Access Virus B

Access Virus B Image
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Following up on the success of the popular Virus, Access unleashed an upgraded model in 1999, the Virus B. The original Virus A had 12-voice polyphony, but the new OS in the Virus B doubles the polyphony from 12- to 24-voices and the oscillators, from 2 to 3 per voice. The new OS also added an enhanced programmable 32-band vocoder. There are now up to 82 simultaneous effects, a retro-phaser (6-stage stereo phaser with 24 filter-poles), chorus/flanger, ring modulator, multiple forms of distortion, an analog boost algorithm, and an envelope follower. Up to five FM (Frequency Modulation) modes are also on-board now and many new sounds have been created for this bigger and better version of the Virus.


OS 4.0 was released in late 2000 with even more amazing features! The update is downloadable from Access (free of charge!) and comes installed in all new Virus synths to ship after its release. OS 4.0 adds a reverb with advanced features such as pre-delay sync-able to Midi clock. There's also a groove delay, surround sound capability, external effect sends using the individual outputs, an Intelligent Random Patch Generator, sound categories to sort all your patches in a logical order, Direct FX to use your Virus as an effects-processor while maintaining full polyphony, 16 independent arpeggiators with numerous patterns and realtime parameter access, and an advanced distortion module with lo-fi and filter dsp-effects. OS 4.0 makes the Virus one of the best analog modeling synthesizers to date! Complete control of parameters is available via MIDI. "Adaptive Control Smoothing" ensures ultra smooth parameter changes. There's also a free Emagic sound-driver based Editor/Librarian for Windows and MacOS.

Access VirusKB Image


Virus KB


Pictured above is the Virus KB. It packs all the guts of the Virus B into a full sized keyboard with 61 velocity and aftertouch sensitive keys. There are also individual and assignable Pitch and Mod wheels. Nice emulated wood panels and a layout that remains faithful to the module's intuitive design make the Virus KB model an excellent dance and electronic music synthesizer for professional quality music and groovy results.

Access Virus Rack Image

Virus Rack

In 2001, the Virus Rack (pictured above) was released. This module retains most of the features through version 4.0 but sacrifices polyphony and an oscillator. This was to make the Virus significantly more affordable. Polyphony has been reduced to 16-voices but multitimbrality is still 16-parts. Instead of four, there are three oscillators per voice (two main oscillators plus one sub oscillator). Otherwise it has all the same great features as the Virus B! In 2002 the entire B series line of Virus synths were replaced by all new versions: the Virus C, Virus KC and Virus Rack XL.

Virus Indigo


Late 2000 also saw the release of a sleek, newly styled Virus called the Indigo (pictured above). Dubbed the 'Virtual Analog Roadster', the Indigo is a retro-styled twist on the amazing Virus synthesizer. It blends classic Roland, Moog and ARP style with the great features and sounds of the Virus B (OS 4.0). It adds a stout 37-note keyboard and a cool new grey/blue look. It's compact, easy to play, fun to tweak, and is a powerful synth! In 2002 it was replaced by the Indigo 2.

Viruses have been used by Astral Projection, BT, Überzone, The Crystal Method, KMFDM, Cosmosis, and Nine Inch Nails.

Click here for a PDF comparison chart between all Virus products from 1997 through 2002.

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Demos & Media

Access Virus B synthesizer - Ambient chillout music drone demo
Audio Clip 1 These are various demo sounds and grooves from the Virus B
Audio Clip 2 These are various demo sounds and grooves from the Virus Indigo.


Polyphony - 24 voices (Rack model has 16 voices)
Oscillators - 3 Osc per voice plus 1 Sub-Osc: Sawtooth, variable pulse, sine, triangle, oscillator sync. 5 FM Modes: 64 digital FM spectral waveforms. (Rack version has just 2 Osc. plus 1 Sub-Osc.)
LFO - 3 LFOs with 68 waveforms
Filter - 2 independent resonant filters; lowpass, hipass, bandpass, band reject, parallel, split & 2 serial modes with up to 36dB/voice (6-poles), overdrive/saturation.
VCA - 2 ADSTR envelopes
ModMatrix - 3 Sources, 6 Destinations
Effects - 82 simultaneous effects (34 to 66 in Rack version): 16 Phasers, 16 Choruses, 16 Distortions, 16 Ring Modulators, Delay, 32-Band Vocoder, Surround Sound (not available in Rack version).
Keyboard - Virus KB: 61 Keys with note-on/off velocity, pitch bend, modwheel and two switches/control pedals and aftertouch.
Indigo: 37 keys
Memory - 1024 programs (256 User / 768 ROM / 128 Multi)
Control - MIDI (16 multitimbral parts)
Date Produced - 1999 - 2002


Images from Access Music Electronics and Perfect Circuit Audio.

Review updated May 2011.