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Software Technology VAZ Modular 2.1

Software Synth/Sampler By Martin Walker
Published March 2000

If you have a powerful enough processor, the sky's the limit! Here's a classic 3‑oscillator Minimoog Model D, along with the modern sounds of the Metal Master synth (complete with Overdrive and Waveshaping), a sequencer, and the 16‑channel Mixer.If you have a powerful enough processor, the sky's the limit! Here's a classic 3‑oscillator Minimoog Model D, along with the modern sounds of the Metal Master synth (complete with Overdrive and Waveshaping), a sequencer, and the 16‑channel Mixer.

Software Technology's VAZ Modular promises the authentic sound of analogue synthesis in software form. Martin Walker tests out their claim.

There is now a wide variety of soft synths available for both PC and Mac and, as you might expect, different programs represent different approaches to the challenge of combining flexibility with an accessible user interface. For instance, Native Instruments' Generator (reviewed SOS September '98) and Reaktor (reviewed October '99) allow you to design complete synths from the ground up, providing a huge number of modular building blocks and access at a very low level when required. This provides the greatest versatility, but at the expense of a steep learning curve.

At the opposite end of the soft‑synth spectrum is Seer Systems' Reality, which is a strictly hard‑wired design with a huge number of controls. Although this might initially seem restrictive, Reality still provides a wide range of synthesis types, and is easier to get to grips with.

Martin Fay's VAZ Modular aims to provide the best of both worlds. Its modular approach leaves you free to design your own synths, but the modules themselves are comparatively high‑level, so that a simple design might only use seven or eight modules, and even your most complex creations will only need a couple of dozen. It is capable of up to 16‑note polyphony, and from version 2.0 onwards is also up to 16‑part multitimbral.

VAZ stands for Vurtual (sic) Analogue Synthesizer, and its creator's main claim for it is the accuracy of its analogue sound simulations. Apparently many people can't tell the difference between the sound of VAZ and that of vintage analogue synths such as the Minimoog, Roland SH101, and ARP Odyssey. Software Technology (who market the VAZ range) even provide audio files on their web site allowing you to compare it with the real thing! However, VAZ isn't limited to analogue sounds: modules are included that provide multisampling playback and granular synthesis, and comprehensive step sequencer facilities are built‑in.

Main Structure

You don't have to restrict yourself to monophonic synths — whack up the polyphony for a rich‑sounding string ensemble.You don't have to restrict yourself to monophonic synths — whack up the polyphony for a rich‑sounding string ensemble.

VAZ has an overall Main Window with a main menu bar, and any other open windows (Synths, Sequencers, or Mixers) can be arranged inside it. Like all soft synths, VAZ employs its own nomenclature, but thankfully for once it's fairly self‑explanatory. You create Synths, of which up to 16 can be open simultaneously for multitimbral operation; within these, you can save Patches, which store the entire synth design, plus the position of every control. You can open an associated step Sequencer (see later) for each Synth in a separate window, and the output of all the synths passes into a comprehensive Mixer window, where you can balance levels and add effects. Both Mixers and Sequencers can also be loaded and saved as separate items.

When you have assembled a combination of one or more Synths, one or more Sequencers, and a single Mixer, the entire setup can be saved as a Bank. You can move between any open windows using either the standard Ctrl‑F6 key combination, or via the Windows menu on the main VAZ toolbar, which is subdivided into Mixer, Synths, and Sequencers. The main window menu options change as you select different types of window. For instance, when a Synth window is open there is an extra section in the main File menu to Open, Save, Rename and create New Patches, along with a new Module menu (for choosing synth building blocks) and Synth menu (for changing the order in which items appear in drop‑down lists, and mapping MIDI controllers to individual Synth controls).

Designing A Synth

Up to 16 Synths can be mixed together, complete with multiple DirectX and VST‑compatible effects.Up to 16 Synths can be mixed together, complete with multiple DirectX and VST‑compatible effects.

A well‑written tutorial in the help file (there is no separate manual) shows you how to build a simple synth step‑by‑step, and once you have followed this, everything falls into place very quickly. The individual synth modules are accessed either from the 'New' section of the Module menu in the main window, or more quickly by right‑clicking anywhere in a Synth window and selecting from the drop‑down menu boxes that appear. The options are divided into eight submenus, largely ordered by their likely place in the signal chain (see Modules box).

When you select a new module, it appears in the Synth window and can be dragged into a suitable position relative to other modules using the mouse. Each module consists of a small front panel with one or more slider, button, or switch controls, and each parameter requiring an input from elsewhere has a small text box. Clicking on this displays a drop‑down menu containing every available source signal. So, for example, the Input of a Filter can be connected to an Oscillator waveform, the Input of an Amplifier to the output of the Filter, or the Frequency Modulation input of a filter to the output of an LFO.

This approach neatly avoids having to have graphic patch cords dangling everywhere, without restricting your options, and makes designing synths quick and easy. Creating a basic VCO‑VCF‑VCA synth chain, complete with envelope generators for filter and amplifier, took me about 90 seconds, including all the source routing, and this immediacy makes creating new synths a real pleasure.

If you lay out your modules carefully you can still see basic signal flow from left to right (as with most analogue synth front panels); however, complex designs can still become unwieldy, and to help with this, each module has a 'window shade' control to reduce it to just the title bar. You can reduce clutter by creating several rows of title bars, and then drop down their associated panels only when you need to tweak a particular module (see screenshot, right). You can also select different colours for the title bar of each module, to easily distinguish all the oscillators, filters, and so on.

Creating A Sound

The built‑in sequencer has comprehensive facilities for step editing, real‑time MIDI performance, and sync'ing to MIDI clock.The built‑in sequencer has comprehensive facilities for step editing, real‑time MIDI performance, and sync'ing to MIDI clock.

Each new synth starts with a Master Controls module already installed. This contains left and right input‑selector boxes, a stereo output‑level slider, selection of MIDI channel and polyphony (from one to 16 notes), and a duplicate set of Transport controls for the sequencer (see later).

For most designs, the other obvious requirement is a way to interface your synth to an external MIDI source (such as a keyboard or external MIDI sequencer): adding a CV Converter module does just this. It lets you select the MIDI channel, amount of pitch‑bend, note range, two MIDI controllers which can be used as modulation sources by other modules, Mode (Solo, Poly, or Unison, with a Unison Detune slider), Glide (aka portamento, with an associated Glide Time slider), and an External Clock input.

Beneath these controls the CV Converter has four more buttons. Clicking on the Note button auditions the current sound, while the Sequencer button launches a separate Sequencer window (see later). The Arp button activates the built‑in arpeggiator, the final Arp Mode button letting you choose from Up, Down, Up & Down, Random 1 and Random 2, over a range of one to four octaves.

Once your synth has an input and output, the next step is to add some sort of sound source. For many purposes the basic Oscillator module will be sufficient: this provides saw and pulse waveforms, frequency control over a six‑octave range, variable pulse width (the saw also morphs into a triangle wave), a sync input, two frequency‑modulation inputs, and a pulse‑width modulation input. For more dense sounds the Multi‑Oscillator module has similar facilities, but produces four simultaneous waveforms with detune controls. A Noise module is also available, with colour infinitely variable from White through Pink to Red, while the Live Input module (currently available only if you are using ASIO drivers) lets you treat an external audio signal.

The Sample module is a simple fixed‑pitch sample‑playback device for mono WAV files, with tuning over two octaves, and is ideal for drum sounds. The WTVoice (Wavetable Voice) module has a much larger six‑octave range, lets you load multiple samples and map them to specific note ranges, and has two playback modes: One Shot plays the sample through once, while Loop repeats the complete sample (or its looped section if one has been defined). It also has a built‑in ADSR amplifier envelope, and these combined facilities should make it ideal for most sample‑playback purposes.

However, the most comprehensive of the sample playback modules is the Wavetable. This adds support for stereo samples, and offers an additional playback type: Wavetable mode lets you continuously vary the position of a shorter loop within a larger file to vary the spectral content. When using this mode, two additional controls also become active: Wavetable Position lets you set the initial position of the loop in the larger file, while Wavetable Modulation lets you use another signal to vary this dynamically. There are wonderful possibilities here!

The Granular Oscillator is yet another source new to the latest 2.1 version of VAZ, and plays back short 'grains' of sampled sound crossfaded together. The controls are largely the same as those of the Sample module, but with extra ones for Sample Position (where in the sample each new grain is started), Grain Rate (the length of each grain), and Grain Shape (the crossfade length between grains). It's not as comprehensive as NI's Transformator — there are no formant shifting options for instance — but you can still create a huge range of sometimes unrecognisable new sounds from an existing sample.

Further Processing

Here is an example of using the windows 'shades' to fold down front panels: all modules remain connected to the synth, but their controls are whisked out of the way to reduce clutter.Here is an example of using the windows 'shades' to fold down front panels: all modules remain connected to the synth, but their controls are whisked out of the way to reduce clutter.

Sound sources can be passed through a variety of modules devoted to processing. There are lots of filters (including low‑pass, band‑pass, and high‑pass types in 1‑pole, 2‑pole and 4‑pole versions), a single‑band parametric EQ, and a Ring Modulator. Some of the more exotic modules include the VowelFilter (a triple band‑pass filter based on human vowel sounds, with morphing between five selectable vowel sounds), and the SubOscillator (to generate pulse or saw waveforms one or two octaves lower than the input). Those who enjoy in‑your‑face sounds will appreciate the Overdrive and Waveshaper (both of which generate additional harmonics), and the Decimator (which provides independent control over sample‑rate and bit‑depth reduction, for added grunge).

Most modules have inputs for modulating various parameters (such as Oscillator Pulsewidth, Filter Frequency, or Amplifier Amplitude for instance), and there is a comprehensive complement of modulation sources which includes various LFOs, a 16‑step mini sequencer, and an envelope follower. The envelope generators not only include the standard ADSR type, but also a more advanced Super Envelope with Delay, Attack, Hold, Decay, Sustain, and Release controls.

The selection of Mod Processing modules let you alter existing modulation signals in various ways, and includes an Inverter, which reverses the phase of the waveform; a Quantizer, which turns a continuous control voltage into 128 equal steps for note generation; a Scaler, which turns any size of input signal into a full‑range control signal; and two Sample & Hold modules. The first simply samples the input waveform at regular intervals, while the S&Cascade has four outputs, each of which can be delayed by up to 255 steps (there are some wonderful control possibilities here!).

The Routing modules let you mix together or switch between various input signals, or pan them between the speakers. Both the Switches and Panner have modulation inputs, so that you can control them in real time using other signals. VAZ Modular also includes five of its own Effects modules (Chorus, Delay, Flanger, Phaser, and Reverb). These are useful, although somewhat basic, but this is not a limitation, since VAZ also has a Plugin Effect module. This lets you select any DirectX or VST‑compatible plug‑in, so you instantly get access to the entire range of plug‑ins already installed on your PC. This is such an excellent but obvious idea for a soft synth that I'm surprised that it isn't more widely implemented. The final set of Modules is labelled Visualization, and includes meters, an oscilloscope, and a text box for adding notes about your creation.


Like the rest of the system, the Mixer is simplicity itself to learn and operate, and consists of 16 input channels (one for each synth in a multitimbral setup), arranged in two banks of eight either side of the central stereo output section. Each of the input channels has two rotary Aux Sends, a Pan control, an On/Off switch, and an output‑level slider with a readout in dB. When you first start working with a new synth only one channel of the mixer will be enabled, but you can click on the numbered strip at the top of any unused mixer channel to create a new synth on that channel.

In the centre of the mixer are the main output faders, along with an LED level meter. Above these are controls for the two Aux Send Effects and two Master Insert Effects. Each input channel also has an Insert effect. All of these effects consist of three parts: a text box showing the currently selected effect, along with buttons marked 'B' (Bypass) and 'E' (to launch its Edit window). As with the synth modules, you can either choose from the five built‑in effects, or any DirectX or VST‑compatible ones. Having Aux Sends makes it possible to set up global effects (such as chorus or reverb) that can be applied in varying amounts to multiple synths, saving processor power. When the Mixer window is selected, an extra menu item also appears in the main window for 'MIDI Control', so that you can map external hardware devices to move any on‑screen mixer control.


A separate Sequencer can be launched for each Synth, and these are certainly versatile, with up to 16 chained patterns available, each with between one and 16 steps. Each step has a note slider ranging over the full 128‑note MIDI range, plus button controls for Double‑length step, Rest, Slide, and Accent. Beneath these are two further rows of sliders for Control A and B levels, which can be sent to any module — for instance, I used them to control filter frequency and resonance respectively. If you have already defined MIDI controllers for Control A and B in the CV Converter module, both values add together. Each slider row also has a Gang toggle switch that lets you move all controls together (which is very useful for key changes), and global controls are available for Gate Time (momentary to legato), and Accent Level.

Each pattern can be played back in a cyclical or random order, in either a forward or backward direction. The patterns themselves can be played individually, or any section of the 16 possible patterns (such as 2 to 5, or 7 to 12) can be selected to run in a cycle or a random order. Even more control is provided in the Song mode, where a separate Song Editor lets you define a sequence of up to 255 patterns, each with a Transpose interval.

Each Sequencer has a Tempo control, and if you open several sequencers to control different synths simultaneously they are all stopped and started in perfect sync, even when running at differing tempos. Useful extra options appear in the two extra main window menus. The Pattern menu has entries for cutting, copying, pasting and clearing patterns, along with a Randomize function that lets you generate new patterns (you can mask any control out of this procedure, and set limits for those included). The MIDI menu provides comprehensive options to let you superimpose the sequence as offsets over MIDI note values, as well as letting you sync sequences to MIDI clock.

In Use

VAZ Modular is so easy to use that you can start designing your own synths within a few minutes of installation, and I had a multitimbral setup running with multiple sequencers and random patterns within a couple of hours. I did find fine‑tuning some of the controls a bit fiddly using the mouse, but you can either click near a control to adjust it, or use the normal keyboard shortcuts for cursor movements. In fact, all VAZ functions can be controlled from the keyboard for those who prefer not to use a mouse.

VAZ Modular is so easy to use that you can start designing your own synths within a few minutes of installation...

You can take a Snapshot of the current Synth settings at any time: these then appear in its Patch list, and can be subsequently selected either using the Patch menu, or by MIDI Program Change commands. However, each Snapshot is actually saved as a separate patch file on disk rather than within the Synth data, so creating lots of sounds for the same synth generates loads of small disk files, making file management more difficult (this probably explains why all of the supplied Synths have only a single Patch).

Like all soft synths, VAZ Modular 2.1 can eat processor power, so you will get a lot more out of it if you have a fast processor. Having said that, you can get a big sound from even a monophonic synth in VAZ, and if you are using intricate sequences you may not need huge polyphony. Even so, if your PC can't manage to run a MIDI + Audio sequencer at the same time, the Capture function lets you capture VAZ's entire output as an audio file; Capture Sequence does the same, but starts and stops with the sequencers. If you do want to run VAZ directly from an external sequencer, you will need a MIDI loopback driver such as Hubi's Loopback to do it.

The Acid Test

The big question of course is the sound, and although VAZ is not indistinguishable from a real analogue synth, it certainly sounded significantly better at analogue simulations than most other soft synths. The filters in particular were very rich and squelchy, and capable of a wide range of wonderful resonant sweeps. A few comparative tests with NI's Reaktor and Seer Systems' Reality showed that the VAZ filters came out on top, with Reality a good second, and Reaktor sounding distinctly nasal by comparison.

VAZ Modular may not have Reality's range of synthesis types, or Reaktor's versatility, but if you want quality analogue sounds, and one of the easiest interfaces around to use, it's the best of the bunch. Software Technology certainly make it easy to order if you have Internet access: not only can you download a demo version, but you can also order the full version on‑line, and it will arrive as an email attachment (2.25Mb) within a few hours. The bottom line is that if you like analogue sounds, you'll love this!


Like most other softsynths, VAZ Modular is constantly being developed, and each new version adds yet more juicy options. The latest version 2.1 and the previous 2.0 each added 14 new modules, bringing the current total up to 66. Here they are:

  • MIDI to CV modules: Accent Extractor, Clock, Control Converter, CV Converter, Trigger Converter.
  • Audio Sources: Granular Osc, Live Input, Multi‑Oscillator, Noise Source, Oscillator, Sample, Wavetable, WTVoice.
  • Audio Processing modules: Amplifier, Comb Filter, Decimator, Equaliser, Filter, Frequency Shifter, One‑Pole Filter, Overdrive, Ring Modulator, Sub‑Oscillator, SVFilter, Vowel Filter, Waveshaper.
  • Modulation Sources: Delay Envelope, Envelope, Envelope Follower, Fixed Value, Gate, LFO, Modulated Value, Multi‑Phase LFO, Sequencer Row, Sine LFO, Super Envelope, Triangle LFO, Voice Number.
  • Mod Processing modules: Comparator, Gate Logic, Inverter, Pulse Divider, Pulse Stepper, Quantiser, S&Cascade, Sample & Hold, Scaler, Slew Limiter.
  • Routing modules: 2‑Input Mixer, 2‑Way Switch, 3‑Input Mixer, 4‑Input Mixer, 8‑Way Switch, Matrix, Panner.
  • Effects: Chorus, Delay, Flanger, Phaser, Plugin Effect, Reverb.
  • Visualisation modules: CV Meter, Meter, Oscilloscope, Text.

Setting Up

The Set Preferences menu has five pages: Audio, for choosing and setting up your soundcard; MIDI, to select the MIDI input device and clock sync options; Synth, which allows you to choose master tuning and various display and control options; Import, which provides various options if loading in patches created using the cheaper VAZ+ synth; and Plugins, which lets you point to the folder in which your VST plug‑ins are installed.

The soundcard options in the Audio page are as comprehensive as I've seen anywhere, with support for MME, DirectSound, and ASIO drivers. Both MME and DirectSound options have a slider control for buffer size and a corresponding readout of latency, and when you choose an ASIO driver the Options menu has an extra entry so that you can directly launch the ASIO Control Panel. VAZ will initially set up some conservative settings for you, but it's worth tweaking to achieve the lowest possible MIDI‑to‑Audio latency.

With my Pentium II 450MHz machine and Echo Gina card I managed 30mS with the version 5.02 DirectSound drivers, 7mS with ASIO, and an amazing 5mS latency with its MME drivers. However, with my SW1000XG card the ASIO drivers only managed a disappointing 152mS, 30mS with MME, and 19mS with DirectSound. It certainly pays to try out all the options!


  • Very easy to use.
  • Fat analogue sound.
  • MME, DirectSound and ASIO soundcard drivers are all supported.
  • Synths and Mixer can both use DirectX and VST plug‑ins.


  • No separate manual, although the help file is well written.
  • No undo control.


VAZ Modular is an easy‑to‑use modular synth with fat sounds, wonderful filters and a versatile range of options, at a reasonable price.