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Access Virus Rack Virtual Analogue Synth Module By Gordon Reid
Published October 2001


Rather than rack up their recent flagship Virus Indigo, Access have made the Virus Rack a lower‑spec version at a keen price. Gordon Reid considers whether this Virus is still infectious...

When Access announced the Virus Rack, it was clear that it was not going to be a second‑generation Virus in a 1U rackmount case. From the start, its specification was much closer to that of the now‑discontinued Virus A, with lesser polyphony and lesser multitimbrality than its more expensive brethren. In addition, the comparison chart published on Access's web site promised a substantially emasculated effects structure, and a return to the Virus A's dual‑oscillator voicing.

Therefore, it was with some trepidation that I received the Virus Rack for review. My worries grew when I switched it on to discover that it was loaded with the already‑superseded v1.00 operating system (see the box on upgrading below). Nonetheless, the Rack is still a Virus, with a pedigree that is worthy of considerable respect. So, with that in mind, I began to investigate what it offers, and to see how it differs from its predecessors.

The Major Differences

First things first: the Rack offers 16‑note polyphony rather than the 24‑note polyphony of its siblings. Secondly, the Rack has reverted to the Virus A's dual‑oscillator voicing (although there is also a sub‑oscillator). It's a shame that Access feel the need to exaggerate the Rack's specification in some of their promotional material by describing it as offering "three oscillators per voice. Two main oscillators plus one sub‑oscillator". Anyway, while neither limitation is good news, neither is particularly bad news... nobody complains about the five voices of the Sequential Prophets, or the eight of the Roland Jupiter 8, Oberheim OB8, or Yamaha CS80, all of which are dual‑oscillator synths.

The good news is that contrary to the statements in my review of the Virus Indigo (see SOS June 2001), the Rack is not eight‑part multitimbral — it's now 16‑part multitimbral, Access having upgraded the spec in the interim. I emphasise this because a visit to the Access web site a few weeks ago would have told you otherwise. Indeed, a number of synth sites — such as — still do as SOS went to press.

The second major area of change lies in the effects structure. The effects on the larger Viruses are adequate, but not great, being superior to those of the Waldorf Q, but significantly inferior to those of the Novation Supernova II — the Virus Rack's immediate rivals. Unfortunately, the Rack falls even further behind, losing no fewer than 48 of the Virus B's, Indigo's and Keyboard's effects.

Let's be explicit. Sixteen of the Rack's effects are independent chorus units for each of the multitimbral parts. A further 16 are the so‑called 'analogue boosts'. The 33rd effect is a single, global reverb/delay. The Rack's 34th effect (if you can legitimately call it that) is the 32‑band vocoder. Hmm... in my world, that's 16 enhancements to the basic voicing, 16 insert effects, one global effect, and a vocoder. What is clear, however, is that (notwithstanding subjective views regarding the competition) in truncating the operating system from Virus OS v4.0x to the Rack OS v1.0x (or OSR, as it is known), 16 ring modulators, 16 phasers, and 16 distortion units have disappeared. Oh yes, and the Rack loses the Surround capabilities of its more expensive brethren.

The user interface is the final, inevitable area of change between the Rack and the other Viruses. With just five rotary encoders (that's knobs, mate), 12 buttons, 12 LEDs, and a 16 x 2 LCD, it's a long step backwards from the desktop and keyboard Viruses. Overall though, I should praise Access on the transition from control surface to 1U front panel, because the Rack is far from impenetrable, and the combination of knobby controls and menus, as well as 'Easy' and 'Expert' programming modes, does much to ease the pain.

On the other hand, there are times when I could scream! I'll give you an example. When I set up the Rack, the LCD was not pointing directly at me. No problem, I'll just adjust the contrast (I thought). Thirty minutes later, I still couldn't see the screen. I had read the manual from cover to cover, but I couldn't find out how to access the appropriate menu item. In order to check, I downloaded the manual in PDF format and performed a search. I was right... although mention is made of the LCD contrast control, the instructions on where to find it are missing! Furthermore, the Rack's manual has no index, no block diagrams, and no function maps. That's simply not good enough.

Hooking It Up

The Virus Rack offers a line‑level input on its front, and its rear plate sports dual analogue inputs for treating external signals and for giving access to the Vocoder. There are also four analogue outputs, which is adequate, but, curiously, there are holes and blanking plates for a third stereo pair of outputs. Furthermore, there's a hole and blanking plate for an internal 90V‑260V power supply. According to Access, a hardware upgrade is in the works which will allow users to take the spec of the Rack up to that of the Virus Indigo — and in addition to a third stereo output, this enhanced unit will also apparently offer an internal power supply; hence the blanking panels. This strikes me as odd, because if you have to replace the motherboard in the Virus Rack and the power supply, there won't be much more than the casing left from the original instrument. As yet, no price has been fixed for this upgrade, but Access reckon that the Virus Rack and the upgrade combined won't cost less than the price of the Virus B.

Eventually, I found the LCD contrast command (you'll find it not in a Utilities menu, but instead at the right‑hand end of a very long LCD menu selected using the 'Arpg/Ctrl' button, of all places), and once I had mastered the Rack's controls, it was time to put it through its paces. And very nice paces they are, too. I have long had a soft spot for Access's oscillator and filter algorithms, and the interpolation of quantised values to remove zipper noise remains an excellent feature. The retention of the 62 spectral waves (see the Virus Indigo review at" target="_blank for more on these) is also very welcome, although I would still like to see this side of the Virus extended further into wavetable synthesis. Likewise, the 16 independent arpeggiators survive the transition to the Rack, as does the modulation matrix. Equally importantly, the Rack retains the squeaky‑clean reproduction of the larger Virus models, and sounds just as smooth and creamy as its predecessors.

My only real complaint lies with the new effects structure. For example, compare the Rack to the Novation Nova. OK, I admit that the Nova is somewhat more expensive, but 16 choruses and a global reverb/delay do not compete against the Novation's huge number of simultaneous, truly multitimbral effects.

Before finishing this review, I took my time to step through all 512 factory voices. As on other Viruses, these rely far too heavily on arpeggiated dance, trance and related sounds for my liking. However, that's where a large proportion of the Virus's market lies, so I can't blame Access for taking this route. Once you discover some of the superb pads, or the expressive lead sounds, though, the Rack comes alive. Better still, start programming, and you'll soon feel the urge to overlook the Rack's shortcomings.

Indeed, by the time I had finished this review, I was rather pleased that I had not lobbed the thing off the parapet of the local church. The Rack is not perfect, but it still does what all other Viruses do... it sounds superb. With 128 Multis and 256 patch memories in RAM (the others are in ROM) there's adequate space so save your own sounds, so I suggest that you get programming. It can be a very satisfying experience.


Trying to summarise the Virus Rack is what our American friends call "a tough call". On one hand, it shares most of the strengths (as well as the weaknesses) of previous Viruses. This makes it a very satisfying instrument, and I doubt that I will ever tire of its sound. Furthermore, it requires very little space, and doesn't cost an arm or a leg. On that basis, the Rack is a heck of a lot of synth for the money.

On the other hand, it offers neither the gritty sound of the Waldorf Micro Q, nor the superlative flexibility of the Novation Nova. So, while the Rack is undoubtedly the most powerful virtual analogue synth for the money, you might want to ask yourself whether you would be better served spending a little extra. As I said, it's a tough call.

The Upgrade Game

Just before I finished this review in early August, the v1.02 OS for the Rack was posted on the Access web site at www.access‑ This is the second update, the other being v1.01, which seems to date from June. The major changes since v1.00 include better parameter handling, improvements to the Global parameters for the arpeggiator and delay/reverb effect, and an auto‑repeat function for the scroll buttons. Other improvements include bug fixes and, to quote Access, "loads of little enhancements".

Note, however, that the Access web site has already announced a hardware modification to the spec of the Virus Rack. According to Access, this is because the Motorola DSP chips used for the earliest versions of the Rack (now known as the Virus S) have become scarce, and Access have had to continue manufacture with a different chip, which in turn requires a slightly tweaked OS version. The 'new' Virus Rack is known as the Virus T. This means that as of the next OSR update, you will need to load the system appropriate to either the T or S version of the synth. Given that the Rack has only existed for a few weeks, I find this rather disquieting. Access claim that performance of the synth is unaffected, for better or worse, but at the time of writing, no 'T' versions of the Rack had yet shipped, so I was unable to put this claim to the test.

Brief Specification


  • Polyphony: 16 notes.
  • Multitimbrality: 16 parts.
  • Oscillators per Voice: Two (plus one sub‑oscillator).
  • Analogue‑style waveforms: Sawtooth, variable pulse, sine, and triangle.
  • Spectral waveforms: 62.
  • Number of filters per voice: Two.
  • Filter modes: Low‑pass, high‑pass, band‑pass, band‑reject.
  • Maximum filter cutoff slope: 36dB per octave.
  • Number of LFOs per voice: Three.
  • Envelopes per voice: Two.
  • Number of arpeggiators: One per part.
  • Part effects: one chorus and one 'boost' per part.
  • Master effect: Delay/reverb.


  • Number of ROM Programs: 256.
  • Number of RAM memories: 256.
  • Number of Multis: 128.


  • Number of inputs: Three.
  • Number of outputs: Four.

Test Spec

Virus OS version reviewed: v1.00 for Rack (version 1.02 was posted to the Access web site at the end of the review period, but not in time to be considered in this review).


  • A superb‑sounding synth engine in a small space.
  • Solidly built.
  • Comes with a free version of Emagic's Sounddiver editor for Windows and Mac.


  • Very limited effects structure.
  • The manual is poor.
  • Access's patch programmers do them no favours... get editing.


The Virus Rack sounds superb, and is an excellent complement for other instruments with greater polyphony and better effects. There is a handful of annoying niggles, but given the price and sound quality, it should be a winner.