access virus b owner's manual

2000 Access Music GmbHmany. Virus is a trademarAccess Music GmbH. All ottrademarks contained herethe property of their respeowners. All features and sptions subject to change winotice.

Written by Christoph KempG. Hnig, Wiland Samolak Marc Schlaile.Translation by Thomas GreGraphic Design and DTP byBabylonwaves Media.

http://[email protected], Ger-k of her in are

ctive ecifica-

thout

er, Uwe and

en.

de

CONTENT

INTRODUCTION - 15

The Virus ...................................The Amplifier Envelope .........The First Filter ..........................Filter Modulation ....................The Saturation Stage .............The Second Filter.....................Filter Routing ...........................The First Oscillator..................The Second Oscillator ............The MIXER Section..................The LFOs ....................................LFO 2 ...........................................Velocity ......................................Unison Mode............................The Chorus/Flanger Effect....The Delay Effect.......................More to Come ..........................

CONCEPT AND OPERATION

Operating Modes ....................The Multi-Single Mode..........Edit Buffers ...............................

HANDLING - 59

...............16

.............. 20

...............23

...............25

...............27

.............. 28

...............32

.............. 34

...............37

.............. 39

............... 41

..............46

.............. 48

..............49

.............. 50

............... 51

...............52

- 53.............. 54...............55...............57

Parameter Selection and Data Entry ...............................................60Knob Modes ........................................... 63Display of values ................................... 64

ALL ABOUT THE MEMORY - 67Store ......................................................... 68Compare..................................................69

MASTER CLOCK & MIDI-CLOCK - 71Master Clock and Midi-Clock ..............72

THE MODULATION MATRIX AND DEFINABLE KNOB - 75

Creating Modulation Configurations via Assign ................................................ 76The Definable Knobs.............................78

THE EFFECTS SECTION - 81The Effect Section ................................. 82

AUDIO INPUTS - 83

Audio Inputs ........................................... 84OSC Volume / Input.............................. 85Input Level Indicator ............................86

INTERNAL AUDIO ROUTING

Aux Buses..................................The Audio Outputs .................

ADDITIONAL FUNCTIONS

Panic Function .........................Audition function....................Reset Function .........................

THE PARAMETERS

Sound Parameters with a DeControl Element ......................LFO 1 Panel .............................LFO 1 EDIT Menu...................LFO 2 - Panel .............................LFO 2 Edit-Menu ......................LFO 3 ...........................................OSCILLATOR 1- Front Panel....Oscillator 2 front Panel.......OSCILLATOR EDIT-Menu....

Menu parameters for Oscillator-2...107 Menu-Parameter for Oscillator-3... 109Menu-Parameters of the Suboscillator ...........................................111Mixer-Parameters within then

- 87.............. 88..............89

- 91.............. 92.............. 92.............. 92

- 93dicated ..............94.............. 95.............. 97............ 100............. 101.............102............ 104.............105............ 106

Oscillator-edit-Menu ........................... 112Mixer ........................................................ 113Filters Panel .........................................114Filter-Edit-Menu....................................118Amplifier ................................................ 122Main Edit Menu (Common)............... 123Assign......................................................129Velocity................................................... 133

WITHIN THE CTRL-MENU - 135COMMON .............................................. 136ARPEGGIATOR....................................... 137DEFINABLE 1 / DEFINABLE 2 .............. 140MULTI MODE parameters.................. 142

PARAMETER OF THE FX-MENU- 149The internal Effects .............................150Input........................................................150Follower (Envelope-Follower) ........... 154Ringmodulator ..................................... 155Vocoder .................................................. 156Distortion............................................... 157

Analog Boost ......................................... 158Phaser .....................................................159Chorus..................................................... 161Delay/Reverb.........................................162

GLOBAL-, MIDI- AND SYSTE PARAMETERS

Global Parameters ..................System .......................................

RANDOM PATCH GENERAT

Random Patches......................

CATEGORIES

Sound Categories....................

THE KEYBOARD VERSIONSTHE VIRUS

The Virus kb and the Virus InLocal off and Three in OneKeyboard & Company............The Keyboard-Modes.............

THE VOCODER OF THE VIRUS - 201

Vocoder ................................................. 202The parameters of the vocoder .......204Notes about the vocoder ...................210

M- 173

............. 174

............ 180

OR - 183.............184

- 187.............188

OF - 189

digo... 190............ 190.............192.............195

THE VIRUS AND SEQUENCERS - 213Parameter Control via MIDI .............. 214Organizational Information.............. 214Handling MIDI Parameter Control ..216Notes on Adaptive Parameter Smoothing ............................................. 217Problems Related to ParameterControl .................................................... 221DUMP: The Sound in the Song .........222

TIPS, TRICKS AND OTHER WORDS OF WISDOM - 227

MULTI SINGLE Mode .......................... 228Value Buttons ...................................... 229All abouts Inputs ................................. 229About the Delay/Reverb..................... 231The Virus as an Effect Device............232Envelope Follower ...............................233Oscillators ............................................. 234Filters.......................................................237SATURATION for Added Dirt ............ 239

LFOs ........................................................240Volume Control ................................... 242ASSIGN and the DEFINABLE Knobs. 243ARPEGGIATOR ...................................... 244MIDI ............................................PRIORITY ....................................Installing an operating systeupdate........................................Loading the Operating SysteOne Virus to Another .............Software Updates ...................

APPENDIX

System Exclusive Data...........Parameters Describtion.........Multi Dump Table...................Classes .......................................Mod Matrix Sources ..............Mod Matrix Destinations......Definable Knobs DestinationMIDI Implementation Chart.FCC Information (U.S.A).........FCC Information (CANADA)..Other Standards (Rest of WoDeclaration of Conformity....Garantie Bestimmung ...........Warranty ............................................... 245

............ 247m ............ 247m from ............249............ 250

- 251.............252............ 258.............273............ 276............280.............281s ........ 282............ 284............286............288rld).....289............290............ 292............ 293

ACCESS VIRUS OS4

7

Important Safety Remarks

Please read and heed the follow-ing safety guidelines!

A few fundamental rules odling electrical devices foll

Please read all notes carefubefore you power the devic

Set-up

Operate and store the deenclosed rooms only.

Never expose the devicedamp environment.

Never operate or store thin extremely dusty or dirtyronments.

Assure that air can circulfreely on all sides of the deespecially when you mounrack.

Dont set the device in thdiate vicinity of heat sourcas radiators.

Dont expose the device to direct

n han-ow.

lly e up.

vice in

to a

e device envi-

ate vice, t it to a

e imme-es such

sunlight.

Dont expose the device to strong vibrations and mechanical shocks.

Connections Be sure to use exclusively the included mains power supply adapter.

Plug the device only into mains sockets that are properly grounded in compliance with statutory regu-lations.

Never modify the included power cord. If its plug does not fit the sockets you have available, take it to a qualified electrician.

Always pull the power plug out of the mains socket when you wont be using the device for pro-longed periods.

Never touch the mains plug with wet hands.

8

CHAPTER

2 Safety Remarks

Always pull the actual plug, never the cord, when youre unplugging the device.

Operation

Dont set beverages or anreceptacle containing liquithe device.

Make sure the device is pon a solid base. Set it on a tabletop or mount it to a r

Make sure that no foreigobjects fall into or somehoup inside the devices houthe event that this should switch the device off and ppower plug. Then get in touan authorized dealer.

Used on its own and in ction with amps, loudspeakheadphones, this device is generate levels that can leirreversible hearing damagthis reason, always operatereasonable volume level.

Memory battery change

The Virus stores its sound pro-grams in a battery-buffered RAM. This battery (general type designa-tion: CR2032) should be replaced

y other ds on

laced stable ack.

n w end sing. In occur, ull the ch with

onjunc-ers or able to ad to e. For it at a

every three to four years. The hous-ing has to be opened to change the battery, so take the device to a qualified service technician. Do your part in protecting our envi-ronment and take it to a shop that disposes of batteries properly.

Before you have the battery changed, save the entire memory content of the RAM by loading it to a sequencer via "Total Dump". Be advised that RAM content is lost when the battery is swapped (see Midi Dump TX on page 174).

Care Do not open the device, it is not equipped with any user-service-able parts. Repair and mainte-nance may only be carried out by qualified specialists.

Use only a dry, soft cloth or brush to clean the device.

ACCESS VIRUS OS4

9

Do not use alcohol, solvents or similar chemicals. These can dam-age the surface of the housing.

Fitness for Purpose

This device is designed excto generate low-frequencysignals for sound engineerrelated purposes. Any othenot permitted and automainvalidates the warranty exby Access Music Electroniclusively audio ing-r use is tically tended

s GmbH.

10

CHAPTER

2 Safety Remarks

ACCESS VIRUS OS4

11

Prologue

Dear Virus Owner,

Congratulations on your chthe new Virus. You have pua cutting-edge synthesizercomes fully loaded with serevolutionary features. Herjust a few of the highlights

The Virus delivers the sounacteristics and tone of tradanalog synthesizers - for inthe Prophet 5 or Memorymname just two popular exaof the species - in a previouunparalleled level of qualithandling ease. Were not kthe Virus actual delivers thauthentic response of an asynth via a digital signal prchip, although the sound sand voicing options out-pethose of it historical predeby a considerable margin.

The Virus comes with 512 sstoring SINGLE sounds. Theorganized in four banks. Thtwo banks (A and B) are locthe RAM, so you can overwthem with new sounds. Th

two banks are hard-wired, i.e. oice, rchased that veral e are :

d char-itional stance oog to mples sly y and idding, e nalog ocessor haping rform

cessors

lots for se are e first ated in rite e other

theyre programmed into the FLASH ROM.

The Virus offers a maximum of 24 voices. In Multi Mode, these are allocated dynamically to sixteen simultaneously available sounds.

You have no less than three audio oscillators plus one suboscillator, a noise generator, a ring modulator, two Multi Mode filters, two enve-lopes, a stereo VCA, three LFOs and a saturation stage (SATURATOR) for cascade filtering, tube and distor-tion effects.

The Virus offers a veritable arsenal of effects. You have seven powerful sound-sculpting functions, includ-ing chorus, phaser and distortion, at your disposal, with each effect available separately for every sound. Thus, in 16-way MULTI mode, the Virus offers 80 effects, no less!. You also get a global reverb/delay unit that lets you cre-ate high-quality reverb effects and rhythmic delay taps. Delay time can be synced up to MIDI clock.

12

CHAPTER

3

Prologue

With the benefit of two external audio inputs, the Virus may also serve as an FX device and signal processor that you can use cre-atively to come up with all kinds of effects. External signals caprocessed with filter, gate effects, routed to the Virussection and serve as a modsource for frequency and riulation.

Beyond that, you can use inor external signals as sourcthe Virus on-board vocodeThe vocoder works with upfilter bands and offers divemanipulation and modulaoptions.

The three main oscillators 66 waveshapes, three of wdynamically mixable so thtral effects are possible witconfines of a single oscillatconventional synthesizers,type of effect requires sevelators. Synchronization, fremodulation and ring modubetween the audio oscillatdelivers additional completral effects that you can uskinds of sound shaping pu

The filters can be switched in series or in parallel within the voices via several options. When you switch the filters in series, the saturation stage is embedded n be and lo-fi effects ulation ng mod-

ternal es for r serve. to 32 rse

tion

produce hich are at spec-hin the or. In

this ral oscil-quency lation

ors x spec-e for all rposes.

between the filters. Consequently, an overdriven filter resonance can be re-filtered within the same voice! A maximum of six filter poles (36 dB slope!) enables radical tonal manipulations.

The LFOs feature 68 continuous variable waveshapes each, includ-ing a triangle with variable sym-metry and infinitely variable aperiodic oscillations for random variation of the controlled parame-ters. The LFOs are capable of poly-phonic as well as monophonic oscillation. In other words, if sev-eral voices are active, the LFOs can run independently or in sync. A number of keyboard trigger options enable you start LFO wave-shapes with variable phase lengths at the beginning of a note and/or to cycle once only, like an envelope.

Next to the numerous hard-wired or fixed modulation config-urations, you can assign three modulation sources to up to six different modulation destinations

ACCESS VIRUS OS4

13

via the Modulation Matrix. For your modulation sources, you have LFOs, velocity, the pitch bender, aftertouch, the modulation wheel, numerous MIDI controllers and other sources to chose fromyour modulation destinatican select any sound paramthe Virus that is conducive remote controlled.

Up to 16 arpeggiators are ain MULTI mode. These givecountless options for creatarpeggios, which can also bsynced up to MIDI clock.

Sounds and effects are patout via six audio outputs wcourse can also be used to three stereo signals out.

In additional to its killer soand tone, the Virus was deto deliver ultimate handlincontrol comfort. It is equipwith dedicated knobs and for the crucial synthesizer tions, further parameters aaccessible via data entry prdures. We distinguished bethese two levels of expertienable you to create comp

sounds while keeping the user interface as clear and uncluttered as possible.

In all modesty, we are especially

. For

ons, you eter of

to being

vailable you ing e

ched hich of

route

unds signed g and ped buttons func-re oce-tween

se to lex

proud of a feature we developed called Adaptive Parameter Smoothing. For the first time in the history of synthesizers equipped with memories, you can manipulate a knob or control fea-ture without an audible step or increment. In other words, the sound does not change abruptly but SEAMLESSLY. No more zipper noises! The Virus responds just as smoothly as analog synthesizers did prior to the introduction of dig-ital sound storage

And users of contemporary soft-ware sequencers will appreciate the fact that the Virus sends all sound shaping commands imme-diately in the form of MIDI Control-ler or Poly Pressure data (and of course accepts all of the corre-sponding Controller and SysEx messages). This feature lets you dynamically control the Virus and all its functions via computer.

14

CHAPTER

3

Prologue

Although far from complete, the features listed above give you some indication that you now own an exceptionally versatile, high-quality musical instrument that will give you plenty of joy fto come. We certainly hopecan fully exploit the enormpotential of this fine instru

Have fun and enjoy!Your Virus Development Te

By the way: a rack mountinoptionally available for theFeel free to get in touch wilocal authorized dealer forinfo.

Many thanks to:Ben Crosland, Thomas GreeHartmann, Uwe G. Hnig, JHttner, Oliver Kser, AndrMason, Thorsten MatuschoPaul Nagle, Kai NiggemannPapen, Wieland Samolak, HScarr, Hans-Jrg Scheffler, JSimon, Matt Skags, Joeri Vabilck, Jay Vaughan, Jens Weand Daniel Wewer.or years you ous ment.

am

g kit is Virus b. th your more

n, Axel rg

ea wski, , Rob oward enny nkeirs-gerhoff

Introduction

16

CHAPTER

4

Introduction

THE VIRUS

This section provides deliberate, step-by-step guidelines on operat-ing and handling the Virusthose of you who are new world of synthesizers and MThe following covers basicshow to connect the Virus tpower supply, your MIDI syand your audio system. Thewill guide you through a seexperiments designed to dstrate the different functiogroups, their control featurthe tasks they execute.

After you have finished reathis section, you will be abhandle virtually all of the sgenerating and sound shapfunctions of the Virus. All oare described in context, alwith their control featuresthe majority of less significfunctions, accessible via mare discussed here. You wildetailed, comprehensive dtion of all functions of yousynthesizer in the section fing this introduction.

Please keep in mind that within confines of this introduction, we are unable to impart all of the knowledge and skills in acoustics, sound synthesis and MIDI control for to the

IDI. such as o an AC stem n we ries of emon-nal es and

ding le to ound ing f these ong . Even ant

enus, l find a escrip-r new ollow-

you might desire or need to acquire. If you are keen to learn more about these subjects, you should consider becoming a regu-lar reader of one or several of the leading trade publications in your country. Your local musical instru-ments dealer or more experienced musicians will be able to recom-mend the best magazines to you. And of course there is a wide range of books available on these sub-jects.

If you decide to read this section, we recommend you read it in its entirety from the start - rather than begin with a subsection that is of particular interest to you. A fitting metaphor for the basics dis-cussed in this section might be a house where each bit of informa-tion in a subsection is a brick that builds on a preceding brick and interlocks with those next to it. You want your knowledge base to be a sound structure so you wont run into problems when you find one of the bricks is missing.

ACCESS VIRUS OS4

17

The Virus

Cable Connections

Before you connect the Virus to an AC outlet and the rest of your equipment, ensure that all of the devices are switched OFF. If your Virus does not have a buildboard, then connect the Mof the desired MIDI send d(keyboard, computer, hardwsequencer, etc.) with the Mof the Virus.

Connect the audio outputsVirus with the signal inputaudio system. In order to resignal, as a minimum you mconnect the output OUT 1 RMONO. However, we recomyou also connect the outpuL so you are able to enjoy treo sounds of the Virus.

Once you have establisheddesired cable connections,sure the main volume contall the connected devices (MASTER VOLUME, located upper left hand of the contpanel) are dialed to the lowsible setting. Switch the dein the following sequence:MIDI send device (computeter keyboard, etc.) first, thesound generators (Virus an

other signal sources), followed by the mixing console and finally the amplifier.

Now while you are sending notes

-in key-IDI OUT evice

are IDI IN

of the s of your ceive a ust

/mend t OUT 1

he ste-

the make rols of Virus: at the rol est pos-

vices on the r, mas-n the d the

on MIDI Channel 1 of the Virus, turn the master volumes of the connected devices up in the same order that you switched the devices on. Be sure to keep on eye on the signal level indicators of your mixing console.

Listening to the Factory SoundsThe program memory of the Virus was loaded with sound programs (SINGLE PROGRAMs) and sound combinations (MULTI PROGRAMs) before it left the factory. To hear the SINGLE PROGRAMs (and gain an initial impression of the possi-bilities your new instrument has to offer in terms of sounds), first make sure your MIDI source is sending on MIDI Channel 1.

Press the SINGLE button. A num-ber, a letter, number and name appear in the display. These indi-

18

CHAPTER

4

Introduction

cate the the MIDI Channel, the cur-rent Program Bank (A to D) as well as the number and name of the current sound program. Now if you play notes you should be able to hear this sound and a noround dot at the end of thestaff is solid black) should in the display every time yoa key and release a key. If ynot hear a sound but you snote (blank note head) chesee if you are sending on thwrong MIDI Channel.

Press the VALUE button to the 128 single programs ofin sequence. (The VALUE poinactive in this operating morder to hear the sound prin banks B, C and D, simplyPARAMETER/BANK buttonfrom one program bank toanother.

Youll find that some soungrams are labeled with theviations INP or VOC. Ththe external audio input assource for the filter sectionvocoder (VOC). This meansyou wont hear anything uroute an audio signal into external audio inputs.

te (the note

appear u press

ou do ee a half

ck to e

call up Bank A t is ode.) In

ograms use the s to step

d pro- abbre-ese use a signal (INP) or that ntil you the

Listening to the Multi Pro-gramsThe Virus not only has the capabil-ity of playing SINGLE PROGAMs, but also combinations consisting of more than one sound simulta-neously (MIDI Multi Mode). To call up the MULTI PROGRAMs, press the MULTI button and select these combination programs via the VALUE button. The Virus features only 128 MULTI PROGRAMs, so you dont have to switch back and forth between banks they way you just did while activating single pro-grams.

The majority of available MULTI PROGRAMs contain sound combi-nations that are controlled via a single MIDI channel. In these MULTI PROGRAMs, the sounds involved are allocated side-by-side (split) or on top of one another

ACCESS VIRUS OS4

19

The Virus

(layered) on the keyboard. In other MULTI PROGRAMs, the sounds are divided up over several MIDI chan-nels to make it easier to work with a sequencer. If you activate a MULTI PROGRAM and hearsound only, then you can cthis MULTI PROGRAM via schannels.

Your First Sound Progra

If you have never created ochanged a sound on a syntwe now have the pleasureducing you to this fascinatcess.

Select the single program START -. Press any key on tnected keyboard. You shoua sound that, for lack of bedescription, is a bit harsh obut above all completely stshould start immediately apress a key and sustain indfor as long as you hold thedown. As soon as you releakey, the sound should end abruptly. This sound is not designed to be especially pant; it is intended to be as

as possible to give you a basis from which you can begin creating or shaping your own sound. a single ontrol everal

mr hesizer, of intro-ing pro-

A127 - he con-ld hear tter r biting, atic. It fter you

efinitely key se the

leas-neutral

20

CHAPTER

4

Introduction

THE AMPLIFIER ENVE-LOPE

Long-term exposure to this sound will definitely grate on youso lets get started with chit into a signal you might ehearing, beginning with thume characteristics. Locatesection labeled

AMPLIFIER

bottom right of the contropanel of the Virus. Here yosee five pots labeled

ATTAC

DECAY

,

SUSTAIN

,

TIME

and

R

respectively.

These controls will help yoin volume characteristics camplifier envelope and puto the nerve-racking dronemay remind you of one of cheesy organs that you heaB-movie sound tracks.

Rotate the

ATTACK

pot while you repeatedly engage a key to hear the note. The further you turn the pot up, the longer it takes for the sound to achieve maximum vol-

r nerves, anging njoy e vol- the at the l feature u can K, ELEASE,

u to dial alled an t an end that those r in 60s

ume after the start of the note. So you can say ATTACK controls the initial volume swell of the sound.

Presumably the ATTACK pot was set to a random position before you made any adjustments. Never-theless the volume automatically increased to the maximum level before you started rotating the pot. The reason for this is that an ATTACK value of 0 is saved in the sound program - START - and this value remains valid until you determine a new value by adjust-ing the position of the pot, even if you turn it ever so slightly.

Take a look at the display of the Virus to gain an impression of the difference between these two val-ues. It shows two numeric values when you dial a pot: at the left you can see the value stored in the sound program and at the right,

ACCESS VIRUS OS4

21

The Amplifier Envelope

the numeric equivalent to the value determined by the current position of the pot.

Always keep in mind thaprogrammable synthesizerposition of the control featpot does not necessarily indthe actual value of the givetion. The reason for this is twhen you first activate a soprogram, it will reflect the pgrammed value. You have tthe control feature before tgrammed value is supersedthe value you determine m

Now fiddle with the

DECAY

while you repeatedly pressactivate a note. Hold the kefor good while. You will notthe volume, once it reachemum level at the end of th

ATTACK

phase, drops until ireaches a minimum level. T

DECAY

pot determines theor in synthesizer jargon, thwhich the volume decreas

However, the

DECAY

level dalways drop to the minimuyou can determine a rando

between the maximum and mini-mum levels at which the volume remains constant. This level in turn is controlled via the

SUSTAIN

pot.

t for a the ure or icate n func-hat und ro-

o adjust he pro-ed by anually.

pot a key to y down ice that

s maxi-e t he

speed, e rate at es.

oes not m level; m value

Whenever the SUSTAIN level is set to maximum, the volume cannot drop during the DECAY phase; in other words, in this situation the DECAY pot is ineffective.

The individual functions of a synthesizer are designed to inter-act; many functions are dependent on other functions. In a number of cases this means that some func-tions are subordinate to others, i.e. the effectiveness of a control fea-ture is altered, modified or even negated completely by other related functions.

The final pot, RELEASE, determines the speed or rate at which the vol-ume decreases when you release the key: At low values the sound ends relatively abruptly, at high values, the sound fades out more gradually and softly. The length of the RELEASE phase also depends on which level the amplifier curve is at when you release the key: The

22

CHAPTER

4

Introduction

lower the level, the shorter the

RELEASE

phase. If you dialed in a brief

DECAY

or

SUSTAIN

-

TIME

phase and it ended while you held the key down then of course there will not be an audible

RELEASE

The next phase of the ampenvelope is determined by

TAIN

-

TIME

pot: If the pot isthe center position (12 oclocated by the mathematicasymbol, then the

SUSTAIN

lremains constant throughend of the note.

If you turn it counter-clockthe left (towards FALL), thelevel drops off at an increastowards the minimum levein the manner you just expenced with the

DECAY

pot;turn the pot clockwise to t(towards RISE), the level risincreasing rate to maximuremains there until you relkey.

The amplifier envelope candescribed as a variable curwhich, depending on the tduration of attack, hold anrelease data, automaticallyences an imaginary volum

(turns it up or down). At the begin-ning of the note,

ATTACK

controls the rise or rate of increase to the maximum level. Once the maxi-mum level is achieved,

DECAY

phase.

lifier the SUS- set to ck) indi-

l infinity evel to the

wise to n the ing rate l much eri-

If you he right es at an m and ease the

be ve ype and d influ-

e pot

determines the fall or rate of decrease to the SUSTAIN value, which is infinitely variable between the minimum and maxi-mum levels. The amplifier enve-lope may remain at this value until the end of the note, fall towards the minimum level as determined by the variable TIME value, or even rise again towards the maximum level. After the end of the note, RELEASE controls the fall or rate of decrease to the minimum level. Consequently, the control pots labeled ATTACK, DECAY, TIME and RELEASE control a speed or rate, where as SUSTAIN actually con-trols a level.

ACCESS VIRUS OS4

23

The First Filter

THE FIRST FILTER

Now we will take a look at a com-ponent of a synthesizer that is generally regarded as the mimportant functional unit enables drastic sound shapmeasures: the filter - or in of the Virus, the two filters

But first we will concentrajust one of the two filters.

Locate the

CUTOFF

pot (noconfused with

CUTOFF

2!) isection labeled

FILTERS

, dirabove the section labeled

AFIER

. Rotate the pot to the right and note how the sou

becomes muddier and clearer in response to the direction in which you turn the pot. (To ensure this effect and the following aural experiments are most pronounced,

ost as it ing

the case .

te on

t to be n the ectly

MPLI-left and nd

adjust the amplifier envelope so that the Virus generates a constant level while you hold a key down).

This is how a low pass filter works: it suppresses, or in technical jar-gon, attenuates the higher fre-quencies in a signal and allows the lower frequencies through. Think of the CUTOFF pot as a bouncer and the Virus as your pub. You can tell it which frequencies to let in and which frequencies to keep out. The frequencies above the so-called cutoff or filter frequency are suppressed, those below it remain unaffected.Now locate the FILT 1 MODE switch, which is also located in the FILTERS section. It enables you to select a filter operating mode from the four available options:

LLLLPPPP the low pass filter we have just discussed.

24

CHAPTER

4

Introduction

HHHHPPPP

the high pass filter which works in the opposite manner of the low pass filter: It suppresses the lower frequencies in a signal and lets the higher frequencies pass.

BBBBPPPP

the band pass filtersuppresses both ends of thspectrum and allows only rowly defined bandwidth ooriginal sound to pass.

BBBBSSSS

The band stop filterreject filter or notch filter wworks in the opposite manthe bandpass filter. It allowthe frequencies of a signalfor a narrow frequency banaround the cutoff to pass. term notch is fairly descryou might say this filter chnotch out of the sound sp

Now activate the different operat-ing modes and rotate the

CUTOFF

pot to get a feel for the way each filtering option works.

which e tonal

a nar-f the

, band hich

ner of s all of

except d

The iptive; ops a ectrum.

Along with the CUTOFF pot, the RESONANCE pot is the most impor-tant control feature of a filter. The filter resonance increases the vol-ume of the frequencies located near the cutoff frequencies and suppresses the more remote fre-quencies. This sound shaping fea-ture has a striking effect - especially when used in conjunc-tion with the low pass filter: it pro-duces a nasal or honking type of tone which increases as you turn the resonance up. Experiment by varying the RESONANCE setting in the different operating modes in conjunction with different CUTOFF settings. You will find the effect that the RESONANCE pot achieves is markedly different for the band stop filter in comparison to the effect it has on the other filter types: as the resonance increases, the bandwidth of the notch decreases; in other words more frequencies on both sides of the filter frequency are allowed to pass.

ACCESS VIRUS OS4 25Filter Modulation

FILTER MODULATIONOf course we dont want to require you to execute every sound modifi-cation manually by twiddliAll kinds of sound modificathe Virus can be executed matically much in the wayprevious experiments withume controls: The amplifielope can be described as a curve which, depending ontype and duration of attackand release data, automatinfluences (turns it up or dimaginary volume pot.

Similar procedures are appto the filter frequencies. ThTERS section features its owlope, the structure of whicidentical to the amplifier elocated directly above the fier envelope on the controture panel. Much like the aenvelope, the filter envelopmatically rotates the CUTpot.

However there is one signidifference between the twlopes. With the amplifier eyou are always dealing wit

tial volume level of 0 because of course you want absolute silence prior to the beginning of a note. After the RELEASE phase, it is again highly desirable that your box is ng pots. tions in

auto- of your the vol-r enve-variable the , hold

ically own) an

licable e FIL-n enve-

h is nvelope, ampli-l fea-mplifier e auto-OFF

ficant o enve-nvelope, h an ini-

silent. With the filter envelope, the situation is somewhat different: It always starts at the CUTOFF value that you determined manually. And it is definitely not always desirable that the filter frequency is brought to the maximum level.

Consequently, you need a tool that limits the effective range of the fil-ter. This is why we equipped the Virus with a control labeled ENV AMOUNT (short for Envelope Amount). When the pot is turned counter-clockwise to the far left, the filter has no effect on the cut-off frequency; the further you turn the pot to the right, the greater the effect the filter envelope has on the filter frequency. The maxi-mum level of the envelope may lie outside the audible range when the filter has already been partially opened via the CUTOFF pot or was manipulated via other control options. In extreme cases where the filter is already completely

26 CHAPTER 4Introduction

open, the filter frequency cannot be increased regardless of how high you set the ENV AMOUNT.

Go ahead and spend some experi-menting with different ENAMOUNT, CUTOFF and RESONANCE settings for the divter operating modes. Also varying the settings for thefier envelope. You will findwith just these few paramyou are able to come up wiamount of sound settings.are among the many musiwho are associative listenemight say many of the settproduce sounds reminiscenstringed-instruments; sompicked, plucked or snappedsound bowed.

For your next experiment samplifier envelope so thathear a constant level whenpress and hold a note. Nowvate the filter envelope by the ENV AMOUNT to 0. Set1Filter-1 to low pass mode adecrease the filter frequenyou just barely hear a mudnal when you play notes inmid-range.

Now play a few higher and lower notes. You will find that the lower notes have a greater overtone con-tent, whereas the higher notes sound muddier and their volume V -

erse fil-try

ampli- that eters th a vast If you cians rs, you ings t of

e sound , others

et the you you deacti-

setting Filter-nd

cy until dy sig- the

decreases until the notes are com-pletely inaudible. You might already suspect what this is all about: As the notes are transposed ever lower, more portions of the signal fall below the cutoff fre-quency, whereas with the notes that are transposed ever higher, more portions of the signal rise above the cutoff frequency and subsequently are suppressed until the root note and the last audible portion of the signal is silenced.

To avoid this effect - or if desirable, to amplify it - you have the option of influencing the cutoff frequency via the pitch of the note, i.e. the note number. The degree of influ-ence is determined by the KEY FOL-LOW pot.

Please note that KEY FOLLOW is a so-called bipolar parameter: Its control range is not limited to the positive end of the spectrum (0 to a maximum of 127). Bipolar con-trols effect negative values as well, in this case from the negative

ACCESS VIRUS OS4 27The Saturation Stage

maximum of -64 through 0 an on to the positive maximum of +63. Consequently, if this pot is set to the center position (12 oclock or 0) the pitch of the notes correspond-ing to the keys on your keyhas no effect on the cutoffquency. If on the other hanturn the KEY FOLLOW pot cwise towards the positive crange, you will find that thopens up increasingly as thincreases with higher notelower notes, the filter closeagain. If you turn the pot cclockwise towards the negcontrol range, the KEY FOLeffect is reversed. With theyou will encounter this feaintensity control via a bipoparameter - again in conjuwith other modulation souand targets.

Now experiment as much like with different KEY FOLsettings and tune the settithe CUTOFF pot. And remebring all of the other paramyou have encountered thusplay.

THE SATURATION STAGEIn the signal chain of the Virus, Fil-board

fre-d you lock-ontrol

e filter e pitch

s. At s down

ounter-ative LOW Virus, ture - lar nction rces

as you LOW ngs via mber to

eters far into

ter-1 is followed by a saturation stage. It enables you to add over-tones to the filtered signal via dis-tortion. Locate and press the button labeled EDIT in the FILTERS section.

01111111111111111112

1 SATURATION Curve Off 61111111111111111154

The display will read SATURATION CURVE OFF, which means exactly what it says. With the VALUE but-tons or the VALUE pot, you can now select from a number of satu-ration/distortion curves. Next to the distortion curves, the SATURA-TION stage offers further DSP effects such as the shaper, rectifier and filter. These are explained in detail in the section on the SATU-RATION stage.

At this point we would like to men-tion the OSC VOL pot in the MIXER section. The portion of the control range from the far left to the cen-


ter position (12 oclock) determines the volume of the filter sections input signal. The portion of the control range located to the right of the center position (12 oclock) does not achieve any increvolume; it simply intensifiedegree of saturation or disThis effect is only achievedyou have activated a saturcurve. The intensity of the ing available DSP effects iscontrolled via the OSC VOL

Feel free to experiment widiverse saturation curves sure to vary the OSC VOL seNote how the different CUand RESONANCE settings inthe saturation curve.ase in s the tortion. when ation remain- also knob.

th the and be ttings.

TOFF fluence

THE SECOND FILTERYou probably noticed that by a adding a bit of saturation to the signal you can come up with a pretty heavy, aggressive sound - especially with a low filter fre-quency level and high resonance. Youre probably thinking these types of sounds could do with some more filtering. We had the same idea, which is one of the rea-sons why we equipped the Virus with another filter per voice.

ACCESS VIRUS OS4 29The Second Filter

The technical design of this second filter is identical to the first, so we wont discuss it in as much detail as we did the first filter. However, there are few differences in how you handle the second filte

Only two control featureVirus are allocated exclusivFilter-2: CUTOFF 2 and FILT 2

The RESONANCE, ENV AMand KEY FOLLOW pots can cated to either of the two fboth simultaneously. Use tSELECT buttons located at right of the FILTERS sectionselect the desired operatinFor instance, if you press thSELECT button, then the vaset via the RESONANCE, ENAMOUNT and KEY FOLLOWapply exclusively to Filter-2corresponding parameterster-1 remain unaffected. Onother hand, if you press boSELECT buttons at the samthe values that you dial in the same measure to Filter2.

In the sound program we afor our experiments, the LEboth buttons are illuminat

that all adjustments to the given parameters affect both filters. However, you have yet to actually hear the effect of Filter-2 on the signal because it is mixed out of r:

s of the ely to MODE.

OUNT be allo-ilters or he two the far to g mode. e FILT 2

lues you V pots . The of Fil- the

th e time,

apply by s 1 and

re using Ds of ed, so

the audible signal path of the Virus.

Before we get started with our next experiment, deactivate SATU-RATION, set the ENV AMOUNT of the filter envelope to zero and set CUTOFF 2 to the center position (12 oclock) so that Filter-2 always has the same cutoff frequency as Fil-ter-1 (well explain CUTOFF 2 a bit later). Set CUTOFF to a medium or middle value and turn the RESO-NANCE pot counter-clockwise to the far left to achieve a relatively muddy sound. Now locate the FIL-TER BALANCE pot at the upper right hand of the control panel and rotate it from the left to the right. You will note the sound becomes muddier as you turn the pot towards the center position (12 oclock) and that the sound is somewhat brighter at the far right of the control range then at the far left.


The reason for this effect is that when you turn the FILTER BALANCE pot to the far left, only Filter-1 is audible. When you rotate the pot to the right, Filter-2 is blended in so that it follows Filter-1 in thchain. When you turn the FBALANCE pot clockwise, Filblended out of the signal cuntil at the far right positioFilter-2 is active and audibl

Each filter in the Virus normfeatures 2 poles. However iFILTER ROUTING operatingSER 6, Filter-1 operates withpoles, so the signal patchethrough Filter-1 (FILTER BALthe far left) is trimmed motically than when it is routthrough Filter-2 (FILTER BALthe far right). When you seTER BALANCE pot to the ceposition (12 oclock) - as wetioned before - the two filtrouted in series, which mearespond as if they were a ster with 6 poles and consea great deal of slope. This ithe input signal is trimmedstantially when you set thethis position.

Experiment with the diverse FILTER BALANCE positions to get a feel for the different degrees of slope. Rotate the CUTOFF pot or activate the filter envelope (for both fil-e signal ILTER

ter-1 is hain n only

e.

ally n the mode

4 d ANCE to re dras-ed ANCE to t the FIL-nter men-ers are ns they

ingle fil-quently s why sub- pot to

ters!) to hear the filters in action.

The CUTOFF 2 pot is a special fea-ture: It controls the cutoff fre-quency of the second filter, but is subordinate to the CUTOFF pot located above it. In other words, at the center position (12 oclock) the manually selected frequency of Fil-ter-2 is identical to that of Filter-1. When you rotate the pot to the left the cutoff frequency level of Filter-2 is increased relatively to Filter-1, when you turn to pot to the right the cutoff frequency level is decreased relatively. Now when you adjust the CUTOFF pot, you adjust the cutoff frequency of both filters by the same measure! This feature lets you determine a differ-ence in values in the filter frequen-cies (called an offset) via the CUTOFF2 pot which remains con-stant whenever you adjust the CUTOFF pot.

ACCESS VIRUS OS4 31The Second Filter

Yet another experiment in which you can come up new filtering characteristics that are typical of the Virus:

Set the FILTER BALANCE pocenter position (12 oclock) CUTOFF 2 to the maximumThe FILTER ROUTING operamode must remain SER 6. SOFF and RESONANCE to a mvalue and select a clearly aSATURATION curve.

Now you can filter this comsignal produced by a combof the saturation stage anFilter-1 yet again. Rotate thOFF 2 pot slowly towards tter position (12 oclock). Youhear how Filter-2 graduallyfies the distorted signal. Yoset a RESONANCE value forif you press the FILT 2 SELECton and rotate the RESONAto the desired position. SetCUTOFF 2 pot to a positionright of the center positionconfiguration can be descricomplex non-linear filter swhere the cutoff frequenctrolled via the CUTOFF pot.dial in a wide range of souning option via CUTOFF 2. Al

modifying the resonances of both filters as well as the SATURATION curve to come up with different fil-tering characteristics.t to the and level. ting et CUT-iddle

udible

plex ination d the e CUT-he cen- can modi-u can Filter-2 T but-

NCE pot the to the . This bed as a et up y is con- You can d-shap-

so try

Now experiment with the diverse filter modes and listen closely to the effect of the parameters RESO-NANCE, ENV AMOUNT and KEY FOLLOW in conjunction with the SELECT button. Please also keep in mind that the chances of choking a sound off are substantially greater when you are using both filters: For instance, if the first filter is used as a low pass with a low cut-off frequency and the second as a high pass with a high cutoff fre-quency, the Virus will not generate an audible signal when you set the FILTER BALANCE pot to the center position (12 oclock).

Regardless of which FILTER ROUTING option you chose, the SATURATION stage is always post-Filter-1, i.e. after Filter in the signal chain.


FILTER ROUTINGThe final parameter well discuss for the time being is FILTER ROUT-ING. This feature offers sevter routing options which ayou to operate the filters ini.e. patch one after the othsignal chain, or in parallel, means side by side in the schain:

SER-4 The filters are switseries; with two poles eachOkt.), both filters have theslope for a total of four filt(24dB/Okt.).

SER-6 The filters are switseries; Filter-1 has four poleOkt.), Filter-2 has two polesOkt.) so the overall slope islent to six poles (36dB/Okt

PAR-4 The filters are switparallel and feature two po(12dB/Okt.).

SPLIT The filters are switched in parallel and feature two poles each (12dB/Okt.). Additionally, they receive independent input signals (more on this later). Each of the eral fil-llow series,

er in the which ignal

ched in (12dB/

same er poles

ched in s (24dB/ (12dB/ equiva-.).

ched in les each

two oscillators routes its signal into one of the two filters whose signals can be spread in the pan-orama via a parameter called UNI-SON Pan Spread.

ACCESS VIRUS OS4 33Filter Routing

Here is the filter routings capabthe Virus.ilities of


THE FIRST OSCILLATORTo this point, we have turned our attention exclusively to sound-shaping functions and havstarted with the same basrial: a so-called sawtooth wThis waveshape is especialsuited as a neutral startingas it contains all of the so-natural scale of overtones,give the filter plenty of quamaterial to work with.

The filters, with the exceptnotch filter or band stop (Bthe far reaches of the tonatrum, so for instance a signsounds muddier after it harouted through a low passYou can well imagine that tof sound modification is sutial but insufficient for shamore subtle differences in For instance the tone of a tdiffers significantly from thsaxophone even though nowould seriously claim thatof the instruments has a mtone than the other.

What you need is a sound-shaping option for the portion of a signal that a filter allows to pass. And of course you also need a tool for determining the pitch of a signal. e always ic mate-

ave. ly well- point

called which lity

ion of a S), trim l spec-al s been filter. his type bstan-ping tone. rumpet at of a one

either uddier

In synthesizers, both of these tasks are executed by oscillators. They oscillate at a variable pitch that can be modulated and they also generate different waveshapes which give the filters a wider vari-ety of material to work with.

The Virus is equipped with two main oscillators and a so-called suboscillator. We will first take a look at Oscillator 1, which is the oscillator you have already heard in action during your experiments thus far.

Dial in the same basic sound that you started with at the very begin-ning. Now modify the amplifier envelope so you are working with a less grating sound, but hold back on any other filter or saturation modifications so you can hear the purest oscillator signal possible.

Locate the section labeled 1, it is bordered off in a separate area at the far left of the section labeled OSCILLATORS. No check out the two

ACCESS VIRUS OS4 35The First Oscillator

pots labeled SHAPE and WAVE SEL/PW. These enable you determine the waveshape and consequently the tonal spectrum of Oscillator 1.

In the sound program, SHApreset to the center positiooclock), which is equivalenvalue of 64. On the pot, thition is identified via a grapdepiction of a sawtooth wcan definitely see why thisshape bears the name sawPress and hold a key and slturn the pot clockwise. Yoube able to hear how the tobecomes increasingly more

low-sounding. You might say this effect thins the sound out, but in any case, the entire tonal spectrum is affected by an equal measure, which is an audio result filters are PE is n (12 t to a s posi-hic ave. You wave-tooth.

owly should ne hol-

unable to achieve.

The waveshape that is audible when you turn the SHAPE pot to the far right is a so-called pulse wave. The graphical representation of this waveshape on the control panel gives you a good idea of its appearance. It is unique because the duration of the negative pulse is equal to the duration of the pos-itive pulse: It has a so-called pulse width of 50%. The tone of a pulse wave is different to that of a saw-tooth wave because it does not contain all overtones in the natural overtone scale, only the odd-num-bered tones, i.e. the first (the root note that determines the pitch), third, fifth, and so forth. By turning the SHAPE pot from the sawtooth control range towards the pulse control range, you are actually dial-ing every other overtone out of the mix, which explains why the sound becomes thinner.


You can continue modifying the sound by reducing the symmetri-cal width of the pulse wave. In the Virus, you can execute this sound-shaping measure via the WAVE SEL/PW (PW = pulse widthPROVIDED THE SHAPE POT IA POSITION IN THE RIGHT HITS CONTROL RANGE (LATER12 OCLOCK). Rotate the WAPW pot slowly from the lefright and leave the SHAPE the far right position. You chow the treble content of sound increases while the becomes ever thinner. At thright position, the signal islonger audible because thewidth is equivalent to 0% asequently the wave no lonoscillates.

Starting at the center posioclock) indicated by the saturn the SHAPE pot countewise towards the left. You chow the overtones are incrmixed out of the signal uncan only hear the root notesound is produced by a so-sine wave, one of 64 othershapes that you have at yoposal for sound generationpurposes. These waveshap

also be activated via WAVE SEL/PW (WAVE SEL: Wave Select), PRO-VIDED THE SHAPE POT IS SET TO A POSITION IN THE LEFT HALF OF ITS CONTROL RANGE (EARLIER THAN 12 ) pot, S SET TO ALF OF THAN VE SEL/t to the pot at an hear

the sound e far

no pulse nd con-

ger

tion (12 wtooth, r-clock-an hear

easingly til you . This

called wave-ur dis- es can

OCLOCK). Regardless of the cur-rent SHAPE setting, you can also select a wave in the EDIT menu under OSCILLATOR 1 WAVE.

Go ahead and check out the differ-ent waveshapes. The second of the 64 waves is a triangle wave, the remainder of the waveshapes are each a unique tonal blend. After you have familiarized yourself with this raw material, experiment with the parameters of the FILTERS and AMPLIFIER sections you have dealt with thus far (dont forget about SATURATION and the correspond-ing function of the OSC VOL pot), to get a feel for how the diverse waveshapes respond to filtering, saturation and amplifier modifi-cations.

ACCESS VIRUS OS4 37The Second Oscillator

THE SECOND OSCILLA-TORAs we mentioned previously, in addition to the other sounsources, the Virus is equippa second oscillator. Judgingthe amount of control featthis oscillators section of ttrol panel, you have probabalready gathered that it hasound-shaping options thalator 1.

Dial in the basic sound prothat you had at the very bechange the amplifier envesuit your taste. In the soungram, the OSC BAL (Oscillatance) pot in the MIXER secpreset to the far left. In ordhear Oscillator 2 in action, the OSC BAL (Oscillator Balpot in the MIXER section toright. Towards the center p(12 oclock) you will hear hotone is modified and as yothe pot further to the rightthe intensity of this modifireduced. This effect is knowthe comb filtering effect. Itwhen two signals with thefrequency but different ph

lengths are mixed. Press the same key on your keyboard several times with the OSC BAL set to the center position (12 oclock). You should notice that each note has a slightly d ed with from

ures on he con-ly s more n Oscil-

gram ginning; lope to d pro-or Bal-tion is er to rotate ance) the

osition w the

u rotate , how

cation is n as

occurs same ase

different tone. The oscillators are the source of this effect. The oscil-lators of the Virus oscillate freely, consequently every time you play a note, the phase constellation between the two oscillators is dif-ferent. For now, leave the OSC BAL POT at the center position (12 oclock).

You are already familiar with Oscil-lator 1s SHAPE and WAVE SEL/PW pots. These functions are identical for Oscillator 2, so we wont go into detail on them again.


Locate the pot labeled DETUNE and slowly rotate it to the right from the far left position (which is preset in the sound program). You can hear the tone start to waver and as you turn the pot furthe right, how this vibrato increases until Oscillator 2distinctly out of tune withtor 1. This wavering or vibraeffect has a popular traditisynthesizers. It is used to achorus effects, create sounniscent of stringed instrumstring sections or simply bthe sound.

The SEMITONE pot enablestranspose Oscillator 2 by pminus four octaves in semsteps while Oscillator 1 mathe pitch. This feature is esinteresting when used in ction with two other oscillations: synchronization andfrequency modulation.

Locate and activate the SYNton in the OSCILLATOR 2 se(the LED must illuminate). chronization function forcelator 2 to restart its wave cthe same time as Oscillatoshape starts its cycle. The i

effect of this measure is that the wavering tone that resulted from detuning and mixing the oscillator signals disappears.ther to effect sounds Oscilla-to-type onal in chieve ds remi-ents/

eef up

you to lus/itone intains pecially onjunc-tor func-

C but-ction The syn-s Oscil-

ycle at r 1 wave-nitial

The SYNC effect really becomes interesting when you transpose Oscillator 2 upwards in comparison to Oscillator 1 via the SEMITONE pot. What happens is that the wave cycle of Oscillator 2 is inter-rupted as soon as Oscillator 1 starts its cycle. The pitch of the second oscillator no longer has the expected effect, instead it gener-ates special tones, in some cases for lack of a better description screaming type effects.

The other effect that benefits from manipulating the interval between the oscillators is frequency modu-lation (FM). It generates new tonal spectra in which the signal of the first oscillator controls the fre-quency of the second oscillator similar to the manner in which fil-ters can be controlled via enve-lopes. And here too you have a pot which allows you to control the intensity of: FM AMOUNT. Basi-cally, this effect is similar to a vibrato, although here youre deal-ing with an extremely fast vibrato

ACCESS VIRUS OS4 39The MIXER Section

featuring a frequency within the range of human hearing. This sig-nal is not actually audible as a vibrato effect. Instead, youll hear a sound modulation, in some cases, a very drastic one at that. Cthe pure sine waveshape folator 2. In conjunction withsine wave, the frequency mtion generates very clear, incases bell-like, spectra.

In the Virus you have the ocombining the two functiocalled oscillator synchroniz(SYNC) and frequency mod(FM AMOUNT, to generateharmonic spectra. Switch Sand experiment with the FAMOUNT. Also try out diffeSEMITONE settings and thewaveshapes of Oscillator.

The Virus is equipped withmaster oscillator that lets ate further oscillations andtra. You can access the paraof this oscillator, which aredescribed in a later chapteOSCILLATOR EDIT menu.

THE MIXER SECTIONYou have already come across two parameters of the MIXER section: hoose

r Oscil- the odula- some

ption of ns ation ulation new YNC on M rent diverse

a third you cre- spec-meters

r, via the

OSC BAL determines the mix ratio between Oscillators 1 and 2; in the left half of its control range, OSC VOL determines the master vol-ume of the oscillator mix. In the right half of the control range from the center position to the far right, OSC VOL increases the saturation intensity when a SATURATION curve has been activated.

Now well take a closer look at the final control element, the SUB OSC pot: It controls the volume of the fourth oscillator, the so-called SubOscillator, which always oper-ates an octave below Oscillator 1.

The SubOscillator is mixed to the Oscillator 1 and 2 master mix signal as determined by the OSC BAL pot. The master volume of the compos-ite mix is controlled by the OSC VOL pot. The only other parameter available for the SubOscillator is accessible via the OSCILLATOR EDIT menu where you have the option


of selecting a triangle or pulse waveshape (SUB OSCILLATOR WAVE SQUARE/TRIANGLE).

Another voice-internal signsource of the Virus has no control features on the conpanel: the Noise Generatordedicated sound parameteits volume and coloration (Volume and Color in the OTOR EDIT menu). On the mposition of NOISE Color theGenerator produces whitePlease keep in mind that th

of the Noise Generator is not sub-ject to the master volume con-trolled by the OSC VOL pot. In other words, it is audible even when OSC VOL is set to zero.al visible trol . The rs are NOISE SCILLA-iddle Noise

noise. e level

The VIRUS ring modulator is a new sound source. The output of the two oscillators is multiplied to cre-ate interesting sounds with rich enharmonic overtones. These over-tones are highly dependent on the frequency coherence of both oscil-lators and its waveforms. The fre-quency coherence can be changed, for instance use the OSC2 SEMI-TONE parameter. To blend in the ring modulator use EDIT: RING-MODULATOR VOLUME (in OSCILLA-TOR EDIT Menu). If the RINGMODULATOR VOLUME is zero, the ring modulator is switched off. OSC VOL does not affect the ring modulator level (or indeed the noise volume). Therefore the origi-nal oscillator signal can be leveled independently of the ring modula-tor. Be sure to check out what the ring modulator does when you select a sine wave for Oscillator 1 and 2.

ACCESS VIRUS OS4 41The LFOs

Now we can go on and solve the mysteries of the signal flow as determined by the FILTER ROUTING operating mode SPLIT: Here Oscil-lator 1 and the SubOscillator are routed to Filter-1, whereas tor 2 and the Noise Generarouted to Filter-2. Althoughsound sources are split intosignal paths, you can still cthe volume levels of the dielements as well as OSC VOusual manner.

THE LFOSWhen you first started this series of experiments with sounds, we Oscilla-

tor are the two

ontrol fferent L in the

promised that many of the func-tions the Virus can be pro-grammed so that they are executed automatically. You have already learned how to control the volume and cutoff frequencies of both filters as well as the pitch and intensity of the frequency modula-tion of Oscillator 2 via prepro-grammed envelopes. These options are great, but you have already encountered a number of functions where it would be a helpful if you could also program them to be executed automati-cally. And of course envelopes are great modulation sources, but you have to play a note every time you want to initiate an envelope. Dur-ing your experiments you probably came across a function or two you would like to be able to control periodically - independently of notes. Some features that come to mind are traditional techniques such as vibrato (periodic pitch con-trol) and tremolo (periodic volume


control). Another option you might like to have at your disposal is ran-dom parameter control.

In the Virus, both of these tasks are executed by a so-called LFOfrequency oscillator) that oat frequencies below the arange. An LFO is similar to oscillators you have encouthus far, but it oscillates sigcantly slower so that its ousignal is too low for humaning. So what good are theycant hear them? LFOs are much the same manner aslopes, with the major diffethat the are repeated inde

LFO 1Start with the usual basic sconfiguration or chose a msound to suit your taste. LoRATE pot in the LFO 1 sectiocontrol panel. The RATE poequipped with an LED thatcates the speed of the LFOas its waveshape. Turn thepot and check out how thethe LED indicates the chanpace as you rotate the pot. (low scillates udible the ntered

nifi-tput hear-

if you used in enve-rence finitely.

ound odified cate the n of the t is indi- as well RATE flash of ge of

Currently you are unable to hear the effect of the LFO as its modula-tion intensity is set to 0 in the sound program. In order to change this setting, you must access the AMOUNT button which works in conjunction with five vertically arrayed LEDs labeled OSC 1, OSC 2, PW 1+2, RESO 1+2 and ASSIGN: Press the AMOUNT button repeat-edly and observe how the LEDs flash in succession (the LEDs OSC 1 and OSC 2 flash separately as well as in unison). The corresponding modulation targets appear in the display, along with the modulation intensity values as determined by the VALUE pot and VALUE buttons. (You can also scroll through the


modulation targets via the PARAMETER button after you have pressed the AMOUNT button once.) Once you have dialed in a value other than 0 for a modula-tion target, the correspondilluminates continually. Thture tells you at a glance thmodulation is underway evwhen the display indicatesother type of operation.

Here are the definitionthe modulation target

OSC-1 refers to the frequoscillator 1

OSC-2 refers to the frequoscillator 2

PW 1+2 means that the pwidths of both oscillators atrolled in unison

RESO 1+2 refers to the resonances of both filters. Please keep in mind that although each set of these parameters is assigned a common modulation intensity, you can still ing LED is fea-

at a en some

s for s:

ency of

ency of

ulse re con-

dial in different sound-shaping set-tings manually. In other words, the audible result of a joint modula-tion varies according to the values you have determined for the other parameters.

ASSIGN Here you can freely select any modulation destination.Modulate the five parameters sep-arately and in combinations with different intensities. Try to antici-pate the sound you will come up with when you modulate the first oscillator, the second oscillator or both oscillators at once and see if the results match your expecta-tions. If you can fairly reliably pre-dict the outcome of your sound-shaping efforts, you should have a handle on the information dis-cussed thus far and can use your knowledge to create specific sounds you have in mind.

During the course of your experi-ments, it is entirely possible that you have generated modulations that have no effect whatsoever on


the sound, for instance if you mod-ulate the frequency of Oscillator 2 although it is dialed out of the oscillator mix. When you run into this type of problem, check out the signal routing, if any confitions conflict with each othmemorize the situation, prand solution. If you make aout of this, you wont paniyou run into similar situatiinstead youll keep your colyze the unexpected soundthe mix.

You are currently using a tras the LFO waveshape. Youshouldnt have any problemciating the periodic up andfluctuation of the target pter with this waveshape. Nvate the other available waveshapes for LFO 1 and tpicture the respective wavand associate it with the rethe modulation.

The third waveshape is a ding sawtooth wave. You cavert it into to an ascendingsawtooth by simply dialingrequisite negative modulaintensities (AMOUNT).

In the WAVE setting, you have access to 64 LFO waveshapes. Select these in the display section using the VALUE buttons:gura-er and

oblem habit

c when ons; ol, ana- and fix

iangle

asso- down

arame-ow acti-

ry to eshape sults of

escend-n con- in the

tion

S&H (Sample and Hold) is a struc-tured random modulation. Here random modulation values are generated. The value is held until the next beat impulse, then it abruptly jumps to a new random value.

S&G (Sample and Glide) is a con-tinual random modulation. Here the random values glide seam-lessly into one another, the rate of which is determined by random modulation of the RATE value.The following 62 waveshapes are identical to the oscillator sections digital waves. These can be used to create interesting rhythmic effects.

Continued your experiments with different LFO waveshapes. Note that after a while you no longer consciously hear minimal modula-tion intensities - depending on the waveshape and modulation target (e.g. S&G +1 on OSC 1 or 2). How-ever they do pep up the sound of


lend it a certain vitality. The key to many great sounds are these types of minimal modulations.

You may have gathered that the LFOs of the Virus are polypIf several notes are played neously, these are controllededicated LFOs, each with slightly varied rate. This effens up the sound of chordscially when they are sustaienhance this effect, activatLFO 1 KEY FOLLOW in the LMenu.

This function enables you trol the rate of the LFOs viapitch, or more accurately, vMIDI note number, so thatnotes generate faster LFO rresult, when you press andseveral notes you will hear of substantially different pfluctuations.

Finally, the LFOs can also bas additional envelopes. Thtrol feature for this effect iENV MODE button. When ypress this button, two thinoccur: For one, the LFO no linitiates its cycles periodicaonly once at and in sync w

start of a note, and for the other, the active range of the LFO is switched from bipolar (in both directions from the zero position) to unipolar (from zero in one direc-honic:simulta-d by

a ect liv-, espe-ned. To e the

FO-EDIT-

to con- the

ia the higher ates. As hold all kinds eriodic

e used e con-

s the ou

gs onger lly, but

ith the

tion only). Please note that this applies to the modulation target but not the modulation intensity. Here you can still determine a value in the entire bipolar range.

This effect is especially prominent when used in conjunction with the sawtooth wave, which enables a fade-out type of effect (when you dial in a positive AMOUNT value) or a volume-swell type of effect (negative AMOUNT) for the avail-able modulation targets. Using the LFO Curve parameter located in the LFO EDIT menu, you can have the ramp rise or fall exponen-tially. If you choose a triangle for your waveshape, the device will generate an ascending phase (attack) and a descending phase (decay). LFO Curve also lets you determine the temporal relation-ship between attack and decay; in other words, their respective rates.. Dial in the desired speed via the RATE pot.


You can also use S&H and S&G in ENV MODE to come up with some attractive results: S&H generates a single random value at the start of a note (in this case, the RATE pot has no effect); S&G works same manner although in tthe RATE value is crucial. Itmines the amount of timeto glide from the previous new random value.

LFO 2The design of the second LFO is essentially the same as the first, so in the

his case deter- it takes to the

well spare you the repetition of details SHAPE 1 and 2 are available as a joint modulation target; the filter frequencies and the Pan-orama position can be manipu-lated individually. You may also freely select a parameter for your modulation destination.

ACCESS VIRUS OS4 47LFO 2

Volume and Panorama Posi-tionYou probably noticed that the many of the sound shaping options available in the Virsionally influence the volumFor instance, an unfiltered tooth is naturally louder thhighly filtered sawtooth bewhenever you blend a partfrequency spectrum out ofmix, you are automaticallying the overall volume of tnal. This is why the Virus isequipped with a programmvolume pot for each SINGLGRAM. It enables you to baout the volume levels of yosound programs.

Locate the parameter PATCUME in the COMMON sectthe EDIT menu.

0111111111111111

1 COMMON PatchVolume 106111111111111111

Its value is set to 100 so thhave a reserve or headroomvolume increments when ydealing with highly filteredsounds.

You have already dealt with the Panorama position as a modula-tion target of LFO 2. Here you can not only modulate it, but also determine settings manually. For us occa-e level.

saw-an a cause of the the reduc-he sig- able

E PRO-lance ur

H VOL-ion of

1112

0 1154

at you of 27

ou are

this purpose, use the parameter PANORAMA which is also located in the OUTPUT section of the EDIT menu. Like many other parame-ters, Panorama is a starting point for modulations. For instance you can modulate the Panorama posi-tion via LFO 2 even if you have already set the Panorama to the far left position. In this case of course you will only hear the Pan-orama position shift to the right.


VELOCITYVelocity is one of the preferred modulation sources of keyboard players: A light key attack gates a low velocity value fogiven note, a heavy touch gates a high velocity value. IVirus you have ten modulagets available for Velocity. the VELOCITY section in thmenu.

0111111111111111

1 VELOCITY Osc1Shape 6111111111111111

There you will find the modintensities for:

OSC 1 SHAPEOSC 2 SHAPEPULSE WIDTHFM AMOUNTFILT 1 ENV AMTFILT 2 ENV AMTRESONANCE 1

RESONANCE 2VOLUMEPANORAMAener-r the ener-

n the tion tar-Locate e EDIT

1112

+01154

ulation

which you can manipulate inde-pendently of one another in the familiar bipolar control range.

A light key attack generates a low velocity value for the given note, a heavy touch generates a high velocity value.

ACCESS VIRUS OS4 49Unison Mode

UNISON MODEWhen we talked about the oscilla-tors, we mentioned that by subtly detuning signals, you can bsounds and achieve string-sounds. The Virus is equippfeatures that allow you to ttype of tonal manipulationfurther. On of these is the sUNISON MODE. It enables initiate two or more voicesnote played, which in turn detune many oscillators. UMODE also offers the optiospreading the voices generone note in the stereo panand shifting the phases of LFOs so that all types of peeffects can be used to prodeven more exciting signal.

Locate the parameter grouSON in the EDIT menu.

0111111111111111

1 UNISON Mode Twi6111111111111111

UNISON mode determinesmany voices the Virus will render a played note. In a n

it determines how fat the sound will be. You can use the UNISON Detune parameter to determine to which extent the active voices are detuned. UNISON PanSpread dis-eef up like ed with ake this a step o-called you to for each lets you NISON n of ated by orama their riodic uce an

p UNI-

1112

n 1154

how use to utshell,

tributes them uniformly across the stereo panorama, a process by which you can also determine the width of a sounds stereo base. When you activate UNISON mode for a sound, it can still be played polyphonically. However, depend-ing on the number of voices youve dialed in, its polyphony will of course be considerably reduced in UNISON mode. The most efficient and the standard setting is UNI-SON mode = Twin, where two voices are played for every note. In the OFF position, one voice per note is played.


THE CHORUS/FLANGER EFFECTAnother function that delivers great effects based on pitcation is the so-called choruChorus actually consists ofdelay (generally up to apprms) which is varied periodimodulating the delay, the signal is slightly detuned tinput signal (the so-called effect). This inconsistency ibetween the original and esignal is the source of the ceffect. Feedback in the delaenhances this effect. The lenal side is automatically mlated in a different mannerthe right, so a chorus effectfor converting mono signastereo signals.

If the delay is less than appmilliseconds, than the effecalled flanging or a flangerrather than chorus. In this feedback is even more signbecause it generates resonthat can be modulated andyet another source of radiceffects. If you determine hiback values, you can clearly

how the two sides of the signal are modulated differently - in reverse phase - by the LFO.

Locate the parameter group CHO-

h fluctu-s effect. a brief ox. 50 cally. By delayed o the Doppler n pitch ffects horus y line ft sig-odu- than is great ls into

rox. 10 ct is effect

case ificant ances is thus

al sound gh feed- hear

RUS in the EFFECTS menu.

01111111111111111112

1 CHORUS Dir/Eff OFF 61111111111111111154

CHORUS DIR/EFF determines the balance between the original sig-nal and the processed signal. The parameters RATE and SHAPE con-trol another LFO that was installed specifically for the chorus LFO. DELAY is used to set the delay time, DEPTH determines the modulation intensity, and FEEDBACK controls the feedback level. When you want to generate a flanger effect, the FEEDBACK parameters negative control range lets you dial in softer characteristics for the flanger. Please keep in mind that the Cho-rus section in the Virus is fully ste-reophonic: Stereo positions as well as panorama modulations and ste-reo spread values that you have dialed in elsewhere remain intact in the effects signal.

ACCESS VIRUS OS4 51The Delay Effect

THE DELAY EFFECTA delay effect is traditionally used to generated an echo of the input signal. Locate the parametDELAY in the EDIT menu.

0111111111111111

1 DELAY EffectSend 6111111111111111

Here you fill find parameteare virtually identical to thparameters of the CHORUSDo not allow yourself to befused by the slightly differminology: The delay time ithe parameter entitled TIM(equivalent to DELAY in theRUS section); the other feaare FEEDBACK with a dedicLFO and the familiar paramRATE, DEPTH and SHAPE.

Only two functions in the Dsection are different to thesection: For one, it featuresEFFECT SEND instead of thance parameter DIR/EFF. EFSEND is especially significaMULTI MODE, where severawith different levels are pathrough the same delay ef

For the other, LENGTH enables you to create substantially longer delay times, for instance to achieve com-plete echoes (maximum of 693 ms) that are fully audible. The LFO er group

1112

0 1154

rs that e group. con-

ent ter-s set via E CHO-

tures ated eters

elay Chorus an e bal-FECT nt in l PARTs

tched fect.

allows you to modulate the delay as you would the chorus to achieve similar detuning effects. A stereo effect is achieved via different modulations of the left and right sides of the signal.


MORE TO COMEWe have come to the end of these detailed instructions for novices. We hope we were able to hbecome a bit more familiayour new synthesizer and gsome confidence in how toit. As we mentioned earlierjust an introduction and docover all the functions andtures of the Virus, only thecomponents and how theythe sound of the Virus. Younow be able to come to terthe in-depth look at the Vithe following section. elp you r with

ain handle , this is es not

fea- basic affect should ms with rus in

Concept and Operation

54 CHAPTER 5Concept and Operation

OPERATING MODESIn the Virus you can select from two basic operating modes, SIN-GLE MODE and MULTI MOD

In SINGLE MODE, the Virusto generate a single soundgram only. All 24 voices, alland most importantly, all cfeatures (with the exceptioMULTI button) function in tion with this one sound pYou might say a SINGLE proa combination of all functieffects that determine theof the Virus. In other wordsGLE program is a sound oVirus, that can be stored anrecalled.

The Virus provides access tSINGLE sounds. Next to theRAM sounds (Bank A and Byou have two banks availaa total of 256 factory soundbanks, C and D, are stored iFLASH ROM and can not bewritten via STORE.

The MIDI receive channel in SIN-GLE MODE is the Global Channel. You can change the Global Chan-nel in the CTRL menu.E.

is able pro- effects ontrol n of the conjunc-rogram. gram is

ons and sound : A SIN-f the d

o 512 256

ank B), ble with s. These n the over-

In MULTI MODE, the Virus can com-bine up to sixteen (SINGLE) sound programs, among which the maxi-mum available number of 24 voices are allocated dynamically. All simultaneously available sounds can be manipulated in real-time; for this purpose the control panel enables you to switch among the sixteen so-called PARTS.

In MULTI MODE, the actual sound parameters are augmented with other functions that deal with how the involved SINGLE programs are structured or organized. These include the volume levels of the single programs, their MIDI chan-nels, output assignments, etc.

On the Virus, we differentiated fundamentally between SINGLE mode and MULTI mode. This dis-tinction is reflected in the contents of the menus: If the LED on the SINGLE button lights up, the CTRL and EDIT menus let you access the sound parameters of the current

ACCESS VIRUS OS4 55The Multi-Single Mode

SINGLE program. If the LED on the MULTI button lights up, the CTRL and EDIT menus will contain the appropriate administrative parameters for the current MULTI program. For example, herehave the option of selectinSINGLE program for each oMULTI PARTs.

THE MULTI-SINGLE MODEIn MULTI mode, the EDIT and CTRL you

g the f the 16

menus are responsible for admin-istering the 16 PARTs. Conse-quently, you cant access SINGLE program parameters directly here. Beyond that, youre unable to change the SINGLE programs directly here, which would admit-tedly be a handy option when youre working with a sequencer. This is why the Virus features MULTI SINGLE mode, which, strictly speaking, is more an alter-native view of MULTI mode rather than a further mode in its own right.

Activate MULTI SINGLE mode by pressing the MULTI and SINGLE buttons simultaneously. The name of the selected MULTI program will disappear and instead youll see the name of the SINGLE program for the selected PART. Now you can page or scroll through the 16 PARTs using the PART buttons and select a SINGLE program for every chan-nel. You can process the currently selected PART or, more accurately, edit its sound, using the control


features. The CTRL and EDIT menus let you access the usual SINGLE parameters. In this operating mode, youll find that the CTRL menu has been expanded to include some organizationparameters, for instance, thPARTs volume level, panoraoutput assignments. Youllsee the number of the selePART on the upper left in thplay. The PART buttons donally change sounds, they simthe user interface of the Vithe desired PART. Irrespectithe given setting, all PARTscontrolled simultaneously MIDI. Consequently, MULTImode, which makes handlimuch easier, is the ideal chwhen youre working withnected sequencer.

Please bear in mind that MSINGLE mode is really just view of the normal MULTI MULTI SINGLE mode doesnunique data type for storinsounds, it always works wiMULTI program currently sin normal MULTI mode. Allnormal MULTI mode param(keyboard zones, etc.) remaintact and in force even th

you cant view or vary them in MULTI SINGLE mode. You can set the device to normal MULTI mode at any time by pressing the MULTI button. To return to the MULTI SIN-al e ma and

always cted e dis-

t actu-ply set

rus to ve of can be via SINGLE ng so oice a con-

ULTI another mode. t offer a g th the elected of the eters in

ough

GLE mode view, simply press the MULTI and SINGLE buttons simul-taneously.

When youre working with a sequencer, start with a MULTI pro-gram that features neutral set-tings for its administrative parameters, for example, the MULTI program M0 Sequencer. Here the PART numbers are identi-cal to the MIDI channels of the PARTs. Now when you work in MULTI SINGLE mode, the Virus responds as if it were in SINGLE mode, except that you have 16 sounds available simultaneously on 16 MIDI channels. Use the PART buttons to select these sounds.

You only need to exit MULTI SIN-GLE mode when you want to store the MULTI program, for example, to save the current global delay/reverb setting. In MULTI mode, these settings are not stored along with SINGLE sounds.

ACCESS VIRUS OS4 57Edit Buffers

In addition, you can activate another complete MULTI program in MULTI mode only.

EDIT BUFFERSWhenever you play or edit a SIN-GLE program, its current data is

stored in an edit buffer. This is an individual memory slot for SINGLE programs that has nothing to do with the memory slots in the sound banks. When you activate a new SINGLE, its data is copied to the edit buffer. There you can edit it as you see fit while the original remains unchanged in the bank. When you activate STORE (more on this in a bit), the content of the edit buffer is copied back to the original slot in the bank (or, if you so desire, to another memory slot).

In MULTI mode, you have one MULTI edit buffer and 16 SINGLE edit buffers for the PARTs at your disposal. When you activate another a MULTI program, its data is copied from the MULTI bank to the MULTI edit buffer. The MULTI program in turn contains address information for the SINGLEs involved, in other words, the bank and program numbers. These addresses are also copied from the SINGLE banks into the 16 SINGLE edit buffers for the PARTs.


When you store a MULTI program, only the addresses of the SINGLE programs original slots are saved, but not, however, the sound data in the 16 SINGLE edit buffers. These must be stored separately SINGLE program banks.

This type of edit buffer is umost synthesizers; its advaare many:

It lets you edit copies of without sacrificing the origsounds.

Edit buffers can be storesequencer and sent from itVirus independently of thestored in the device (see DThe Sound in the Song onpage 222).

In MULTI-Mode (or MULTGLE-Mode) the same SINGgram can be recalled and edifferent parts. In this caseinvolved EDIT-buffers contaations of the same originain the

sed in ntages

sounds inal

d in a to the sounds UMP:

I-SIN-LE-pro-dited on all in vari-

l sound.

Handling

60 CHAPTER 6Handling

PARAMETER SELEC-TION AND DATA ENTRYIn the Virus, we distinguished between two types of paraOn the one hand, it featureparameters that are essengenerating or synthesizingon the other hand it has soparameters and organizatiparameters that are more peripheral nature. This distis apparent in handling antion of the Virus: All essentsound parameters feature cated knob or button so thcan access these directly - cially while you are playinga few cases (where appropwhere it facilitates better hdling), the control featuresdual functions.

Peripheral parameters, on other hand, are compiled inmenus. Among these men

above all the EDIT, the CTRL (short for Control and the EFFECTS menu as well as the four local EDIT menus in the individual function blocks. The EDIT menus contain meters. s

tial in sounds, und onal of a inction d opera-ial a dedi-at you espe-!. In just riate or an-

have

the

us are

parameters that you will require less frequently, but some of these are nonetheless indispensable for programming sounds. The local EDIT menus are there for a purpose to help you distinguish clearly between the various parameters. Here youll find parameters that affect directly the given functional section, but are not equipped with dedicated control features.

Irrespective of which operating mode you may have activated, the EDIT menu contains the sound parameters of the selected SINGLE program (in SINGLE mode and MULTI SINGLE mode) or organiza-tional parameters for MULTI mode. In SINGLE mode and MULTI SINGLE mode, the CTRL menu contains fur-ther SINGLE parameters such as the arpeggiator, etc.

access virus b owner's manual

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