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Line 6 Variax

Modelling Guitar By Paul White
Published June 2003

Not content with modelling guitar amps, Line 6 have now turned their attention to the guitars themselves.

Few music products have created as much interest amongst players as the Line 6 Variax, an electric guitar with built-in electronics that enables it to emulate a number of popular electric, semi-acoustic and acoustic guitar models, as well as metal-body resonator guitars, a banjo and even a sitar. It is not a guitar synthesizer and does not use MIDI, so issues like tracking and delay are irrelevant in this context. Everything is done by reshaping the sound from the strings themselves.

Line 6 VariaxPhoto: Mark Ewing

Although mainstream guitar modelling was pioneered several years ago by Roland with their VG8 system (which uses a special six-way pickup that fits your own guitar), the Line 6 approach is to build all the electronics into a good-quality guitar, which makes the system cost-effective and easy to operate, the down-side being that you can't use your own guitar. Whereas the Roland VG8 and VG88 combine guitar modelling, amp modelling and effects, the Variax confines itself just to guitar modelling.

Like the Roland system, the Variax uses a separate pickup for each string, though in this case it's an integral bridge-mounted piezo transducer rather than a narrow magnetic pickup, so there are no visible pickups at all — straightaway this gives the guitar a distinctive look. A side benefit of using piezo transducers is that they are not susceptible to radiated hum and interference from transformers and computer screens in the same way magnetic pickups are — a factor that will be welcomed by many recording guitarists.

Successful guitar modelling can only be accomplished using separate pickups for each string, as that enables things like angled pickups and pickup combinations to be emulated, so while amp modelling works fine with any guitar (including Variax if you plug it into a Pod or other modelling amp), an external guitar modelling box for use with a regular guitar would be very limited.

Another advantage of providing the guitar and electronics as an integrated package is that the designers know exactly what signal to expect from the bridge pickups, which is vitally important, as part of the modelling process relies on converting the frequency spectrum produced by the pickup to the frequency spectrum produced by the instrument being modelled. In the case of acoustic guitars and banjos, the resonant attributes of the body must also be modelled, while, with electric guitars, the pickups themselves make a pretty complex contribution to the sound.

Modelling Technology

The extent to which the various guitar sounds have been analysed and the processing used to recreate their sounds is clearly something of a trade secret, but I think it's safe to assume that in addition to the spectral modelling described, there's also a dynamic element to the processing to emulate the sustain characteristics of the original instrument and, in most cases, some kind of overall body resonance. The modelling has to be done for each pickup position (and combination) on the original instrument so that when the pickup switch on the Variax is moved, the tonal results match what you would expect if you were playing the real thing.

Line 6 Variax £799
  • Plays just like a regular guitar.
  • Modelled guitar sounds are subjectively convincing.
  • Not susceptible to induced hum and buzz.
  • Useful acoustic and resonator sounds.
  • No tremolo version available.
  • Some background noise when using high levels of overdrive, though this is typically well below the hum and buzz level we normally have to put up with.
The Variax has done for guitar modelling what the Pod did for amp modelling, and provides acceptably close emulations of many classic guitars, as well as a few less usual instruments. Its immunity to electromagnetic interference is a huge benefit in the studio, especially where there are CRT monitors.


According to Line 6, they started by analysing every element of a guitar's tone, which meant devising new ways to measure the interactions of vibrating strings, resonant bodies, and magnetic pickups, then ascribing mathematical values to them. New DSP hardware was developed to do the necessary modelling at an affordable price. One of the challenges that isn't obvious at the outset is that the sound needs to change instantly when you change pickup positions. This is very difficult to achieve if you have to change algorithms, as you'll know from how long it takes to change patches on most effects boxes, but there's no obvious delay or glitching when you change Variax settings.

Noise is always a problem with electric guitars, because of the large amounts of gain and high-end boost added by a typical guitar amplifier. In order to reduce noise levels in the Variax, low-noise analogue electronics and high-resolution digital converters are used, but, even so, some residual noise is inevitable. In practice, the noise from the Variax is considerably less than you'd get from a normal guitar in a typical playing environment, but what noise there is manifests itself as broadband hiss rather than the more usual hum. This is subjectively inaudible with clean amp settings, but can become more noticeable when high gain settings are used.

The Guitar

The guitar itself, which is actually a rather nice instrument in its own right, is made in the Far East to Line 6 specifications and has a standard 25.5-inch-scale, 22-fret neck, just in case you want to change the maple neck provided. The rosewood fingerboard has a 10-inch radius and is fitted with medium-gauge frets, while the body is made from basswood. No tremolo version is yet available, or even officially planned, but from the number of enquiries Line 6 have had about this, maybe it's something they'll think about for future models, even though the only guitars emulated that have tremolos are the Fender Stratocaster, the Gretsch 6120 and the Epiphone Casino. The neck is bolted to the body and the strings fit via ferrules set into the back of the guitar, rather like on a Fender Telecaster. A metal plate covers the battery compartment and, in emergencies, the AA battery tray can be removed and a single 9V battery connected, though the operating time is reduced in that case to around 1.5 hours.

Storing a setting involves pulling up the model selector knob, moving the pickup selector switch to an appropriate destination position, and then switching the model selector knob to one of the Custom positions before pushing it back down.Storing a setting involves pulling up the model selector knob, moving the pickup selector switch to an appropriate destination position, and then switching the model selector knob to one of the Custom positions before pushing it back down.Photo: Mark EwingThe model selector control is a rotary switch designed to blend in with the more conventional volume and tone controls, and the included A/B footswitch has both a regular quarter-inch jack output and a balanced XLR connector. Having the two different connectors is useful for sending acoustic sounds to a full-range amplifier, PA or recording system via the XLR while the jack feeds the electric sounds to a guitar amplifier. The footswitch also serves as a convenient means of powering the guitar (via the supplied separate adaptor that connects to the pedal), because, although the guitar can run from batteries, six AA cells only last around 12 hours, which is neither economically nor ecologically attractive.

If there are batteries in the guitar and it is left plugged into the footswitch (via the included TRS jack lead), the battery will drain if power to the footswitch is removed. The guitar can be used without the footswitch (providing batteries are fitted) by using a regular guitar cable. On the guitar's connector panel there is also a blanked-off computer-style connector which is currently unused, but which may come into play with future upgrades. Available in Sunburst, Black, or Candy Apple Red, Variax comes with a gig bag, adjustment tools, footswitch and PSU, TRS cable and a mercifully brief and easy-to-follow manual.

The user interface couldn't be more guitarist friendly, with a volume control, a tone control, a selector knob and a five-way switch similar to the ones used for pickup selection on modern Fender Guitars. The selector knob (really a rotary switch) is used for choosing the guitar model type and has a built-in pull switch that is used when saving your own setups to the user memories. Ten switch settings are available for calling up preset model types, plus there are two further user positions, and each one accesses five further models depending on the setting of the five-way 'pickup selector' switch. For example, the Spank setting, which is based on the Fender Stratocaster, has models for all five pickup switch settings, whereas the Reso setting accesses two different resonator guitars, a banjo, a sitar and a model based on the sound of a Danelectro 3021.

To save a setting in one of the ten user locations (two knob locations and five selector switch positions), you first set up the sound you want, then pull out the Model Select knob. Next put the five-way switch in the position you want to save at, then turn the Model Select knob to one of the Custom positions and push it back in — setup saved! Tone control settings are saved with the patch and only change if the tone control is moved after recalling the patch.

A Tour Through The Models

The first modelling option is T-Model, based on the sounds of a 1960 and a 1968 Fender Telecaster. Two of the five switch positions are used to access the bridge and neck pickups of the '60 model, with two more calling up bridge/neck and neck on the '68 model. As with the original 1960 model, the tone control is bypassed in the neck position, and with all models the effect of turning down the volume control has been emulated as closely as possible. Spank is based on a 1959 Fender Stratocaster, but has all five pickup combinations, as on a modern model. The only obvious departure from convention is that the tone control also affects the bridge pickup.

The electronics which do the complex modelling processing are built into the body of the guitar itself, and they can be powered from six AA batteries, allowing you to plug the Variax directly into a guitar amp just like a normal guitar.The electronics which do the complex modelling processing are built into the body of the guitar itself, and they can be powered from six AA batteries, allowing you to plug the Variax directly into a guitar amp just like a normal guitar.Photo: Mark EwingLester replicates the sound of the Gibson Les Paul, with three positions dedicated to a 1958 Standard, one to the bridge position of a 1952 Gold Top fitted with P90s and one based on a three-pickup 1961 Custom where both the bridge and middle pickups are used. Gibson's back catalogue attracts further attention with tributes to the Les Paul Junior, Les Paul Special and Firebird V in the Special section. Then it's onto hollow bodies with the R-Billy options — the two guitars honoured here are the 1959 Gretsch 6120, where all three pickup combinations are accessible, and the 1956 Silver Jet, with a choice of neck or bridge pickups.

Chime brings back memories of the Byrds with both six- and 12-string Rickenbackers — a 1968 Rickenbacker 360 and a 1966 360-12. The 12-string sound is correctly emulated, with unison strings on the top two strings and high octaves on the bottom four. The six-string has all three pickup combinations available, while the 12-string has either neck or bridge variations. Continuing in the hollow-body theme, Semi delivers all three pickup combinations of a 1961 Gibson ES335 and the neck and bridge pickups of a 1967 Epiphone Casino, while Jazzbox does the same for a 1957 Gibson ES175 and a 1953 Gibson Super 400.

Accurate acoustic modelling has always been tricky, but what Line 6 have achieved here is as good as I've heard to date, and certainly good enough for live performance or for background parts in recording. Five models are available: 1959 Martin D28, 1970 Martin D1228, 1967 Martin O18, 1966 Guild F212 and a 1995 Gibson J200. Because conventional tone controls are inappropriate to acoustic guitars, the tone knob emulates the effect of moving the mic and adds more or less 'body' to the sound. That leaves Reso, where you'll find models of a 1935 Dobro Model 32 metal-body guitar, the Coral electric sitar, a 1965 Danelectro 3021, a Gibson Mastertone banjo and a 1928 National Tricone resonator. As always, Line 6 are very careful to point out that there is no endorsement by any of the actual guitar manufacturers and all trademarks are acknowledged.

Model Behaviour?

Before starting to examine the sound of the various models, the guitar itself is worthy of comment, as it is well-built, comfortable to play, and exhibits decent tuning stability. It borrows design attributes from a number of sources, but directly copies none of them and has a friendly, playable neck. I particularly like the fact that all the technology is hidden, both visually and operationally. The quality of setting up is as good as for most other new guitars I've had experience of, but a fine-tune by a setup technician would nevertheless be a good investment, as the nut slots could be a hint deeper and the action would probably go lower without any problems.

There's no outward sign of the piezo pickups, as these are built into the bridge saddles, the bridge itself being similar in design to those fitted to non-tremolo Stratocasters. Not having any visible pickups makes the guitar look a little unusual, but it's actually very practical, as you don't find yourself catching your pick on the pickups — a problem I sometimes have with Strats if the pickups are cranked up fairly close to the strings. In fact the only disadvantage of having no magnetic pickups is that, if you use an E-bow, the tone doesn't change much as you move the bow along the string, though I'm sure that taping a fridge magnet to the scratchplate would fix that particular shortcoming!

The residual noise is at a far lower level than the hum and buzz you normally get from magnetic pickups, and you can stand as close to your amp as you like — everything stays clean. In a recording situation where high-gain overdrive is being used, any of the simpler denoisers or even expanders would work fine to mop up the last bits of noise which, ironically, can be all the more obvious because there's no hum and buzz to mask it! The sounds of the different models all appear to be subjectively similar in level, and, by my estimation, 2-3dB hotter than the real thing. This means your amp/processor's overdrive settings may need a tweak if they've been set up to work on a conventional guitar.

 Design Philosophy: Marcus Ryle Of Line 6 
 I asked Marcus Ryle of Line 6 to provide some insight into the design philosophy of Variax: "The Variax is a musical instrument first and foremost, despite the significant digital inner workings used to unlock its collection of instrument sounds. One of the most important aspects of a great instrument is its ability to inspire musical creativity and, to achieve this, the instrument has to allow the musician's full range of expression to be realised and its technology must be transparent. With the Variax, each nuance of performance, from pick position, angle, and force, to palm muting, to fret pressure, to harmonics, and so on, can be explored and fully reproduced. This is because, regardless of what instrument model is selected, the actual sound that gets 'played' through that model is the sound of the strings themselves.

"Here's basically how it works. The string vibrations are detected by the hexaphonic bridge pickup and are converted directly into digital signals through six 24-bit A-D converters. These signals are processed through the software algorithms that capture the interaction of each modelled instrument's pickups, each pickup's placement, height, magnetic aperture and nonlinearity, the tone controls, and details of the modelled instrument's physical structure. Unlike MIDI instruments or guitar synths, Variax is dynamically altering the signal of each string's natural vibrations to match the modelled instrument's unique tonal characteristics. This means that there's no 'tracking' or 'MIDI delay' to worry about; what you play is what you get. After passing through the algorithms, the signal is then converted back to analogue and sent out of the quarter-inch jack, so it can be plugged directly into any electric guitar amplifier."


Even Better Than The Real Thing?

I usually play Strats these days, and have a few lying around the house, as well as splendid Pink Paisley Telecaster and a Les Paul Standard, so I was able to do direct comparisons in these three cases. The Telecaster sounded quite close, to my ears, with the right kind of jangle and presence on the bridge pickup balanced by suitable depth and warmth on the neck pickup, though purists might describe it as a close caricature rather than an exact copy.

I was also pleased with the Strat model, which managed to capture the essential character of all five pickup positions, though I'm not sure the level balance between the individual pickups and pickup pairs was quite authentic — to me it seemed better balanced than the real thing. Variax also omits to model the effects of the magnetic drag that conventional pickups impose on the strings, which is largely a good thing, as this can reduce sustain and make high notes on the low strings sound somewhat out of tune. Of course a lot depends on how you space the pickups from the strings on the original. Although there's no tremolo arm, I'd be happy to play Variax instead of my usual Strat.

Connecting the Variax to its footswitch with the included TRS cable has two benefits: firstly, you can power the guitar's modelling electronics from the mains via an adaptor which plugs into the pedal; and, secondly, you can switch between feeding an amp (for electric sounds) and a mixer directly (for acoustic sounds) using the switch.Connecting the Variax to its footswitch with the included TRS cable has two benefits: firstly, you can power the guitar's modelling electronics from the mains via an adaptor which plugs into the pedal; and, secondly, you can switch between feeding an amp (for electric sounds) and a mixer directly (for acoustic sounds) using the switch.Photo: Mark Ewing

There's plenty of variation amongst the Gibson solid-body electric models and, though I currently don't have all of them for comparison, I reckon the essence of the Gibson sound is captured pretty well, especially the little Junior model. Using the Les Paul model via a Pod XT set to replicate the Bluesbreaker Marshall amp sound, it was possible to get very close to that John Mayall/Eric Clapton Beano-album tone, but in a direct shootout Variax lacked some of the tonal weight and complexity of the real thing. I also enjoyed the semi-acoustic models, especially the blues classics such as the Gibson 335 emulation, which really convey a sense of body resonance.

A full-range amplifier is needed to do justice to the acoustic models, which, although not entirely authentic (they still have a slightly scratchy character to the high end), do provide a very passable alternative to an acoustic guitar with an built-in pickup system, and are as good as any other acoustic emulation I've heard. In live performance, the footswitch can be used to switch the acoustic sounds to a suitable full-range amp or PA system, which is a good idea. However, the semi-acoustic and acoustic 12-strings are only approximations at best, because the pitch-shifting technology used to create the 'missing strings' sounds electronic to me and gives a slightly flange- or chorus-like feel to the end result. If you're playing 'Eight Miles High' at the local social club, no problem, but I wouldn't record with the 12-string models. To be fair, this also applies to other systems I've heard that attempt 12-string emulation in this way.

That leaves the weirder inclusions such as banjo, sitar and resonator guitar. In fact the resonator guitars and banjo come close enough to the authentic sound that, as long as you hear them in a mix, you'll probably accept them as real. How well they come over as solo instruments depends as much as anything on the skill of the player, but they're certainly impressive and are guaranteed to bring a smile to your face. Comparing the sitar model with a real sitar is a little unfair, as the model emulates an electric sitar, where the tone control varies the contribution of the sympathetic resonating strings. Again the overall effect is uncannily good — ideal for that Spinal Tap flashback moment. One further point worth reiterating is that changeover between switch settings and even between models is as near instant as you could want.

Variax Verdict

Although Variax isn't the first attempt at guitar modelling, it's the first product to put all the technology inside the guitar, and it's certainly the easiest to use. It has a number of benefits both live and in the studio, and, aside from its chameleon-like tonal abilities, it is virtually immune to magnetic interference and can be used close to CRT monitors. There is a small noise penalty in terms of the nature of the background noise, but, as stated earlier, it's actually a lot quieter than the level of hum and buzz you get with most conventional guitars. The volume control is wired so that any background noise reduces when the guitar volume is turned down. There's no built-in gating, so you don't suffer cut-off notes, and one factor many players don't appreciate is that hum can modulate the guitar sound in unpleasant ways — a problem that Variax doesn't suffer from.

On the whole, I feel the guitar modelling works very well, and though you'd never swap your real Gibson 335 or '50s Strat for a Variax, it is genuinely useful in situations where you need access to a whole range of trademark guitar sounds without carting around lots of gear and different instruments. Although some people may argue the sounds aren't exactly accurate, they do convey the flavour of the real thing and they're enjoyable to play. Indeed, it's hard to believe you aren't playing a guitar with conventional pickups — and that, after all, is the whole point.

infop.gif £799 including VAT.
infot.gif Line 6 Europe +44 (0)1788 821600.