Sound-controlled
synthesis and effects
is manual is released under the Creative Commons Attribution 3.0
Unported License. You may copy, distribute, transmit and adapt it, for
any purpose, provided you include the following attribution:
Virta and the Virta manual by Madrona Labs. http://madronalabs.com.
Version 1.0, March 2016. Written by George Cochrane.
Illustrated by David Chandler.
Typeset in Adobe Minion using the TEX document processing system.
Any trademarks mentioned are the sole property of their respective
owners. Such mention does not imply any endorsement of or associ-
ation with Madrona Labs.
Introduction
Synthesizers and eects. In this crazy mixed-up world, what could be
better? On and on, we tweak and twist, searching for something. Smiles
creeping across our faces all the while. e roiling sea of knobs and but-
tons and lights are magnetic. We seek, pure of heart, to merge with the
world of sound.
Alas, we sometimes nd ourselves stopped short. O, that this too solid esh could melt... And,
It can be a tall order to get the level of expression and immediacy
that you crave with traditional synthesizers and processors. is goes
double if you’ve got to work quickly, but want to maintain a satisfying
amount of complexity and variance in your sound. Perhaps, in the heat
of a creative moment, you have wished to simply dive into a synth or
eect and command it by thought. ere is no shame in that. I mean, people talk to their PETS, for crissake.
is, to a large degree, is why we’ve created Virta—a modular syn-
thesizer and eects processor that responds directly to you.
When you route your voice (or any kind of audio) into Virta, the
sound analysis engine precisely extracts information about its pitch,
timbre, and dynamics over time. ese new signals can control nearly
any parameter in Virta, just the same as you can with MIDI or OSC.
like, seep into the jacks of my modular.
is makes for an instrument that can easily follow your every twist
and turn. Living the dream, really. en again, Virta is modular, so
audio-controlled synthesis is just one road you can travel. You can also
make stu like:
• Expressive vocal processing chains
• 4-voice MIDI-controlled pitch shiers
• MIDI/OSC-controlled synths (with or without audio control)
• Drones for days
• First-ever faithful emulation of the mating call of the Space Pony
A Quick Overview
Virta’s interface has four main sections, from top to bottom:
• e header section, where you’ll nd the patch menu, along with the
version and registration status of your copy of Virta.
• e signals and shapes section, where AUDIO and MIDI/OSC (KEY)
signals ow into Virta, and where the oscillators (OSC1 and OSC2)
and modulators (LFO, and ENVELOPE) reside.
• e patcher section, where connections between modules are made
and unmade.
• e processing and output section, where the sounds you make are
massaged and processed to perfection by the FORMANT, GATE, DE-
LAY, and OUTPUT modules.
4
Of course, there is much more to learn about the ways of Virta. Let’s
go on a little cosmic journey together.
A Little Book of Power
If Virta is your rst foray into anything modular, or your rst audio-
controlled alien communicator, let this manual be your guide. What-
ever your perspective, we mostly hope that you have fun exploring this
new instrument, making sounds you’ve never heard before.
is manual is arranged in three sections:
• Where Keyboards Fear to Tread—A little background on the con-
cepts behind Virta.
• Getting to Know Virta—Info on how Virta ts into your system, and
how to use the various types of controls and connections that you’ll
nd.
• Module by Module—A guided tour through the dierent parts of
Virta, module by module.
5
1 Where Keyboards
Fear to Tread
Virta is all about immediacy of expression. We all want to make evoca-
tive synth parts and process sounds in novel ways, but oentimes, doing
so takes a little more thinking than we’d like—a lot of futzing with con-
trollers, note and parameter values, automation, and so on. at’s all
well and good, but sometimes you just want to let y, make bold moves,
and get compelling results. is can be a challenge in a world where
the most responsive control mechanisms we’ve got are keys, knobs, and
faders. Virta to the rescue!
You feed sounds into Virta (oen voice, but it could be anything),
and they are analysed by the AUDIO module. is derives pitch, ampli- e AUDIO module is optimized for mono-
tude, on-o state, and some timbral details from your audio, and outputs
them as signals you can use to control anything in Virta, just like you
can with MIDI or OSC. When you’re doing audio-controlled synthesis,
you’ll oen patch these signals rst into the pitch and timbre control
inputs for the oscillators, which are only too happy to follow along.
phonic input signals, but feel free to try
anything you like, if you’re okay with unpredictable results.
en, you can use the FORMANTS and GATE modules to apply the
timbre & amplitude of your input source to this new synthesized sound
in a wide variety of ways. Add on a pitch-shiing delay eect (also
chock-full of control inputs), and you’ve got quite a hot musical pie.
In other guises, you could patch up a keyboard-controlled synth, and
use FORMANTS like a really nice vocoder to shape the sound with in-
coming audio. Use your voice to vary delay time or control the intensity
of modulations—or move a dozen things at once, all in whatever range
of motion you want. e creative avenues aorded by being able to treat
audio as both a multi-parameter controller and useful musical signal are
legion. Even without audio control, Virta is still a powerful, patchable
synth and processor.
Virta is quite modular, so the way you patch it dictates the way it will
act. May you patch with verve and reach new horizons.
8
2 Getting to Know Virta
is chapter shows you how Virta ts into your computer ecosystem,
and gives you a working knowledge of the various types of controls you’ll
nd throughout. Some of Virta’s controls act just like you would expect,
but some have more personality than that.
First ings First
Virta is a soware plug-in that comes in both VST and AU formats. A
plug-in does not run on its own. It runs within an application (known
as a host or Digital Audio Workstation). Some good hosts include Able- e rest of this guide assumes that you’ve
ton Live (on Mac and Windows), Logic and Numerology (Mac), and FL
Studio (Windows). All of these hosts provide easy ways to use plug-ins
like Virta.
Every host handles instruments a little dierently, so for more infor-
mation on using instrument plug-ins in your own system, please see the
user guide that came with your DAW.
got Virta up and running just ne. If you
have problems with installing or operating Virta, please search our forums
at http://madronalabs.com or, if that
fails, send us your questions at sup-
port@madronalabs.com. We, and the
growing community of Virta users, are here to
help you.
Routing Audio & MIDI or OSC
If you’re using Virta with audio input only (no MIDI or OSC input), you
can go ahead and simply drop Virta onto an audio track in your DAW.
Once you’ve done that, you can enable recording or input monitoring
for that track, start pumping in the audio of your choice, and you’re o
to the races. However, for many uses, you’ll want both audio and MIDI
or OSC to be able to ow into Virta.
e procedure for doing this will dier from DAW to DAW, but as
an example we’ll show you how to do this in Ableton Live: As much as we might like to, we can’t explain
• Create an audio track and a MIDI track. Assign the intended inputs
to both tracks
• Insert Virta on the audio track.
• Using the output selectors on the MIDI track, set its output to the
audio track containing Virta, and then to Virta itself.
• Record-enable both tracks by holding the Command key and press-
ing the record arm buttons on both tracks.
how to use every DAW here. But between your
DAW’s manual, your DAW’s friendly support
people and ours, hopefully you can get Virta
happily munching down audio and MIDI data
without too much trouble.
10
An Annotated Map of Virta
is section gives a quick description of each of Virta’s areas, to give
you a little familiarity before we go deep. For in-depth information on
each module, control, and feature, see Chapter 3, “Module by Module.”
1. Header
is area’s most vital item is a nice big preset selection menu with
back and forward buttons for fast switching. On the right, you can
nd your license information as well as the plug-in format for the
current instance of Virta. Click the gear-shaped icon to access the
global settings that aect the way Virta displays info and responds to
MIDI & OSC.
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2. KEY
e KEY module receives the note and control signals you send Virta
over MIDI or OSC, and makes them available to the rest of Virta’s
devices. If you have experience with CV-controlled synths, you can
think of the Key module like a MIDI-CV converter box that outputs
digital control ”voltages.”
3. AUDIO
e AUDIO module is the key to Virta’s powers. It receives incom-
ing audio, analyses it, and outputs a slew of useful signals that you
can use to control and interface with the rest of the modules. It also
outputs the raw audio input signal, so you can run it through Virta’s
processing tools.
4. LFO
e LFO module creates low-frequency oscillating control signals,
useful for modulating all sorts of parameters. A variety of traditional
LFO waveforms are available, as well as a couple that may surprise We apologize about the shirt. Is it dry-clean
you.
only?
5. OSC 1 & OSC 2
Now arriving at Grand Waveform Station. OSC 1 & 2 create syn-
thesized signals that can form the core of your synth sound, or act
as carrier signals to feed the FORMANTS module (and a lot more
besides). With a wealth of control inputs, these OSCs are all about re-
sponding to you, whether you use audio or MIDI/OSC to get things
going. Each oscillator has two modes: one for making traditional
analog waves, and one for expressive vocal tones.
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6. ENVELOPE
e ENVELOPE module creates time-based control vectors, com-
monly used to control volume or timbre as notes are struck and/or
held. Envelope is a fairly standard ADSR (Attack-Decay-Sustain-
Release) type, but with fully mod-able settings, and a trigger input
that lets you get creative about how to re things o.
7. PATCHER
e Patcher is the dark central strip in the plug-in window, sur-
rounded on all sides by the Modules. e patcher lets you connect
signals from the outputs of modules to the inputs of modules. It is
notable that multiple inputs can be fed from a single output, or mul-
tiple outputs to a single input. We think this is way more powerful
and easy to use than a ton of menus.
8. FORMANTS
e FORMANTS module acts a lot like a vocoder, but with sev-
eral big surprises up its sleeve. Several modes of multi-band ltering
are available, all designed to coax interesting, expressive, vocal-like
sounds out of whatever waveforms it touches.
9. GATE
If you’re familiar with modular synth jargon, the GATE mod-
ule can be described as as a VCA (Voltage Controlled Ampli-
er/Attenuator) or an LPG (Low Pass Gate) depending on the mode
you choose. Either way, GATE works in concert with signal sources
like ENVELOPE and LFO to change the level (VCA mode) or the level
and low-frequency cuto (LPG mode) of the input signal.
13
10. DELAY
Love crazy pitch-shiing delay eects? Fancy controlling one
with your mind? You’ll adore the DELAY module. is delay in-
cludes the aforementioned pitch shier and a diusor in its feedback
path, and a variety of ltering and panning options.
11. OUTPUT
e OUTPUT module is where all of your audio comes together be-
fore venturing out into the wilds of your DAW. It includes controls
for mixing and panning the output of the DELAY module (and thus,
the whole bottom row of processors) along with any signal(s) you
care to patch into the provided Aux input. It also contains a handy os-
cilloscope, which gives you visual feedback about the sounds you’re
making.
Presets
We labored heavily to make Virta simple and inviting to use, but ip-
ping through the preset sounds rst is a good way to hear what it can
do, and see how it’s done. Virta comes with both user and factory pre-
sets. e user area is where you’ll keep your own creations, and where
we put contributions from other Virta users that we include. e fac-
tory presets are meant to be a small and well-rounded set of sounds that
you’ll come back to oen.
14
Using Dials
So, you’d like to go beyond the presets? Of course you would! Meet dials.
ey’re found in every module. Like knobs on any piece of gear, dials
are mainly good for two things: manipulating signals and giving you
information. However, whereas most knobs inform you merely about
a single unchanging value they’ve been adjusted to, Virta’s dials act as
tiny signal viewers as well. is means they not only show you the value
you’ve adjusted them to, they also show you the values they’re being
pushed and pulled to by incoming modulation signals.
To modulate a dial’s signal, just make a connection to the dial’ssignal
input in the patcher. Every signal that can be modulated has a signal
input next to it—this is how Virta can provide so much control with-
out using menus. Signal inputs are like small dials without displays, or
regular knobs, if you like. We’ll cover the patcher and signal inputs thor-
oughly in a later section.
Dials as Controls
To set the position of a dial, you can do any of the following:
• Click in the dial’s track (the dark area within it) to set the value to the
click position. While still holding, drag up and down to adjust the
value.
• Hover over a dial and use the scroll wheel to ne-adjust the posi-
tion. At slow speeds, each click of the scroll wheel corresponds to
the smallest currently visible increment of the dial. Scrolling faster
accelerates the change.
15
• Click and drag vertically on a dial outside the track area to adjust the
dial from the current position.
• Double-click or command-click a dial to return it to its default value.
Holding down the shi key before any of these motions are done will
modify the motion to be a ne adjustment. is allows particular values
to be set precisely.
Dials as Displays
Each dial controls a signal that can be modulated, and shows the most
recent sample values of that signal every 1/30th of a second. at means
that static or slow-moving modulation will cause the pointer to stay still
or move slowly back and forth.
A faster modulation signal will cause the pointer to show a waveform
of the dial’s position under modulation. Modulation is shown cumula-
tively, so a dial receiving more than one modulation signal will show the
sum of the incoming signals.
e dial’s display is just like a classic oscilloscope display, but
wrapped around the center of the dial in what are called polar coor-
dinates. Time moves outward from the center of the dial, and every
value of the signal is a straight line going outward from the center. So,
a constant value creates a straight-line image in the dial.
Whether a MIDI note is being sent to Virta or not, it always calcu-
lates as many voices as the voices dial in the KEY module is set to. When
animation is on, each voice is displayed as a separate line in every signal
dial. So, if you set the number of voices to four, play a four-voice chord
and send just the steady pitch output of KEY to OSC 1 OR 2 pitch, you
will see four straight lines in the pitch dial.
16
If you send more complex modulations to the pitch dial, you will see
multiple scribbly lines, all animated.
Detents
Some dials, such as the OSC 1 & 2 pitch, have detents. Detents are useful
default positions. For example, the pitch knob has a detent at an A note
in each octave (110Hz, 220 Hz, 440 Hz...) to keep the oscillator tuned
to MIDI notes. Normal use of these dials makes them stop only on the
detents. By shi-clicking a dial with detents, or holding down shi and
dragging it, you can adjust it to any position in between the detents.
Numeric Displays
All of Virta’s dials show their current value both in the (oen changing!)
pointer position, and in a numeric display below each control. e nu-
meric display does not show the modulated value, only the center value
that you have set on the dial itself. e numeric displays are not directly We tried it the other way, and all those ashing
editable, so just get that crazy idea out of your head.
e Show numbers toggle in the global settings on the header lets
you turn o all the numerical displays, if you’d rather not see them.
numbers were a bit much.
Dial Scales
While many dials are linear (the change per degree from high to low is
constant), some dials have logarithmic scales where the change is much
larger as the value gets higher. is was done in cases in which a loga-
rithmic scale matches the changes you perceive better than a linear one,
as in oscillator pitch, for example.
17
In a logarithmic scale, equal movements of the mouse in dierent
positions on the dial will produce dierently-sized changes. For exam-
ple, 55, 110, 220 and 440 Hertz are all equally spaced apart on the rate
dial in the oscillator modules.
Using Buttons and Switches
ere’s not a lot to say here, only that switches need only be clicked to
be toggled (you’ll see the little dark switch move back and forth) and the
same goes for the buttons. Dark is o, bright is on.
Using the Patcher
e patcher is the grand connector. With it, you’ll bring together the
tools Virta oers, to do really fun stu. e patcher is both the place
from which much of the joy of working with Virta springs, and the part
of Virta most likely to confuse you at rst.
e Patcher is the large dark central area surrounded by all the mod-
ules. It lets you patch signals from the outputs of modules to the inputs
of modules by drawing patch cords. Each patch cord has an arrow on
it that shows which way the signal is owing. Note that though signals
tend to ow down, from ENVELOPE to GATE, for example, this isn’t
always the case, because inputs can be found on both the top and the
bottom of the patcher.
ere are no signals underneath the patcher that can ow up, but
signals from above the patcher can go to other modules on top. And
remember, modulation and audio signals are both the same thing, just
made up of dierent frequencies, so it’s perfectly ne to experiment by
connecting any output to any input.
18
Some signals are bipolar, meaning they can have negative as well as
positive values. Negative signals light up the outputs just like positive
signals. In other words, the absolute value of the signal controls the
output brightness.
Signal Outputs
ese are the tiny circles on the edge of the Patcher; the places from
which all patch cords start. ey light up to show the current value of
the signal.
You can use the LFO to see this, even without using any patch cables,
as follows: turn the rate dial on LFO to 1.0. Double-clicking the dial
will do the same thing, because 1.0 is the dial’s default value. Now, turn
the level dial up towards 1.0. You can see the LFO signal output lights
pulsing more and more brightly.
Signal Inputs and Modulation
ese are the small dials bordering the Patcher; the places where all
patch cords end. Each signal input connects to just one dial. When you
connect a varying signal to an input, it modulates the dial’s signal just
as if you were moving the dial itself, but possibly at much faster rates.
Signal inputs are also knobs that let you adjust the amount of mod-
ulation applied to the dial. ey do not display incoming signals them-
selves, because you can always see the eect in the dial. Some inputs
are bipolar, meaning the value by which they multiply the signal can be
either positive or negative. Like the bigger dials, each signal input dial
has a default value, and returns to this value when double-clicked.
19
For example, the exponential pitch inputs to OSC 1 & 2 have a de-
fault value that corresponds to standard tuning when the pitch output
from the KEY module is connected. Changing this input dial makes nice
music into weird tones very quickly. But by double-clicking to restore
the default value, normalcy can be quickly restored if desired.
Envelope Trigger Input
Virta’s ENVELOPE module can accept trigger signals, and it does so
through a triangle-shaped input labeled “trig.” You patch signals into
this input just as described above. e big dierence is that there is no
dial to set the level of trigger input—a signal either triggers the intended
response, or it doesn’t. For this reason, you’ll want to make sure that
the signals you patch into the trigger input are appropriately “triggery,”
whether they’re purpose-built trigger signals like the gate output of the
KEY or AUDIO module, or a particularly spiky audio or control signal.
Patching
To make a patch cord, drag from an output to an input. As you drag,
you’ll see a glowing line with an arrow at the end stretch from one to the
other. is shows the new connection you are making. is is a pretty
niy thing, since such routing does not involve deciphering menus or
matrixes of things you can’t see—you only need to look at what’s on the
screen, which is everything. is ease of use is intended to keep Virta
feeling like an instrument; something you can grab, pull, and mess with
uidly.
20
You can make patch connections while holding a note down, and
they will aect the currently playing note just as patching a hardware
modular would. By holding a note and touching a patch cord end to
various signal outputs, you can even get intermittent glitchy sounds that
are reminiscent of playing with a live electrical circuit, or circuitbending.
Multitudes Within Multitudes
Almost every module panel in Virta’s interface is really a controller for
as many copies of the module as there are voices. And each voice has its
own internal patcher. When a patch cord is made using the patcher UI,
it is made simultaneously in the patcher within each voice. For example,
if you connect the output of the LFO to OSC 1 pitch, you are connect-
ing LFO of voice 1 to pitch of voice 1, LFO of voice 2 to pitch of voice 2,
and so on. e KEY module is the exception: it is more like one module
with a signal output for each voice. When a note is played repeatedly,
the KEY module sends the note signal to each voice’s patcher in turn to
create polyphony.
Since they are controlled by the common patcher UI, and one set of
dials, the patch created for each voice is identical. But the signals that
ow through each voice’s patch can be very dierent. us, each voice is
separately controllable, in timbre, modulation, and all of its parameters.
A patch cord always takes on the color of the module it is coming
from. is helps you see at a glance what is going where. To modify
a patch cord aer it’s made, rst you must select it. To select a single
cord, just click directly on it. When multiple cords are running over the
point you click, clicking repeatedly will rotate through all the cords at
that point. Youcan also select a group of cords in the patcher by clicking
on an empty part of the patcher, then dragging over multiple cords.
21
Removing or Repatching a Cable
When a cord is selected, its handles are visible. Handles appear as cir-
cles at either end of the cord—you can drag them to move the ends. If
multiple cords are selected starting or ending at the same place, clicking
the handle there will move all of the selected cords.
You can also delete a patch cord or multiple selected cords by drag-
ging either end to a place with no input or output. An X will appear
instead of the handle at the end, and POOF. It’s gone. Again, the changes
happen in real time for any currently held notes.
Mixing and Multing
If multiple cables go to a single input, the signals are mixed together.
e sum of all these signals is then multiplied by the input dial value.
If multiple cables go from one output to more than one destination, the
signal has been multiplied, or multed.
at’s not terribly important information, but it’s good to have your
terminology straight, especially if you move on to other modular instru-
ments.
Unipolar vs. Bipolar
Some output signals, such as the envelope outputs, send only positive
values, and are unipolar. Others, like the pitch output on the KEY mod-
ule, and the LFO, swing both positive and negative. ese are bipolar.
Negative and positive signal values follow all of the same rules that real
numbers do in algebra.
22
For example, if a negative-valued signal is multiplied by a negative
signal input dial, its eect on the modulation will be positive.
Default Signal Routing
We’ve seen how easy it is to patch Virta’s modules together, but it’s im-
portant to know that some connections in Virta are pre-made for you.
e FORMANT → GATE → DELAY → OUTPUT signal path, con-
sisting of all the modules below the patcher, is pre-routed. e dials
between those modules let you set the wet/dry balance of the FORMANT
and DELAY processes.
e pre-patched modules below the patcher can be called the pro-
cessing modules. While the modules above the patcher generate signals,
the ones below are where the sounds you hear are shaped. Of course, this
being a patchable instrument, there are exceptions to this rule. How you
proceed is up to you! e Aux in input in the OUTPUT module gives you
a chance to send a signal directly from a top-row module to the output,
bypassing all bottom-row processing.
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3 Virta: Module by Module
is chapter will take you on a more detailed tour of the various modules
that compose Virta, one by one.
e Header
Apart from reminding you which amazing plug-in you’re currently us-
ing, Virta’s header mainly deals with patch access and management, and
user interface options. All the things that don’taect the sound, in other
words. e big drop-down menu in the middle displays the current
patch name, and lets you select patches from a hierarchical list. e
menu is refreshed each time you click on it, so new patches you save or
import will show up right away.
e patch menu
e drop-down patch menu has three main sections. e rst section
holds the Copy, Paste, and Save commands. When you select “Copy to
clipboard,” the current patch is saved in a text-only format that you can
paste into other text documents.
is lets you send a patch to a friend in an email, or post it on a forum,
for example. “Paste from clipboard” does the reverse.
“Save as version” lets you quickly save a new version of the currently
loaded patch (with whatever tweaks you may have made since loading
it) without having to enter a new patch name. e new patch is named
aer the current patch, followed by a revision number in brackets, in-
crementing with each new version you save.
“Save” permanently updates the current patch with any parameter
changes you’ve made since loading the patch. is is, by denition, a
bit risky, unless you’re sure of the changes you’ve made. In many cases,
you’ll be safer using “Save as version” or “Save as...” when making in-
cremental changes to an existing patch.
“Save as...” brings up a le chooser from which you can create a new
le to save the patch to, or choose an existing one to overwrite. Patches
from the Audio Units version of Virta are saved in the .aupreset for-
mat. is is a compressed XML format, compatible with Logic, Live and
other Audio Units-friendly applications. Patches from the VST version
of Virta are saved in the .mlpreset format. is is the same XML format,
but uncompressed.
“Revert to saved” returns all parameters in the currently loaded patch
to their original, saved settings. You can also activate the Revert to Saved
feature by sending MIDI program change 128 to Virta. is can be use-
ful when recording multiple takes of Virta dial-twiddling as audio in
AbletonLive. In the Clip View for the MIDI clip you’reworking with, set
the “Program” parameter to 128. Each time that MIDI clip is launched
(with its launch button or a stop-and-start of the transport), Live sends
program change 128 to Virta, reverting the patch to its saved value. is
gets you back to a consistent starting point for the next recording pass.
26
Below the commands are all of Virta’s patches in two more sections:
the so-called “factory presets,” in directories all starting with “Virta,”
followed by storage space for your own personal patches. Some user
presets, contributions from fellow Virta users, are installed here by de- anks, wonderful sound-crazed Virta users,
fault.
for all your contributions!
Presets are all stored on your hard disk in the right place for user
data on your operating system of choice. For simplicity, factory presets
are stored in the same place as your own patches. In the unlikely (but
perfectly valid) scenario that you have multiple people with accounts on
the same computer all using Virta, each person can have a copy of the
factory presets along with their own patches in their home directory. On Mac OS, the user directory is in (your home
directory) / Library / Audio / Presets. On
Selecting patches via MIDI
If you’d like to be able to load patches by sending MIDI program changes
to Virta, create a folder titled “MIDI Programs” (note the capitalization
and the space between words) in one of the following locations, depend-
ing on your platform:
• Mac OS: /Library/Audio/Presets/Madrona Labs/Virta
Windows 7, it’s in (your home directory) / User-
Data. If you’re trying to copy your preset les
using Windows Explorer, be aware that even
though it’s the recommended path for user
data, Windows makes this directory invisible
by default. Likewise, Mac OS 10.7 Lion and
more recent versions hide the Library folder.
You can navigate to the Library folder in the
nder by choosing the “Go” menu and holding
down the option key.
• Windows: (Your home directory)/UserData
Copy the patches you’d like to access with MIDI program changes
into the “MIDI Programs” folder you’ve created. e folder is scanned
by Virta on startup, and the presets in it are assigned numbers, in al-
phabetical order. To rearrange the programs, give them new names If you look at the MIDI Programs folder in
so they are in a dierent alphabetical order. Send a program change
to Virta that corresponds to your chosen patch, and Virta will dutifully
Virta’s preset menu, you will see each preset
listed, followed by its MIDI program change
number.
switch to that patch.
27
Global Settings
Click the gear-shaped button on the right of the header to access the
global settings. Show numbers lets you toggle the numeric displays that
sit next to each dial on or o. Animate dials lets you toggle the animated
scope-like displays inside the dials on or o. Reset editor size returns
Virta’s window to its default size. e Input protocol menu lets you spec-
ify whether you wish to use MIDI or OSC to control Virta. e OSC port
offset menu lets you specify the OSC port you wish to use for control.
For example, if your base OSC port is 6000, and you set the oset to 5,
Virta looks for OSC control signals on port 6005.
Version and registration
e right top corner shows the version of Virta you are running, as well
as your registration info. When you purchase a copy of Virta for your-
self, we encode your name and account information into it. is shows
to you and the world that you are supporting what we do—from our end
it means we have agreed to help you out with Virta if any problems arise,
and to maintain and improve it.
KEY
e KEY module receives all the MIDI data you send Virta’s way, and
turns it into useful control signals that you can route to other modules
with the Patcher. If your MIDI controller was a basket of fresh fruit, you
could think of KEY as a robot that bakes pies that the other modules long
to eat.
28
Tuning menu
e menu on the top selects the tuning table that Virta uses to map in-
coming MIDI notes to specic frequencies. 12-equal, the default tuning,
is short for 12-tone equal temperament. It is the basis for most modern
Western music, but there are around a hundred others to try, included
with Virta. ere are too many scales to describe here, but if you open
up the .scl le for a scale you’re interested in, you can read it as text, and
oen nd a bit more information that can lead to an article on the sub-
ject. As a start, we’ve selected some of the public-domain scales from
the Scala archive and sorted them into the tuning menu according to
what musical culture they’re from.
You can also add tuning les in .scl format to the scales directory
yourself, or make your own using the free soware Scala, available at
http://www.huygens-fokker.org/scala/.
Voice controls
• voice: is control lets you set the number of voices of available
polyphony, from one to four. Monophonic, duophonic, triphonic,
quadrophonic. e choice is yours.
• bend: is control lets you set the amount that the pitch output
varies when MIDI pitch bend messages are received. It is calibrated
in semitones from zero to 24. Yes, 24-count-em-twenty-four semi-
tones, which really means a range of 48 (+- 24), or four octaves. Can
you handle such power? No? OK, then set it to 7, or something.
29
• unison: is button lets you toggle Unison mode on or o. Unison
mode combines all four voices into one monophonic voice, which
can make for some very big sounds. If multiple oscillators at exactly
the same pitch are added together, the result can sound quieter than
a single oscillator because the waveforms cancel each other out. is
is hardly ever what anyone wants, so Virta’s sound engine applies a
small random frequency dri to the pitch of each oscillator to main-
tain a nice, big sound.
• glide: is dial lets you bring a little or a lot of portamento (pitch
glide between notes) to the party. Set it to the amount of time (in
seconds) you wish Virta to take when sliding between notes.
itemmod cc#: is control lets you select which MIDI continuous
controller signal to output through the Mod output. When set to 1,
it will use the Mod wheel. e subsequent two MIDI CCs above the
number you choose will drive the +1 and +2 outputs.
Outputs
• pitch: is output turns incoming MIDI notes into a pitch signal
Virta can use. When MIDI note A3 is played, the pitch signal output
is 0. is has the same result on a patcher input as when nothing is
connected. A4, an octave higher, outputs the value 1, and A2 outputs
-1. Another 1 is added or subtracted for each octave up or down. It’s like the 1.0 volt per octave standard of some
is scaling was chosen so that keyboard input maps naturally to all
the various control signals.
modular hardware, but there are no actual
volts involved. So we can call this just 1.0 per
octave.
30
In the patcher, any input dials that control pitches (such as OSC
1 & 2 pitch and GATE level) are all calibrated so that when you con-
nect a pitch input and set the default scaling (double-click), they will
track the same frequencies or intervals according to the 1.0 per octave
standard.
• vel: is output sends a signal proportional to the velocity of in-
coming MIDI notes. is signal maintains its value aer each key
is released, allowing neat things like whacking on a drum pad at dif-
ferent levels of velocity to set lter cuto over time, and such.
• vox: is output sends a signal proportional to the number of each
voice: 0.0 for voice 1, 1.0 for voice 2, and so on. is can be used to
quickly make changes to the patch that are dierent for each voice,
such as panning all the voices across the stereo eld, or setting each
lfo to a dierent rate.
• after: is output sends polyphonic aertouch data for each key, Channel aertouch sends one value for the
added to the channel aertouch value. ere’s nothing like routing
aertouch to a few parameters, and discovering a new dimension of
control over notes you’re already holding down! Really, do it. It’s
awesome.
• mod: is output sends a continuously-variable control signal, set by
whatever MIDI CC (continuous control) you’ve specied in the mod
cc# dial above.
MIDI channel, and polyphonic (or poly key
pressure) sends a dierent value for each key.
Very few keyboards have true polyphonic
aertouch, so we decided these two kinds
of aertouch could share a signal output. If
you don’t have a keyboard controller with
aertouch, you can still use the output in Virta
by sending messages from a MIDI knob or
fader controller.
• +1 and +2: ese outputs send continuously-variable control signals,
set by the two subsequent MIDI CCs (continuous controls) above the
value you’ve specied in the mod cc# dial. For example, if the mod
cc# dial is set to 10, the +1 output responds to CC# 11, and the +2
output responds to CC# 12.
31
AUDIO
e AUDIO module is the magical place where incoming audio is ana-
lyzed in real time, producing a wealth of control signals you can use to
make the rest of Virta come to life.
Controls
• input: is dial sets the level of the input signal before it reaches the
Compressor.
• thresh: is dial sets the amount of compression applied to the input
signal. Gain is compensated automatically as you add more com-
pression, so no output gain control is needed. e eect starts out
rather gentle, and develops more and more attitude as you crank it.
• lo cut / hi cut: ese dials set the corner frequencies of a pair of
24 dB/octave lters that act on the input signal. e lters cut fre-
quencies quite sharply, and are useful for isolating certain areas of
frequency in the input signal. Cutfrequencies starting from the bass-
end with lo cut and from the treble-end with hi cut.
• trig: is dial sets the trigger threshold for the gate output. When
the input signal exceeds the threshold you set, the gate output ips
to ”1” (signifying that a signal has tripped the trigger) and stays there
until the signal drops below the threshold again.
• quant: Enable this toggle to quantize the output of the pitch detector
to the musical scale you’ve chosen in the KEY module. Disable it to
allow continuous (non-stepped) pitch output.
32
Outputs
• pre: is outputprovides the raw audio input signal, for use in patch-
ing to other modules in Virta.
• comp: is output provides the audio input signal aer it’s been run
through the compressor and hi/lo-cut lters.
• gate: is output provides trigger signals derived from the audio in-
put signal, as directed by the thresh control.
• env: is output gives you an envelope-style control signal that fol-
lows the shape of incoming audio (aer compression and ltering).
You might send this signal to the GATE module to link the volume
of a synth patch to the amplitude of incoming audio.
• pitch: is output gives you the pitch control signal derived from
audio input by the pitch detector. You can send this signal to the
oscillators to control the pitch of synth patches, or to any input you
like, for fun real-time control.
• noise: is is the output of the noise detector, which, in a nutshell,
listens to the input signal and determines how ”noisy” it is. A sine
wave has a noisiness of 0, whereas white noise would have a noisiness
of 1. Most sounds you introduce will fall somewhere between those
values. Patch this to various things for another level of timbre-based
real-time control.
• peak: is output gives you a value that describes the overall bright-
ness of your input signal, eectively tracking the highest center of
frequency content. e brighter your signal is, the higher this value Also known as the ”spectral centroid” in
will be.
computer-music-speak.
33
LFO
e LFO module is a Low-Frequency Oscillator—one of the canonical
modulation sources in synthesis. Practically every synth has an LFO.
ose that don’t tend to mope around a lot, thinking of all that could
have been.
e drawing on top shows the currently chosen LFO shape. e
menu below it gives you access to all available shapes. Currently, our
list of noble shapes includes:
• sine one: A sine wave, the most harmonically pure of all shapes. is
sine wave varies from zero to one, which is good for modulating an-
other thing either up or down.
• sine two: Another sine wave, this time centered around zero. As a
modulator, this wave is useful for making FM synthesis. Try it with
the linear pitch inputs of the oscillators.
• triangle: A very triangular wave. It’s all business.
• square: Either zero or one, a simple proposition.
• saw up: Up-going sawtooth wave.
• saw down: Down-going sawtooth wave.
• noise: Noise usually means randomness. But this noise is a little dif-
ferent. It simply loops a short pseudo–random shape, the exact shape,
in fact, that you see in the drawing. e advantage of it not being
truly random is that it will repeat itself reliably every time you play
back your composition. When set to a low rate, the wavering value
is not likely to be noticed as a repetition.
34
• blip: We call this one the blip. It’s the shape that the envelope of a
vibrating object makes, more or less, aer it is hit—in physics terms,
an exponential decay. It’s useful as a kind of third envelope.
Controls
• rate: is dial sets the oscillation rate of the LFO. Set it low to go
slow, high to go fast, or in the middle to just cruuuuise.
• sync: Enable this toggle to set LFO speed as a rhythmic subdivision
of host tempo. Disable it to let the LFO y free.
• level: is dial lets you set the output level of the LFO signal.
OSC 1 & 2
OSC 1 & 2 are formidable sound sources, providing the raw waveforms
that then go on to be processed by the FORMANT module and other
processors. eir inputs let you control the pitch and timbre of your
synth patches in real time, with whatever control signals (from audio
or MIDI or other modulators) you prefer. Each oscillator can be set to
one of two modes: Classic mode makes juicy analog waveforms, and
VOSIM mode makes even juicier voice-inspired sounds. Some control
functions dier depending on which mode is selected. Most controls
feature at least one Patcher signal input, so get modulating!
35
Controls
• pitch: is dial controls the resting pitch of the oscillator— A.K.A.
the pitch produced when you plug in a signal from the Key mod-
ule’s Pitch output and hit MIDI key A3. Unlike other dials, the pitch
dial has two Patcher inputs: one exponential and one linear. e ex-
ponential input is calibrated to match the one per octave standard of
Virta’s mod signals. e linear input has a much wider range and can
be modulated for fast ”thwips,” inharmonic sounds and other eects.
• noise: (Classic mode) is dial fades the oscillator’s output between
your choice of waveform and noise that is bandpass ltered to match
the sine wave frequency.
• formants: (Vosim mode) is dial lets you specify the number of for-
mants used in the vowel synthesis. Higher settings introduce higher
harmonics.
• shape: (Classic Mode) is dial lets you control an antialiased wave-
shaper that fades between a sine in the center, a square on the le,
and a saw on the right. Patching LFO or Sequencer signals to this
control can create pleasing PWM-like eects.
• peak: (Vosim Mode) is dial lets you control the formant peak
of the vowel synthesis algorithm. is dial describes a trajectory
through a two-dimensional space of vowels from ”OH” to ”’AH” to
”EE.” Controlling this parameter with the peak output from the AU-
DIO module can help to make a kind of synthesized speech. At the
top end of the peak dial, noise is faded in. If the oscillator’s signal
is intended to be used as a carrier for the FORMANTS module, that
added noise makes consonants clearer, and speech more intelligible.
36
• level: is dial lets you set the output level of each oscillator.
ENVELOPE
is module is an envelope generator with a standard ADSR control
layout. e display shows the current shape of the envelope.
ENVELOPE is an ADSR generator, so your old pals Attack, Decay,
Sustain and Release each have their own control. Each control has an
input for control signals.
Envelope has a trigger input that lets you trigger it with signals such
as the gate output from the AUDIO or KEY module... Or something
trickier (so long as it’s “trigger-y”).
FORMANTS
e FORMANTS module is a big part of what makes Virta’s vocal-ish
processing special. Using one of four vocoder algorithms, it analyses
a sound or signal (which enters through the “program” input), and ap-
plies multi-band ltering based on that analysis to another signal (which
enters through the “carrier” input). In this way, it applies the timbral
essence of one signal to another, over time.
If you’re doing audio-controlled synth stu, or a vocoded synth with
synth pitches coming from MIDI/OSC you’ll likely patch one or both
oscillators into the carrier input, and your audio (from the pre or comp
outputs of the AUDIO module) into the program input. at said, that’s
not the only way to do things.
37
If you’re not planning on using FORMANTS at all in a given patch,
you’ll probably still want to patch your audio or oscillator signals into
the program input, so that it will ow into the GATE and DELAY mod-
ules, to the output. In this instance, you’ll want to turn up the pgm dial
between FORMANTS and GATE, so that the audio is audible. Some folks prefer it that way.
FORMANTS comes with a bunch of dierent ltering modes, all de-
signed to do wonderful things while under the spell of vocal sounds.
at said, you can pipe any sound you like into Virta, and it will do your
bidding dutifully, oen with unexpected results.
Formant Displays
e top bar-graph display shows you the detected frequency content of
the program signal, spread across as many bands as you’vespecied. e
display below it shows the actual position of the formant lters, which
can dier from the detected positions, once you’ve put your grubby
mitts all over the shift and stretch controls.
Voices to the Unvoiced
Because most carrier signals (even brighter waveforms like sawtooth
or square) don’t have enough high-frequency information to accurately
synthesize the ”unvoiced” parts of speech or singing (or the atonal, tex-
tural bits of other sounds), classic analog vocoders of yore oen had
what was called an “unvoiced detector.” e idea is to detect when an
input program is a consonant, or any sound with high frequency energy
that requires a noisy carrier to reproduce. When such an input is de-
tected, a noise generator, or sometimes a little bit of the program input
itself, is injected into the carrier input.
38
In Virta, we provide other tools which you can take your pick of, out-
side of the FORMANTS module, for handling this scenario. e noise
and peak outputs of the KEY module provide dierent but complemen-
tary ways of detecting “unvoiced-ness.” ese signals can be sent to
various destinations in order to make the carrier you send to the FOR-
MANTS module more noisy. In particular, try sending the peak output
to the peak input of the oscillator in VOSIM mode! ey are made for
each other.
Controls
• shift: is dial lets you shi the detected vocal formants up or down
in frequency, before they are applied to the carrier signal.
• stretch: is dial lets you stretch the relationship between the de-
tected formants like tay before they are applied to the carrier signal.
You can bring them closer together, or further apart, or even invert
the relationships entirely (low on top, high on bottom).
• q: is dial sets the width of the formant lters. At lower settings,
each lter passes a fairly wide band of frequencies. Higher settings
pass narrower ranges of frequencies, and ring out over time, ap-
proaching the sound of oscillators.
• quant: is toggle turns quantization of formant frequencies on or
o. When on, each frequency snaps to the closest note in the musical
scale selected in the KEY module, instead of moving continuously.
• mode: is selector lets you choose the number of lters that FOR-
MANTS uses. Choose from classic vocoder-like modes (from 8-
32 bands), and the unabashedly digital FFT-based 256-band mode.
39
Vocoder 8-32 also oer a quant switch, that locks the formants to
frequencies that correspond to the current scale selection in KEY.
• pan: is selector sets the way in which individual formants are
spread across the stereo eld. Mono is just that, everything is in the
center. L->R places formants low-to-high from le to right across
the stereo eld. R->L does the opposite. Spiral places formants in an
overlapping back-and-forth pattern across the stereo eld. Clumps
spaces groups of formants across the eld. Random places formants
at random. Even-Odd stacks even harmonics toward the le, and odd
toward the right.
GATE
e GATE module is a dynamic volume control, akin to the VCAs (Volt-
age Controlled Ampliers) found in modular synths. Its input comes
from the FORMANTS module, with the wet/dry ratio between the raw
carrier signal and the ltered output blended according to the small
knobs in between the two modules. Its output is sent to the DELAY mod-
ule. You send GATE control signals, typically envelopes, and it nicely
increases and decreases the amount of input signals passed to the out-
put. e control signals you send ow through a vactrol emulation, this
time with a settable decay, which opens up a world of cool, percussive
envelopes.
e GATE is an important tool used to sculpt the dynamic prole of
Virta’s sound, and it’s pretty magical beyond that. at magic comes into
play when you ip it into LPG (Low Pass Gate) mode, and commence
synth-bongoing ’til dawn.
40
Controls
• level: is dial sets the static level of the Gate module’s level attenu-
ator. Signals from the level patcher input modulate the level, as well.
For normal, keyboard-like playing, you’ll probably keep this control
at zero, so only incoming envelope signals triggered by key presses
aect the sound’s volume. For drones or reverse-enveloped sounds,
try raising it higher.
• lopass: is toggle turns on low-pass gate (LPG) mode. In LPG
mode, the gate’s gain-changing cell is replaced by a low-pass lter,
the frequency of which is modulated by the level signal. e modu-
lation aorded by the vactrol emulation makes percussive envelopes
with a very particular sonic signature.
• decay: Sets the decay constant of the vactrol algorithm. At low decay
settings, the GATE will follow incoming mod signals very snappily.
At higher settings, the decay of the vactrol rings out more and more.
DELAY
e DELAY module is a sprightly delay with a pitch-shier and diusor
in its feedback loop. is means that delayed signals can be pitch-shied
and diused again each time they repeat, with skyward-climbing or
oorward-lurching results. is eect can be quite subtle, or can be
the or’s hammer you need to really smash things to bits.
41
Controls
• input: is dial lets you set the input level to the delay eect.
• pitch: is dial lets you set the amount of pitch-shi applied to the
delayed signal, from 0 (no shi) to plus or minus an octave.
• diffuse: is dial controls the amount of diusion applied to the de-
layed signal. Lower settings give you cleaner delays, whereas higher
settings smudge the lens a bit, for more organic delay decay (as in an
analog or tape delay unit).
• lo-cut / hi-cut ese dials set the corner frequencies of a pair of shelv-
ing lters that act on the delayed signal. Cut frequencies starting
from the bass-end with lo cut and from the treble-end with hi cut.
• feedback: is dial lets you specify the amount of delayed signal to
feed back into the input of the delay. e higher the setting, the more
repeats you’ll hear. Keep in mind that because the pitch shier
• delay (ms): is slider sets the length of the delay line. Smaller values
give shorter delays, and higher values, longer.
and diusor processes live in the feedback
loop, the signal is shied and diused again
each time it repeats. Blast o!
• L/R ratio: is dial tilts the delay ratio for the le and right channels.
Lower settings shorten the le delay time and lengthen the right.
Higher settings do the opposite. At the center, the delays are of equal
length in each channel. is control comes in handy for ping-pong
stereo delay eects.
42
OUTPUT
e Output module lets you mix and blend your lovely new signals be-
fore they’re sent out into the cruel, cruel world. Here, you’ll nd an Aux
In that lets you patch signals directly to the output, bypassing all the
processing in the lower row of modules. You’ll also nd level and pan
controls, and a niy little oscilloscope that shows you the waveforms
you’re making. All controls have signal inputs on the patcher.
Controls
• aux in: is dial sets the output level of the signal patched to the
Aux In input. If nothing is patched there, this dial has no eect. An
accompanying Pan dial lets you set le-right balance for this signal.
• delay in: is dial sets the output level of the signal arriving from the
DELAY module (and thus, all the processors in the bottom row of
modules). An accompanying Pan dial lets you set le-right balance
for this signal.
Aer the output
Well, that’s a pretty thorough description of all the modules and how sig-
nals ow through them to make sound. But what happens to your sound
when it leaves Virta? is is an important thing to consider. Virta has
been designed to give you the purest possible sound from its oscillators,
if you choose, and an extremely wide dynamic range.
43
Because Virta has a nice collection of vocoders at its heart, and be-
cause the output levels of vocoders can vary so much depending on the
carrier and program signals, we have built a limiter into Virta aer the
output mixer. e eects of this limiter can be seen in the waveform
display in the OUTPUT module. And when it’s working, you will see
the limiter light go on, at the bottom of the waveform display. When
the light is o, the limiter is not aecting the signal. When it is on, the
limiter is engaged, preventing the signal output from going over 0dB.
ere’s no harm in running your Virta patch with the output light
stuck on, if you like the resulting sound. We don’t judge! But if a sound
with high dynamic range is your goal, you will want to back o the var-
ious levels we’ve discussed when you see that ashing light.
Finally, a high-quality audio interface is really a must to get the best
sounds out of Virta. Part of the reason soware synthesizers can sound
like they are missing something in comparison to their analog brethren
is that computers do not usually come equipped with good audio hard-
ware. Turninga stream of digital data, in a noisy electrical environment,
into accurate and stable analog voltages is a very demanding task, and
it’s a safe bet that the cheapest device you can nd will not sound good.
e good news is, the price of truly listenable interfaces is getting lower
all the time. e landscape is constantly changing, but as of this writ-
ing we can recommend digital to analog converters from Metric Halo,
Apogee, RME, and MOTU. As always, the only enduring advice is: use
your ears and your own good judgement.
44
A Frequently asked questions
Why “Virta?”
It’s the Finnish word for “current,” as in both electrical power and a water
stream.
Where is it? I installed it but I can’t nd it in the Start Menu / Dock /
Applications.
Virta is a VST and Audio Units format plugin. To run it, you need a
VST or AU host on your computer. Please see the Introduction to this
manual for more info, and try asking on our web forums if you need
advice nding a host to use.
Is Virta supposed to sound like this?
Probably, unless you hear an abrasive series of glitches. Here’s a good
way to check that Virta is functioning well: select the “default” patch
from the factory patches section of the patch menu. Change the voices
control if needed to get all four voices running.
Now, turn the level dial in the GATE module up a little bit. You
should hear a mellow, slowly shiing drone. If there are any glitches
in the audio, they will be readily apparent.
I hear the glitches, how do I get rid of them?
e most common thing that needs adjustment is buer size. Your host
gives you a controlsomewhere over the size of the small buers it lls up
with calculations, over and over, to generate a steady stream of sound. If
this buer is too small, the calculation takes much longer, and even the
fastest computer won’t be able to keep up. Try turning the buer size
up to some number greater than 256. is should let Virta run as fast as
possible. In Ableton Live, the buer size control is under “Preferences...
/ Audio / Buer Size.” For other hosts, it’s probably something similar:
please check your host’s manual for details.
If the buer size made no dierence, it’s possible that your computer
is not fast enough to run all of Virta’s voices. You can try turning the
voices control down to 1, and turning up the audio again on the default
patch. If this helps, then it’s almost certainly the case that CPU power
is the issue. You can try adding voices one by one to hear where the
problems come up. For reference, as of version 1.0, each voice of
If you are running the 64-bit version of Virta in a 64-bit VST or AU
host, you can expect to get around a 10% performance boost compared
to the 32-bit version.
Finally, turning o animations with the Animate dials global setting
Virta takes around 10% of the CPU time on
an 2.4 Ghz Intel i5 processor. Since all of the
audio processing is constantly running, Virta
will take this time whether or not a MIDI note
is playing.
or hiding the Virta interface altogether will increase performance, for
those times you are trying to squeeze out that last few percent and get
your mixdown to happen.
46
Performance is aected by many, many variables including choice of
audio interface, drivers, host application and OS version. We can only
give guidelines here. To tap into the collective wisdom of Virta users on
this topic, visit the ongoing discussions at madronalabs.com.
I bought one license for Virta. Can I use it on my Mac and my PC too?
Yes. Virta’s license is very simple, but dierent from some you may have
encountered. One purchase gives you a license for both Mac and Win-
dows. You are restricted to running Virta on one computer per license
at any one time. If you want to run the soware on more than one com-
puter at a time, you must buy a licensed copy for each computer.
How does your copy protection work?
Virta does not have copy protection. Copy protection always creates
hassles for legitimate users. Our approach is dierent.
What we do is stamp each copy of Virta securely with user data, con-
sisting of your name and a unique ID. is is your own copy of Virta,
and you are free to make as many copies as you want. But do so care-
fully. When you run a copy, it may unobtrusively check to ensure that
this data is intact and no other copies with the same user data are run-
ning anywhere. Since another copy running somewhere else could stop
yours from running, we assume you will be careful about where your
watermarked copies go.
We imagine, for example, that you might put a copy on your studio
machine as well as your home machine, or on a USB stick to take to a
mixdown session.
47
Can I load presets made in Virta 1.0 in version 1.2 or 1.3?
Yes. Virta presets will always be compatible with future versions, even
as we add controls and features.
On the other hand, if you try to load newer presets in an older version
of Virta, you will get errors.
I’ve got a Madrona Labs Soundplane controller. How do I set it up to work
with Virta?
Virta detects your Soundplane’s presence (provided you’ve got it plugged
in and set up), and automatically switches its control behavior to make
full use of the OSC/t3d control data Soundplane provides. Just plug in,
and play.
I’m not playing any notes, so why is Virta eating my CPU time?
We designed Virta as a very general-purpose sound-making machine
that behaves very much like an analog modular synthesizer. So Virta
has free-running oscillators that are updated whenever your DAW is
processing audio. Just like on a modular, you can simply turn the level
dial on the GATE up to hear the oscillator, even if no notes are playing.
Virta seems to be stuck on, how can I get it to stop?
Is the level dial on the GATE module turned up to a nonzero value?
at’s usually the problem.
If not, maybe there’s a stuck note, even though we haven’t heard one
for a long time. Try turning the voices control to reset the KEY module.
48
e decay control on the gate module doesn’t seem to have any eect. Why
not?
e decay controls the time constant of the Vactrol emulation. is is
a special kind of low pass lter applied to the level input itself, not the
audio. So you probably won’t hear it if the signal controlling the en-
velope already has a long decay. Try setting all the envelope controls
to their minimum values to get a very brief tick, patching that into the
level input, and adjusting the decay control. You should denitely hear
a dierence then. Or just re up the “deep bongo” preset.
How do I make Virta’s dials change in response to MIDI data?
e KEY module’s mod and +1 and +2 outputs turns MIDI continuous
controllers into continuous signals, which can then be sent to any desti-
nation in the patcher. is is a very exible way of using MIDI controller
data, because you can route and scale it quickly as a signal. e mod cc#
dial sets the control number sent to the Mod output, and the +1 and +2
outputs are driven by the two subsequent MIDI CCs above that setting.
Virta does not provide its own interface for changing a dial’s posi-
tion directly from a MIDI controller, oen referred to as MIDI learn.
Most plugin hosts, such as Live, Logic and Numerology, provide good
interfaces for MIDI learn that work well with Virta. Please consult the
manual for your host for details.
We recognize that some hosts out there lack good MIDI learn fea-
tures, or the particular ones you want. So, we plan to address this
somehow in a future version.
49
B Index
Ableton Live, 10
AUDIO module, 12, 32
audio-controlled synthesis, 7
aux input, 43
bipolar, 22
buttons, 18
compression, 32
converters, D/A, 44
copy protection, 47
DAW, 9
DAW setup, 10
DELAY module, 14, 41
detents, 17
dials, 15
ENVELOPE module, 13, 37
envelope triggering, 20, 37
FAQ, 45
feature overview, 10
lters, 32, 41, 42
formants, 37
FORMANTS module, 13, 37
GATE module, 13, 40
glide, 30
glitches, 46
header, 11, 25
KEY module, 12, 28
LFO module, 12, 34
LPG, 40
MIDI CCs, 30, 31
MIDI program change, 27
mixing, 22
multing, 22
noise, 33, 36
numeric parameter displays, 17
OSC 1 & 2 modules, 12
oscillators, 35
OUTPUT module, 14, 43
patch menu, 25
Patcher, 13, 18
patching, 20
peak detection, 33, 36, 38
pie, temperature of, 8
pitch bend, 29
plug-in hosts, 9
polyphony, 29
presets, 14
quantization, 32
registration, 28
saving patches, 25
Scala, 29
signal inputs, 19
signal outputs, 19
Soundplane controller, 48
switches, 18
tuning tables, 29
unipolar, 22
unison, 30
VOSIM, 35, 36, 38
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