With version 2 of their Guitar Rig, Native Instruments are taking amp modelling into the realms of modular synthesis.
In the decade or so since Line 6 launched Amp Farm, software amp modelling has come a long way in both quality and diversity. Among the many high-quality packages now available, Native Instruments' Guitar Rig stands out as the only truly modular system there is. Its free-form interface allows the user to choose any number of elements from a list that includes amps, speakers, stompbox and studio effects, and arrange them in any order to create their own guitar sound.
NI also broke new ground by making a hardware unit integral to their software package. Guitar Rig came with Rig Kontrol, a floor unit that didn't act as an audio interface, but served both as an impedance-optimised DI box and a foot controller for the software.
Time marches on, and NI have produced a thorough overhaul of both Guitar Rig and Rig Kontrol. The software now includes numerous new amps — including, for the first time, bass amps as well as guitar amps — new cabinets and new effects, as well as an entire new category of module called Modifiers. The hardware is now not only a controller and DI box, but also a USB 2.0 audio and MIDI interface, meaning that you no longer need a third-party soundcard to use Guitar Rig on your Mac or PC.
With so many new features to talk about, I won't go into detail here about the modules that were already included in version 1, and I suggest that anyone unfamiliar with Guitar Rig should read Paul White's review in SOS September 2004.
The new Rig Kontrol is a smart-looking beast with a reassuringly thick metal skin. It could probably survive being run over by a car, and should certainly be robust enough to stand up to stage use. It terms of the control it offers, it's similar to version 1 except that there are now six rather than four independent footswitches (plus the switch built into the rocker pedal). Like the original, Rig Kontrol 2 transmits its control messages to the computer not as MIDI, but embedded inaudibly in the audio signal from your guitar. The difference is that this signal is converted to digital within the Rig Kontrol 2 and sent to the computer over a USB cable with no need for a separate soundcard. This will be a boon for many people, but particularly for those using Guitar Rig live. The new Rig Kontrol handles all audio inputs and outputs and puts them at your feet just like a conventional multi-effects board, cutting down clutter and reducing the number of ways for things to go wrong.
As an audio interface, the Rig Kontrol 2 is pretty well specified. There are two high-impedance inputs, each with its own gain control, so you can connect two guitars at the same time, with their input levels matched; again, this will be handy for live players who switch guitars for different songs. There are left and right stereo outputs on balanced quarter-inch jacks, with an associated button that switches the output level between high (for connection to keyboard amps, mixers or powered monitors) and low (for output to guitar amps). There's also a headphone output, with a level control that I found to be a little on the sensitive side, plus inputs for two expression pedals, and MIDI In and Out. A large two-digit LCD shows you the current patch number, and four LEDs show the presence of signal at the input and output, MIDI data activity, and the on/off status of the foot pedal's switch. What's more, the Rig Kontrol 2 is powered over USB, so there's no need for a separate power supply (and, in fact, no input for one). Live players rejoice!
USB 2.0 has been standard on new computers for the last few years, but as yet, most audio interface designers have chosen to support Firewire or stick with the low-bandwidth USB 1.1. I've talked to several manufacturers about this, and have heard some tales of woe about how hard it is to write a good low-latency USB 2 driver. I guess Native Instruments haven't listened to these tales, because the Rig Kontrol 2 connects via USB 2 and offers buffer sizes down to 1ms (which equates to a 2ms round-trip latency). The Rig Kontrol 2 has the simplest installation procedure I've ever seen, and its ASIO Configuration page offers just a few simple controls. You can set the buffer size and sample rate, from a choice of 44.1, 48 or 96 kHz.
I started with a 4ms buffer size, giving a round-trip latency of 8ms which I found comfortable for playing. Initially this seemed to work, but after a while, I began to notice the odd click and splat — often, but not always, when the cooling fan in my laptop started or stopped. Unfortunately, the next lowest buffer size is 8ms, with a round-trip latency of 16ms, which was high enough to put me off when playing. After hours of testing and many emails to NI, we couldn't detect any CPU spiking or throttling going on, and were forced to conclude that this was just the best setting that could be achieved on my computer. In fact, Native Instruments told me that only the fastest computers will be able to handle the 4ms buffer size, and that most guitarists are happy with a 12ms round-trip latency.
This raises a couple of questions. If a newish 2GHz Centrino laptop isn't fast enough to run the Rig Kontrol with 4ms buffers, then what is? And if NI believe 12ms is acceptable, why isn't it possible to set the latency to 12ms? In the end, I chose to keep the buffers set at 4ms and put up with the clicks, which were not very frequent. My machine doesn't perform any better with other USB interfaces, so I don't want to be too gloomy about this — there are plenty of people running USB devices at lower latencies in other systems, so I'm sure this will be the case for the Rig Kontrol too.
It's probably worth pointing out a couple of consequences of the fact that Rig Kontrol 2 is a USB 2 audio interface as well as a controller. The first is that you'll need a recent operating system: on the PC, Windows XP Service Pack 2 is required, while Mac users need OS 10.3 or better. The second is that you can't just use the analogue circuitry of Rig Kontrol 2 as a DI box for another interface, as you would with RK1. The third is that its qualities as an interface are not a lot of use to Pro Tools users, since PT doesn't support open driver standards such as ASIO. You can, of course, still use Guitar Rig as an RTAS plug-in, but you'll need to input your guitar via some Digidesign hardware. There are, however, Direct X and MME drivers for those running non-ASIO programs, and Core Audio support for the Mac fraternity.
Finally, I came across a couple of minor problems with the Rig Kontrol 2. There were times when I started my computer up to use it and the pedal completely failed to work. Guitar Rig 2 's Pedal Calibration function always got it working perfectly, so in practice it's only a problem if you forget to do this. I also found that the stand-alone version of Guitar Rig always crashed if I switched to a different program when its ASIO Configuration page was open, not that this is something you'd often want to do.
The new Loop Machine module is a sampling delay along the lines of the Lexicon Jam Man and Akai Headrush, designed to allow the guitarist to build up a layered texture by repeatedly overdubbing loops. As you'd expect, it offers buckets of recording time, and there are some nice additional touches such as the ability to A/B two separate loops, reverse the loop, overdub a longer part onto a shorter loop, and vary the recording level and pan position at each pass. However, what's really impressive about the Loop Machine is the way Native Instruments have integrated it into the Guitar Rig environment.
It appears as just another module in the Tools section, and it can be installed as either the first or the last module in the rack, enabling you to loop either 'dry' or 'wet' sounds. The really neat thing about it, though, is that once you've dragged it into the rack, it sticks around when you switch between different Guitar Rig patches and banks, so you can build up a multi-layered loop that incorporates any number of different GR sounds.You could, for instance, begin by laying down a rhythmic bed in one of the step sequencer-based patches, before using an octaver patch to add a bass part and others for more conventional lead and rhythm guitars.
What's more, if you assign Rig Kontrol buttons to the Loop Machine's Play/Record and Stop controls, Guitar Rig will remember these assignments when you change patch, even if that means over-riding the control assignment that's built into the new patch. This is exactly how it should work, since the Loop Machine is only really useful with a foot controller attached.
Another really cool feature is the ability to export the resulting loops as audio files. Not only can you export the bounced loop that you hear from Loop Machine, but you can also export every layer as an individual file. If you export the bounce, you get to name the file and choose WAV or AIFF format; layers are automatically saved as WAVs called 'Layer 1', 'Layer 2', and so on. It's also possible to save an entire Loop Machine setup as a single '.LS' file. You can't import other audio files into Loop Machine, but GR2 's tape modules can do that.
As with every major software update, there are plenty of utilitarian enhancements in Guitar Rig 2 that make it easier to work with, but could hardly be described as exciting. For instance, the browser structure has been changed to improve preset handling — not thrilling, but very worthwhile in a program that comes with several hundred patches and will inspire you to create plenty more.
Fortunately, there's also plenty that can and should be described as exciting, in the shape of a veritable army of new modules. The original Fender Twin, AC30, Plexi and 'Instant Gratifier' models have been joined by no fewer than four new amplifier modules, beginning with Tweedman. Based on a '60s Fender Bassman head, this is one of those models that will find uses in numerous different styles of music. It can, of course, be used as a bass amp, but it's also a very versatile tool for recording electric guitars. With bright and warm channels that can be blended to taste, Tweedman is ready for pretty much anything from clean country picking to clanging power chords. It has nice response to playing dynamics and a sound that sits somewhere between the ringing clarity of a Twin and the rasping distortion of an AC30. Tweedman is definitely my favourite of all the amps on offer here, and is a real highlight of Guitar Rig 2.
Jazz Amp gives you a virtual Roland JC120, or at least the clean channel of a JC120. That amp, of course, was a fairly standard transistor affair, the key to its popularity being the built-in ensemble effect, which could provide either vibrato or chorus. Said effect is reproduced here, and to my ears it sounds pretty authentic. However, if I'm after an ultra-clean sparkly sound, I'm usually happy to DI the guitar without any amp simulation, and Ensemble is available as a separate effect, so I didn't find that much use for Jazz Amp itself.
Lead 800 replicates the Marshall JCM800. Although this is one of the most popular high-gain valve amps, it's never been on my own Christmas list, and I probably won't turn to Lead 800 all that often for exactly the same reasons. The clean sounds tend towards the brittle — more so here than I remember from the real thing — and to my ears, turning the preamp gain more than about 5 percent of the way up turns everything into sonic mush, just like the original. But if that's your bag, it does seem to do the goods for '80s heavy metal soloing and palm-muted riffing, and as with the other valve models, you'll find plenty of scope for fine-tuning in the Expert parameters accessed by clicking a plus symbol at the right-hand side of the module.
Flicking through the bank of presets labelled Bass, I was surprised to find that not many of them actually use the new BassVT amp module, and none of them use the Bassman emulation. Most of them sound fine anyway, perhaps indicating that the choice of cabinet is as important as the choice of amp for bass. Be that as it may, the Ampeg model is comprehensive, with a graphic EQ and several other tone-shaping options on top of the usual amp tone controls. It sounds good, too, particularly for rockier bass parts, with an upper-mid snarl that doesn't detract from a meaty low end. For warmer, more middly bass tones redolent of the 1960s, the Tweedman module is a good alternative.
Doubling the number of amp models has done a lot to increase the sound palette available to Guitar Rig users, and the modular nature of the program means you're not subject to the same restrictions as with 'real' amps. For instance, I managed to create a truly evil sound by routing the output of the Tweedman directly into the input of the Plexi amp. Probably not a trick you would want to attempt in real life...
To go with the new amp models, there's an even wider range of cabinets than before, and yet more virtual mics to record them with. As well as the appropriate partners for the new guitar amp models, there's now a range of bass cabs including Ampeg and SWR models, along with the new open and closed Leslie models from NI's B4 II. These are worthwhile inclusions, as even when you don't want a spinning effect, have a very distinctive tonality. As you'd expect, different mics have been modelled for the bass cabinets.
As most guitarists have probably had to explain to their spouses at some time or other, no two distortion pedals sound exactly the same, and that's why we need to have lots of them. Guitar Rig 2 will satisfy your gear lust in that respect, containing as it does no fewer than 10. New models simulate, at one end of the scale, a clean gain boost, and at the other, the overkill of the Boss Metalzone, whilst the most intriguing addition is a model of the original Sansamp PSA1. There's something vaguely circular about simulating an amp simulator, and it made me wonder whether NI had included the Transamp model just to show off how far technology has come since it was introduced! Certainly, when used on its own, Transamp sounds nothing like as good as NI's amp models; but used as a preamp, it makes a versatile distortion box.
There are no new modulation effects, but the EQ section has been expanded. Crywah is an alternative to the original Wah and Talkwah units, modelled on the Crybaby, and is a worthwhile addition if wah is your thing. Pro Filter, meanwhile, is derived from the filter section in NI's virtual Prophet 5. A continuous rotary knob moves the filter shape from low-pass through band-pass toward high-pass, and the slope can also be varied in any degree from 12 to 24 dB/octave. Cutoff frequency and resonance can also be adjusted, and real-time movements are smooth and free of zipper noise. Pro Filter is not very exciting with static settings, but comes into its own when you assign its parameters to the foot pedal or to a Modifier (OK, OK, I'll get to them in a minute...). The other notable addition in this bank is Auto Filter, an auto-wah effect intended primarily for bass. Modelled on a Boss unit, this is basically a resonant filter controlled by an envelope follower, and it works really well, with a smooth and rich sound that is devoid of glitching or stepping. Funky.
Elsewhere, the old Noise Gate has been joined by a more sophisticated Noise Reduction unit based on dynamic filtering. In general, low-level signals from your guitar contain little high-frequency information, so this technique employs a low-pass filter to clean up quiet signals. When the signal level drops below the Threshold setting, it is gated completely. You can set the Threshold automatically by hitting the Learn button whilst not playing. Although I found this erred on the conservative side, the Noise Reduction module is a very handy addition, particularly if you're putting together high-gain patches. Also new in the Vol collection is the Stomp Compressor, an idiot-proof and good-sounding compressor.
One of the neat things about Guitar Rig 1 was the ability to split the input signal into two paths and have independent amp and processing chains for each. That facility is still there in version 2, but there's another way of doing it, courtesy of the Crossover Mix module. What this does, in essence, is send the high-frequency component of the input signal down one path, and the low-frequency component down another. You can, of course, specify the crossover point, and split either path further if you want yet more control. This has lots of applications, but perhaps the most obvious are for bass patches. There are a number of effects that sound good on bass, but if you apply them to the full-bandwidth signal, play havoc with the bottom end. Setting up a Crossover Mix allows you to split off the treble component of the bass signal and apply chorus or flange to it while keeping a solid low-frequency base to the sound.
Finally, we come to an entire new category of module. With its modular nature, Guitar Rig 2 already went beyond mere emulation of hardware amps, but the new Modifiers take it into the realm of synthesis. In fact, anyone familiar with basic synth architecture will have no difficulty grasping what these modules do: they generate not audio signals but control messages. Five Modifiers are available: a flexible LFO, an envelope follower, a multi-stage envelope which can be triggered by audio input, and two varieties of step sequencer. There's no room here to list all the features on offer for each of these modules, but all are well specified, with parameters carefully chosen for the job in hand, and can sync to host tempo where appropriate.
Setting up the Modifiers is child's play. Each has a big square button labelled Assign. Click on that and drag the mouse to the parameter you want to control, and it's done. And yes, Modifiers can be assigned to multiple destinations, in different amounts. Each Modifier has a drop-down menu listing its Targets and the amount by which it is modulating them. This can be adjusted from -100 to 100 percent using a slider. The same slider can also be accessed by right-clicking the destination parameter, in just the same way as you would to assign it to a Rig Kontrol pedal or switch.
The scope of what's possible with Modifiers is boundless. You want to assign an LFO to the Pitch Pedal pitch-shifter, so as to create a vibrato? No problem. How about a vibrato that gets faster as the note sustains? Easy: Modifiers can be modulate each other, so add an Envelope module and assign that to LFO Rate. OK, so how about we keep that vibrato, but also use the Pitch Pedal to turn single notes into tunes? It's the work of minutes. Add an Analog Sequencer module, assign that to the Pitch Pedal as well, and set the sliders for each step to 'play' the pitch-shifting. This sort of thing becomes completely addictive, and you can create amazing effects by modulating the most unlikely Guitar Rig parameters.
The only thing I found limiting was that the LFO module has no level control of its own: this makes it difficult to modulate the amount of LFO that is applied to another parameter, for instance when you want vibrato or tremolo to fade in on sustained notes. Even better would be a general way of applying one Modifier to the connection between another Modifier and its Target, allowing you for example to modulate the amount of LFO that reaches the Target. This small restriction aside, however, I absolutely love the way NI have implemented Modifiers, and I feel they really do take the program to a new level. Perhaps the future of guitar synthesis lies not in MIDI pickups and so on, but in something like this.
Guitar Rig 2 's CPU demands depend on how many modules you use. On my 2GHz Centrino laptop, its CPU meter went from 2 percent, for simple effects patches with no amp module, to 17 or more for complex dual-amp patches. Typical setups came in around the 8 to 10 percent mark, so a modern computer should handle three or four instances within a mix. New in GR2 is a High Res button, which switches the internal processing to a high sample rate. This does make it sound slightly smoother, but at the cost of a huge CPU hit.
I have never reviewed a product that has given me as much pure enjoyment as Guitar Rig 2. I lost count of the number of occasions I found myself thinking 'Ah, but it would be really cool if it did that...' only to discover that NI's designers had been thinking along exactly the same lines. The modular setups you can put together are limited only by your imagination, and it's easy to while away the hours just tinkering with Modifiers and Splits. At the same time, if you need to get a sound fast, a couple of mouse clicks is often all that's required. The only real worry I have concerns the Rig Kontrol 2. If my experience is typical, then it will be frustratingly difficult to run it at an acceptable latency without some glitching, so I really hope this isn't universal.
Anyone who owns and likes version 1 should definitely upgrade their software to version 2. Whether it's also worth trading in your Rig Kontrol for the new hardware (latency issues aside) is less clear; it doesn't offer that much more control than the original, although the two extra buttons will be very useful if you want to use the Loop Machine. It seems to me that those planning to use it live have most to gain by upgrading, since cutting down the number of wires and computer peripherals in the rig has got to be a good thing. By contrast, those who use a multi-input soundcard in the studio might not want to tangle with running a separate USB interface alongside it, and it's of little use to Pro Tools users.
With products such as this, the question that matters most to many people is 'How realistic is it?' If, by that, you mean 'Can you use Guitar Rig 2 to get recorded sounds that will be indistinguishable from a real amp?' I would say yes, at least within the context of almost any real-world mix. If, on the other hand, you mean 'Will the experience of playing through Guitar Rig 2 be exactly like playing through a real amp?', then no, it won't. To me, the fact of sitting in front of a computer to play means you'll never be in quite the same state of mind as with half a dozen smoking valves behind you. You'll evaluate sounds differently and make different choices — and there will be options available that you have never had before. It's in this department that Guitar Rig 2 really shines, and where it leaves the competition behind. If you want to copy hardware amp setups in software, Guitar Rig 2 is at least as good as any other program, but to do only that would be a waste of its potential. When you want to go beyond what's possible in hardware, nothing else comes close.