Jomox Mod FM User manual

USER MANUAL
Preliminary Version
Will be updated soon.
Please check www.jomox.de frequently.

JoMoX Elektronische Musikinstrumente GmbH
Sophie-Charlotte-Str. 15
14059 Berlin

3
JoMoX Mod FM
CONTENT
INTRO 4
What is Mod FM? 4
Installation / Rack Mounting 5
Operating Panel 7
Control Elements and Displays 7
Editing Parameters 8
Changing Presets 9
Connection Sockets 9
SOUND GENERATION 10
Signal Path Overview 10
FM Engine (Experimental Field and Key to outstanding Timbres) 10
  AnalogueProcessing(EfcientParameterswithrealanalogueFlavor)  10
Effects Section (Adding sonic Spice) 10
Signal Output (Make it audible) 10
External Control (Link to the Eurorack System) 10
  SignalFlow      11
Menu Overview 12
FM Engine 13
Enter the Matrix 13
Operators 14
  Howtooperatethematrix     15
  MatrixMenue      15
Algorithm Menue 17
  OperatorEnvelopes      18
LFO Menue 19
Sound Processing 21
Filter / VCA 21
Effects (FX) 23
Randomisation and Reset Functions 25
SINGLE-/MULTIMODE 26
Single Mode 26
Multi Mode 26
STORE PRESETS 28
EXTERNAL CONTROL 29
MIDI 29
External Control via CV/Gate and Control Voltages 32
CV/Gate 32
  Modulationwithexternalcontrolvoltages 32
ADDENDUM 36
FM Algorithms 36
MIDI Implementation
 TechnicalSpecications      42
Imprint 43

JoMoX Mod FMINTRO 4
INTRO
WelcomeandthankyouforpurchasingyourJoMoXModFM!Wewishyoulotsofcreativefunwithyour
newJoMoXsynthesizer.
Your JoMoX team
What is Mod FM?
ModFMisaneight-voicepolyphonicFMsynthesiserwithmultimode.ItisintendedforuseinaEurorack
frameandcanbecontrolledviaMIDI(TRSorUSB-C)andCV/Gate.
Mod FM provides some interesting features:
• ModFMisself-contained-inotherwords,acompletesynthesiserinjustonesingleEurorackmodule.
 Apartfromapowersupply,noothermodulesarenecessaryforoperation.
• ModFMhasahybridsoundgeneration.Thismeansthatitworksbothdigitallyandrealanalogue.
• ThedigitalpartofthesoundgenerationusesFMsynthesis,theanaloguepartcomplementsclassic
 subtractivesynthesis.
• TheFMenginehasfouroperatorsthatcanbeinterconnectedinanywayviaamatrix.Fixed
 FMalgorithms,asusuallyfoundinclassicFMsynthesizers,arealsoavailable.
• ModFMmakesiteasytocreateinterestingharmonictimbresandtonalsounds.Abovethat,ModFM
 providesawiderangeofoutstandingandunusualtimbres.
• Thelter/VCAsectionmakesiteasytoaddrealanalogueavourtotheFMtimbres.
• ModFMsportsthreeinternalaudioeffects(reverb,2xdelay)whichaddsomemorespicetoevery
timbre.
• ModFMhasaneasytouse8channelmulti-mode.Eveninmulti-mode,ModFMcanbecontrolled
 withCV/Gate.
• NumeroussoundparameterscanbecontrolledviaexternalvoltagesfromanEuroracksystem.
• Mod FM stores up to 128 single and 128 multi presets.
Rtfm...!
We pray to you: Please read (and internalise) the f... manual! You will do your-
selfabigfavour,becauseitwill(hopefully)helpyoutondaquickaccessto
your new Mod FM. And that means: more and faster fun with your new synthe-
sizer. Sounds good, eh...? Thank you so much!

JoMoX Mod FM INTROJoMoX Mod FM 5
Installation / Rack Mounting
Please power off your Eurorack prior to installation!
OnthebacksideoftheModFMmoduleyoucanndthisconnector:
RackMounting
PleaseconnecttheincludedribboncabletotheEuroracksystembusrailsasshownonthepictures.The
Mod FM module needs +/-12 Volts at a supply current of maximum 130mA on +12V and about 70mA on
-12Volts.Theoptional5VoltsandtheCV/GateontheA-100Doepferbusarebothnotwiredinsidethe
Jomox module and not needed.
Other10pinsystemsmaybeusedaswellifonlythelowerpartofthe16pinconnectorisconnected.
Pleasepayattentionforthepositionofthevoltagesandthegroundpins!Theprintedvoltageinformation
havetomatch,pleasecheckthewiresagainandmakesurenopinisleftorbent.
There are protection diodes inside the modules but please take extra care to
protect the rack and the module!
TheA-100Doepferbus.(TheDoepferGmbHenterpriseandalloftheirshownproductsareregistered
trademarks.WithfriendlyapprovalofDoepferMusikelektronikGmbH)

JoMoX Mod FMINTRO 6
TheJoMoXModFMeuroracksupplyconnector.Pleaseconnectthepowersupplyoftheeuroracksystem
bus here.
Attention: DO NOT connect, under any circumstances, the power supply cable
to the Jomox Inter-D-module bus!!!
The rack power supply and the module could get seriously damadged!
ThenpleasemountthemoduleontherackrailsusingthesuppliedmetricM3screws.Therackmountingis
nowcompletedandModFMreadytoplay.

JoMoX Mod FM INTROJoMoX Mod FM 7
Operating Panel
Control Elements and Displays
Ontheuserinterfaceyouwillndthefollowingcontrolelements:
Buttons:
• Menubuttons:
 Theyareusedtoaccessthevariousmenus.
• Cursorbuttons:
 Thecursorbuttons<and>areusedtochangethedisplaypageswithinamenu.
The cursor buttons and are used to change the current preset.
Knobs:
The knobssetcertainparametervalues.Dependingonthemenu,theychangetheirfunction.
Displays:
Bothdisplaysprovideinformationaboutoperatingstatesandparametersettings.Theybasicallyshow
severalpiecesofinformationandparametersatthesametime,summarisedonmenupages.
Tomakeiteasiertondyourwayaroundthedisplaycontents,thefollowingdisplaymodesapply(please
refertothegureonthenextpage):
• Onallpagesoftheleftdisplay,thetoplineshowsthecurrentpresetnameandnumber.
• Namesofmenupagesareshowninvertedandareusuallylocatedinthetopright-handcornerofthe
left-hand display.
• Aneditableparameterisshownwithashortenedname(e.g.FRQ) and a little knob symbol.
• Thepositionoftheslidermarkroughlyshowsthecurrentparametervalue.
• Ifaparametercontrolsasignallevel,alittlebarisdisplayedinsteadoftheknobsymbol.
• Whenthecorrespondingknobisturned,thedisplaybrieyshowstheparametervalueasanumber
instead of the shortened parameter name.
• Somedisplaypages-suchasenvelopecurves-areanimatedandchangetheirshapeaccordingto
 thecorrespondingparametervalues.
External control of
operator envelopes
(sockets and menue
button)
External control of
matrix parameters
(sockets and menue
buttons)
CV/Gate inputs
(sockets and menue
button)
Matrix knobs for
editing matrix and
other parameters
Menue buttons for
selecting menues
Cursor buttons for
changing presets and
meneu pages
MIDI ports
Display
Display
Audio outs
Parameter knobs
for editing div.
menue parameters

JoMoX Mod FMINTRO 8
Editing Parameters
Example for the right
handeddisplay:
Example for the left
handeddisplay:
Tooptimisethelivespanofthedisplays,ascreensaverswitchesonafter30secondswithoutaninput.
Touching any control element calls up the normal display again.
• Menue buttons open the
menues.
• Cursor buttons < / >
change menue pages.
• Cursor buttons /
change the current preset.
• Knobs change parameter
settings.
(Sometimes both “Para”- and
“Matrix” knobs are used to
accessparametersshowninthe
twodisplays)
Analog Bass 1012
FRQ MIX VCO WAV
FM1
FM2
FM3
FM4
LFO 1
Change
Parameter Value
Display shows
Parameter Value
Turn Knob
Preset
Name / Number
Parameter
Name
Menue Page
MET
FMV 2PL
4PLNOI
LP
LFO
FRQ
WAV01
LFO
INT
INP MIX
SHP
Change
Parameter Value
Level
Parameter
Any other
Parameter
Display shows
Parameter Value
Turn Knob

JoMoX Mod FM INTROJoMoX Mod FM 9
Connection Sockets
• Audio
 Ontherightaretheaudiooutputsockets(individualoutputsforalleightvoices,stereomixoutput.
 Theyprovideasignallevelof10Vpp(Eurorackstandard).
• MIDI
 AtthetoparetheMIDIconnections(mini-TRS,USB-C).
 PleasedonotuseMIDI-TRSandUSBatthesametime!
• Control Voltges
On the far left and bottom left are CV inputs for external control of sound parameters. They handle
 controlvoltagesfrom0Vto5V.
• CV/Gate
AtthebottomareCV/gateinputsforpitchandtriggerofalleightvoices.ModFMhandlesgate
 signalsof3Vto15V,accordingtotheEurorackstandard.
The control voltage inputs and the CV/Gate inputs of the Mod FM are
compatible with the Eurorack standard and should only be operated
with signals from suitable Eurorack modules!
External Control of
operator envelopes
(sockets and
corresponding
menue button)
External Control of
matrix parameters
(sockets and
corresponding
menue buttons)
CV/Gate inputs
(sockets and
corresponding
menue button)
MIDI Ports
Audio Outs
Changing Presets
AfterswitchingModFMon,thepresetthatwaslastactivebeforepoweringdownisalwaysactive.Itcan
bechangedatanytime.Thisworksinsingleandmultimode.
• Changethecurrentpresetwiththe/Cursor buttons.
Please note that unsaved changes will be irretrievably lost when changing
presets.Sopleasebesuretosaveyoureditedpresetsrst!(Pleasereferto
page 28).
Analog Bass 1012
TUN OVT0 AL00 VOL
C1
C2
C3
C4
MATRIX

SOUND GENERATIONSOUND GENERATION JoMoX Mod FM10
SOUND GENERATION
Signal Path Overview
FM Engine (Experimental Field and Key to outstanding Timbres)
ThesoundgenerationofModFMisbothdigitalandrealanalogue:AnFM engine servesasthemain
signalsource.Itconsistsoffour operators (sine oscillators). They are interconnected in the form of a
matrix,sothateachoperatorcanfrequency-modulateeveryotheroperatorwithindividualintensity.At
thesametime,eachoperatorcanitselftbemodulatedbyallotheroperators.
Each of these four operators sports two ADSR envelope generators.Oneofeachcontrolsthevolume
curve,theotherthepitchcurveofitsoperator.
26 preset FM-algorithms offer sensible and easy-to-use interconnections of the matrix.
A so-called overtone functionscalestheoperatorstoharmonicovertonesandthussimpliesthepro-
gramming of tonally playable sounds.
AnalogueProcessing(EfcientParameterswithrealanalogueFlavor)
The signal of the FM engine is fed into a post-processing sectionwithatrueanaloguesignalpath.It
consists of a multimode lter,aVCAaswellastwoenvelope generators and LFOs each for modulat-
ingthelterandVCA.
TheLFOscanbeoperatedintheaudiorangeandthenusedasadditionalaudiooscillatorstogetherwith
theFMengineoralternatively.
Inthissectionyouwillalsondanoise generator as a further signal source.
Effects Section (Adding sonic Spice)
Theanaluguepostprocessingsectionisfollowedbyaneffects sectionsportingthreeeffects:reverb,
delay 1 and delay 2.
Signal Output (Make it audible)
The outputsignalisavailableeitherviatheMainOut,withvoices1,3,5,7attheleftoutputchannel,and
2,4,6,8attherightoutputchannel.Nexttothis,individualoutputsforeachvoicecanbefound.
External Control (Link to the Eurorack System)
SeveralparametersoftheFMmatrixcanbecontrolledbyexternal voltages.
Theseare:
• pitchandvolumeenvelopeamountofeachoperator(EV/OP CV sockets)
• modulationamountsbetweeneachoperator(Amt 1 – 4 sockets)
• pitch of each operator (FM1 – 4 +/- sockets)
ThegureonthefollowingpageshowsasimpliedrepresentationofModFM’sentiresound
generation.
Lots of information about FM sound synthesis can be found on the internet.