The Access Virus B is a desktop/rackable module version of Access's expanded virtual analog synthesizer. Building upon the original Virus, the Virus B features upgraded hardware with newer, faster DSP chips that deliver increased polyphony and enhanced effects capabilities. The module maintains the sleek design aesthetic of the original but with brighter red paint, squarer knobs, and smaller, smoother buttons with LEDs moved onto the control panel itself.

The Virus B offers significant hardware improvements including 24-bit D-A and 18-bit A-D converters, doubling the polyphony to 24 notes (from the original's 12), and adding support for up to five effects per multitimbral part. The module includes a hardware MIDI Thru port (which was lacking in the original Virus) and comes with a more compact external power supply.

The physical layout remains broadly similar to the previous version, with dedicated sections for oscillators, filters, and LFOs. Several additional buttons have been added, including a dedicated effects menu button and part selection buttons for multimode operation. The "Expert" and "Easy" modes from the original have been consolidated, with many parameters now only revealing further pages when specifically activated.

The synthesis architecture has been significantly expanded with the addition of a third oscillator, accessible through the Oscillator 2 Edit menu. While not as full-featured as the main oscillators, Oscillator 3 can function independently with its own waveform, level, and tuning, or as a slave to Oscillator 2. The sub-oscillator now offers a choice between triangle and square waveforms.

Filter capabilities have been enhanced with new saturation modes including Rectifier, Rate Reducer, Bit Reducer, Rate & Keyfollow, and a 1-pole low- or high-pass filter. These can dramatically modify the output of Filter 1, adding various degrees of distortion and grit.

The LFOs now access all 64 digital waveforms available to the main oscillators, in addition to the standard waveform shapes. A new Contour parameter allows bending of the LFO waveform shape, and the Envelope Mode button transforms the LFO into an additional envelope that cycles through once with the shape of the selected waveform.

Effects processing has been significantly expanded, with each multitimbral part capable of using five effects simultaneously, plus access to a global stereo delay and a 32-band vocoder. New effects include various distortion types, a 6-stage stereo phaser, an Analogue Boost enhancer, a filter for the stereo delay, ring modulation, and an input follower for external audio processing.

The Virus B excels at creating warm strings, sweeping pads, dirty solos, squelchy basses, alien soundscapes, and bright digital tones. With the addition of the third oscillator, Unison mode, and the Analogue Boost parameter, it can now generate powerful, speaker-shaking bass sounds. User sounds can be stored in two banks of 128 patches, with an additional two banks of ROM patches included.

Technical Specifications

General

• Type: Modelled Analogue Synthesizer
• Format: Rackmountable desktop module
• Polyphony: 24 notes (reduced by 6 notes when using Oscillator 3)
• Multitimbral Parts: 16
• Memory: 128 user patches (2 banks), 128 ROM patches (2 banks), 128 Multi setups
• Conversion: 24-bit D-A, 18-bit A-D
• OS: Upgradable via MIDI

Synthesis Architecture

Oscillators

• Oscillator 1 & 2:
  • Waveforms: Sawtooth, Square, 64 digital waveforms
  • Controls: Tune, Shape, Wave Select, Pulse Width
• Oscillator 3:
  • Can function as Slave to Oscillator 2 or independently
  • Independent mode features: own waveform, level, and tuning
  • Shares modulation with Oscillator 2 when using fixed mod routings
• Sub-Oscillator:
  • Waveforms: Triangle or Square
• Noise Generator:
  • Adjustable color from dark to bright
• Ring Modulator:
  • Can process external signals (including stereo)
• FM:
  • Oscillator 2 can be modulated by any Oscillator 1 waveform, noise, or external signals

Filters

• Dual Multi-mode Filters:
  • Configurable in serial or parallel operation
  • Filter types: Low-pass, High-pass, Band-pass, Band-stop
• Filter 1 Saturation Options:
  • Rectifier
  • Rate Reducer
  • Bit Reducer
  • Rate & Keyfollow
  • 1-pole low-pass or high-pass

Envelopes

• ADSR envelopes for amplitude and filter
• LFOs can function as additional envelopes with Envelope Mode

LFOs

• 3 LFOs with standard waveforms:
  • Sine, Triangle, Saw, Square, S&H, S&G
  • Access to all 64 digital oscillator waveforms
  • Contour parameter for waveform shaping
  • Key follow mode
  • Poly or mono operation
  • Envelope mode (one-shot operation)

Modulation

• Fixed Modulation Routings:
  • LFO 1 to Oscillator 2 Pitch
  • Envelope 1 to Oscillator 2 Pitch
  • Plus others indicated by yellow LEDs
• Modulation Matrix:
  • 3 sources with up to 6 destinations each
  • 27 possible sources
  • 90 possible destinations
  • Sources include Random (new value at each key press)
  • Destinations include effects parameters
• Input Follower:
  • Uses external audio input level as a modulation source

Effects

• Per-part Effects (5 per multitimbral part):
  • Chorus
  • Phaser (up to 6 stages with Spread parameter)
  • Analogue Boost (enhancer with Tune parameter)
  • Distortion (multiple types including Rectifier, Bit Reducer, etc.)
  • Ring Modulator (requires input signal)
• Global Effects:
  • Stereo Delay with filter in feedback path
  • 32-band Vocoder with auto-sense feature
• Vocoder Controls:
  • Frequency
  • Q-Factor
  • Frequency Spread Centre
  • Carrier/modulator Balance
  • Attack
  • Release
  • Spectral Balance
  • Band Quality

Performance Features

• Unison Mode: Stack up to 16 voices
• Arpeggiator: Various modes including random and chord functions
• MIDI clock sync for delay and arpeggiator with Auto mode

Connections

• MIDI In/Out/Thru
• 3 stereo output pairs (6 outputs total)
• Stereo input
• External power supply