit ADCs, 24-bit 96KHz DACs
Packing list
The box contains:
Twin Waves module
4x M3 black mounting screws + washers
Eurorack-compliant 16pin supply cable
Quick setup notice
Klavis products, including PCBs and metalwork, are designed and manufactured in Europe.
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