When Pro Tools manufacturer Digidesign and hardware synthesizer company Access Music jointly released the Access Virus TDM plug-in a few years back, it

When Pro Tools manufacturer Digidesign and hardware synthesizer company Access Music jointly released the Access Virus TDM plug-in a few years back, it wasn't that radical of an idea. Others at that time capitalized on the burgeoning soft-synth phenomenon by building plug-ins that emulated analog-revivalist synth hardware. But below the surface, the Virus plug-in was different in a significant way: It was the first plug-in to take advantage of Digi's robust TDM architecture. This meant that, unlike others at the time, the Virus soft synth could pack a ton of power into a plug-in without draining a host computer's limited performance resources. The plug-in found its way into many studios and was a big success for both companies.


Like in the movie business, success in a plug-in breeds sequels to continue the lineage. In this case, Digidesign and Access Music have teamed up again for the Virus Indigo plug-in. Like their previous effort, Virus Indigo is based upon the recent Access keyboard counterpart. Also similar is the basic sound engine principal; Indigo uses analog modeling to create timbres that closely resemble classic analog synthesizers. Although it may appear to be a brand-new synth, Indigo is an improved second version of the original red Access Virus.

Existing users can upgrade to the new Indigo TDM for $95 through the Digidesign online store. Indigo provides a maximum of eight plug-in instances per session, each offering as many as 20 voices per DSP chip. This means that you can build 160 voices on expanded Pro Tools|HD systems running at 44.1 or 48 kHz. The voice count drops to 80 when operated at 96 kHz, and Pro Tools Mix users are reduced to 16 voices per DSP for a total of 128 potential voices per session. This new and improved Virus features an additional oscillator and a much improved effects section. And the library pull-down menu offers an astonishing 1,000-plus preset patches. But perhaps Indigo's coolest new feature is the Easy Page.


The Virus user-interface navigation works in Pages, allowing you to leaf through all of he control sections. Although it makes for a very logical layout scheme, the original Virus plug-in had the potential to be a real head-scratcher for novice synth programmers. It contained pages and pages of options and seemingly endless rows of interrelated knobs, pull-downs and on/off switches. But the new Easy Page — the first page in the Indigo hierarchy — provides access to a patch's main controls in one sparse area. Think of it as a master control interface when you just don't want to get that heavily into reprogramming a patch. It's also a nice way to manipulate a patch's key aspects while automating or mixing, for example. I found the master cutoff, effects send and OSC volume knobs to be particularly useful once I'd already developed an overall sound that I liked. It does, however, lack master mix and output-level knobs, which would have been nice additions.

Beyond the Easy section, the remaining Pages are ordered in a natural sequence: OSC, Filters/Env, LFO, FX-1, FX-2/Global and ModMatrix. The OSC Page includes three separate but related oscillators. The first alters wave shape, pitch and tuning and establishes the key-follow setting. The second oscillator digs in much deeper by introducing mostly frequency-modulation controls. The third adds a further level of complexity to sounds with more wave shapes, as well as additional pitch and detuning controls. The remainder of the OSC page includes various means to thicken sounds and change the timbre, plus a mixer section to balance the various aspects. The Filters/Env Page includes a pair of filters and envelope generators. Both filters have two poles, but the first can be used as a 4-pole, providing a huge punch to the overall sound. Indigo includes three low-frequency oscillators in the LFO Page that are used to modulate the overall sound characteristics.


The effects sections of the Virus received a nice face-lift with the release of Indigo. It is now divided into two Pages: FX-1, which includes analog boost, chorus, phaser, distortion, an additional ring modulator and a detailed delay/reverb section. The updated delay/reverb section features numerous control options, including beat-focused parameters. The delay itself has two pull-down menus: one to select from a variety of time-synched ping-pong settings and one to change the LFO type. Reverbs are very effective and available in ambience, small room, large room and hall algorithms. Reverb can also be synched to a multitude of clock options that stay true to the Pro Tools bpm setting. The ring modulator features a single knob that has a dramatic effect on an overall sound. The phaser and chorus are more subtle but also sound great and are very effective additions.

FX-2/Global naturally introduces global controls for overall tuning and tweaking, but it also features an extensive Vocoder section, an arpeggiator, an envelope follower and the external input selector. Unfortunately, the input selector has the same frustrating behavior as the original Virus plug-in; Indigo defaults to the Off setting in Input mode with every preset. This is natural if you're recording a MIDI track; the problem is that when used as an insert on an audio track, the lack of input mutes the track's signal. This means that every time you pull down a new patch to audition, you have to go into the FX2/Global page and switch the Input mode setting to Static. Operation would be much more intuitive if Indigo had the ability to adapt its Input mode to the task at hand. Rounding out the pages, the ModMatrix page is your signal-routing section. Here, you're provided the means to manage source-destination and modulation assignments.


Okay, enough about the details; it's time to get into the sounds. Virus patches are divided into 17 library preset categories: Init Sounds, Acid, Arpeggiators, Bass, Classic, Decay, Drums, Effects, Input, Leads, Organ, Pads, Percussion, Pianos, Pluck, Virus Indigo and Vocoder. Within each subfolder, you're presented with pull-down lists of varying lengths. The Piano and Percussion options are relatively short, whereas categories such as Arpeggios, Leads and Effects are very deep.

The presets are simply breathtaking in sound. Some are natural, such as many of the organ sounds and the Rhodes, whereas others are intentionally hyped. Too often when navigating through sounds on hardware and software synthesizers, you have to fight your way through lame nylon guitar or cheesy piano patches as you search for something cool. This is not so with Indigo. Although there are more than 1,000 patches, the overwhelming majority of them are useful; inspiring; and, dare I say, beautiful. Take the patch “Basic” under the Bass section for example. It's a pretty standard synth-bass sound in the initial attack, but as it sustains, the character is revealed as incredibly rich, with a gorgeous yet subtle stereo spread and a warmth that belies its utilitarian name. As the note is released, you don't hear any artifacts whatsoever, just a pleasant fade of the sound into silence. This is what you ask for in a quality synth, and the Indigo delivers. My one issue with the presets is the same problem I had with the original Virus: the inconsistency in output volume among different presets.

As mentioned, there is a stunning selection of arpeggio patches with a wide variety of tones and patterns, from chiming bells to edgy electronica to the aptly named “Nice Arp.” The Classic category is pure retro delight, although I could have done without another boring sitar patch. The pads are lush and deep, and the leads are exciting and varied. The vocoders not only sound great, but they're very useful tools for lead vocal tracks. Inserted on an aux track with a lead vocal bused to it, the Voc Delay preset made for a rich performance that I think I'll keep through to the final mix. Two related categories I would have liked to see expanded are the Drums and Percussion sections. The Drums category is moderately thorough, but it mostly features 909-style sounds and classic kit instruments you'd find on any other synth. This may not be such a bad thing, however, because they provide a nice starting point. If you're a drum programmer, then you will have to actually do some thorough programming to get unique sounds. The Percussion section is far too light for my needs: You only get 21 presets, and few of them inspire much excitement.

Thanks to the Easy Page, programming Indigo can be as simple or as deep as you want it to be. If you have done much programming in the past, everything is in its right place, and you have ample room to explore. The idea with Indigo is to go ahead and get lost in it and save your own custom presets as you go. (One of the beauties of programming a software synth such as this is the ability to save an unlimited number of custom patches.) If you find yourself getting too lost or you simply need slight tweaks, the Easy Page is your life jacket. However, if Digidesign and Access were planning a Virus version 3, the ability to create your own custom Easy Page would be a godsend.


If you already own the hardware Access Indigo synthesizer, then you can dump patches between the software and hardware versions, even ones you have created yourself. This is a great feature if you're a devoted Access junkie or want to mimic exactly what happened in the studio in a live context without needing to sample. But it may be redundant for studio hermits because the sounds are identical. Incidentally, another benefit of owning the physical board is that you can control plug-in automation with the Indigo keyboard's knobs.

Thanks to its tight integration with Pro Tools, Indigo's automation capabilities are powerful, smooth and thorough. Automation is available in two modes: normal Pro Tools automation or MIDI automation. Pro Tools automation is straightforward as always: You choose a parameter, put it in Auto-Write mode and perform your knob moves. What's not standard is the ability to use a MIDI-compatible control surface to write MIDI automation. Although more involved than standard automation, you can map a MIDI control surface with a selection of your most-used parameters of choice.


The following are few important notes about installation for previous red Virus users: Indigo now requires an iLok Smart Key for copy protection. Make sure that you have the bug fix available on Digidesign's Website. The original software installation places all of your old presets in the trash, but the problem is fixed with the updated installer. Also, even with the bug fix, older sessions with previous patches now show up with the Indigo window, but your sessions will read the patch as , even though your patch is there and audible. This means that you'll have to dig around the library and remember which patch belonged to which session. Also keep in mind that because Indigo is an upgrade and not a separate synth, installation will remove the previous red version; you cannot use the two synths together.

The Indigo manual includes a number of useful tutorials, which are a tremendously helpful starting point for sound-design novices. Demo sessions with memory locations and written automation show how Indigo's numerous control parameters affect a given patch's timbre. The addition of application-specific tutorials — such as how to set up Indigo for drum programming — would have been a nice touch, but the provided approach gives a thorough explanation of the many ways Indigo works.

Like its predecessor, the Virus Indigo TDM is a powerful; deep; and, most important, gorgeous-sounding software version of analog-modeling synth technology. Although some of the problems that occurred in the original still remain, Indigo is superior to the first incarnation in every way imaginable, most notably in sound quality, effects and ease of use. Powered by TDM muscle, Virus Indigo succeeds not only in preserving the tradition of classic analog sound, but also in expanding the new tradition of excellent TDM synthesizer design.

Product Summary



Pros: Excellent-sounding factory presets. Streamlined programming interface. Extensive sound-design and automation facilities.

Cons: Minor bugs when upgrading from previous version.

Contact: tel. (800) 333-2137; e-mail; Web

System Requirements

Pro Tools|24 Mixplus or Pro Tools|HD running on a Digidesign-approved Mac or PC