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Access Virus

Advanced Simulated Analogue Synthesizer (Preview) By Paul Nagle
Published November 1997

Access's strangely‑named Virus is another digital synth emulating the analogues of yesteryear — but this one might be the best of the bunch so far. Paul Nagle brings you a sneak preview of the first Virus to hit the UK.

The Access Virus is red, knobby and supposed to digitally simulate an analogue synth. Does this sound familiar? Well, comparisons with Clavia's Nord Lead are to be expected, but the Virus is far more than just a cheaper copy of the Nord. It has a character all of its own, and, in my opinion, scores over its Swedish rival with 12‑note polyphony, 16‑part multitimbrality, two superb filters, effects, models of digital as well as analogue waveforms, three LFOs, an LCD, 256 onboard user patches, 128 onboard multis, and upgradable operating software via the MIDI In (which proved particularly useful while writing this preview). The Virus is also generously endowed with three stereo output pairs plus a pair of stereo inputs for processing external signals via its filter and effects sections. In this preliminary review, we'll take a quick whizz around the synth's features, sounds and operation; the detailed review will follow as soon as Access have completed the final operating system software and as soon as I can tear myself away from the production model.

First Impressions

You may remember Access as the German company who produced the hardware programmers for the Waldorf Microwave and Oberheim Matrix 1000 (see SOS September '96). Since the company's expertise lies in producing quality controllers, it will come as no surprise that the user interface of the Virus is beautifully thought out, with the right balance of features and complexity, and without compromising its, well, accessibility. Construction is first‑class, with 32 firm knobs (titter ye not!), 27 positive switches and a 2 x 16‑character display. Of particular note, too, are the 52 yellow LEDs. These pulse in time with the LFO cycle, and have a fair crack at representing the particular waveform by varying their intensity as the LFO cycles; so with a triangle waveform, the LEDs gradually fade up and down, whilst with a sawtooth they throb percussively. Apart from being visually very appealing, this is one of those touches that assure you that this instrument has class.

The back panel has the MIDI In and Out sockets (no Thru), the six audio outputs and two inputs, and the connector for the (huge) wall‑wart PSU.

When the pre‑production Virus arrived for this preview, it had no onboard sounds, and operating system software that was more than a little flaky. After a little web surfing, I unearthed a bank of factory sounds and a much improved OS — v1.08 — from Access's German site (see URL at the end of this review). I did still manage to crash the Virus once after that, and several features were still not in place, but there was enough to get a feel for what the final instrument should offer. Within half an hour of starting to program it, I had saved away a number of patches which were almost as good as the ones my old Jupiter 6 once produced before it developed dodgy oscillator syndrome. I was immediately struck by the quality of the filters, which were smooth and responsive. There must be some fancy computation going on under the bonnet, because here were cutoff sweeps every bit as convincing as a real analogue synth, with killer resonance thrown in too. RIP zipper noise, and good riddance.


The Virus operates on two levels. If you prefer, you can simply turn the knobs to rustle up the sounds you need, in the traditional style. For many people, this will be more than sufficient. Indeed, you should be able to conjure all your favourite 'normal' analogue patches in this manner. For those who want the more complex or less common features, there's an 'Expert Mode' behind the LCD menus, where you perform edits using the data entry knob and switches — more on what this offers in the full review. There are two user‑definable knobs, although in all the early factory patches I've heard, these are always set to portamento time and delay send.

Casting a beady eye over the basic synth architecture, the two oscillators have the now familiar virtual sawtooth and square waves, with a fairly convincing pulse width modulation. Unusually, and perhaps as an insurance policy against the whims of fashion, Access have added a further 64 digital waveforms so that you can produce PPG‑like textures and then process them via the filter section. The waveshape can be modulated via velocity or LFO so you don't get stuck with the static and lifeless raw sounds that many people associate with digital synths. A single knob controls the balance between the oscillators (I wish it had been two separate level controls!), and the sub‑oscillator (offering a choice of either square or triangle wave) adds some extra sonic muscle, although the Virus is already very unlikely to have sand kicked in its face. If you do want to thicken things up, Twin Mode is a means of allocating two voices to every note with detune and pan options to add 'mush' and spread the sound across the stereo image, but of course in this mode the Virus's polyphony is halved to six notes.

Modulation & Envelopes

The two main LFOs divide their labour so that the first modulates the pitch and pulse width of Oscillators 1 and 2, plus the resonance for filters 1 and 2 and filter gain. The second LFO handles the waveshape of Oscillators 1 and 2, FM amount, Filter 1 and 2 cutoff, and pan. The third LFO is accessible only via the LCD, and is dedicated to oscillator pitch although it does still have the same waveforms as the other two, namely triangle, sawtooth, square, sample and hold (S&H) and S&G. This last waveform is a smoothed‑out version of S&and, if applied in small amounts, is ideal for creating those subtle pitch variations everyone tried so hard to minimise in real analogues but now strive for again because they've realised it sounded cool after all! LFOs may operate in single or polyphonic mode; they can also work as mini‑envelopes with a simple 'one‑shot' action. Speaking of envelopes, there are two of these, hard‑wired to filter and amplifier, although Envelope 1 can also modulate the pitch of Oscillator 2 — handy when using oscillator sync.

Filter & Effects

The most crucial sound modifier of an analogue synthesizer is its filter, and the Virus comes supplied with not one but two. Both of these feature resonance and may operate in low‑pass, high‑pass, band‑pass or band‑reject modes. If that isn't enough, Filter 1 may operate in either 2‑ or 4‑pole mode. Different configurations allow the filters to be connected in series or parallel up to a maximum of 6‑pole operation — that's 36dB rolloff! In addition, Filter 1 has a shaper/distortion option for increasingly more aggressive overdrive effects.

The filters may be linked or controlled separately, or can even process each oscillator separately and spread the results across the stereo panorama. If you remain as yet unconvinced that a digital synth can produce a warm, powerful, smooth filter sweep, you simply must hear the Virus.

The built‑in effects are fine without being over‑complex. At present, just simple delays and chorus are offered, but the Access web site promises reverb, phasing and flanging, so I'm hopeful that these will be ready in time to make the finished version. Delay can add so much to an analogue synth and the chorus makes Juno‑style pads easy to program.

Routing & MIDI

The Virus has three stereo outputs, plus a stereo input for external signals. With some clever routing, you can send the output of certain patches out for external processing then return it via the inputs to be handled by the rest of the synthesizer section. This flexibility means you can add effects before the filter, envelope, and amplifier sections if you so wish. The internal buss system is unusual, as it allows the reprocessing of patches with other patches in Multi mode. You can use two separate signals or a stereo input and process this via the filters and stereo VCA.


This is one Virus I wouldn't mind getting. The filters are first‑rate and the fact that the oscillators produce both digital and analogue‑sounding waveforms gives it a palette far broader than anything in its class. The 16‑part multitimbrality, built‑in effects, multiple outputs and inputs for external processing should make people sit up and take notice, but better than all of this, it simply sounds great.

Of course, there are still things I'd like to see implemented/finished. For example, a unison mode, a note‑reserve function for multis, some improvements to the arpeggiator, and response to aftertouch, but since these are all easily added in operating system upgrades, I won't start bleating until I get my hands on the final version. Physically, the Virus is a bit of an odd shape, but if it can be made to fit comfortably in a rack (a rack kit is planned, apparently), and if the final power supply is rather smaller than the housebrick supplied with the preview model, then I confidently predict Access will have a hit on their hands. Don't buy a virtual analogue until you've heard it!

MIDI Matters

In the manner of all good modern synths, every knob on the Virus's front panel responds to a dedicated MIDI controller, and will send that controller from the MIDI Out socket for sequencer automation. There's another nice MIDI‑related touch, too; instead of the usual MIDI indicator LED, the Virus LCD shows a note icon, controller icon or SysEx icon depending on what it's receiving. Tasty!


I picked up a MIDI file from the Access web page containing a bank of factory sounds. I've no idea if all of these will make the final‑release Virus (nor, it seems, do Access yet), although many deserve to. Here are some of my favourites:

  • A11 PP?‑PAD
    Sounds like a PPG and shows that the repertoire of the Virus encompasses far more than brassy farts and squelchy basses.
  • A12 NO‑SEQ
    This uses the arpeggiator and delay for a great sequenced effect.
  • A20 SAT‑SYNC
    One of those big sync lead sounds that are ideal for the soundtrack to the sort of films that always seem to have titles like Large American Cop III.
  • A22 ZZ‑BASS
    It's rich and Minimoog‑like. What more could you want?
  • A54 V‑BIRTH3
    An arpeggiated patch which just cries out "tweak me!" Grab those knobs and hold onto your cheque book.
  • A55 V‑RESO2
    If you're not sold on the Virus's filter after listening to this patch, this isn't the synth for you.

Various analogue drum sounds are thrown in, too: hi‑hats, bass and snare drums, even wood blocks.

Features At A Glance

  • 12‑note polyphonic.
  • Two oscillators per voice plus a sub‑oscillator and noise source.
  • Each oscillator may be a sawtooth or square wave (complete with modulatable pulse width) or one of 64 digital waveforms.
  • Two filters usable in series or parallel for 12‑36dB operation with a remarkably flexible routing system.
  • Three LFOs, two envelopes.
  • Oscillator Sync and Frequency Modulation.
  • Built‑in effects (delay, chorus and so on).
  • Three pairs of polyphonic stereo outputs.
  • One stereo input.
  • Arpeggiator (more on this in the full review).
  • 16‑part multitimbral (with the ability to use up to four different chorus effects on individual parts of a multi).
  • Operating system upgradable via SysEx.
  • Full MIDI control of parameters.
  • 256 user patches, 128 multis.
  • Quality knobs and zipper‑free sweeps plus LCD for more complex programming.
  • Sounds bloody good!