Access Virus Rack User Manual

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All other trademarks contained herein are the property of their respective owners. All

features and speciﬁcations subject to change without notice.

Written by Christoph Kemper, Uwe G. Hönig, Wiland Samolak

Guido Kirsch and Marc Schlaile.

Translation by Thomas Green. Graphic design and DTP by Babylonwaves Media.

http://www.access-music.de

The Virus - Resistance is futile.

info@access-music.de

Important Safety Remarks



- Set-up 6

- Connections 7

- Operation 7

- Memory battery change 8

- Care 8

- Fitness for Purpose 8

Prologue



Introduction



The Virus 14

- Cable Connections 15

- Power Up the Virus 15

- Listening to the Factory Sounds 16

- Listening to the Multi Programs 17

- Your First Sound Program 17

The Amplifier Envelope 19 The First Filter 22 Filter Modulation 25 The Saturation Stage 27 The Second Filter 28 Filter Routing 32 The First Oscillator 34 The Second Oscillator 37 The MIXER Section 39 The LFOs 41

- LFO 1 42

- The modulation targets 42

- LFO 2 45

Volume and panorama 46

- Volume and Panorama Position 46

Velocity 47 Unison Mode 48 The Chorus/Flanger Effect 49 The Delay Effect 50 More to Come 51

Concept and Operation



Operating Modes 54 The Multi-Single Mode 55 the Edit Buffers 57

Operation



Parameter Selection and Data Entry 60 Display of values 64

All About The Memory



Store 66 Compare 67

Modmatrix And Definables



Creating Modulations via Assign 70 The Definable Knobs 72

Master Clock And Midi-Clock



Master Clock and MIDI-Clock 74

The Effects Section



The Effect Section 76

Audio Inputs



Audio Inputs 78

- OSC Volume / Input 79

- Input global Settings 80

- Input Level Indicator 80

Audio Routing



The Audio Outputs 82

Introduction

CHAPTER 4 Introduction

THE VIRUS

This section provides deliberate, step-bystep guidelines on operating and handling the Virus for those of you who are new to the world of synthesizers and MIDI. The following covers basics such as how to connect the Virus to an AC power supply , your MIDI system and your audio system. Then we will guide you through a series of experiments designed to demonstrate the different functional groups, their control features and the tasks they execute.

After you have ﬁnished reading this section, you will be able to handle virtually all of the sound generating and sound shaping functions of the Virus. All of these are described in context. Even the majority of less signiﬁcant functions, accessible via menus, are discussed here. You will ﬁnd a detailed, comprehensive description of all functions of your new synthesizer in the section following 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 you might desire or need to acquire. If you are keen to learn more about these subjects, you should consider becoming a regular reader of one or several of the leading trade publications in your country. Your local musical instruments dealer or more experienced musicians will be able to recommend the best

magazines to you. And of course there is a wide range of books available on these subjects.

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 discussed in this section might be a house where each bit of information 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 won’t run into problems when you ﬁnd one of the “bricks” is missing.

ACCESS VIRUS RACK

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 build-in keyboard, then connect the MIDI OUT of the desired MIDI send device (keyboard, computer, hardware sequencer, etc.) with the MIDI IN of the Virus.

Connect the audio outputs of the Virus with the signal inputs of your audio system. In order to receive a signal, as a minimum you must connect the output OUT 1 R/MONO. However, we recommend you also connect the output OUT 1 L so you are able to enjoy the stereo sounds of the Virus.

Once you have established the desired cable connections, make sure the main volume controls of all the connected devices are dialed to the lowest possible setting. Switch the devices on in the following sequence: the MIDI send device (computer, master keyboard, etc.) ﬁrst, then the sound generators (Virus and the other signal sources), followed by the mixing console and ﬁnally the ampliﬁer.

Power Up the Virus



Power up the Virus Rack by pressing the POWER button. T o shut the device down, press and hold this button for approx. two seconds.

Now while you are sending notes 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.

CHAPTER 4 Introduction

Listening to the Factory



Sounds

The 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 possibilities 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 number, a letter, number and name appear in the display. These indicate the the MIDI Channel, the current Program Bank (A to D) as well as the number and name of the current sound program.

You’ll ﬁnd that some sound programs are labeled with the abbreviations ”INP” or ”VOC”. These use the external audio input as a signal source for the ﬁlter section (INP) or vocoder (VOC). This means that you won’t hear anything until you route an audio signal into the external audio inputs.

Now if you play notes you should be able to hear this sound and a quarter note (the round dot at the end of the note staff is solid black) should appear in the display every time you press a key and release a key. If you do not hear a sound but you see a half note (blank note head) check to see if you are sending on the wrong MIDI Channel.

Press the VALUE button to call up the 128 single programs of Bank A in sequence. (The VALUE encoder is inactive in this operating mode.) In order to hear the sound programs in banks B, C and D, simply use the PARAMETER/BANK buttons to step from one program bank to another.

Listening to the Multi



Programs

The Virus not only has the capability of playing SINGLE PROGAMs, but also combinations consisting of more than one sound simultaneously (MIDI Multi Mode). T o 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 don’t have to switch back and forth between banks they way you just did while activating single programs.

The majority of available MULTI PROGRAMs contain sound combinations 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 (layered) on the keyboard. In other MULTI PROGRAMs, the sounds are divided up over several MIDI channels to make it easier to work with a sequencer. If you activate a MULTI PROGRAM and hear a single sound only, then you can control this MULTI PROGRAM via several channels.

ACCESS VIRUS RACK

The Virus



Your First Sound Pro-

gram

If you have never created or changed a sound on a synthesizer , we now have the pleasure of introducing you to this fascinating process.

Press the button single program “A127 - START -” by using the on the connected keyboard. You should hear a sound that, for lack of better description, is a bit harsh or biting, but above all completely static. It should start immediately after you press a key and sustain indeﬁnitely for as long as you hold the key down. As soon as you release the key, the sound should end

VALUE

SINGLE

buttons. Press any key

and select the

CHAPTER 4 Introduction

abruptly. This sound is not designed to be especially pleasant; it is intended to be as neutral as possible to give you a basis from which you can begin creating or shaping your own sound.

THE AMPLIFIER ENVELOPE

ACCESS VIRUS RACK

The Amplifier Envelope

Long-term exposure to this sound will deﬁnitely grate on your nerves, so let’s get started with changing it into a signal you might enjoy hearing, beginning with the volume characteristics.

Locate the two vertically arrayed buttons next to the seven LEDs. Use these UP and DOWN buttons to select from among the seven parameter groups and/or sections. The appropriate LED lights up to indicate that the given section has been selected. Select the ﬁve encoder knobs for this section read

ATTACK RELEASE

These controls will help you to dial in volume characteristics called an ampliﬁer envelope and put an end to the nerveracking drone that may remind you of one of those cheesy organs that you hear in ‘60s B-movie sound tracks.

ENV

section. The labels on the

DECAY, SUSTAIN, SUS TIME

and

The section labeled envelope. On a synthesizer, an envelope is used to modulate sound over time. The Virus has two envelopes, one for volume (AMP ENV) and one for the ﬁlters (FILT ENV), which we will learn more about later . The ﬁve encoder knobs serve to shape either the ampliﬁer envelope or the ﬁlter envelope. Make sure that you can see AMP ENV in the display, and not FILT ENV. If this is not the case, use the PARAMETER buttons to set the section to the ampliﬁer envelope.

ENV

addresses the

CHAPTER 4 Introduction

Rotate the

ATTACK

encoder while you repeatedly engage a key to hear the note. The further you turn the encoder up, the longer it takes for the sound to achieve maximum volume after the start of the note. So you can say

ATTACK

controls the initial volume swell of the sound.

T ake a look at the display of the Virus to gain an impression of the difference between these two values. It shows two numeric values when you dial a encoder: at the left you can see the value stored in the sound program and at the right, the numeric equivalent to the value determined by the current position of the encoder.

Now ﬁddle with the DECAY encoder while you repeatedly press a key to activate a note. Hold the key down for good while. You will notice that the volume, once it reaches maximum level at the end of the reaches a minimum level. The

ATTACK

phase, drops until it

DECAY

encoder determines the speed, or in synthesizer jargon, the rate at which the volume decreases.

However, the

DECAY level does not always drop to the minimum level; you can determine a random value between the maximum and minimum levels at which the volume remains constant. This level in turn is controlled via the SUS- TAIN encoder.

Whenever the SUSTAIN level is set to maximum, the volume cannot drop during the DECAY phase; in other words, in this situation the DECAY encoder is inef- fective.

. The individual functions of a synthe-

sizer are designed to interact; many functions are dependent on other functions. In a number of cases this means that some functions are subordinate to others, i.e. the effectiveness of a control feature is altered, modiﬁed or even negated completely by other related functions.

The ﬁnal encoder, RELEASE, determines the speed or rate at which the volume 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 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 phase.

The next phase of the ampliﬁer envelope is determined by the SUSTAIN-TIME encoder: If the encoder is set to the center position, then the SUSTAIN level remains constant through to the end of the note.

If you turn it counter-clockwise to the left, then the level drops off at an increasing rate towards the minimum level much in the manner you just experienced with the DECAY encoder; If you turn the encoder clockwise to the right, the level rises at an increasing rate to maximum and remains there until you release the key.

T he ampliﬁer envelope can be described as a variable curve which, depending on the type and duration of attack, hold and release data, automatically inﬂuences an imaginary volume encoder (turns it up or down). At the beginning of the note, ATTACK controls the rise or rate of increase to the maximum level. Once the maximum level is achieved, DECAY determines the fall or rate of decrease to the SUSTAIN value, which is inﬁnitely variable between the minimum and maximum levels. The ampliﬁer envelope 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 encoders labeled ATTACK, DECAY, TIME and RELEASE con- trol a speed or rate, where as SUSTAIN actually controls a level.

ACCESS VIRUS RACK 21

The Amplifier Envelope

22 CHAPTER 4

Introduction

THE FIRST FILTER

Now we will take a look at a component of a synthesizer that is generally regarded as the most important functional unit as it enables drastic sound shaping measures: the ﬁlter - or in the case of the Virus, the two ﬁlters.

But ﬁrst we will concentrate on just one of the two ﬁlters.

Use the UP or DOWN buttons to activate the ﬁlter section FILT. The second enco- der knob in this row is labeled CUTOFF (not to be confused with CUTOFF 2!). Rotate the encoder to the left and right and note how the sound becomes muddier and clearer in response to the direction in which you turn the encoder. (To ensure this effect and the following aural experiments are most pronounced, 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 jargon, attenuates the higher frequencies in a signal and allows the lower frequencies through. Think of the CUTOFF encoder as a bouncer and the Virus as your pub. Y ou 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.

ACCESS VIRUS RACK 23

The First Filter

Now we'll look at a parameter that is not assigned a dedicated knob of its own, but can be dialed up in the display. This type of parameter may be selected via the PARAMETER buttons and then adjusted with the VALUE knob or the VALUE buttons.

Select the FILTER 1 Mode parameter via the PARAMETER buttons. To do this, make sure that the display is still in the ﬁlter section FILT. This parameter enables you to select a ﬁlter operating mode from the four available options:

 LP the low pass ﬁlter we have just

discussed.

 HP 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.

 BP the band pass ﬁlter which sup-

presses both ends of the tonal spectrum and allows only a narrowly deﬁned bandwidth of the original sound to pass.

 BS The band stop ﬁlter, band reject

ﬁlter or notch ﬁlter which works in the opposite manner of the bandpass ﬁlter. It allows all of the frequencies of a signal except for a narrow frequency band around the cutoff to pass. The term “notch” is fairly descriptive; you might say this ﬁlter chops a notch out of the sound spectrum.

01111111111111111112

1 FILTER1 Mode Lowpass≤

61111111111111111154

Now activate the different operating modes and rotate the CUTOFF encoder to get a feel for the way each ﬁltering option works.

Along with the CUTOFF encoder, the RESONANCE encoder is the most important control feature of a ﬁlter. The ﬁlter resonance increases the volume of the frequencies located near the cutoff frequencies and suppresses the more remote frequencies. This sound shaping feature has a striking effect - especially when used in conjunction with the low pass ﬁlter: it produces 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 encoder 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

24 CHAPTER 4

Introduction

of the notch decreases; in other words more frequencies on both sides of the ﬁlter frequency are allowed to pass.

FILTER MODULATION

ACCESS VIRUS RACK 25

Filter Modulation

Of course we don’t want to require you to execute every sound modiﬁcation manually by twiddling encoders. All kinds of sound modiﬁcations in the Virus can be executed automatically much in the way of your previous experiments with the volume controls: The ampliﬁer envelope can be described as a variable curve which, depending on the type and duration of attack, hold and release data, automatically inﬂuences (turns it up or down) an imaginary volume pot.

Similar procedures are applicable to the ﬁlter frequencies. The FILTERS section features its own envelope, the structure of which is identical to the ampliﬁer envelope.

Like the aforementioned ampliﬁer envelope, the ﬁlter envelope is located in the ENV section. In that section use the PARAMETER buttons to select FILT ENV.

Much like the ampliﬁer envelope, the ﬁlter envelope automatically “rotates” the CUTOFF encoder. However there is one signiﬁcant difference between the two envelopes. With the ampliﬁer envelope, you are always dealing with an initial 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 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 ﬁlter. This is why we equipped the Virus with a control labeled ENV AMOUNT (short for Envelope Amount). This encoder is positoned in the Filter section. When the encoder is turned counter-clockwise to the far left, the ﬁlter has no effect on the cutoff frequency; the further you turn the encoder to the right, the greater the effect the ﬁlter envelope has on the ﬁlter frequency. The maximum level of the envelope may lie outside the audible range when the ﬁlter has already been partially opened via the CUTOFF encoder or was manipulated via other control options. In extreme cases where the ﬁlter is already completely open, the ﬁlter frequency cannot be increased regardless of how high you set the ENV AMOUNT.

Go ahead and spend some experimenting with different ENV AMOUNT, CUT- OFF and RESONANCE settings for the diverse ﬁlter operating modes. Also try varying the settings for the ampliﬁer envelope. You will ﬁnd that with just these few parameters you are able to come up with a vast amount of sound settings. If you are among the many musicians who are associative listeners,

26 CHAPTER 4

Introduction

you might say many of the settings produce sounds reminiscent of stringedinstruments; some sound picked, plucked or snapped, others sound bowed.

For your next experiment set the ampliﬁer envelope so that you hear a constant level when you press and hold a note. Now deactivate the ﬁlter envelope by setting the ENV AMOUNT to 0. Set Filter1Filter-1 to low pass mode and decrease the ﬁlter frequency until you just barely hear a muddy signal when you play notes in the mid-range.

Now play a few higher and lower notes. Y ou will ﬁnd that the lower notes have a greater overtone content, whereas the higher notes sound muddier and their volume decreases until the notes are completely 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 frequency, 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 inﬂuence is determined by the KEY FOLLOW parameter. You'll ﬁnd this parameter in the ﬁlter section using the PARAMETER buttons just like you did in FILTER 1 mode earlier on.

Please note that KEY FOLLOW is a socalled bipolar parameter: Its control range is not limited to the positive end of the spectrum (0 to a maximum of

127). Bipolar controls effect negative values as well, in this case from the negative maximum of -64 through 0 an on to the positive maximum of +63. Consequently, if this value is set to the center position (0) the pitch of the notes corresponding to the keys on your keyboard has no effect on the cutoff frequency. If on the other hand you turn the KEY FOLLOW parameter clockwise towards the positive control range, you will ﬁnd that the ﬁlter opens up increasingly as the pitch increases with higher notes. At lower notes, the ﬁlter closes down again. If you turn the encoder counter-clockwise towards the negative control range, the KEY FOLLOW effect is reversed. With the Virus, you will encounter this feature - intensity control via a bipolar parameter - again in conjunction with other modulation sources and targets.

Now experiment as much as you like with different KEY FOLLOW settings and tune the settings via the CUTOFF encoder. And remember to bring all of the other parameters you have encountered thus far into play.

THE SATURATION STAGE

ACCESS VIRUS RACK 27

The Saturation Stage

In the signal chain of the Virus, Filter-1 is followed by a saturation stage. It enables you to add overtones to the ﬁltered signal via distortion. Locate the parameter SATURATION 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 buttons or the VALUE encoder, you can now select from a number of saturation/distortion curves.

Feel free to experiment with the diverse

saturation curves and be sure to vary the OSC VOL settings. Note how the differ-

ent CUTOFF and RESONANCE settings inﬂuence the saturation curve.

At this point we would like to mention the OSC VOL parameter, which is next to the SATURATION parameter. The portion of the control range from the far left to the center position (0) determines the volume of the ﬁlter section’s input signal. The portion of the control range located to the right of the center position does not achieve any increase in volume; it simply intensiﬁes the degree of saturation or distortion. This effect is only achieved when you have activated a saturation curve.

28 CHAPTER 4

Introduction

THE SECOND FILTER

You 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 frequency level and high resonance. You’re probably thinking these types of sounds could do with some more ﬁltering. We had the same idea, which is one of the reasons why we equipped the Virus with another ﬁlter per voice.

The technical design of this second ﬁlter is identical to the ﬁrst, so we won’t discuss it in as much detail as we did the ﬁrst ﬁlter. However, there are few differences in how you handle the second ﬁlter:

 Only two parameters of the Virus are

allocated exclusively to Filter-2: CUTOFF 2 and FILT 2 MODE.

 The RESONANCE, ENV AMOUNT and

KEY FOLLOW parameters can be allocated to either of the two ﬁlters or both simultaneously. Use the FILTER SELECT menu in the FILTERS section to select the desired operating mode. For instance, if you choose FILT2, then the values you set with RESONANCE, ENV AMOUNT and KEY FOLLOW apply exclusively to Filter-

2. The corresponding parameters of Filter 1 remain unaffected. On the other hand, if you choose FILT1+2, the values that you dial in apply by the same measure to Filters 1 and 2.

In the sound program we are using for our experiments, both ﬁlters are selected, so 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 the audible signal path of the Virus.

Before we get started with our next experiment, deactivate SATURATION, set the ENV AMOUNT of the ﬁlter envelope to zero and set CUTOFF 2 to the center position so that Filter-2 always has the same cutoff frequency as Filter-1 (we’ll explain CUTOFF 2 a bit later). Set CUT- OFF to a medium or middle value and turn the RESONANCE encoder counterclockwise to the far left to achieve a relatively muddy sound.

Now locate the FILTER BALANCE param- eter in the FILT menu and rotate it from the left to the right. You will note the sound becomes muddier as you turn the encoder towards the center position 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 to the far left, only Filter-1 is audible. When you rotate the parameter to the right, Filter2 is blended in so that it follows Filter-1 in the signal chain. When you turn the FILTER BALANCE clockwise, Filter-1 is

ACCESS VIRUS RACK 29

The Second Filter

blended out of the signal chain until at the far right position only Filter-2 is active and audible.

Each ﬁlter in the Virus normally features 2 poles. However in the FILTER ROUTING operating mode SER 6, Filter-1 operates with 4 poles, so the signal patched through Filter-1 (FILTER BALANCE to the far left) is trimmed more drastically than when it is routed through Filter-2 (FILTER BALANCE to the far right). When you set the FILTER BALANCE to the center position (12 o’clock) - as we mentioned before - the two ﬁlters are routed in series, which means they respond as if they were a single ﬁlter with 6 poles and consequently a great deal of slope. This is why the input signal is trimmed substantially when you set the parameter to this position.

Experiment with the diverse FILTER BAL- ANCE values to get a feel for the different degrees of slope. Rotate the CUTOFF encoder or activate the ﬁlter envelope (for both ﬁlters!) to hear the ﬁlters in action.

The CUTOFF 2 parameter is a special feature: It controls the cutoff frequency of the second ﬁlter, but is subordinate to the CUTOFF encoder located above it. In other words, at the center position (12 o’clock) the manually selected frequency of Filter-2 is identical to that of Filter-1. When you rotate the encoder to the left the cutoff frequency level of Filter-2 is increased relatively to Filter-1, when you turn to encoder to the right the cutoff frequency level is decreased relatively. Now when you adjust the CUTOFF, you

adjust the cutoff frequency of both ﬁlters by the same measure! This feature lets you determine a difference in values in the ﬁlter frequencies (called an offset) via the CUTOFF2 encoder which remains constant whenever you adjust the CUT- OFF encoder.

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

Set FILTER BALANCE to the center position (12 o’clock) and CUTOFF 2 to the maximum level. The FILTER ROUTING operating mode must remain SER 6. Set CUTOFF and RESONANCE to a middle value and select a clearly audible SATU- RATION curve.

Now you can ﬁlter this complex signal produced by a combination of the satu- ration stage and the Filter-1 yet again. Rotate the CUTOFF 2 encoder slowly towards the center position (12 o’clock). You can hear how Filter-2 gradually modiﬁes the distorted signal. Y ou can set a RESONANCE value for Filter-2 if you choose FILT 2 in the FILTERS SELECT menu and rotate the RESONANCE encoder to the desired position. Set the CUTOFF 2 encoder to a position to the right of the center position. This conﬁguration can be described as a complex non-linear ﬁlter set up where the cutoff frequency is controlled via the CUTOFF encoder. You can dial in a wide range of sound-shaping option via CUTOFF 2. Also try modifying the resonances of both ﬁlters as well as the SATURATION curve to come up with different ﬁltering characteristics.

30 CHAPTER 4

Introduction

Now experiment with the diverse ﬁlter modes and listen closely to the effect of the parameters RESONANCE, ENV AMOUNT and KEY FOLLOW in conjunction with FILTERS SELECT. 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 cutoff frequency and the second as a high pass with a high cutoff frequency , the Virus will not generate an audible signal when you set FILTER BAL- ANCE to the center position (12 o’clock).

ACCESS VIRUS RACK 31

The Second Filter

32 CHAPTER 4

Introduction

FILTER ROUTING

The ﬁnal parameter we’ll discuss for the time being is FILTER ROUTING. This feature offers several ﬁlter routing options which allow you to operate the ﬁlters in series, i.e. patch one after the other in the signal chain, or in parallel, which means side by side in the signal chain:

 SER-4 The ﬁlters are switched in

series; with two poles each (12dB/ Okt.), both ﬁlters have the same slope for a total of four ﬁlter poles (24dB/ Okt.).

 SER-6 The ﬁlters are switched in

series; Filter-1 has four poles (24dB/ Okt.), Filter-2 has two poles (12dB/ Okt.) so the overall slope is equivalent to six poles (36dB/Okt.).

 PAR-4 The ﬁlters are switched in par-

allel and feature two poles each (12dB/ Okt.).

 SPLIT The ﬁlters are switched in par-

allel and feature two poles each (12dB/ Okt.). Additionally, they receive independent input signals (more on this later). Each of the two oscillators routes its signal into one of the two ﬁlters whose signals can be spread in the panorama via a parameter called UNISON Pan Spread.

. Regardless of which FILTER ROUTING

option you chose, the SA TURA TION stage is always post-Filter-1, i.e. after Filter in the signal chain.

ACCESS VIRUS RACK 33

Filter Routing

Her is the ﬁlter routings capabilities of the Virus.

34 CHAPTER 4

Introduction

THE FIRST OSCILLATOR

To this point, we have turned our attention exclusively to sound-shaping functions and have always started with the same basic material: a so-called sawtooth wave. This waveshape is especially well-suited as a neutral starting point as it contains all of the so-called natural scale of overtones, which give the ﬁlter plenty of quality material to work with.

The ﬁlters, with the exception of a notch ﬁlter or band stop (BS), trim the far reaches of the tonal spectrum, so for instance a signal sounds muddier after it has been routed through a low pass ﬁlter. You can well imagine that this type of sound modiﬁcation is substantial but insufﬁcient for shaping more subtle differences in tone. For instance the tone of a trumpet differs signiﬁcantly from that of a saxophone even though no one would seriously claim that either of the instruments has a muddier tone 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. 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 variety 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 beginning (A127

- START -). To this end, ﬁrst press the SINGLE button in order to return to Play mode from the selected parameter section. In Play mode, you can switch sounds via the VALUE buttons.

ACCESS VIRUS RACK 35

The First Oscillator

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

In the sound program, SHAPE is preset to the center position. The display shows “Saw” for the sawtooth waveform.

Press and hold a key and slowly turn the encoder clockwise. Y ou should be able to hear how the tone becomes increasingly more hollow-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 unable to achieve.

The waveshape that is audible when you turn the SHAPE encoder to the far right is a so-called pulse wave. It is unique because the duration of the negative pulse is equal to the duration of the positive pulse: It has a so-called pulse width of 50%. The tone of a pulse wave is different to that of a sawtooth wave because it does not contain all overtones in the natural overtone scale, only the odd-numbered tones, i.e. the ﬁrst (the root note that determines the pitch), third, ﬁfth, and so forth. By turning the

SHAPE encoder from the sawtooth control range towards the pulse control range, you are actually dialing every other overtone out of the mix, which explains why the sound becomes thinner.

You can continue modifying the sound by reducing the symmetrical width of the pulse wave. In the Virus, you can execute this sound-shaping measure via the WAVE SEL/PW (PW = pulse width) encoder, PROVIDED THE SHAPE PARAM-

ETER IS SET TO A POSITION IN THE NEGATIVE HALF (RIGHT) OF ITS CONTROL RANGE.

Rotate the WAVE SEL/PW encoder slowly from the left to the right and leave the SHAPE encoder at the far right position. You can hear how the treble content of the sound increases while the sound becomes ever thinner. At the far right position, the signal is no longer audible because the pulse width is equivalent to 0% and consequently the wave no longer oscillates.

Starting at the center position (12 o’clock) indicated by the sawtooth, turn the SHAPE encoder counter-clockwise towards the left. You can hear how the overtones are increasingly mixed out of the signal until you can only hear the root note. This sound is produced by a so-called sine wave, one of 64 other waveshapes that you have at your disposal for sound generation purposes. These waveshapes can also be activated via WAVE SEL/PW (WAVE SEL: Wave Select), PROVIDED THE SHAPE PARAME-

TER IS SET TO A POSITIVE HALF (LEFT) OF ITS CONTROL RANGE (EARLIER THAN 12

36 CHAPTER 4

Introduction

O’CLOCK). Regardless of the current SHAPE setting, you can also select a wave in the EDIT menu under OSCILLA- TOR 1 WAVE.

Go ahead and check out the different 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 (don’t forget about SATURA- TION and the corresponding function of the OSC VOL parameter), to get a feel for how the diverse waveshapes respond to ﬁltering, saturation and ampliﬁer modiﬁcations.

THE SECOND OSCILLATOR

ACCESS VIRUS RACK 37

The Second Oscillator

As we mentioned previously, in addition to the other sound sources, the Virus is equipped with a second oscillator which has more sound-shaping options than Oscillator 1.

Dial in the basic sound program that you had at the very beginning; change the ampliﬁer envelope to suit your taste. In the sound program, the OSC BAL (Oscillator Balance) parameter in the OSCILLATOR menu is preset to the far left. In order to hear Oscillator 2 in action, rotate the Value encoder to the right. Towards the center position (12 o’clock) you will hear how the tone is modiﬁed and as you rotate the encoder further to the right, how the intensity of this modiﬁcation is reduced. This effect is known as the comb ﬁltering effect. It occurs when two signals with the same frequency but different phase lengths are mixed. Press the same key on your keyboard several times with the OSC BAL set to the center position (12 o’clock). You should notice that each note has a slightly different tone. The oscillators are the source of this effect. The oscillators of the Virus oscillate freely , consequently every time you play a note, the phase constellation between the two oscillators is different. For now, leave OSC BAL at the center position (12 o’clock).

You are already familiar with Oscillator 1’s SHAPE and WAVE SEL/PW parameters. These functions are identical for Oscillator 2, so we won’t go into detail on them again.

Locate the encoder 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 encoder further to the right, how this vibrato effect increases until Oscillator 2 sounds distinctly out of tune with Oscillator 1. This wavering or vibrato-type effect has a popular traditional in synthesizers. It is used to achieve chorus effects, create sounds reminiscent of stringed instruments/ string sections or simply beef up the sound.

The SEMITONE encoder enables you to transpose Oscillator 2 by plus/minus four octaves in semitone steps while Oscillator 1 maintains the pitch. This feature is especially interesting when used in conjunction with two other oscillator functions: synchronization and frequency modulation.

Locate and activate the SYNC parameter in the OSCILLATOR 2 menu (Sync On). The synchronization function forces Oscillator 2 to restart its wave cycle at the same time as Oscillator 1 waveshape starts its cycle. The initial effect of this

38 CHAPTER 4

Introduction

measure is that the wavering tone that resulted from detuning and mixing the oscillator signals disappears.

The SYNC effect really becomes interesting when you transpose Oscillator 2 upwards in comparison to Oscillator 1 via the SEMITONE encoder. What happens is that the wave cycle of Oscillator 2 is interrupted as soon as Oscillator 1 starts its cycle. The pitch of the second oscillator no longer has the expected effect, instead it generates 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 modulation (FM). It generates new tonal spectra in which the signal of the ﬁrst oscillator controls the frequency of the second oscillator similar to the manner in which ﬁlters can be controlled via envelopes. And here too you have a encoder which allows you to control the intensity of: FM AMOUNT. Basically, this effect is similar to a vibrato, although here you’re dealing with an extremely fast vibrato featuring a frequency within the range of human hearing. This signal is not actually audible as a vibrato effect. Instead, you’ll hear a sound modulation, in some cases, a very drastic one at that. Choose the pure sine waveshape for Oscillator 2. In conjunction with the sine wave, the frequency modulation generates very clear, in some cases bell-like, spectra.

modulation (FM AMOUNT, to generate new harmonic spectra. Switch SYNC on and experiment with the FM AMOUNT. Also try out different SEMITONE settings and the diverse waveshapes of Oscillator.

The Virus is equipped with a third master oscillator that lets you create further oscillations and spectra. You can access the parameters of this oscillator, which are described in a later chapter, via the OSCILLATOR EDIT menu.

In the Virus you have the option of combining the two functions called oscillator synchronization (SYNC) and frequency

THE MIXER SECTION

ACCESS VIRUS RACK 39

The MIXER Section

You have already come across two parameters of the MIXER section: OSC BAL determines the mix ratio between Oscillators 1 and 2; in the left half of its control range, OSC VOL determines the master volume 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 acti- vated.

Now we’ll take a closer look at the SUB OSC parameter: It controls the volume of the third oscillator, the so-called SubOscillator, which always operates an octave below Oscillator 1.

The SubOscillator is mixed to the Oscillator 1 and 2 master mix signal as determined by the OSC BAL parameter. The master volume of the composite mix is controlled by the OSC VOL parameter. 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 signal source of the Virus is the Noise Generator (NOISE Volume). Please keep in mind that the level of the Noise Generator is not subject to the master volume controlled by

the OSC VOL parameter. In other words, it is audible even when OSC VOL is set to zero.

The VIRUS’ ring modulator is a new sound source. The output of the two oscillators is multiplied to create interesting sounds with rich enharmonic overtones. These overtones are highly dependent on the frequency coherence of both oscillators and it’s waveforms. The frequency coherence can be changed, for instance use the OSC2 SEMITONE parameter. To blend in the ring modulator use EDIT: RINGMODULATOR VOLUME (in OSCILLATOR 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 original oscillator signal can be leveled independently of the ring modulator. Be sure to check out what the ring modulator does when you select a sine wave for Oscillator 1 and 2.

Now we can go on and solve the mysteries of the signal ﬂow as determined by the FILTER ROUTING operating mode SPLIT: Here Oscillator 1 and the SubOscillator are routed to Filter-1, whereas Oscillator 2 and the Noise Generator are routed to Filter-2. Although the sound sources are split into two signal paths,

40 CHAPTER 4

Introduction

you can still control the volume levels of the different elements as well as OSC VOL in the usual manner.

THE LFOS

ACCESS VIRUS RACK 41

The LFOs

When you ﬁrst started this series of experiments with sounds, we promised that many of the functions the Virus can be “programmed” 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 modulation of Oscillator 2 via “preprogrammed” 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 automatically. And of course envelopes are great modulation sources, but you have to play a note every time you want to initiate an envelope. During 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 control) and tremolo (periodic volume control). Another option you might like to have at your disposal is random parameter control.

In the Virus, both of these tasks are executed by a so-called LFO (low frequency oscillator) that oscillates at frequencies below the audible range. An LFO is similar to the oscillators you have encountered thus far, but it oscillates signiﬁcantly slower so that its output signal is too low for human hearing. So what good are they if you can’t hear them? LFOs are used in much the same manner as envelopes, with the major difference that the are repeated indeﬁnitely.

42 CHAPTER 4

Introduction



LFO 1



The modulation targets

Start with the usual basic sound conﬁguration or chose a modiﬁed sound to suit your taste. Locate the RATE encoder in the LFO 1 section of the control panel. The VIRUS is equipped with an LED that indicates the speed of the LFO as well as its waveshape. Turn the RATE encoder and check out how the ﬂash of the LED indicates the change of pace as you rotate the encoder.

Currently you are unable to hear the effect of the LFO as its modulation intensity is set to 0 in the sound program. In order to change this setting, you must access the ﬁve parameters called LFO AMOUNT button which works with the modulation destinations Oscillator1,

Oscillator2, PulseWidth1+2, Resonance1+2 und FilterGain:

 OSCILLATOR1 refers to the frequency

of oscillator 1

 OSCILLATOR2 refers to the frequency

of oscillator 2

 PULSEWIDTH1+2 means that the

pulse widths of both oscillators are controlled in unison

 RESONANCE1+2 refers to the reso-

nances of both ﬁlters. Please keep in mind that although each set of these parameters is assigned a common modulation intensity, you can still dial in different sound-shaping settings manually. In other words, the audible result of a joint modulation varies according to the values you have determined for the other parameters.

 FILTERGAIN This term refers to the

input level of the ﬁrst ﬁlter (and of course the subsequent saturation level) - although WITHOUT THE LEVEL COMPENSATION CONTROLLED VIA OSC VOL. Here you can actually modulate a parameter that is not manually accessible. The effect of a FiltGain modulation is a periodic change in the saturation level which is linked to a corresponding tremolo (periodic change in volume). If the signal is not saturated in any manner , then the only audible result is a tremolo effect.

ACCESS VIRUS RACK 43

The LFOs

Modulate the ﬁve parameters separately and in combinations with different intensities. Try to anticipate 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 expectations. If you can fairly reliably predict the outcome of your sound-shaping efforts, you should have a handle on the information discussed thus far and can use your knowledge to create speciﬁc sounds you have in mind.

During the course of your experiments, it is entirely possible that you have generated modulations that have no effect whatsoever on the sound, for instance if you modulate 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 conﬁgurations conﬂict with each other and memorize the situation, problem and solution. If you make a habit out of this, you won’t panic when you run into similar situations; instead you’ll keep your cool, analyze the unexpected sound and ﬁx the mix.

You are currently using a triangle as the LFO waveshape. You shouldn’t have any problem associating the periodic up and down ﬂuctuation of the target parameter with this waveshape. Now activate the other available waveshapes for LFO 1 and try to picture the respective waveshape and associate it with the results of the modulation.

The third waveshape is a descending sawtooth wave. You can convert it into to an ascending sawtooth by simply dialing in the requisite negative modulation intensities (AMOUNT).

 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 continual

random modulation. Here the random values glide seamlessly 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 section’s 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 modulation intensities depending on the waveshape and modulation target (e.g. S&G +1 on OSC 1 or 2). However 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 polyphonic: If several notes are played simultaneously, these are controlled by dedicated LFOs, each with a slightly varied rate. This effect livens up the sound of

44 CHAPTER 4

Introduction

chords, especially when they are sustained. To enhance this effect, activate the LFO 1 KEY FOLLOW.

This function enables you to control the rate of the LFOs via the pitch, or more accurately, via the MIDI note number, so that higher notes generate faster LFO rates. As result, when you press and hold several notes you will hear all kinds of substantially different periodic ﬂuctuations.

Finally , the LFOs can also be used as additional envelopes. The control feature for this effect is the ENV MODE button. When you press this button, two things occur: For one, the LFO no longer initiates its cycles periodically, but only once at and in sync with the 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 direction 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.

also lets you determine the temporal relationship between attack and decay; in other words, their respective rates.. Dial in the desired speed via the RATE encoder.

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 encoder has no effect); S&G works in the same manner although in this case the RATE value is crucial. It determines the amount of time it takes to glide from the previous to the new random value.

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 available modulation targets. Using the LFO Contour encoder in the LFO section, you can have the ”ramp” rise or fall exponentially. If you choose a triangle for your waveshape, the device will generate an ascending phase (attack) and a descending phase (decay). LFO Contour



LFO 2

The design of the second LFO is essentially the same as the ﬁrst, so we’ll spare you the repetition of details SHAPE 1 and 2 are available as a joint modulation target; the ﬁlter frequencies and the Panorama position can be manipulated individually. You may also freely select a parameter for your modulation destination.

ACCESS VIRUS RACK 45

The LFOs

46 CHAPTER 4

Introduction

VOLUME AND PANORAMA



Position

You probably noticed that the many of the sound shaping options available in the Virus occasionally inﬂuence the volume level. For instance, an unﬁltered sawtooth is naturally louder than a highly ﬁltered sawtooth because whenever you blend a part of the frequency spectrum out of the mix, you are automatically reducing the overall volume of the signal. This is why the Virus is equipped with a programmable volume parameter for each SINGLE PROGRAM. It enables you to balance out the volume levels of your sound programs.

Volume and Panorama

Its value is set to 100 so that you have a reserve or headroom of 27 volume increments when you are dealing with highly ﬁltered sounds.

You have already dealt with the Panorama position as a modulation target of LFO 2. Here you can not only modulate it, but also determine settings manually. For this purpose, use the parameter PANORAMA which is also located in the COMMON section of the EDIT menu. Like many other parameters, Panorama is a starting point for modulations. For instance you can modulate the Panorama position 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 Panorama position shift to the right.

Locate the parameter PATCH VOLUME in the COMMON section of the EDIT menu.

01111111111111111112

1 COMMON PatchVolume 100≤

61111111111111111154

VELOCITY

ACCESS VIRUS RACK 47

Velocity

Velocity is one of the preferred modulation sources of keyboard players: A light key attack generates a low velocity value for the given note, a heavy touch generates a high velocity value. In the Virus you have ten modulation targets available for Velocity. Locate the VELOCITY section in the EDIT menu.

01111111111111111112

1 VELOCITY Osc1Shape +0≤

61111111111111111154

There you will ﬁnd the modulation intensities for:

OSC 1 SHAPE OSC 2 SHAPE PULSE WIDTH FM AMOUNT FILT 1 ENV AMT

which you can manipulate independently 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.

FILT 2 ENV AMT RESONANCE 1 RESONANCE 2 VOLUME PANORAMA

48 CHAPTER 4

Introduction

UNISON MODE

When we talked about the oscillators, we mentioned that by subtly detuning signals, you can beef up sounds and achieve string-like sounds. The Virus is equipped with features that allow you to take this type of tonal manipulation a step further. On of these is the so-called UNISON MODE. It enables you to initiate two or more voices for each note played, which in turn lets you detune many oscillators. UNISON MODE also offers the option of spreading the voices generated by one note in the stereo panorama and shifting the phases of their LFOs so that all types of periodic effects can be used to produce an even more exciting signal.

Locate the parameter group UNISON in the EDIT menu.

01111111111111111112

1 UNISON Mode Twin≤

61111111111111111154

UNISON mode determines how many voices the Virus will use to render a played note. In a nutshell, 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 distributes them uniformly across the stereo panorama, a process by which you can also determine the width of a sound’s stereo base. When you activate UNISON

mode for a sound, it can still be played polyphonically. However, depending on the number of voices you’ve dialed in, its polyphony will of course be considerably reduced in UNISON mode. The most efﬁcient and the standard setting is UNISON mode = Twin, where two voices are played for every note. In the ”OFF” position, one voice per note is played.

THE CHORUS/FLANGER EFFECT

ACCESS VIRUS RACK 49

The Chorus/Flanger Effect

Another function that delivers great effects based on pitch ﬂuctuation is the so-called chorus effect. Chorus actually consists of a brief delay (generally up to approx. 50 ms) which is varied periodically. By modulating the delay, the delayed signal is slightly detuned to the input signal (the so-called Doppler effect). This inconsistency in pitch between the original and effects signal is the source of the chorus effect. Feedback in the delay line enhances this effect. The left signal side is automatically modulated in a different manner than the right, so a chorus effect is great for converting mono signals into stereo signals.

If the delay is less than approx. 10 milliseconds, than the effect is called ﬂanging or a ﬂanger effect rather than chorus. In this case feedback is even more signiﬁcant because it generates resonances that can be modulated and is thus yet another source of radical sound effects. If you determine high feedback values, you can clearly hear how the two sides of the signal are modulated differently - in reverse phase - by the LFO.

CHORUS DIR/EFF determines the balance between the original signal and the processed signal. The parameters RATE and SHAPE control 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 parameter’s negative control range lets you dial in softer characteristics for the ﬂanger. Please keep in mind that the Chorus section in the Virus is fully stereophonic: Stereo positions as well as panorama modulations and stereo spread values that you have dialed in elsewhere remain intact in the effects signal.

Locate the parameter group CHORUS in the EFFECTS menu.

01111111111111111112

1 CHORUS Dir/Eff OFF≤

61111111111111111154

50 CHAPTER 4

Introduction

THE DELAY EFFECT

A delay effect is traditionally used to generated an echo of the input signal. Locate the parameter group DELAY in the EDIT menu.

01111111111111111112

1 DELAY EffectSend 0 ≤

61111111111111111154

Here you ﬁll ﬁnd parameters that are virtually identical to the parameters of the CHORUS group. Do not allow yourself to be confused by the slightly different terminology: The delay time is set via the parameter entitled TIME (equivalent to DELA Y in the CHORUS section); the other features are FEEDBACK with a dedicated LFO and the familiar parameters RATE, DEPTH and SHAPE.

Only two functions in the Delay section are different to the Chorus section: For one, it features an EFFECT SEND instead of the balance parameter DIR/EFF. EFFECT SEND is especially signiﬁcant in MULTI MODE, where several PARTs with different levels are patched through the same delay effect.

similar detuning effects. A stereo effect is achieved via different modulations of the left and right sides of the signal.

For the other, LENGTH enables you to create substantially longer delay times, for instance to achieve complete echoes (maximum of 693 ms) that are fully audible. The LFO allows you to modulate the delay as you would the chorus to achieve

MORE TO COME

We have come to the end of these detailed instructions for novices. We hope we were able to help you become a bit more familiar with your new synthesizer and gain some conﬁdence in how to handle it. As we mentioned earlier, this is just an introduction and does not cover all the functions and features of the Virus, only the basic components and how they affect the sound of the Virus. You should now be able to come to terms with the in-depth look at the Virus in the following section.

ACCESS VIRUS RACK 51

More to Come

52 CHAPTER 4

Introduction

Concept and Operation

54 CHAPTER 5

Concept and Operation

OPERATING MODES

In the Virus you can select from two ba5sic operating modes, SINGLE MODE and MULTI MODE.

In SINGLE MODE, the Virus is able to generate a single sound program only. All 16 voices, all effects and all control features (with the exception of the MULTI button) function in conjunction with this one sound program. You might say a SINGLE program is a combination of all functions and effects that determine the sound of the Virus. In other words: A SINGLE program is a ”sound” of the Virus, that can be stored and recalled.

The Virus provides access to 512 SINGLE sounds. Next to the 256 RAM sounds (Bank A and Bank B), you have two banks available with a total of 256 factory sounds. These banks, C and D, are stored in the FLASH ROM and can not be overwritten via STORE.

The MIDI receive channel in SINGLE MODE is the Global Channel. You can change the Global Channel in the CTRL menu.

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 channels, output assignments, etc.

In MULTI MODE, the Virus can combine up to sixteen (SINGLE) sound programs, among which the maximum available number of 16 voices are allocated dynamically. All simultaneously available sounds can be manipulated in real-

THE MULTI-SINGLE MODE

ACCESS VIRUS RACK 55

The Multi-Single Mode

While being in MULTI Mode, you’re unable to change the SINGLE programs directly, which would admittedly be a handy option when you’re working with a sequencer. This is why the Virus features MULTI SINGLE mode, which, strictly speaking, is more an alternative 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 you’ll 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 channel. You can process the currently selected PART or, more accurately , edit its sound, using the control features. The menus let you access the usual SINGLE parameters. You’ll always see the number of the selected PART on the upper left in the display. The PART buttons don’t actually change sounds, they simply set the user interface of the Virus to the desired PART. Irrespective of the given setting, all PARTs can be controlled simultaneously via MIDI. Consequently, MULTI SINGLE mode, which makes handling so much easier, is the ideal choice when you’re working with a connected sequencer.

Please bear in mind that MULTI SINGLE mode is really just another view of the normal MULTI mode. MULTI SINGLE mode doesn’t offer a unique data type for storing sounds, it always works with the MULTI program currently selected in normal MULTI mode. All of the normal MULTI mode parameters (keyboard zones, etc.) remain intact and in force even though you can’t 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 SINGLE mode view, simply press the MULTI and SINGLE buttons simultaneously.

When you’re working with a sequencer, start with a MULTI program that features neutral settings for its ”administrative” parameters, for example, the MULTI program M0 Sequencer. Here the PART numbers are identical 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 SINGLE mode when you want to store the MUL TI program, for example, to save the current global delay/reverb setting. In MULTI mode, these settings are not stored along with SINGLE sounds.

56 CHAPTER 5

Concept and Operation

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

The MULTI mode parameters feature a dedicated menu called the Multi Edit menu. Access it by pressing the Multi button while the device is in MULTI mode. The LED located over the MULTI button will light up to indicate that the Multi Edit menu is active. Press the MULTI button again to return to normal Play mode. If the device is in MULTI-SINGLE mode, press the MULTI and SINGLE buttons simultaneously to access the Multi Edit menu. It sufﬁces to press either the MULTI or SINGLE button to return to normal Play mode from MULTISINGLE mode.

THE EDIT BUFFERS

ACCESS VIRUS RACK 57

the Edit Buffers

Whenever you play or edit a SINGLE 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 buf fer . 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.

 It lets you edit copies of sounds with-

out sacriﬁcing the original sounds.

 Edit buffers can be stored in a

sequencer and sent from it to the Virus independently of the sounds stored in the device [“Dump - The Sound in the Song” on page 176]

 In MULTI-Mode (or MULTI-SINGLE-

Mode) the same SINGLE-program can be recalled and edited on different parts. In this case all involved EDITbuffers contain variations of the same

original sound.

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 in the SINGLE program banks.

This type of edit buffer is used in most synthesizers; its advantages are many:

58 CHAPTER 5

Concept and Operation

Operation

60 CHAPTER 6

Operation

PARAMETER SELECTION AND DATA ENTRY

The parameters of the Virus Rack are controlled via the ﬁve encoder knobs. The functions of this row of knobs may be assigned to seven parameter groups that are indicated visually by the seven LEDs located to the left of the encoders.

Here's a brief explanation of the parameter groups:

OSC The oscillator section

EFX The effect section EDIT Here you'll ﬁnd various

peripheral sound parameters

ARP/ CTRL

Select parameter groups by means of the two vertically arrayed UP and DOWN buttons located next to the seven LEDs. The function of the knobs corresponds to the respective label on the selected parameter group and/or row.

The Arpeggiator section as well as organizational parameters

FILT The ﬁlter section ENV The envelope section LFO The LFO section

The left knob is labeled "VALUE"; this is a special feature that requires some explanation:

ACCESS VIRUS RACK 61

Parameter Selection and Data Entry

This knob is not labeled on the panel with a parameter name that indicates its purpose. Instead, the name of the parameter and its function is shown in the display . Apart from the envelope section, each of the parameter groups features these peripheral parameters that are grouped in menus. These are ancillary parameters that complement the directly accessible parameters. They may be selected via the PARAMETER buttons and controlled via the aforementioned VALUE knob or the two VALUE buttons.

In order to return to the current Play mode (MULTI, SINGLE or MULTI-SINGLE), press the MULTI or SINGLE button. Then you can switch programs as usual via the VALUE buttons; the VALUE knob is now disabled.

In Play mode, the other four knobs have the same function as in the EDIT parameter group. Accordingly, you can access Filter Cutoff, the two Deﬁnable knobs and Master Volume directly.

If you want to return to the previously selected parameter group or to the previously edited parameter, simply press the UP or DOWN button.

When you call up a parameter in the display menus, you will also determining the function of the dedicated knobs (those with the ﬁxed labels). If, for example, you select the LFO section, then the menu of one of the three LFOs is indicated in the upper line of the display . The parameter that is controlled via the VALUE knob or buttons is indicated in the lower line. When you select the LFO menu, you must also determine which LFO is to be controlled by the dedicated knobs. So if you want to use these labeled knobs to control the functions LFO Rate, Shape, Contour and Keyfollow for LFO 2, you must use the PARAMETER buttons in the display to dial in one of the parameters of LFO 2. This selected parameter may then be edited via the VALUE knob. At the same time, you can control LFO 2's Rate, Shape, Contour and Keyfollow via the four remaining knobs.

62 CHAPTER 6

Operation

Once you've selected a parameter group or section, the individual LEDs located next to the knobs indicate whether or not the knobs are assigned a function in the currently active menu.

This means that if, for example, you edit LFO 3 in the LFO section, then the parameters Rate, Shape and Keyfollow are directly accessible as is the case with LFO 2. However, LFO 3 does not feature the Contour parameter. Consequently, the LED of the Contour knob will not light up since the knob serves no function in this situation.

parameter groups in the direction of the button that you are holding down. This handy feature lets you swiftly go from one parameter type to another, for instance, from all chorus-related to all delay-related parameters. If you also hold the second parameter button down, the menus will automatically scroll in the selected direction. Once you’ve scrolled to the desired parameter group, simply select the desired parameter by pressing the button brieﬂy. You can also step through the parameters by repeatedly pressing the same menu button.

If you press the PARAMETER buttons brieﬂy, you can scroll through the parameters contained in the selected display menu step by step in the desired direction. If you press and hold one of the parameter buttons for a bit longer, the display will automatically scroll through the list of parameters in the given menu. When you press and hold one PARAMETER button and then press the other PARAMETER button, the display will scroll through the menu in

The menus, particularly the EFFECTS menu, contain parameter groups that are related by virtue of their function, for instance, all parameters that are used to control the chorus. When you switch the chorus off (CHORUS Dry/Eff = OFF), all chorus parameters are of course irrelevant and will no longer appear in the menu. In other words, when the chorus is disabled, you can’t view its parameters. The reason for this is to make menus clearer and less cluttered.

ACCESS VIRUS RACK 63

Parameter Selection and Data Entry

The VALUE +/- buttons let you change the value of the selected parameter in steps. When you hold one of these buttons down, the value changes automatically and the longer you hold the button, the faster the pace of the value change. You can increase this pace even further by pressing and holding one VALUE button and simultaneously pressing the other VALUE button. If you press and release both VALUE buttons simultaneously, the parameter is set to its default value (mostly zero). This pertains to unipolar parameters (value range of 0 to 127) as well as bipolar parameters (value range of -64 to +63).

Located next to some of these parameters, you’ll see the abbreviations ”ENA” and ”DIS”. The option ENA means enable and DIS means disable.

well as the current value are displayed for parameters that feature a dedicated knob.

The Virus Rack features numerous parameters. Many of these you can occasionally do without because they are not absolutely essential to basic sound programming, and they do tend to make the device a little more challenging to handle. EXPERT mode can solve this problem. It lets hide and show rarely used parameters in the display menus. You'll ﬁnd the display for EXPERT mode in the ARP/CTRL menu; it is the last parameter in the list. In the chapter "The Parameters", those parameters that belong to EXPERT mode are labeled [XP].

The triangular icon located next to the parameter value indicates in which direction you have to change a value if you would like to reset the parameter to the value that has been stored to date. The previously stored parameter value as

64 CHAPTER 6

Operation

DISPLAY OF VALUES

When a menu is active, different display options are available for parameters with a dedicated knob. These can be selected under the menu item KNOB DISPLAY in the CTRL menu:

 OFF Knob movements are not dis-

played; the current contents of the display remain intact when you turn a knob.

 ON The lower row of the display is

being overwritten by the parameter's value.

 SHORT When you turn a knob, the cur-

rent contents of the lower display line are brieﬂy overwritten by data representing the change in parameter value; once the action is completed, the original contents reappear in the lower display line.

 LONG Same as SHORT, except that -

you guessed it - the display shows the knob data for a longer period of time.

 ON The contents of the display are

overwritten when you turn a knob; the original menu does not reappear in the display.

01111111111111111112

1 SYSTEM KnobDispl Short≤

61111111111111111154

All About The Memory

66 CHAPTER 7

All About The Memory

STORE

The mode structure of SINGLE, MULTI and MULTI SINGLE MODE is mirrored in the STORE functions: In SINGLE MODE, STORE saves the current SINGLE PROGRAM; in MULTI MODE, STORE saves the current MULTI PROGRAM; and in MULTI SINGLE MODE, the SINGLE PROGRAM of the current PART is stored.

The STORE process is always the same regardless of the operating mode: Press STORE. You then gain access to the STORE menu. There you can use the PARAMETER buttons to move among the individual letters in the lower name entry line and the number of the destined memory location as well as the bank number in the upper line. Use the VALUE button to make entries. The term in the upper display line indicates the name of the memory location which you will overwrite when you store the program.

. To belabor the point, when you store

a MULTI program, only the content of the MULTI edit buffer is saved, not however the sound programs in the PARTs. These must be stored individually in MULTI SINGLE mode.

Once all of the entries correspond to the data you have in mind, press STORE again to conclude the process and return to the previously active operating mode of the Virus. If for whatever reason you change your mind and want to cancel the operation, simply press SINGLE or MULTI to return to the previous operating mode without storing the program.

If you want to store the SINGLE programs in the PARTs to their original slots in the SINGLE banks all at the same time, simply press STORE and 1 C126 - Init

01111111111111111112

1 C126 - Init [STORE] TO...

61111111111111111154

COMPARE

When you press STORE and then UP or DOWN, you will activate Compare mode. After you have programmed or edited a SINGLE sound, Compare mode lets you hear the unedited sound that was originally stored in this memory slot. Press UP or DOWN repeatedly to switch back and forth between the Compare sound and the edited sound so that you can - surprise, surprise – compare the two sounds. Use the PARAMETER/BANK buttons and the VALUE buttons to step through the bank and program numbers of the Compare sound. This lets you search for a new memory slot for the edited sound and, at the same time, hear the sound that you will overwrite. The edited sound is not modiﬁed or overwritten during this process. Press STORE to do just that to the edited sound – store it. Press MULTI or SINGLE to quit the STORE process and/or exit Compare mode.

ACCESS VIRUS RACK 67

Compare

01111111111111111112

1 C126 -Init compare

61111111111111111154

68 CHAPTER 7

All About The Memory

Modmatrix And Deﬁnables

70 CHAPTER 8

Modmatrix And Definables

CREATING MODULATIONS VIA ASSIGN

As a rule, it is of course desirable to be able to create modulation routing conﬁgurations on a synthesizer. In other words, you want to enjoy the freedom to combine different modulation sources and destinations as you see ﬁt. Sometimes you may come up with ideas for standard modulations that the ”hardwired” factory modulation routing options simply can’t satisfy. This is why we opted to equip the Virus with a versatile Modulation Matrix – you’re sure to ﬁnd it a welcome addition. On the Virus, you can create modulation routing conﬁgurations freely as you see ﬁt using ASSIGN options. They are located in the EDIT menu, where they appear under the name of – you guessed it – ASSIGN).

The three ASSIGN options let you control up to six modulation destinations via up to three modulation sources. Simply go to ASSIGN, select one of the modulation sources (SOURCE) and one or several modulation destinations (DESTINATION). Each of these conﬁgurations features a parameter that determines modulation intensity (AMOUNT). ASSIGN 1 can control one modulation destination, ASSIGN 2 can control two and ASSIGN 3 can control three modulation destinations, each with independent AMOUNTs.

the keyboard’s modulation wheel, to the desired parameter. Y ou can also chose to use the sound generator’s internal modulators, such as LFOs and envelopes, as modulation sources. The control range of the source may be limited via the AMOUNT values or inverted so that the modulation occurs strictly within the desired value range for the target parameter. For your target parameters, you can chose from among virtually all sound parameters that feature an inﬁnitely variable control range – ergo, you have more than 100 modulation destinations at your disposal! Since the sources and destinations may be selected independently , you may even modulate a single parameter by using up to three modulation sources simultaneously. For this purpose, the control signals of the modulation sources are added up or overlapped. Conversely, you can also modulate up to six parameters with just one controller, which gives you all kinds of sophisticated sound morphing options. For this purpose, select the same source for all three ASSIGN options so that it modulates all six possible destina-

These ASSIGN options serve several purposes: for one, they let you assign an external MIDI controller, for example,

tions. This lets you radically reshape sounds and even transform or morph them into entirely different sounds.

01111111111111111112

1 ASSIGN Source OFF≤

61111111111111111154

. You’ll ﬁnd a list of available sources

and DESTINATIONS in the appendix. [“Appendix” on page 203]

ACCESS VIRUS RACK 71

Creating Modulations via Assign

72 CHAPTER 8

Modmatrix And Definables

THE DEFINABLE KNOBS

The Virus is equipped with two knobs that, rather than being dedicated to predeﬁned tasks, may be assigned to different parameters by you, the user. This option is quite handy, for it lets you control directly the many menu parameters that do not feature a dedicated knob.

These DEFINABLE knobs operate in three different modes:

 GLOBAL The knob controls the param-

eter that you have set to Global in the DEFINABLE menu regardless of what the other settings and the selected SINGLE program may be.

this program. If, however, you have not selected a parameter for this program (DEFINABLE Single = OFF), the setting for DEFINABLE Global is automatically enabled.

 MIDICONTRL Here the controller num-

ber entered in the DEFINABLE MIDI menu is sent regardless of what the other settings and the selected SINGLE program may be. Comparable to a small MIDI fader box, this mode is used to control connected MIDI devices. Note that this information is not processed internally in the Virus.

The setting for the actual DEFINABLE mode is global. Under normal circumstances, you should set DEFINABLE mode to ”Single” because this is the most versatile mode. When you select a SINGLE sound whose DEFINABLE mode is set to ”Single”, this setting is of course enabled. If not, Global DEFINABLE mode is enabled.

01111111111111111112

1 DEFINABLE 1 Mode Single≤

61111111111111111154

 INGLE The knob controls the parame-

ter that you have set to Single in the DEFINABLE menu. The setting for this parameter is stored in the SINGLE program and called up whenever you select

Master Clock And Midi-Clock

74 CHAPTER 9

Master Clock And Midi-Clock

MASTER CLOCK AND MIDI-CLOCK

The Virus is equipped with a global clock generator that lets you sync the LFOs, arpeggiators and delay up to a common song tempo and rhythm. The clock generator works either internally with a freely variable speed or it can, in turn, by synced up to the MIDI clock of an external sequencer. This synchronization occurs automatically when the device receives a MIDI clock signal via its MIDI In. You can vary the speed of the clock generator within a range of 63 to 190 BPM (beats per minute) via CLOCK TEMPO. When the device is synchronized via MIDI clock, the clock generator automatically accepts the speed dictated by the connected sequencer; the internal tempo setting is in this case meaningless and thus disabled. The individual sections of the Virus are synced up to the clock generator at rhythmic intervals such as 1/16, 1/4 and so forth. These values may be assigned individually for every section. (ARPEGGIATOR CLOCK, CLOCK LFO 1, CLOCK LFO 2, CLOCK LFO 3, DELAY CLOCK, see the respective sections).

In SINGLE MODE, CLOCK TEMPO pertains to the current SINGLE PROGRAM and is stored along with it. In MULTI MODE, the CLOCK TEMPO settings for the involved SINGLE PROGRAMs are ignored. Instead, all involved SINGLE PROGRAMs are controlled via the same clock generator. Its

CLOCK TEMPO is saved in the MULTI PROGRAM (as are the settings for the global delay effect).

This feature lets you control the LFOs and arpeggiators of several MULTI P ARTS in a common rhythmic context.

. A small symbol will appear in the dis-

play

. When the Virus is receiving MIDI

Clock data. If you’re sure you do NOT want the device to be synchronized automatically to MIDI clock, set MIDI CLOCK RX to Off (in the CTRL menu).) To avoid confusion, please keep in mind that MIDI Clock is not the same thing as MIDI Time Code. The latter doesn’t deal with tempo at all but with time-related information structured in hours, minutes, seconds, etc. which is of no beneﬁt to you in this context.

The Effects Section

76 CHAPTER 10

The Effects Section

THE EFFECT SECTION

For every SINGLE program and every PART, you can access two stereo effects individually. You’ll ﬁnd these effects – analog boost and chorus – in the aptly named EFFECTS menu.

The vocoder and the delay/reverb section are each available just once, but you can address them individually via the PARTs’ Effect Send parameter. In the signal path, all effects are connected in series in accordance with their sequence in the Effects menu.

Each SINGLE program contains its own settings for the delay/reverb section. In MULTI mode, the sound programs involved share the same delay/reverb section. For this reason, the parameter values are determined by the settings of the currently active MULTI program (also see [“EFX Section” on page 115]).

Audio Inputs

78 CHAPTER 11

Audio Inputs

AUDIO INPUTS

You can also opt to use external audio signals in place of the on-board oscillators for the sound programs or MULTI PARTs. The Virus is equipped with two inputs for external signals. Y ou can route these to its sound generating components (the ﬁlters, the saturation stage as well as the volume and panorama stage) or patch them directly to the effects section of the Virus. External audio signals may also be used as carrier or modulator signals for the vocoder. Any PART that you use to process an external audio signal in MULTI mode can, like every other PART, be routed freely to one or two of the four audio outputs.

The Virus Rack is equipped with two audio inputs on the back panel. Additionally the left input is accessible on the front panel. When you plug a cord into the front input, the rear left input is disabled.

As a rule, when you’re processing external audio signals, you need to distinguish between the following two operating modes:

to 100%, the resonant frequencies of the ﬁlters and oscillators can be played in a tempered manner via the INPUT signal. This lets you play entire chords as well as arpeggiator lines using the ﬁlters. The noise generator is also active in INPUT mode.

 STATIC In Input Static mode, the exter-

nal audio signals are audible via the output without having to trigger a note. Bear in mind that the oscillators as well as all functions that have to do with trigger and pitch are disabled (envelopes, LFO Env mode, Keyfollow...) In INPUT Static mode. When you set the device to this mode, one voice of the Virus is activated automatically. If you select a stereo source (L+R) for INPUT Select, two voices are activated much like in UNISON mode: T win. In this case, you can also use the UNISON Pan Spread parameter to determine the basic width of the panorama and UNISON LFO Phase to shift the LFO phase position between the voices.

 DYNAMIC To make external signals

audible in this operating mode, the volume envelope must be triggered via a note. This option, for example, lets you create typical gater effects. INPUT Dynamic mode is also polyphonic. If you set the KEYFOLLOW value for the ﬁlters

 TOEFFECTS An alternative to INPUT

Static mode, here the audio signal is routed directly to the effects section of the SINGLE program or PART. This mode doesn’t use the voices of the Virus, which means that its polyphonic performance remains fully intact and available. The ﬁlter section is unavailable in this mode.

01111111111111111112

1 INPUT Mode Dynamic≤

61111111111111111154

ACCESS VIRUS RACK 79

Audio Inputs



OSC Volume / Input

When one of the two INPUT modes is activated, the OSC VOL parameter rather than the oscillators controls the level of the INPUT signal in front of the Filter section and of course also the gain of the SATURATION stage. In INPUT Dynamic mode, the level increases quite rapidly when you play several voices polyphonically. The reason for this is that – in contrast to when you’re dealing with several oscillator signals – the voices are correlated because they are receiving an identical input signal. In the event that the Virus generates distortion when you’re dealing with this type of signal routing set-up, be sure to back off the input level a tad via the OSC VOL knob.

80 CHAPTER 11

Audio Inputs



Input global Settings



Input Level Indicator

In the Input menu, you'll ﬁnd a gain switch (INPUT Gain) that increases the input signal by 20 decibels before it is sent to the digital analog converter. This means that with the proper cords you can connect a microphone, an electric guitar or a record player directly to the Virus Rack. However, to attain the best possible sound quality, it is advisable to patch the signal into an appropriate signal processor such as a microphone preampliﬁer , a mixer, or a guitar preamp before you route it into the input of the Virus. Please turn down the Master Volume knob before you turn input gain up. Be aware that boosting the signal by 20 decibels increases the level tenfold!

Additionally the Virus is equipped with an ampliﬁer stage (INPUT Boost), that can boost the signal level of the two inputs continuously by up to 36 dB. The signal is boosted in the digital section of the Virus, so the noise level of the analog-digital converters increases automatically. Consequently you should dial in the cleanest, loudest possible signals at the external sound generator, or use the INPUT Gain switch.

Alternatively, the RATE LEDs of LFO 1 and 2 can also serve as level indicators for the left and right external audio inputs. The Virus automatically switches to this level indicator mode when the selected SINGLE program accesses the external audio inputs. The LEDs will ﬂash rapidly to indicate that the inputs are being overloaded. You should dial in the proper level on the device that is sending the analog signals. The reason for that you want to feed the highest possible clean signal level to the analog-todigital converters of the Virus so that they will deliver the best possible performance ( Siehe “LED Mode” auf Seite 155).

Since record players have a characteristic frequency response, we equipped the Virus Rack with a suitable Phono equalizer. It may be activated via the "INPUT Phono" parameter.

Audio Routing

82 CHAPTER 12

Audio Routing

THE AUDIO OUTPUTS

In MULTI mode, you can choose a mono or stereo audio output in the OUTPUT Select menu independently for every PART.

In contrast to the majority of other effects, the delay/reverb section is not available individually for each PART. Instead, it processes the signals of the PARTs collectively. You can, however, control the intensity of the effect individually for each PART using the respective Effect Send parameter. Consequently, the delay/reverb section has just one signal output, which cannot be distributed to the outputs of the individual PARTs.

This is why , for example, the delay ef fect of a PART that is routed to the pair of outputs labeled OUT 2 will still be audible on OUT 1. This can be desirable yet may also lead to confusion. To encourage the former and prevent the latter, set the Effect Send parameter of the PART to zero when you’re using individual outputs.

In MULTI mode, the delay/reverb section feature its own OUTPUT Select that is independent of the PARTs.

86 CHAPTER 14

Random Patch Generator

RANDOM PATCHES

The RANDOM PA TCH GENERA TOR can be used to generate a new sound automatically or a modify an existing sound at random. The PAR DEPTH and AMOUNT parameters let you determine how radically the sound is changed. Depending on the values that you set here, the RANDOM PATCH GENERATOR will do anything from modifying sound parameters subtly to morphing one sound into an entirely different sound.

The RANDOM PATCH GENERATOR is activated when you presses the button STORE while the display is showing one of the two RANDOM parameters. The results of the computation are stored in the Edit buffer and can be heard immediately. You can also press STORE several times in order to create successive sound changes. If you want store a sound permanently that the RANDOM PATCH GENERATOR has created, simply save it to a SINGLE memory slot in the usual manner. For this purpose, press the SINGLE button to activate PLAY mode (SINGLE mode or MULTI-SINGLE mode) so that the STORE button’s original function is restored.

If you want to restart the process with the original sound settings, simply return to PLAY mode back and select the desired sound again.

PAR DEPTH This parameter determines the number of sound parameters that are inﬂuenced by the RANDOM PATCH GENERA TOR. If you enter a low value for PAR DEPTH, just a few parameters will be modiﬁed. Beyond that, the manner in which the few parameters are edited assures that the sound is manipulated “organically”. This simply means that it isn’t bent radically so that, for example, the given sound can still be played “tonally”.

As you increase the values for PAR DEPTH, other parameters that have a greater impact on the timbre of the sound are changed. At higher values, the RANDOM PATCH GENERATOR tends to generate noise-like sounds or special effects.

01111111111111111112

1 RANDOM [STORE] ParaDepth 0≤

61111111111111111154

AMOUNT This parameter determines the intensity of the RANDOM PATCH GENERATOR’s effect on the sound parameters. At lower values, sound changes are fairly subtle, but you can intensify the effect

by repeatedly pressing the STORE button. Higher values introduce fundamental changes to the sound.

01111111111111111112

1 RANDOM [STORE] Amount 0≤

61111111111111111154

. Be aware that RANDOM PAR DEPTH

and RANDOM AMOUNT are not actual sound parameters. They merely set the parameters for the RANDOM PATCH GENERATOR and only take effect when the RANDOM PATCH GENERATOR is activated. Not until then will the sound be changed.

ACCESS VIRUS RACK 87

Random Patches

88 CHAPTER 14

Random Patch Generator

Additional Functions

90 CHAPTER 15

Additional Functions

ADDITIONAL FUNCTIONS



The Virus features a Panic function to remedy stuck notes caused by MIDI transmission parity errors and the like. When you press the POWER and the STORE button simultaneously, then all voices of the Virus that are still sounding will be released.

Panic Function

A double-click on both buttons initiates a controller reset. The various voices that are still sounding will be cut off instantly and controllers such as the modulation wheel, channel volume and pitch bender are reset to the default settings.



Audition function

On the Virus panel, you can trigger notes without using a keyboard. When you press the UP and DOWN buttons simultaneously , the Virus will play the note C3. If you hold the buttons down for longer than a second, the note will continue to sound after you release the buttons.

ACCESS VIRUS RACK 91

Additional Functions



Reset Function

If you get the impression that the VIRUS is behaving unstable or indeed strange, we suggest you perform a system reset. Holding the PARAMETER LEFT button while switching the VIRUS on, performs a system reset. No data will be lost during this procedure, although some global system settings as ”Global Channel” will be reset.

92 CHAPTER 15

Additional Functions

The Parameters

94 CHAPTER 16

The Parameters

OSC SECTION (ENCODER)

The following section lists all parameters in the Virus, each with a brief deﬁnition or explanation.

. In case, a parameter is only available

in the Expert Mode, the preﬁx [XP] has been used in front of the parameter’s name.

The function of the Encoders depends on the selected section and the currently active display menu. If the given Encoder does not have an assignment, the corresponding LED on the front panel will extinguish. If no menu is activate (none of the seven section LEDs is illuminated), then the Encoder assignments are determined by the Edit section.

EXPERT MODE: The Virus Rack features numerous parameters. Many of these you can occasionally do without because

they are not absolutely essential to basic sound programming, and they do tend to make the device a little more challenging to handle. EXPERT mode can solve this problem. It lets hide and show rarely used parameters in the display menus. In the chapter "The Parameters", those parameters that belong to EXPERT mode are labeled (XP). When EXPERT Mode is switched to "Off", then those parameters are hidden.



Oscillator 1

SHAPE This control feature lets you

determine the waveshape for the WAVE section (one of 64 variable spectral waveshapes). The waveshape is inﬁnitely variable from sawtooth through to pulse waves. Wave or pulse width selection is executed via the SHAPE and WAVE SEL/ PW control features (see appropriate section): If SHAPE has a value less than the value of the center position, then WAVE SEL/PW determines the waveshape; if the SHAPE value is higher than that of the center position, then WAVE SEL/PW determines the pulse width.

ACCESS VIRUS RACK 95

OSC Section (Encoder)

SEMITONE Determines the interval between the second oscillator and the ﬁrst oscillator: Control range +/-48 semitones, assigned in semitone steps.



Oscillator 2

SHAPE Same as OSCILLATOR 1; see para-

graph above.

W AVE SEL/PW has two functions, depending on the SHAPE (see appropriate section) value:

 When SHAPE has a value lower than

that of the center position, then WAVE SEL/PW lets you select from the 64 spectral waveshapes available in the ROM of the Virus. Waveshape 1 is a sine wave; No. 2 a triangle, the remainder of the waves feature different combinations of frequencies.

 When the SHAPE value is higher than

that of the center position, then WAVE SEL/PW determines the pulse width: At the far left position the pulse width is 50%, at the far right it is 0%, which means the wave no longer oscillates.

WAVE SEL/PW Same as OSCILLATOR 1; see paragraph above.

SEMITONE Same as OSCILLATOR 1; see paragraph above.

DETUNE Detunes the second oscillator relatively to the ﬁrst. With this parameter , you can dial in everything from slight deviations in pitch to major ﬂuctuations between the two oscillators.

96 CHAPTER 16

The Parameters

OSC SEKTION (MENU)



Oscillator 1

upwards by one octave for every two ascending octaves you play (quarter note scale); at 0 the keyboard control option is off. Negative values generate opposite control intensities.

WAVE Selects among of 64 spectral waveshapes. This parameter is identical

to WAVE SEL/PW (see appropriate section) when SHAPE (see appropriate section) is set to the left half of its control range. However, in contrast to WAVE SEL/PW, WAVE is always available regardless of the current SHAPE setting.

01111111111111111112

1 OSCILLATOR1 Wave Sin≤

61111111111111111154

[XP] KEY FOLLOW Determines the intensity of the pitch control via the keyboard: At the value +32 (standard setting) the oscillator is controlled normally, i.e. the octave you are playing is identical to the oscillator octave; at +63 every ascending octave you play transposes the oscillator upwards by two octaves (whole note scale); +15 transposes the oscillator

01111111111111111112

1 OSCILLATOR1 Keyfollow +32≤

61111111111111111154



Oscillator 2

WAVE Same as OSCILLATOR 1; see para-

graph above.

[XP] KEYFOLLOW Same as OSCILLATOR 1; see paragraph above.

SYNC Synchronizes the second oscillator with the ﬁrst: The SYNC function forces Oscillator 2 to interrupt its wave cycle and restart it at the same time as Oscillator 1 starts its cycle. The effect of this measure is that pitch deviations and intervals are no longer audible as such; what you hear are tonal modiﬁcations: Repeated interruption of the Oscillator 2 wave cycle generates new tonal spectra with a great deal of overtone content. The tone of a given spectrum can be inﬂuenced via the SEMITONE knob, among other control features.

01111111111111111112

1 OSCILLATOR2 Sync ON≤

61111111111111111154

ACCESS VIRUS RACK 97

OSC Sektion (Menu)

[XP] FM AMOUNT Controls the frequency modulation intensity of the second oscillator by the ﬁrst. Depending on the selected FM AMOUNT and the interval between the oscillators, the frequency modulation generates everything from slightly to radically enriched spectra. In the Virus you have the option of combining the two functions called oscillator synchronization (SYNC) and frequency modulation (FM AMOUNT) to generate new harmonic spectra. The characteristics of the frequency modulation can be modiﬁed with the FM Mode parameter (in the OSCILLATOR EDIT menu). You may also select an external audio signal and have Oscillator 2 modulate its frequency.

01111111111111111112

1 OSCILLATOR2 FmAmt 22≤

61111111111111111154

FILT ENV -> PITCH This parameter determines the intensity at which the ﬁlter envelope controls the pitch of the second oscillator (PITCH OSC 2).

01111111111111111112

1 OSCILLATOR2 FltEnv~Ptch +0≤

61111111111111111154

98 CHAPTER 16

The Parameters

FILT ENV -> FM It determines the intensity at which the ﬁlter envelope controls the frequency modulation (FM AMOUNT). This as well as the previous parameter are ”relics” from the predecessor model of the Virus. Modulations such as these may also be implemented via the Modulation Matrix (see the section ”ASSIGN” below).

01111111111111111112

1 OSCILLATOR2 FltEnv~Fm +0≤

61111111111111111154



Oscillators

OSC BAL Determines the balance

between the Oscillators 1 and 2 volume level.

01111111111111111112

1 OSCILLATORS Balance 64≤

61111111111111111154

VOLUME This knob has two functions:

 In the left half of its control range up

to the center position (MIDI value 64), OSC VOL determines the master volume of the three oscillators prior to the ﬁlter section input. The Noise Generator and the Ringmodulator are not affected by the master volume knob OSC VOL. Their level is controlled separately in the OSCILLATOR EDIT menu (see appropriate section).

 In the right half of the control range

from the center position to the far right, OSC VOL increases the saturation intensity (Gain) for the input of the SATURA- TION stage (see appropriate section); however this adjustment is compensated post-SATURATION stage so that when you adjust the gain you are not actually increasing the volume, only manipulat-

Access Virus Rack User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

Table Of Contents

Introduction

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

VOLUME AND PANORAMA

VELOCITY

UNISON MODE

THE CHORUS/FLANGER EFFECT

THE DELAY EFFECT

MORE TO COME

Concept and Operation

OPERATING MODES

THE MULTI-SINGLE MODE

THE EDIT BUFFERS

Operation

PARAMETER SELECTION AND DATA ENTRY

DISPLAY OF VALUES

All About The Memory

STORE

COMPARE

CREATING MODULATIONS VIA ASSIGN

THE DEFINABLE KNOBS

Master Clock And Midi-Clock

Master Clock And Midi-Clock

The Effects Section

THE EFFECT SECTION

Audio Inputs

Audio Inputs

Audio Routing

THE AUDIO OUTPUTS

Categories

SOUND CATEGORIES

Random Patch Generator

RANDOM PATCHES

AMOUNT This parameter determines the intensity of the RANDOM PATCH GENER­ATOR’s effect on the sound parameters. At lower values, sound changes are fairly subtle, but you can intensify the effect

Additional Functions

Additional Functions

The Parameters

OSC SECTION (ENCODER)

SHAPE This control feature lets you

SEMITONE Determines the interval between the second oscillator and the ﬁrst oscillator: Control range +/-48 semi­tones, assigned in semitone steps.

SHAPE Same as OSCILLATOR 1; see para-

W AVE SEL/PW has two functions, depending on the SHAPE (see appropri­ate section) value:

WAVE SEL/PW Same as OSCILLATOR 1; see paragraph above.

SEMITONE Same as OSCILLATOR 1; see paragraph above.

DETUNE Detunes the second oscillator relatively to the ﬁrst. With this parame­ter , you can dial in everything from slight deviations in pitch to major ﬂuctuations between the two oscillators.

OSC SEKTION (MENU)

WAVE Selects among of 64 spectral waveshapes. This parameter is identical

WAVE Same as OSCILLATOR 1; see para-

[XP] KEYFOLLOW Same as OSCILLATOR 1; see paragraph above.

FILT ENV -> PITCH This parameter deter­mines the intensity at which the ﬁlter envelope controls the pitch of the sec­ond oscillator (PITCH OSC 2).

OSC BAL Determines the balance

VOLUME This knob has two functions:

AMOUNT This parameter determines the intensity of the RANDOM PATCH GENERATOR’s effect on the sound parameters. At lower values, sound changes are fairly subtle, but you can intensify the effect

SEMITONE Determines the interval between the second oscillator and the ﬁrst oscillator: Control range +/-48 semitones, assigned in semitone steps.

W AVE SEL/PW has two functions, depending on the SHAPE (see appropriate section) value:

DETUNE Detunes the second oscillator relatively to the ﬁrst. With this parameter , you can dial in everything from slight deviations in pitch to major ﬂuctuations between the two oscillators.

FILT ENV -> PITCH This parameter determines the intensity at which the ﬁlter envelope controls the pitch of the second oscillator (PITCH OSC 2).