Frap Tools CGM User manual

MANUALONE
A Single, Comprehensive Guide to Frap Tools’ Modules

I’d like to thank a few precious friends for their support during these years, for the discussions we had, and for the
valuable feedback i received — in alphabetical order: Caterina Barbieri, Sebastian Baumann, Alessandro Bonino,
Marco Ciccotti, Enrico Cosimi, Tom Hall, René Margraff, Gianfranco Marongiu, Chris Meyer, Giulio Saltini, Alessio
Santini, Stephan Schmitt, Brian Smith, Trevor Tunnacliffe, Giona Vinti, Andreas Zhukovsky.
And thanks to the amazing people I’m working with — in alphabetical order: Fabrizio Benatti, Federico Foglia, Gio-
vanni Grandi, Antonio Masiero.
Simone Fabbri

TABLE OF CONTENTS
TABLE OF CONTENTS.....................................................................3
SAFETY AND WARRANTY .............................................................5
BEFORE STARTING ..........................................................................6
1Connecting the Power............................................................... 6
2Mounting the Module ................................................................ 6
3Warm-Up and Working Temperature............................ 6
INTERFACES.......................................................................................6
1Arrows (Input, Output)............................................................... 6
2Square and Round Shapes..................................................... 6
3Lines (Solid, Dotted, Dashed)................................................ 7
4Color Coding ..................................................................................... 7
5Combinations................................................................................... 7
CGM – CREATIVE MIXER ................................................................9
1Philosophy and Design ............................................................. 9
2System Setup (Linking)..........................................................10
Master to Group(s) .....................................................................10
Group to Channel(s)..................................................................10
Group Jumpers Congurations.......................................11
3Channel..............................................................................................11
Main VCA & Direct Out............................................................11
Sends...................................................................................................11
Pan, Fader and Other Controls.........................................11
4Group...................................................................................................12
Sends...................................................................................................12
Returns...............................................................................................12
Group Output................................................................................12
Fader and Other Controls.....................................................12
The Safe Solo Function...........................................................12
5Master.................................................................................................12
The PFL Function .......................................................................13
6CGM Mixer Tips.............................................................................13
Stereo Inputs .................................................................................13
More Than 2 Send/Returns Per Channel...................13
Serial Send/Return (and Feedbacks)............................13
SAPÈL................................................................................................. 14
1Philosophy and Design ..........................................................14
2Noise Outputs...............................................................................14
3Voltage Sampling.......................................................................15
Internal Clock and Clock Modulation...........................15
External Clock ...............................................................................15
Clock Mix...........................................................................................15
Manual Sampling .......................................................................16
External Gate Sampling.........................................................16
Clock Outputs (Main and Random)...............................16
4Random Voltages.......................................................................16
Non-Quantized Random Voltages.................................16
Quantized Random Voltages.............................................16
Fluctuating Random Output and Global Rate of
Change (random clock density control) ....................17
5Probability Distribution (Stored Random Voltages)
..................................................................................................................18
FUMANA ........................................................................................... 19
1Philosophy and Design ..........................................................19
Spectral Transfer: A Brief History.....................................20
Panel Overview ............................................................................20
2Audio Inputs...................................................................................20
3Audio Outputs ..............................................................................21
4Audio Processing and Modulation Path....................21
Faders and CV...............................................................................21
Macro Spectral Editing...........................................................22
4.2.1 Tilt ..........................................................................................................22
4.2.2 Parametric Scanning...............................................................22
Spectral Transferring: Modulation Filters and
Envelope Followers................................................................... 22
The ‘Unvoiced’ Section............................................................23
5Filter Design................................................................................... 23
6Patch Examples........................................................................... 24
16-Band Spectral Transfer...................................................24
Dual 8-Band Spectral Transfer ......................................... 24
Hybrid Spectral Transfer........................................................24
Vocoder-Like Behavior ...........................................................24
FALISTRI............................................................................................ 25
1Philosophy and Design.......................................................... 25
2Function Generators................................................................ 25
Times................................................................................................... 26
Shapes................................................................................................26
Trig and Modes ............................................................................ 26
2.3.1 Green Alternative Retrig (On Rest) ................................ 27
Outputs..............................................................................................27
Additional Generator Features......................................... 27
2.5.1 Quadrature...................................................................................... 27
2.5.2 Max ....................................................................................................... 28
2.5.2.1 ADSR.................................................................................................... 28
3Function Processors................................................................. 28
Dual Cascaded Frequency Divider ................................ 28
Four-Quadrant Multiplier .....................................................29
3.2.1 Amplitude Modulation & Ring Modulation (2 vs 4
quadrants)....................................................................................... 29
3.2.2 Trimming..........................................................................................30
3.2.3 Linear Slew Limiter.................................................................... 30
USTA................................................................................................... 31
1Quick start....................................................................................... 31
2Philosophy And Design.......................................................... 32
Architecture ...................................................................................32
Tempo Management............................................................... 32
3Basic Editing and Visual Feedback............................... 33
Editing Projects − Project Menu...................................... 33
Editing Tracks − Track Menu.............................................. 34
3.2.1 Clock Settings............................................................................... 34
Editing, Playing and Looping Patterns.......................34
Editing Stages...............................................................................35
3.4.1 Length................................................................................................ 36
3.4.2 Maintain Pattern Length on Variation........................ 36
3.4.3 CV Layers.......................................................................................... 36
3.4.3.1 Red CV Layer: Value.................................................................. 37
3.4.3.2 Green CV Layer: Variation Index...................................... 37
3.4.3.3 Blue CV Layer: Variation Range........................................ 38
3.4.4 CV Stage Colors ........................................................................... 38
3.4.4.1 USTA Slide vs FALISTRI Slew............................................... 38
3.4.5 Gate Layers...................................................................................... 39
3.4.5.1 Red Gate Layer: Value ............................................................. 39
3.4.5.2 Green Gate Layer: Variation Index.................................. 39
3.4.5.3 Blue Gate Layer – Variation Range ................................ 39
3.4.6 Gate Stage Colors.......................................................................39
4Quick Editing................................................................................. 40
Set All and Shift All .................................................................... 40
Coarse and Fine...........................................................................41
Combining the Buttons.........................................................41
5Performing......................................................................................41
Play/Pause, Reset and Master Track Settings........41
5.1.1 Master Track................................................................................... 41
5.1.2 Play/Pause.......................................................................................41
5.1.3 Reset.................................................................................................... 42
Stage Loop ...................................................................................... 42
5.2.1 Innite Stage Loop.................................................................... 43

Song Mode......................................................................................43
5.3.1 Pattern to song while playing (and vice versa).....44
Live Performance Tools: Pattern Recall......................44
5.4.1 Full pattern recall........................................................................44
5.4.2 Pattern Mix......................................................................................45
Mute.....................................................................................................45
5.5.1 Mute Track.......................................................................................45
5.5.2 Mute Channel................................................................................45
Hold ......................................................................................................45
6Advanced Editing.......................................................................46
Composition Mode....................................................................46
Use an External CV/Gate Keyboard...............................46
Store Pattern: Last Played or Last Full.........................46
Rotate Pattern ..............................................................................47
Cloning...............................................................................................47
6.5.1 Clone a Stage.................................................................................47
6.5.2 Clone a Structure........................................................................48
6.5.2.1 Clone a Layer..................................................................................48
6.5.2.2 Layer Cross-Cloning..................................................................48
6.5.2.3 Clone a Pattern ............................................................................48
6.5.2.4 Clone a Track..................................................................................48
Quick Track Initialization.......................................................49
Quick Song Initialization .......................................................49
7External Controls.........................................................................49
Clock Input......................................................................................49
Auxiliary Trig/Gate Input........................................................49
7.2.1 Reset....................................................................................................49
7.2.2 Run........................................................................................................49
External CV......................................................................................49
7.3.1 Pitch Shift.........................................................................................50
7.3.2 Root Shift..........................................................................................50
7.3.3 Gate Shift..........................................................................................50
7.3.4 Stage Shift........................................................................................50
7.3.5 Vari Shift (Variation Shift)......................................................50
7.3.6 Pattern Shift...................................................................................51
7.3.7 Phase Shift.......................................................................................51
8Additional Operations.............................................................51
Select CV Mode (Raw or Pitch) .........................................51
CV Range..........................................................................................52
Gate Width %.................................................................................52
Swing...................................................................................................52
Current Stage Data ...................................................................52
9Playing in Tune.............................................................................53
Root & Scale – Dynamic Quantization.........................53
Microtonalities ..............................................................................53
Custom Scales...............................................................................54
Set the Reference Note..........................................................55
Custom Temperaments.........................................................55
9.5.1 Absolute or Relative Temperaments............................55
LED Pitch Tables .........................................................................56
10 Additional Maintenance........................................................58
Remove / Insert the SD Card..............................................58
10.1.1 Remove the SD Card................................................................58
10.1.2 Insert the SD Card......................................................................58
Analog Trimming........................................................................58
Project Management and Backups ..............................58
Firmware Update .......................................................................58
11 CHARTS..............................................................................................59
Project Menu .................................................................................59
Track Menu......................................................................................59
Project Hierarchy........................................................................60
12 Scale Tables.....................................................................................61
13 Change Log ....................................................................................68
BRENSO ............................................................................................ 69
1Philosophy, Design and Signal Flow.............................70
2Frequency........................................................................................70
Oscillators.........................................................................................70
2.1.1 Fine and Coarse Tuning.........................................................70
2.1.2 Coarse Frequency Lock.......................................................... 70
2.1.3 V/oct and Integrator................................................................. 71
Frequency Modulation........................................................... 71
2.2.1 FM Routing.....................................................................................72
Sync......................................................................................................72
2.3.1 Lock...................................................................................................... 73
2.3.2 Flip Sync............................................................................................ 73
3Timbre ................................................................................................73
Triangle Shaper............................................................................ 73
Pulse Shaper.................................................................................. 74
3.2.1 Pulse-Width Modulation (PWM)..................................... 74
3.2.2 Waveshaper ...................................................................................74
Wavefolder...................................................................................... 74
3.3.1 Sources ..............................................................................................75
3.3.2 Folding............................................................................................... 75
3.3.3 Symmetry ........................................................................................75
3.3.4 Ping...................................................................................................... 75
Timbre Modulation Bus ......................................................... 76
4Amplitude........................................................................................ 76
Amplitude Modulation and Ring Modulation ....... 76
5Trimmers ..........................................................................................77
Accessible Trimmers................................................................ 77
5.1.1 Coarse Frequency ......................................................................77
5.1.2 Sine Wave Symmetry..............................................................77
5.1.3 Sawtooth Wave Symmetry ................................................. 77
5.1.4 Exponential FM Zero................................................................ 77
5.1.5 Triangle Waveshaper Shape...............................................77
5.1.6 Wavefolder Symmetry............................................................ 77
5.1.7 Four-Quadrant Multiplier ..................................................... 77
5.1.8 Comparator ....................................................................................77
Non-Accessible Trimmers....................................................77
5.2.1 Gain ...................................................................................................... 78
5.2.2 Base......................................................................................................78
5.2.3 Symmetry ........................................................................................78
6Simple Signal Flow.................................................................... 78
333......................................................................................................79
1Design ................................................................................................79
321......................................................................................................80
1Design ................................................................................................80
TECHNICAL DETAILS....................................................................81
1Flow Charts.....................................................................................81
CGM......................................................................................................81
SAPÈL.................................................................................................. 82
333 ....................................................................................................... 83
321 ....................................................................................................... 83
2CGM CREATIVE MIXER VCA CURVES...........................84
3FUMANA TRANSFER FUNCTION..................................... 85
SPECIFICATIONS............................................................................86
1CGM − Creative mixer..............................................................86
2SAPÈL.................................................................................................. 86
3FALISTRI ............................................................................................ 87
4FUMANA ...........................................................................................88
5USTA.....................................................................................................88
6BRENSO ............................................................................................89
7333 ....................................................................................................... 89
8321 ....................................................................................................... 89
WHAT’S IN THE BOX.....................................................................90
LIST OF REVISIONS ....................................................................... 91

Rev. 5 – Jun 2020 Page 5 of 91
SAFETY AND WARRANTY
The Frap Tools srls warranty covers the
following products (hereinafter ‘Frap
Tools’), for two (2) years following the date
of purchase. This warranty covers any de-
fect in the manufacturing of this product.
This warranty does not cover any damage
or malfunction caused by incorrect use as
described in the following instructions.
The warranty covers replacement or re-
pair, as decided by Frap Tools. Please con-
tact customer service at [email protected]
for a return authorization.
Frap Tools warrants that your new Frap
Tools product, when purchased from an
authorized Frap Tools dealer, shall be free
of defects in materials and craft for a pe-
riod of two (2) years from the original date
of purchase. Please contact Frap Tools for
warranty and service outside of Europe.
During the warranty period, Frap Tools
shall, at its sole option, either repair or re-
place any product that proves to be defec-
tive upon inspection by Frap Tools. Frap
Tools reserves the right to update any unit
returned for repair and to change or im-
prove the design of the product at any time
without notice. This warranty can be
transferred to anyone who may subse-
quently purchase the product provided
that such transfer is made within the ap-
plicable warranty period and that Frap
Tools is provided with all of the following
items:
·all warranty registration information
for the new owner;
·proof of the transfer within thirty (30)
days of the transfer purchase, and a pho-
tocopy of the original sales receipt.
Frap Tools shall determine warranty
coverage in its sole discretion: this is your
exclusive warranty. Service and repair of
Frap Tools products are to be performed
only by Frap Tools or an authorized ser-
vice company. Unauthorized service, re-
pair, or modification will void this war-
ranty.
Please follow the given instructions for
the use of the device because this will guar-
antee the correct device operation. Since
these instructions also include indications
concerning Product Liability, they must
be read carefully. Any claim for defect will
be rejected if one or more of the following
points is not observed. Any disregard of
these instructions can void the warranty.
The devices may only be used for the
purpose described in this operating man-
ual. Due to safety reasons, the devices
must never be used for purposes not de-
scribed in this manual. If you are not sure
about the intended purpose of the devices,
please contact an expert or Frap Tools at
the email address above.
Do not use or store the devices in humid
places. Avoid contact with any liquid.
Do not touch any component of the de-
vices when it is power or connected to any
power source.
Do not place the devices on unstable
carts, stands, tripods, tables, or other sur-
faces, or on surfaces that are not perfectly
plane. Such behavior may cause the de-
vices to fall, which could result in human
injury, property damage or improper
functioning of the devices themselves.
The devices are designed for use only
when safely and tightly mounted in a
proper Eurorack case, made of non-flam-
mable materials. If you are not sure about
the intended purpose of the devices, please
contact an expert or Frap Tools at the
email address above.
Do not ever leave the devices switched
on when not in use.
To prevent fire, never place any candle,
flame, or other sources of heat on or near
the devices.
Transport the devices only in the origi-
nal box with original packaging or when
safely and tightly mounted in a proper Eu-
rorack case and handled with care. Never
let the devices fall or topple. Make sure
that during transport and while in use the
devices and their case, have a proper stand
and do not fall, slip or turn over because
of potential human injury to persons or
property damage. Any damage from phys-
ical abuse such as dropping the unit, im-
pact from hard objects or damage to ex-
ternal components as a result of negli-
gence will void this warranty.
Never expose the devices to tempera-
tures above +40°C or below 0°C.
Before any operation, also verify the op-
erating temperature ranges of all the mod-
ules and the power boards in use. Do not
keep or leave the case that hosts the de-
vice, or the devices themselves near heat
sources.
Any modification must be carried out
only by Frap Tools or an authorized ser-
vice company. The devices may not be
modified in any way by any parties not ex-
pressly authorized by Frap Tools. Any re-
pair, modification, tampering, or at-
tempted repair made by unauthorized
personnel will void this warranty.
Frap Tools cannot be held responsible in any
way for problems to persons or property or to
the devices themselves, if the devices are
installed improperly, or if they are improperly
used, maintained, or stored.
Any device shipped to Frap Tools for re-
turn, exchange, warranty repair, update,
or examination must be sent in its original
packaging! Any other deliveries will be re-
jected. Therefore, you should keep the
original packaging, and any technical doc-
umentation or manual provided. The de-
vice must be shipped only with the original
packaging. As specified on the product
box, this box is not intended for shipment:
if you bought the device directly at a phys-
ical reseller’s shop, you should put the de-
vice in the original packaging and put the
packaging in a properly larger box with
proper packaging destined for shipping. If
you received the device via carrier or any
post service, it should have come with a
proper double box packaging.
All non-warranty services are subject to
a minimum fee of €50.00+VAT (within
the European Union). The customer must
pay for shipping to Frap Tools; Frap Tools
will cover return shipping costs.
It is important to note that the front
panel of our modules may get warm and
may warm up the case where it is
mounted. Please do not be alarmed, as this
is normal and is part of its standard oper-
ation.
Shut down your equipment immediately
if it produces smoke, a strange odor, or un-
usual noise. Continued use may lead to
fire. Immediately unplug the equipment
and contact your dealer or Frap Tools at
the address above for advice.
Never attempt to repair this product
yourself. Improper repair work can be
dangerous. Never disassemble or modify
this product. Tampering with this product
may result in injury or fire and will void
your warranty.
Do not allow foreign matter to fall into
the equipment. Penetration by foreign ob-
jects may lead to fire.
If water or other liquid spills into this
equipment, do not continue to use it. Con-
tinued use may lead to fire. Unplug the
power cord immediately and contact your
dealer or Frap Tools at the address above
for advice.
The internal components of our mod-
ules and power supplies can get very hot.
Do not touch any internal components
while it is connected and/or powered and
after they completely cool down after use
for at least 30 minutes.

Rev. 5 – Jun 2020 Page 6 of 91
BEFORE STARTING
1CONNECTING THE POWER
To connect the power cable, carefully follow these two
rules:
·the power connector on the module is the keyed one
in the top;
·the red line on the cable should be placed matching
the −12V side on your power board: please double check
with your power boar supplier that the marked side is the
−12V.
Frap Tools may not be held responsible in any way for prob-
lems or damage to persons or property or to the device itself,
if the device is not connected as indicated above.
2MOUNTING THE MODULE
After connecting the power as explained in the previous
section, install the module in your case using all the 2 or
4 screws provided. Make sure that the module is safely
and tightly connected to your Eurorack case.
Frap Tools modules use the standard Eurorack orienta-
tion and color-coding: the red line on the power cables is
placed at the bottom and stands for the −12V. Please
double check with the power system you want to use that
it adopts the same powering system.
Frap Tools may not be held responsible in any way for prob-
lems or damage to persons or property or to the device itself,
if the device is not connected as indicated above.
Figure 1: Power connection.
3WARM-UP AND WORKING TEMPERA-
TURE
For best performances, we suggest letting the Frap
Tools modules warm up at least around 20 minutes prior
to use it [tested at 25°C]. It is absolutely normal that they
feel warm when touched.
INTERFACES
Here at Frap Tools, we put a lot of effort into designing
a proper user interface for each of our modules.
By “proper user interface” we mean essentially three
things:
1. it must convey the module’s identity at a glance;
2. it must allow for a smooth creative workflow;
3. it must be pleasant to look at.
Moreover, we want our interfaces to be clear, but not
self-explanatory (or, in other terms, cryptic, but not cha-
otic).
The reason for doing so is that, in our vision, the musi-
cian should master the “code” of the instrument before
playing it: a piano does not have the note names on its
keys, a violin does not have marks on its neck — it is up
to the musician to practice and learn how the instrument
works.
In the same way, our modules do not have labels such
as ‘frequency’ or ‘decay time’: instead, they are replaced
with a system of symbols and colors that try to be as con-
sistent as possible. Moreover, a musician approaching
our modules through a “conventional” labeling system
might be tempted to assume that the module behaves in
an ordinary way, which sometimes is not completely cor-
rect.
The modules are explained in detail further in this man-
ual. However, to allow the musician to get acquainted
with the overall symbol system, we provide here a brief
guide to “decode” the most recurrent elements of the
“Frap environment”.
1ARROWS (INPUT, OUTPUT)
An arrow can mean either an input or an output, ac-
cording to its position: if it points towards one or more
jack sockets, it is an input; if it points away from one or
more jack sockets, it is an output.
Figure 2: Arrows.
2SQUARE AND ROUND SHAPES
All the modular world revolves around voltage. The
most basic distinction is, conventionally, between voltage
used for timing pulses (trigs or gates) and voltage used for
audio signals or CV.

Rev. 5 – Jun 2020 Page 7 of 91
The former is a discrete signal with two levels only (“off”
and “on”, “low” and “high”). In our modules it is associ-
ated with square shapes: the reason is that squares have
only two kind of lines (vertical and horizontal), in the
same way a gate or rig signal has only two possible states,
on and off.
Figure 3: Square shapes.
The latter is a continuous signal (or ‘analog’ in its clos-
est meaning). Is associated with round shapes because cir-
cles can be thought of as having infinite sides, in the same
way an analog signal has infinite values.
Figure 4: Round shapes.
A subgroup of audio analog section is the stereo audio.
As you can notice in the CGM series, the group and mas-
ter modules feature stereo in and out out: here, the
left/mono is connected to the solid-colored area, while
the right is connected to the ring that surrounds it. The
reason is that the left output is always the primary (be-
cause it can be used as a mono output as well), while the
right one is more of an accessory to it.
Figure 5: Stereo audio.
3LINES (SOLID, DOTTED, DASHED)
A solid line relates two or more elements of the circuit.
It stands for manual control, which means that a given
knob or switch directly affects the signal passing through
the circuit from an input or to an output.
Figure 6: Solid lines.
A dotted line stands for external CV control, and it of-
ten relates a jack socket to a manual control such as a
knob or a slider. It means that the specific parameter can
be voltage controlled.
Figure 7: Dotted lines.
A dashed line relates two or more inputs or two more
outputs: it means that they are semi-normalled, or, in
other terms, that the signal going to one input or coming
from one output is mirrored by the other jack sockets con-
nected by a dashed line. Such behavior is automatically
overridden once a cable is plugged to another jack socket
(thus “breaking” the normalization).
Figure 8: Dashed lines.
4COLOR CODING
As a rule of thumb, if a module performs more than one
function, the respective controls are marked with differ-
ent colors. In other words, a given color relates to one and
only one section of the module design. In case a module
features two “mirrored” sections (such as SAPÈL’s or
FALISTRI’s generators, or CGM Group’s FX sends),
they are marked in yellow and green.
5COMBINATIONS
All the elements can be combined. For example, an ar-
row within a square pointing towards a jack socket means
that it is a gate/trig input; if a dotted line connects a jack
socket to a knob, and a solid line connects the same knob
to another jack socket, it means that the signal outputted
from the second jack socket can be modified either man-
ually via the knob or automatically via an external CV
patched to the first socket.

Rev. 5 – Jun 2020 Page 9 of 91
CGM – CREATIVE MIXER
Figure 9: CGM Interface
AMain Audio Routing
A.1 Audio Mono Input
A.2 Individual Mono Output
A.3 VCA Level
A.4 VCA Level CV Input
A.5 VCA Pre/Post
A.6 Pan Level
A.7 Pan Level CV
A.8 Channel Fader
A.9 Group Output Left
A.10 Group Output Right
A.11 Group Fader
A.12 Master Output Left
A.13 Master Output Right
A.14 Master Fader
A.15 Auxiliary Stereo Input
A.16 Phones Stereo Output
A.17 Phones Level
BSend/Return
B.1 Effect Send Level
B.2 Effect Send Level CV
B.3 Effect Send Pre/Post
B.4 Effect Send Mono Output
B.5 Effect Return Left Input – Dual
Mono
B.6 Effect Return Right Input – Dual
Mono
B.7 Effect Return Level
B.8 Effect Return Level CV
CPerformance Functions
C.1 Mute Button
C.2 Solo-In-Place Button
C.3 Safe Solo Switch
C.4 Pre-Fader Listen (PFL) Button and
LED
C.5 PFL Blend
1PHILOSOPHY AND DESIGN
The CGM Creative Mixer is a modular mixing solution
for Eurorack modular systems. It is designed to obtain a
flexible setup, providing all the tools you may need in stu-
dio and during a live performance, as well as plenty of
CV inputs for every possible automation.
It is currently composed of three modules: the Channel,
the Group and the Master.
The Channel accepts mono signals. It has a main stereo
VCA with CV in and attenuator (red), a direct output
post-main VCA (pre or post fader), two parallel voltage-
controlled effect sends with individual attenuators and
pre/post fader switches (yellow and green), and a PAN
control with offset CV and offset pot. This, together with
the latching buttons for mute, solo in place, and PFL,
manages the incoming signal and distributes it to the
Group module.
The Group gets and sums the L/R post-fader signals
(white) of all the linked Channels, sums all the signals from
the yellow and green sends, and manages the sends
(mono) and returns (dual mono or stereo), summing it to
the signals from the Channels. It also manages the Solo-In-
Place activation on all the linked Channels and provides a
L/R output for the outgoing signal, or (via a jumper on
the back of the module) a L/R output of the sum of the
return signals. Up to eight Channels may be connected to
a single Group, taking care also of its powering. You can
connect also up to four Groups to a Master module.
The Master sums the incoming signals from the Groups
and manages the Pre-Fader Listening (PFL, stereo) of both
Channels and Groups. It also features an auxiliary stereo in
via a 3.5 mm stereo jack with PFL latching button and a
stereo out via 3.5 mm stereo jack for headphones, whose
signal can be blended between PFL and main out.

Rev. 5 – Jun 2020 Page 10 of 91
2SYSTEM SETUP (LINKING)
In a CGM system, modules share audio and power via
10 poles IDC ribbon cables (please refer to the What’s In
The Box section of the manual to see the content of each
module and to have an overview of the available link ca-
bles for various setups, p. 90).
Note that the the Group module does not have a power
socket: it’s because with a CGM configuration you need
to connect only one Group and the Master (if present). With
just two power connections, you will be able to share the
power across your CGM system, with a better ground
handling.
If you accidentally connect more than one group to the PSU,
fear not: it’s not going to damage your system! It’s just use-
less and may not be optimal for ground.
MASTER TO GROUP(S)
Each Master comes with one link cable to connect a
Group to it. You can connect more Groups using a proper
link cable. The Master module, on its back, has two 10 pole
IDC connectors, the one in the top left corner is for pow-
ering, the other in the bottom without any direction is for
linking. Use this one and patch it to the corresponding
one on the Group to establish a connection between them
(in the Group is the one in line –at the same height– of the
one in the Master).
In the example at Figure 10, the cable continues and
goes to other Groups.
GROUP TO CHANNEL(S)
Each Group comes with two link cables to connect one
Group to up to four Channels. You can connect more Chan-
nels (up to eight) using a proper link cable but remember
that at least one Channel is required for the Group to work.
The Channel module, on its back, has three 10 pole IDC
connectors, the one in the top left corner is for powering,
the other two in the center without any direction are for
linking. Use these and patch them together on the differ-
ent Channel you want to link to a Group and on the Group
too (in the Group these are the two connectors in line (at
the same height) with the two on the Channel). It is im-
portant to double check that all the modules are orien-
tated in the same way, and that all the upper connector
are connecter with one IDC cable, while all the lower
connectors are connected with another IDC cable.
In the example at Figure 11, the cable continues and
goes to other Channels.
It is imperative to do not swap connectors! Frap Tools may
not be held responsible in any way for problems or damage
to persons or property or to the device itself if the device is
not connected as indicated above.
Figure 10: Master and Groups connection.
Figure 11: Group and Channels connection.

Rev. 5 – Jun 2020 Page 11 of 91
GROUP JUMPERS CONFIGURATIONS
Group L/R output can be configured in two ways: look-
ing at the PCB from the back, if the two jumpers on the
top of the module are connected to the pins 2-3 (from the
left) the group outputs the sum of the signals from all the
channels connected to the group itself, and the signals
coming in from the yellow and green return. Otherwise,
if the two jumpers on the top of the module are connected
to the pins 1-2 (from the left) the group outputs the sum
of the signals coming in from the yellow and green return
only.
Please note that these jumper configurations will not af-
fect the signal sent from the Group to the Master via the
IDC cable: only the group outputs on the front panel may
be configured.
It is imperative to do not connect the jumpers to any other
connector except the two mentioned in this section and
shown in the pictures below. Frap Tools may not be held re-
sponsible in any way for problems or damage to persons or
property or to the device itself, if the device is not connected
as indicated above.
Figure 12: Pins 1 and 2.
Figure 13: Pins 2 and 3.
In Figure 12, the Group outputs the sum of the signals
coming in from the yellow and green return only.
In Figure 13, the Group outputs the sum of the signals
from all the channels connected to the group itself, and
the signals coming in from the yellow and green return.
3CHANNEL
MAIN VCA & DIRECT OUT
The top left input of each channel is its mono input
(A.1). The connected signal goes directly to the main
VCA (red): it is the second row of parameter, with a jack
socket on the right and a pot on the left. This stage can
also be identified as gain stage. The CV input range ac-
cepts both modulation signals from 0÷5V or 0÷10V.
When a CV is patched to the VCA Level CV Input (A.4), the
Level pot (A.3) attenuates the CV; when nothing is
patched to the jack socket, the pot works as the unique
primary control for the VCA Level (or for the gain stage).
This section also features a post VCA peak LED.
Practice the VCA Level CV Input with this
Technique:
Sidechain #1
The jack socket on the top right is the Direct Output (A.2).
It is not a duplication of the input, but a post VCA direct
output: it is extremely useful in case of multitrack record-
ing or parallel processing of signals.
Practice the use of the Direct Output with
these Techniques:
FUMANA Feedback #1
FUMANA Feedback #2
FUMANA Feedback #3
The last control is the Pre/Post Switch (A.5), which lets
you define how the direct output works: pre-fader (up, red
dot), or post fader (lower, white dot).
SENDS
The two Sends (yellow and green) work in the same way
and receive the signal after the main red VCA. The Send
Level CV input (B.2) range accepts both modulation sig-
nals from 0÷5V or 0÷10V. When a CV is patched to the
Send Level CV input, the Send Level pot (B.1) attenuates that
CV, while when nothing is patched to the jack socket,
then the pot works as the unique primary control for the
VCA (that is, the signal sent to the send bus). The last
control is the Send Pre/Post switch (B.3) which lets you de-
fine how the send works: pre-fader (up, yellow/green
dot), or post fader (lower, white dot).
PAN, FADER AND OTHER CONTROLS
The Pan control lets you distribute the processed signal
across the stereo image. The pot (A.6) work as in any
other mixer and the CV jack socket connected to it (A.7)
accepts both positive and negative signals (range
−5V÷5V).
The more the positive CV increases, the more the signal
is distributed to right, and vice versa for negative CVs and
the left channel. In case of modulation with a bipolar CV,
the potentiometer works as an offset.
The Channel Fader (A.8) sets the channel final volume as
in any mixers. It can also be the reference when you are
using post-fader settings in the sends or in the direct out-
put.
Below that control there are three performance-ori-
ented buttons with their relative LED: from left to right

Rev. 5 – Jun 2020 Page 12 of 91
they are the Mute button (C.1), which mutes all the chan-
nel’s VCAs, the Solo in Place (C.2), which works only
when the Safe Solo function in the connected Group is
engaged (C.3, see below §4.5) and the Stereo PFL (Pre-
Fader Listening, C.4) accessible via the Master PFL
Crossfader (C.5, see below §5.1).
The Solo in Place selects the channels that are kept active
when the group is in Safe Solo mode, while the Stereo PFL
selects the channels that will be sent to the PFL circuit on
the Master module.
4GROUP
SENDS
The Send jack socket (B.4) outputs a mono signal which
is the sum of all the signal processed for that send by each
Channel connected to the Group.
RETURNS
The Return section is divided in two specular columns,
the left one for the yellow return, the right one for the
green return.
The first two rows from the top are the Return inputs
(B.5, B.6). They are semi-normalled, meaning that they
can work either in stereo (when two cables are plugged)
or in dual mono (when only one cable is plugged into any
of the two inputs). When using two cables for stereo re-
turn the top jack is the left and the bottom one the right.
As soon as an audio signal is connected, it is routed to
the stereo return: each Return section is equipped with its
own stereo VCA, which is identical to the ones used in
the red, yellow and green sections of the Channel module.
The CV inputs (B.8) and accept both signals with a
range 0÷5V or 0÷10V, allowing any creative use of the
stereo effect returns. When a CV is patched to the jack
socket VCA input (B.8), then the Level pot (B.7) attenuates
that CV, while when nothing is patched to the jack
socket, the pot acts as a Level control for the VCA (i.e. the
return stage).
Practice the Send/Return modulation with
this Technique:
Sidechain #1
GROUP OUTPUT
The top jack sockets (A.9, A.10) are used for the Group
Output: it is a stereo output and can be configured to out-
put the sum of the signals from the returns only or the
sum of the signals from the returns and the connected
channels. Please refer to the chapter about Group Jumper
Configuration to setup properly the group module.
FADER AND OTHER CONTROLS
The Group Fader (A.11) sets the group final volume as in
any mixer. This is the volume of the sum of the connected
channels and the returns. It comes coupled with a pair of
peak LEDs on the top left and right of the knob.
Below that control there are two buttons and a switch
with their relative LED: from left to right they are the
Group Mute (C.1), for all the connected Channels and
send/return signals; the Safe Solo switch (C.3), which en-
ables the Solo In Place function on each of the connected
Channels when moved to the left, and the Stereo PFL
(C.4), accessible via the Master module for all the con-
nected Channels and Send/Seturn signals.
THE SAFE SOLO FUNCTION
The Solo function allows the musician to isolate certain
channels in the mix, thus muting all the remaining ones.
It is achieved through two operations: pushing the Solo in
Place button on the Channel module and moving the Safe
Solo switch on the Group module: the Solo in Place button
will determine which channels will be soloed (which will
be marked with the white LED) and which ones muted;
the Safe Solo switch will put this selection into practice (and
the group too will display a white LED). It is called Safe
Solo because it safely allows you to select the channels you
want to solo in advance, without affecting the ongoing
performance.
Please note that if you activate the Safe Solo without hav-
ing selected at least one channel through its Solo in Place
button beforehand, all the group will be muted!
The Safe Solo is different than the Mute function, not only
because it allows to mute many channels at the same
time, but also because the Mute works over the channel
VCA, thus muting the sound at the source, while the Solo
in Place works over the channel Fader. In this way, the Solo
In Place will mute the channel, while still allowing the sig-
nal to flow through all the parts set to work in Pre-Fader
Mode, such as Direct Output (A.2) or Effect Sends (B.2).
5MASTER
The Master module is the last step in a CGM setup. It
adds a lot of functionality to the CGM system like the
Auxiliary Stereo Input, the headphones section with the
management on the PFL, the sum and connection of mul-
tiple groups and additional ~6dB of gain.
The Auxiliary input (A.15) uses a stereo 3.5 mm jack
socket with dedicated potentiometer to set its gain and a
PFL button.
The Headphones section is based on a stereo 3.5 mm jack
output (A.16) with two potentiometers: the top one (C.5)
blends the main out (white) and the PFL signal (blue),
while the bottom one (A.17) sets the Headphone volume.

Rev. 5 – Jun 2020 Page 13 of 91
The Master uses a main Fader (A.14) to set the system
level output, featuring also a dedicated stereo LED VU-
meter [-6dBu, −1dBu, +4dBu, +7dBu, +10dBu].
The outgoing signal can be picked up from the left
(A.12) and right (A.13) main output.
THE PFL FUNCTION
PFL (PreFader Listening) allows the musician to send to the
Headphones output any channel, group or the Aux input
when their main fader is at 0, in order, for instance, to
preview it before it is mixed.
PFL is achieved through two operations: pushing the
PFL button (C.4) on the Channel or Group modules or on
the Aux input (the blue LED will light up) and adjusting
the PFL level through the PFL Blend knob (C.5).
PFL previews the Channel’s sound before the main fader:
this means that its amplitude will be determined by the
Red VCA level, which means that the the green and yel-
low Sends cannot be PFL’d from the Channel.
This is when the Group PFL comes in handy: in order to
pre-listen the effect sends and returns before sending
them in the mix, you can mute the Group’s and activate
its PFL button: from now on, everything that is managed
by the Group will be safely pre-listened without affecting
the main mix, including individual Channels’ Main
Fader settings, sends and returns.
Please note that Safe Solo overrides PFL: this means that
you can perform Safe Solo in when a Group is in PFL, but
you cannot PFL a channel whose Solo in Place button is
off when its Group is in Safe Solo mode: the reason is that,
as explained above, the Safe Solo works as a “Mute region”,
i.e., muting all the unselected channel’s red VCAs.
6CGM MIXER TIPS
STEREO INPUTS
The returns on the group manage audio signal in the
same way as the mono input on each Channel. This means
that they can be creatively used as actual auxiliary stereo
inputs, not limited to the effect return. In this case, you
will gain two additional stereo VCAs for your mix, but
you will lose control over the effects section.
MORE THAN 2 SEND/RETURNS PER CHANNEL
In case you have more than one Group on your CGM
system, you can use the direct out of a channel linked to
a Group to patch it to the mono input of another Channel
linked to another group.
In this way you will use the RED VCA of the original
channel, and its CV, to shape the amplitude of your sig-
nal, then on the second, add the 3rd and 4th parallel Send
to it, taking advantage of the second group.
SERIAL SEND/RETURN (AND FEEDBACKS)
Since the two effect Send/Returns are in parallel, it is vir-
tually impossible to have two effects (say, reverb and de-
lay) in series.
There is, however, a simple workaround that lets you
achieve this function, with additional CVs over the differ-
ent returns: just patch the delay return to a Channel linked
to the same group and send it back into the reverb: this
will allow independent controls over delay, reverb and
both. On the other hand, if the delay send of this last
Channel is set to a high value, it will cause feedbacks.
The two sends are patched with a delay and a reverb,
respectively. You can bypass this setting the return of the
delay on a channel linked to the group of the delay and
reverb, and gradually increase the amount of reverb send
on that signal too.
Be aware that adding some delay to the channel of the
delay return will result in undesired feedback, so be ex-
tremely careful.

Rev. 5 – Jun 2020 Page 14 of 91
SAPÈL
Figure 14: SAPÈL interface.
AClocks
A.1 Clock Input
A.2 Clock Rate
A.3 Single/Both Switch
A.4 Main Clock Output
A.5 Random Clock Output
A.6 Random Clock Mode
A.7 Gate/CV Modulation Input
A.8 Gate/CV Modulation Switch
A.9 Sample-and-Hold (S&H) Button
BStepped Random Voltages
B.1 S&H Output
B.2 n+1 Output
B.3 n+1 Value
B.4 n+1 Value CV Input
B.5 2ⁿ Output
B.6 2ⁿ Value
B.7 2ⁿ Value CV Input
CFluctuating Random Voltages
(FRV)
C.1 FRV Output
C.2 FRV Rate and Global Rate of
Change
C.3 FRV Rate and Global Rate of
Change CV Input
DNoise Outputs
D.1 Blue Noise Output
D.2 White Noise Output
D.3 Pink Noise Output
D.4 Red Noise Output
EProbability Distribution
E.1 Probability Distribution
E.2 S&H Probability Distribution
Switch
E.3 Fluctuating Probability Distribu-
tion Switch
E.4 n+1 Probability Distribution
Switch
E.5 2ⁿ Probability Distribution Switch
1PHILOSOPHY AND DESIGN
SAPÈL is an analog generator of random control volt-
ages for Eurorack modular systems.
Its main section is composed of two identical clusters of
four Sample and Hold circuits each (yellow and green),
which generate as many different random values at the
same time.
Three of the four S&H circuits in each cluster provide
stepped random voltages: two are quantized (in “notes”)
and one is unquantized; the last S&H circuit features an
integrator to generate a fluctuating stream of random
voltages.
The three stepped voltage generators are synced, which
means that they will output three different values at the
same time. The yellow and green generators have two in-
dependent internal clocks, which can be replaced with an
external one, or temporarily overridden either via
external gate or manual button. A copy of the trig used
to sample the stepped random values is available, as well
as a random trig output.
The fluctuating voltage generator, on the other hand, is
independent and has its own potentiometer to define its
rate.
Each of the two S&H clusters samples its values from
analog noise, thus providing a “true” and completely un-
predictable randomness.
The second section of SAPÈL features four analog noise
outputs, which are derived from the analog noise used to
sample random values.
2NOISE OUTPUTS
This section features four analog noise outputs, which
are, from top to bottom:

Rev. 5 – Jun 2020 Page 15 of 91
·D.1 Blue Noise (+3dB/oct spectrum);
·D.2 White Noise (0dB/oct spectrum);
·D.3 Pink Noise (-3dB/oct spectrum);
·D.4 Red Noise, also known as brown or Brownian (-
6dB/oct spectrum).
Each noise “color” has its own distinct tone, which can
be used for sound-designing purposes.
Theoretically, White Noise has an equal distribution of
intensity across all the frequencies per bandwidth. Prac-
tically, in the analog domain, White Noise is a sound
which has a flat spectrum in the audible range, or, in sim-
pler terms, which can “hit” all the frequencies with equal
amplitude at the same time. It is perceived as a highly
inharmonic sound but, to the peculiar nature of the hu-
man ear, it appears slightly unbalanced towards higher
frequencies.
For this purpose, SAPÈL features also a Pink Noise out-
put. Pink Noise is basically a White Noise filtered through
a −3dB/Oct filter, which “smoothens” its higher fre-
quencies in order to deliver a more “balanced” sound for
the human ear. Pink Noise features an equal distribution
of intensity per octave, instead of bandwidth.
Red Noise is similarly generated, but the filter has a
slope of −6dB per octave. The result is a low, “rumbling”
tone.
Finally, Blue Noise is a kind of inharmonic sound whose
intensity increases proportionally to the frequencies. In
other words, the higher part of the spectrum will appear
to be louder, and the overall result is a high-pitched hiss-
ing sound which lacks bass frequencies.
Practice the Noise Outputs with these
Techniques:
Percussion Sounds #1
Percussion Sounds #2
Percussion Sounds #3
Accents #2
3VOLTAGE SAMPLING
The yellow and green generators, as said above, work
independently the one from the other. Each of them sam-
ples three random values at the same time: one which is
unquantized (i.e. with no fixed “pitch”), one quantized in
semitones and one quantized in octaves.
The sampling process happens when a trig or gate acti-
vates the S&H circuit, which “picks” the value played by
the noise source at a given time, and “holds” it until an-
other trig or gate is generated. There are four ways to
activate the S&H circuit for each of the two generators:
internal clock, external clock, manual S&H button, exter-
nal S&H gate, plus an “extra” mode which combines the
clocks (let it be internal or external) of both the green and
yellow generators.
By default, each generator is driven by an internal
clock. The clock section generates a regular clock signal
(called Main Clock) and two Random Clocks (on which see
below). Both the yellow and the green random sources
have their own independent clock. The regular train of
impulses provided by the Main Clock is used to sample the
random values and is also routed to the Main Clock output
(A.4). The Random Clock does not affect the S&H circuit,
but it is available for advanced modulation purposes
through the Random Clock output (A.5).
INTERNAL CLOCK AND CLOCK MODULATION
The built-in clock frequency is managed by the Clock
Rate knob in the center of the module (A.1). Rotate the
knob counterclockwise to decrease the sampling rate and
clockwise to increase it.
It is possible to modulate the frequency of the clock via
the Gate/CV Modulation Input (A.7).
This input can have two separate functions, selectable
via the dedicated switch (A.8): it can route the incoming
CV to modulate the clock frequency, or it can use any
voltage higher than 3V to trig the S&H cluster (see below,
§3.5).
When such a switch is set to the right, the incoming CV
will modulate the clock frequency: a positive CV will in-
crease the clock speed, and a negative one will decrease
it.
EXTERNAL CLOCK
It is possible to use any external trig to activate the S&H
by patching it to the External Clock Input (A.1).
Whenever a cable is patched to this input, the internal
clock is bypassed (i.e. it will no longer trig the S&H cir-
cuit). This input welcomes trigs and gates only: this means
that in order to sample a value, it needs an incoming sig-
nal with a really steep rising edge, such as square waves,
pulse waves or sawtooth waves with negative ramp (be-
side of course trig and gate impulses). Other kind of im-
pulses such as sine or triangle waves will be ignored.
CLOCK MIX
It has been said that the green and yellow sections of
SAPÈL have their own independent clock generation. It
is possible, however, to blend them in a more creative
way through the Single/Both switch (A.3), which feeds the
other generator’s clock into the one currently in use. To
activate the clock mix, set the switch to the position
marked by a square of the other generator’s color.
This feature works with both internal or external clocks,
and it affects the sampling section only: all the clock out-
puts will maintain their regular behavior.

Rev. 5 – Jun 2020 Page 16 of 91
MANUAL SAMPLING
No matter if you are using the built-in clock or an ex-
ternal one, that stream can be temporarily bypassed with
the manual S&H Button (A.9).
By pushing the S&H button the stream of impulses is
overridden by a gate high signal, which samples a value
and holds it until it is released. A dedicated LED will light
up as long as the button is pushed. The main clock out-
put, however, will still output a trig signal.
Practice some uses of the buttons with this
Technique:
Hold
EXTERNAL GATE SAMPLING
This last operation can be automated using the Gate/CV
Input (A.7).
When the switch (A.8) is set to the rightmost position,
any CV signal higher than 3V can be patched in the
Gate/CV Input and used to override the internal clock.
With this configuration it is possible to use other signal
than gates and trigs to drive the S&H cluster, such as sine
or triangle waves or even the internal fluctuating random,
however a gate or a square signal generally provide best
results.
CLOCK OUTPUTS (MAIN AND RANDOM)
Every time the S&H Cluster samples a value, a 2ms trig
is outputted from the Main Clock output (14A.4). If a steady
pulse is used, such as the internal clock or an external one,
this output will provide an exact copy of the clock.
On the left of the Main Clock output lies the Random Clock
output (A.5), which can either add or subtract trigs from
the one in use through its switch (A.6), located between
the two clock outputs.
When the switch is up, or in additive mode, it outputs
all the clock impulses generated from the clock with the
addition of other random clocks; when the switch is
down, or in subtractive mode, it randomly subtracts trigs
from the ones generated to trig the S&H Cluster, i.e. it
outputs only some of the trigs that are outputted by the
Main Clock out.
In both modes, the random clock density depends on
the Global Rate of Change (See below, §4.3).
Practice the clocks with these Techniques:
Random Clocks #1
Random Clocks #2
Ratcheting-Like Effect #3
Clock Bursts #1
Clock Bursts #2
Since SAPÈL’s clock is 2 milliseconds long, it
works really well if patched to FUMANA’s Mod-
ulation Input:
Percussion Sounds #2
4RANDOM VOLTAGES
SAPÈL is designed to provide a vast array of random
voltages with different articulations at the same time.
Each of the two S&H clusters (yellow and green) can be
divided into two units: the first one generates three ran-
dom voltages simultaneously, and it is activated by the
clocks or gates described above; the second one generates
continuous, fluctuating random values and it is com-
pletely independent from the clocks and gates.
NON-QUANTIZED RANDOM VOLTAGES
The most basic stepped random values generator is the
Sample and Hold circuit, which outputs its values
through the S&H output (B.1)
This generator is designed with an independent ran-
dom generator and creates non-quantized stepped volt-
ages with a range varying from 0 to 7.5V. Non-quantized
means that if the values are used, for example, to modify
the pitch of an oscillator, the result will be a series of
sounds whose frequency may not sit within the conven-
tional 12-semitone Western chromatic scale. It can be
used for more experimental music compositions or, more
traditionally, to modulate other non-melodic parameters
such as timbre, filter frequency, amplitude…
QUANTIZED RANDOM VOLTAGES
The other two stepped random voltage generators out-
put voltages which are quantized (i.e., “forced”) to the
1V/octave standard. If applied to an oscillator’s fre-
quency, the result will be a series of random “notes”
The design of these two generators follows the historical
Buchla module Source of Uncertainty Model 266, but
with a substantial different approach. The circuit has
been designed from scratch in order to obtain a more
“random” voltages distribution and an extremely precise
voltages quantization, capable of generating precise sem-
itones or octaves.
At first glance, the main difference with the S&H circuit
mentioned above is that the quantized random voltage
generator features a knob which controls the n parameter
and whose range goes from 1 to 6, as in the original 266
module. The role of the n parameter varies according to
each generator’s label: 2n and n+1.
The 2n Output (B.5) is quantized in 1/12V steps, or sem-
itones in the 1V/oct scale. In this case, the Value knob sets
the exponent of 2 which, in turn, determines the number
of different values that may be generated by the circuit.

Rev. 5 – Jun 2020 Page 17 of 91
Given that n can be any number from 1 to 6, there are 6
possible ranges of values that this circuit can generate:
n Knob value
Number of generated voltages
2¹
2
2²
4
2³
8
2⁴
16
2⁵
32
2⁶
64
Table 1: n values for 2n quantized random voltages.
Please note that higher is the number, the larger be-
comes the range of voltages (or “notes”) that are gener-
ated, starting from 1 (0V) up to 64 (5.25V). This will guar-
antee the musician more control over the final output and
will lead to more expressive results: for example, a low n
value will always generate smaller intervals and low
pitches, while a high hone may provide larger leaps from
one semitone to the other, as well as higher notes. Please
refer to the graph below (Figure 15) for a graphic repre-
sentation of the exponential note distribution across all
the n settings:
Figure 15: 2 n quantization chart.
The n+1 output (B.2) is quantized in 1V steps, or octaves
in the 1V/oct scale. In this case, the Value knob (B.3) sets
the number which will be summed to 1, which, in turn,
determines the number of different octaves that may be
generated by the circuit. Again, given that n can be any
number from 1 to 6, there are 6 possible ranges of octaves
that this circuit can generate:
n Knob value
Number of voltages generated
1+1
2
2+1
3
3+1
4
4+1
5
5+1
6
6+1
7
Table 2: n values for n+1 quantized random voltages.
Even in this case, that higher is the number, the larger
becomes the range of voltages (or “octaves”) that are gen-
erated, starting from 1 (0V) up to 7 (6V). Please refer to
the graph below (Figure 16) which displays the linear in-
crement of the octaves across the different n settings.
Figure 16: n+1 quantization chart.
Both the 2n and the n+1 can be controlled via external
CV (B.4, B.7) thus allowing the musician to automatically
vary the range of values to be outputted.
Practice the use of the n+1 output with these
Techniques:
Ratcheting-Like Effect #2
Voice Spread #1
FLUCTUATING RANDOM OUTPUT AND GLOBAL RATE
OF CHANGE (RANDOM CLOCK DENSITY CONTROL)
The main purpose of this section is to output (C.1) a
continuous, fluctuating random voltage which ranges 0
to 7.5V and whose rate of change (or “frequency”) is con-
trolled by its potentiometer (C.2).
This random generator is the only one (in both the S&H
clusters) which is not affected by the main clocks or gates;
however, on the other hand, it can affect the clock gener-
ation itself.
The second purpose of this section, is in fact, to control
the rate of change of the random clocks: by rotating the C.2
knob clockwise, both the fluctuating voltage frequency
and the random clock density (let it be in more than or less
than mode) are increased, and vice versa.
Just like for the quantized voltage generators, this pa-
rameter can be modulated with any CV using the its CV
input (C.3). The external modulation will affect both the
fluctuation rate and the random clock density.
Practice the Global Rate of Change with this
Technique:
Fluctuating Random & Global Rate of Change
24
8
16
32
64
-0,75
0,25
1,25
2,25
3,25
4,25
5,25
0
8
16
24
32
40
48
56
64
1 2 3 4 5 6
Volts
Number of stages
nvalue
2
3
4
5
6
7
0
1
2
3
4
5
6
1
2
3
4
5
6
7
1 2 3 4 5 6
Volts
Number of stages
nvalue

Rev. 5 – Jun 2020 Page 18 of 91
5PROBABILITY DISTRIBUTION (STORED
RANDOM VOLTAGES)
The four S&H generators can be controlled as for mag-
nitude of the voltages that are more likely to be generated:
this parameter is called probability distribution, it is glob-
ally set by the Probability Distribution knob (E.1) and it can
be activated independently per each of the four S&H cir-
cuits through the four Probability Distribution Switches
(E.2, E.3, E.4, E.5).
The knob sets the magnitude of voltages which will be
generated more frequently: by default, it is set to the mid-
dle position, which means that medium voltages will be
outputted more often than high or low ones. Rotate it to
the left to raise the probability of generating lower volt-
ages, and to the right for higher ones.
Please note that this setting will not block the SH& cir-
cuits to generate different voltages than the ones whose
probability is set to be higher: they will just be generated
less frequently.
This is a significant difference, for example, from the n
Knobs function of the quantized random voltages: in that
case, the value defines the “pool” of values that may be
picked; here, on the contrary, the Probability Distribu-
tion Knob sets the magnitude of voltages that are more
likely to be generated within the “pool” selected above.

Rev. 5 – Jun 2020 Page 19 of 91
FUMANA
Figure 17: FUMANA interface.
AAudio Inputs
A.1 Main Odd Input
A.2 Main Odd Level
A.3 Main Even Input
A.4 Main Even Level
A.5 Mod Odd Input
A.6 Mod Odd Level
A.7 Mod Even Input
A.8 Mod Even Level
A.9 Unvoiced Input
A.10 Unvoiced Level
BAudio Outputs
B.1 All Output
B.2 Odd Output
B.3 Odd Output Phase
B.4 Even Output
B.5 Even Output Phase
B.6 Individual Band Outputs
CControls and CV Inputs
C.1 VCA Faders
C.2 VCA CV Inputs
C.3 Tilt Control
C.4 Tilt CV Input
C.5 Tilt CV Input Attenuverter
C.6 Peak/Notch Control
C.7 Peak/Notch CV Input
C.8 Peak/Notch CV Input Attenuverter
C.9 Center Control
C.10 Center CV Input
C.11 Center CV Input Attenuverter
C.12 Width Control
C.13 Width CV Input
C.14 Width CV Input Attenuverter
DControls and CV Outputs
D.1 All Envelope Followers Output
D.2 Individual Envelope Followers
Outputs
D.3 Envelope Followers Rise Control
D.4 Envelope Followers Fall Control
1PHILOSOPHY AND DESIGN
FUMANA is a dual all-analog fixed filter bank. Each
filter bank is composed of an array of 16 independent
bandpass filters tuned to specific frequencies.
FUMANA is designed around one basic core principle:
modify the spectral content of the incoming audio signal
by filtering it through 16 bandpass filters in parallel and
then vary the amplitude of each resulting band.
Even though this core principle is relatively simple, the
key feature of FUMANA is that it provides a wide set of
controls over the bands’ amplitude: the spectral content
of the incoming sound can be thus modified by the faders,
which are individually CV-controllable; by the envelope
followers which are generated by the analysis of the sound
patched in the Modulation input; by the global paramet-
ric controls such as Tilt and Scan.
Furthermore, a flexible input/output signal routing al-
lows the musician to “split” the 16 filters into two 8-band
spectral processors by grouping the odd and even bands
separately. It will be possible to process two independent
signals, or to blend two signals into one output, or even
to perform two different sonic treatments over the same
signal and route it to two different output sections.
Individual outputs are available for each band, both for
the Main sound (i.e. the filtered one) and for the Mod
sound (i.e. the resulting envelopes).
Since a spectral transfer tool may be used as a “vocoder-
like-effect”, the FUMANA provides an input for an

Rev. 5 – Jun 2020 Page 20 of 91
external noise which may be used for fricative/sibilant
sounds.
SPECTRAL TRANSFER: A BRIEF HISTORY
In the modular synth domain, the most famous device
for performing spectral transfer was the legendary Model
296, designed by Donald Buchla in the seventies. It was
a 16 bands equalizer, which featured one input for the
odd bands and one for the even bands: this solution al-
lowed the artist to process two different signals at the
same time, but it also allowed to transfer the harmonic
content of one to the other via dedicated switches. It was
thus possible to analyze the odd bands and transfer their
amplitude to the even bands, and vice versa.
This design was clever because it took advantage of a
single array of 16 filters, but the resulting spectral transfer
was somehow “approximated” because the modulation
signal came from the analysis of the adjacent band, i.e.
another frequency area of the spectrum, albeit quite
close.
The FUMANA pushes this concept even further, but
still within the analog domain. An additional bank of 16
filters is added, specifically for analysis purposes, with a
different band-pass slope (see below §5).
When performing a spectral transfer, it is fundamental
to consider the harmonic content in both main and mod-
ulation audio signals. Remember that if there is no har-
monic to excite the content on the main signal, there will
not be that much outcoming audio, even if all the VCAs
are opened at their maximum level:
Poor harmonic content on the Main signal: if a pure sine
(one harmonic) or any signals with poor harmonic con-
tent is used, there are not many chances to hear good re-
sults exciting several bands. Supposing it is a sine wave
with a frequency of 105Hz (which lies then on band 3),
theoretically something happens only when band 3 is ex-
cited from the modulation signal.
Rich harmonic content on Main signal: this means more
chances to have several bands excited by the envelope
followers control voltages created by the modulator fil-
terbank.
Poor harmonic content on Modulator signal: allows cre-
ation of very selective envelope followers signals, which
translates in an extremely selective spectral transfer. If the
modulation signal changes pitch or has a very variable
content, it will for sure result in a more heterogeneous
spectral transfer.
Rich harmonic content on Modulator signal: allows a
very rich spectral transfer. Just keep in mind that if you
are using a square wave in the modulation with frequen-
cies varying from 100 to 200 Hz, probably you won’t hear
that much difference, due to the richness of harmonics of
the square wave.
PANEL OVERVIEW
A consistent color and graphic coding make the front
panel easy to understand at a glance, once properly un-
derstood.
The main graphic solution is the distinction between
the odd and even bands: since the two groups can work
independently, every input or output related to the even
bands is marked by a circle around the jack socket. (The
bands are numbered 1-16 from left to right: odd bands
are band 1, 3, 5, 7, 9, 11, 13, 15; even bands are 2, 4, 6,
8, 10, 12, 14, 16).
Another key coding is the distinction between the Main
filter array and the Mod filter array. Everything that re-
lates to the Main filter bank, which is the circuit directly
affecting the sound that is heard, is marked by the color
blue, let it be audio output, CV input or even the faders’
LED color.
On the other hand, everything that relates to the Mod
filter bank, which is the one that extracts the envelopes
from the modulating signal and modifies the harmonic
content of the main filter bank, is marked in grey, includ-
ing the individual envelope output LEDs (which flash
white when active).
Finally, the green and yellow colors mark the Global
Spectral Editing tools: the former relates to the Tilt con-
trol, the latter to the Scan controls.
2AUDIO INPUTS
FUMANA has two pairs of inputs, which are called
Main In (blue), and Mod In (gray), short for “modulation
input”, plus a fifth input called Unvoiced. (A.1, A.3, A.5,
A.7, A.9).
Each pair is composed of inputs for the Odd and Even
bands, which are semi-normalled together. This means
that when only one patch cable is connected to one of the
two inputs, it automatically feeds the other. If you want
to use different sources for odd and even bands, simply
use two different cables. If instead, you want to feed only
the odd bands and not the even (or vice versa), simply
feed the odd input, and plug a dummy cable to the other
input (or vice versa).
Each of the four inputs has its own amplitude potenti-
ometer (A.2, A.4, A.6, A.8): different levels can thus be
set for odd or even filters within each pair of input. This
also means that if you want to emphasize even bands on
the main signal, you can simply add more gain to them,
and less to the odd ones.
The fifth input, named Unvoiced, is designed for adding
some depth to the fricative consonants that might be
missed when performing vocoding-like operations. It fea-
tures its gain control as well (A.10).
The red LEDs connected to the odd and even inputs
light up displaying the amplitude of the incoming audio
after the gain level.