The Access Virus KB is the keyboard version of the Virus B synthesizer, housed in a solidly-made, rounded black metal body with attractive wooden end cheeks. Functionally identical to the Virus B module in terms of synthesis capabilities, the KB features the same advanced 24-bit D-A and 18-bit A-D converters, 24-note polyphony, and comprehensive effects processing, but in a complete keyboard instrument format.

The KB's semi-weighted keyboard action is exceptionally playable, comparable to the highly-regarded Kawai K5000 additive synthesizer. The keyboard transmits channel aftertouch plus attack and release velocity, and features solid modulation and pitch wheels for performance control. The keyboard lacks ribbon controllers, pads, or log controllers, maintaining a classic and streamlined appearance.

As with the Virus B module, the KB offers an expanded synthesis architecture with three oscillators per voice (plus sub-oscillator), comprehensive modulation capabilities, and versatile multi-mode filtering. The same expanded effects system is present, allowing each multitimbral part to use five effects simultaneously, with access to a global stereo delay and a 32-band vocoder.

On the rear panel, the KB features three stereo output pairs and stereo input, plus sockets for a hold pedal and an assignable pedal (initially set to control volume). The power supply is internal, eliminating the need for an external power brick.

The KB includes master keyboard functions accessed via the Ctl button, including transposition, sensitivity settings for aftertouch, and Local On/Off settings (separately configurable for knobs and keyboard). The MIDI transmission mode can be set to send on a single channel or on multiple channels corresponding to the current Multi setup's key ranges. The KeybToMIDI option allows layering of internal and external sounds across definable keyboard zones.

While the KB serves well as a master keyboard, some parameters that would typically affect only MIDI notes transmitted (such as the Transpose functions) actually work on internally-produced sounds. This reflects the instrument's development history from module to keyboard. Additionally, the arpeggiator controls are accessed through menu pages rather than dedicated front panel controls, and there is no dedicated headphone socket (headphone operation requires removing both main audio leads and plugging headphones into the left channel).

The Virus KB delivers the same exceptional sound quality as the Virus B module, with the ability to create everything from warm analog-style pads and leads to aggressive bass sounds and experimental digital textures, all with the added convenience of an integrated keyboard for immediate performance capabilities.

Technical Specifications

General

• Type: Modelled Analogue Synthesizer
• Format: 5-octave keyboard with velocity and aftertouch
• 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

Keyboard

• Semi-weighted action
• Transmits channel aftertouch
• Transmits attack and release velocity
• Pitch and modulation wheels
• Master keyboard functions:
  • Transposition
  • Aftertouch sensitivity settings
  • Local On/Off (separate for knobs and keyboard)
  • Single or multi-channel MIDI transmission
  • Keyboard zoning capabilities

Connections

• MIDI In/Out/Thru
• 3 stereo output pairs (6 outputs total)
• Stereo input
• Hold pedal input
• Assignable pedal input (default: volume)
• Internal power supply IN