Klavis Twin waves User manual

Klavis Twin waves user manual V1.7 Page 1of 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:
oV/Oct tracking over 10 octaves
oThrough zero and linear FM
oSub-octave output
oHard & soft synchronization
oVCA control and CV algorithm selection
oQuantizer with various scales
oAlgorithm-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 2nd oscillator
Noise with LPF, BPF, or resonant VCFs
Features in LFO mode:
oSimultaneous signal and trigger outputs
oExternal wave synchronization
oClock controlled rate with multiplier and divider
oCV and knob control of output level
oAlgorithm 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]1JACK ............................................................................................................................................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]1JACK ........................................................................................................................................... 16
SUMMARY OF BUTTONS USE..............................................................................................................................16
SINGLE BUTTON USE ............................................................................................................................................. 16
DUAL BUTTON USE ............................................................................................................................................... 16

Klavis Twin waves user manual V1.7 Page 3of 19
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

Klavis Twin waves user manual V1.7 Page 4of 19
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.

Klavis Twin waves user manual V1.7 Page 5of 19
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,
oa message confirms the success of the update
oboth 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

Klavis Twin waves user manual V1.7 Page 6of 19
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.

Klavis Twin waves user manual V1.7 Page 7of 19
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.

Klavis Twin waves user manual V1.7 Page 8of 19
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-values-
only approach by allowing for integer values. This offers a much smoother change in the effect

Klavis Twin waves user manual V1.7 Page 9of 19
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.

Klavis Twin waves user manual V1.7 Page 10 of 19
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.