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Line 6 Flextone Plus

100 Watt Stereo Guitar Amplifier By Paul White
Published June 1998

Line 6 Flextone Plus

Line 6 claim to have put physical modelling technology into a combo amplifier that any guitarist will feel immediately at home with. Paul White puts their claims to the test.

You may not have heard of American company Line 6, but it is an organisation with impressive credentials. It's headed by Marcus Ryle and Michel Doidic, a team which, over the years, has been involved in the design of Oberheim's synths, the Alesis ADAT and the Alesis Quadrasynth range, as well as many other high‑profile music products. Now they look set to scale similar heights in the guitar amp market under their own company name, sidestepping the solid‑state versus valve argument by using software physical models as an alternative to either technology.

Their new range of physically modelled, DSP‑powered guitar amplifiers purports to offer all the classic amplifier sounds, along with effects and reverb. This is obviously attractive to the gigging player who wants to be able to switch between several different sounds during the course of an evening, but the fact that the stereo headphone outlet (which includes a speaker simulator) can also be used for DI recording makes these amplifiers very useful in the studio. Line 6 are also doing a TDM software equivalent for Pro Tools system users.

The first amplifier from Line 6 was the AxSys 212, a fully programmable beast capable of emulating a number of leading amplifiers and speaker cabinets, complete with fully programmable effects. The 212 is a great amplifier — in fact I use one myself — but it isn't particularly pretty, and the number of editable parameters it offers may frighten off the more traditional guitar player, even though it's actually very easy to use.

Looks Familiar

Line 6 Flextone Plus

Under review here is the Flextone Plus, one of a series of three new amplifiers comprising the 60W 1x12 Flextone, the 100W stereo 2x10 Flextone Duo and the 100W 1x12 Flextone Plus. The Flextone Plus is actually a stereo amplifier but normally operates in mono via its internal 12‑inch speaker, unless an extension speaker cabinet is used. Without the extension speaker, the power is limited to 60W, whereas connecting the external speaker produces up to 50 Watts per channel. Having an extension speaker rather than two speakers in one cabinet produces a wider stereo spread, but even with only one speaker a stereo recording output is still available via the phones jack. The preamp used is essentially a computer/DSP engine with a 24‑bit analogue‑to‑digital converter on the input, while the power amps are based around dedicated ICs, of the type used to power large in‑car sound systems.

The Flextone amps are extremely loud and punchy when required to be. Indeed, if you didn't know differently you'd probably swear they were valve amps.

Looking like a cross between a Fender Deluxe and a Vox AC30, the Flextone Plus appears very much like any other guitar amp, right down to the controls. The usual Drive, Channel Volume and Master Volume controls are on traditional knobs, as are the Bass, Mid and Treble tone controls, plus Reverb Level, but two rotary switches, seven push‑buttons and a knob labelled Effects Tweak signal a definite departure from conventional guitar amp design. Between the Master Volume knob and the Drive control is a 16‑way rotary switch used to select the amp model you're listening to, while another 16‑way switch provides a choice of effect type.

Physical Modelling

The Line 6 design team studied and measured both individual valve amp gain stages and complete amplifiers from a number of manufacturers, then set about designing DSP signal algorithms that would have exactly the same effect on a guitar signal as the real amplifiers. These models include emulating the EQ frequencies and ranges of the original amp types, right down to the interaction between EQ controls, as well as the touch responsiveness of amplifiers, where playing the guitar harder makes them overdrive more. (For a complete list of the amplifiers modelled, see the 'Model Performer' box.) All the amps that originally had built‑in spring reverbs are given a spring reverb effect, whereas all the others get a room simulation reverb.

When the Manual button is active and illuminated, the amp behaves like any other — the controls do as their position indicates and the amp model is the one selected by the rotary Amp Models switch. It's also possible to dial up one of 15 effects or effect combinations independently of reverb and to control one parameter of the effect via the Effects Tweak knob. The effects are mainly delay‑based and include hybrid chorus delays, where the delay time/modulation rate can be set up using a Tap Tempo button on the control panel. Traditional effects such as Tremolo and Chorus sit alongside Compressors and Rotary speakers, and a nice touch is that although only the delay time and intensity is editable, the feedback amount is automatically adjusted so that slower delays have more repeats.

Though there's no display, no MIDI and no elaborate programming system, it's possible to set up four 'snapshots' of the control settings, for instant recall, using four buttons labelled A, B, C and D. Pressing Store, followed by one of these buttons, then Store again, saves all the amp settings other than the Master Volume level. When a stored patch is called up, the controls will no longer match the selected parameters, but if you hold down the Store button and watch the LED on the Manual button, you can turn the controls one at a time until the LED indicates that they match their stored values.

Using the optional Floor Board pedalboard, it's also possible to access further amp setups and to add a wah‑wah pedal to your repertoire (see 'Floor Board' box). The Floor Board (or the smaller optional FB4 channel selector footswitch) connects to the amp via the included networking cable. Unfortunately, there's no basic footswitch socket for bypassing the effects section, which would have been useful for players needing only minimal control.

The Flextone Plus will probably appeal most to those guitar players who need an amp both for gigging and for studio work.

In order to keep the amplifier reasonably quiet, there's a built‑in noise gate that shuts out low‑level hum and buzz from the guitar when it's not being played. You can't adjust this gate, but you can bypass it, if you prefer, by holding down Tap Tempo, then selecting Bypass on the Effects switch. Though it's fine for heavier styles, the noise gate can be a little too eager to shut down if you like playing with the guitar volume control at any position other than maximum, so leaving it off may be a better option for some players.

The Sounds

The Flextone Plus may not be as versatile as my AxSys 212, but it allows you to set up a sound incredibly fast, and the palette of tones on offer should cover most styles, from hard rock, through blues, to jazz. Line 6 have managed to capture the low‑end thump and touch sensitivity of a real valve amp remarkably well, and though the real thing is still a touch more responsive, they've managed to get very close indeed. What's more, unlike a typical valve amp, the Flextone sounds the way you want it to at any Master Volume setting. Certainly the main amp types are broadly like the originals, and I'm also amazed at how spring‑like the spring reverb emulation is. I find myself wanting to kick the amp to see if it will go 'thoing' — which, of course, it doesn't! In terms of noise, the circuitry seems on a par with most 'real' amps, and, as you might expect, the hum and buzz you get from your guitar pickups is no better or worse than it ever was unless you use the gate to keep it out.

All the usual guitar pedal effects can be emulated by the Effects section, and the compressor is particularly good for adding warmth and sustain to clean sounds. The flanged and chorused delays are strong and dynamic, without being too overpowering, and the Tremolo gives you that old '60s surf sound but without the thumping. Monitoring via the rear panel headphone jack, or using the extension speaker, gives a nice spread to the reverb and chorus, though I'm pretty sure the delays remain in mono.

Because the modelling includes speaker simulation, taking a feed from the headphone socket produces a tonality that is broadly similar to listening to the amp in a room, but just a little brighter at the top end, no doubt due to the limited bandwidth of the 12‑inch speaker. This may necessitate a little EQ adjustment, either on the amp or your mixing console if you choose to DI. For a more live sound, it would be nice to be able to combine the DI'd sound of the amp with an ambience mic or two set up across the room from the amp, but as plugging into the headphone socket kills the speaker ouput, you can't do this.

Just in case the on‑board effects don't do all you want, it's also possible to patch in a stereo external effects unit, via the Effects Send and Return jacks on the rear panel. These tap in before the Master Volume control and are optimised for line‑level rack units rather than low‑level pedals. Any pedals you do have can be plugged into the amp's input, as usual.


The Flextone Plus will probably appeal most to guitar players who need an amp both for gigging and for studio work. This one does a pretty good job in either capacity. Its main strength is the wide tonal range offered by a choice of amp models and effects, though being able to call up an amp sound which has the right type and level of effect with a single button is pretty great too.

In the studio, that tonal variety means that you can get very close to just about any musical style with a single amplifier, and because the sound remains consistent at all but the very lowest volume levels, you can choose whether to mic the amp or DI it. The only limitation here is that inserting a jack into the phones socket mutes the speaker output, which may not be what you want if you're recording as part of a band or want to combine DI with miking. You could take a DI feed from the insert send, but then you'd need to add an external speaker simulator.

While the Flextone is exceptionally good, it isn't perfect, and as a user of the very flexible 212 AxSys, I found the inability to adjust delay feedback independently of delay time rather frustrating, even though the amp tries to do this for you automatically. I also think it would have been useful to have access to more glassy, clean sounds, even though these tend to be associated more with studio DI techniques than amp characteristics. These limitations are a function of making the amplifier very simple to use, so I suppose it would be unfair to whine too loudly, though the lack of an effects bypass jack will probably be a frustration to those players who have no need to use one of the more elaborate foot controllers.

There's no denying that the Flextone Plus is infinitely better looking than the AxSys 212, and it's rather lighter to carry, but considering how little extra money the 212 costs, if you're working mainly in the studio I feel that the 212 is a more useful amplifier. However, if you want to get a wide range of good sounds quickly and you're also after an amplifier that's reasonably portable, the Flextone Plus has a lot going for it. Being able to add an extension cab gives a wider stereo image than the 2 x 10 Flextone Duo, but then the Duo might be better suited to people who want to walk away from a gig or session with their guitar in one hand and their amp in the other.

The Line 6 modelled amplifier simulations come closer to the real thing than any of the competition I've tried so far, and this latest generation will appeal strongly to the guitarist who wants loads of classic valve amp sounds and effects, but doesn't want to be confronted by menus and displays. These new Flextones also look like traditional guitar amplifiers, and, despite their solid‑state output stages, they are extremely loud and punchy when required to be. Indeed, if you didn't know differently you'd probably swear they were valve amps.

Floor Board

Originally developed for the AxSys 212, the Floor Board provides access to additional features as well as providing a means to control existing Flextone parameters. The two pedals provide volume and a classic wah‑wah, and there's a digital tuner and on/off controls for the amp effects. Furthermore, you can store two additional banks of four amp setups, as well as being able to access 16 new preset amp setups directly from the footswitches.

The Floor Board is strongly constructed from steel and doesn't require a separate power supply. It can operate in either Channel Select mode or Effect On/Off mode, and the amp's Tap Tempo facility is duplicated on one of its footswitches for easy live use.

The Effects

  • Compressor
  • Tremolo
  • Chorus 1
  • Chorus 2
  • Flanger 1
  • Flanger 2
  • Rotary Speaker
  • Delay
  • Delay/Compressor
  • Delay/Tremolo
  • Delay Chorus 1
  • Delay/Chorus 2
  • Delay/ Flanger 1
  • Delay/ Flanger 2
  • Delay/Swell

Model Performer

Jazz Clean1987 Roland JC120
Small Tweed1952 Fender Deluxe
Black Panel1964 Fender Deluxe
Modern Class A1996 Matchless Chieftain
Brit Class A1960 Vox AC15
Brit Blues1964/5 Marshall JTM‑45
Brit Classic1968 Marshall Plexi
Brit Hi Gain1986 Marshall JCM800
Rectified1994 Mesa Boogie Dual Rectifier
Modern Hi Gain1989 Soldarno SLO
Flextone Clean21st Century Clean
Flextone CrunchThick Grindage
Flextone DriveIndustrial Strength OD
Flextone LayerClean plus Drive
Fuzz1960s Arbiter Fuzz Face

All trademarks respected as property of their existing owners.


  • Traditional styling.
  • Incredibly easy to use.
  • Huge range of clean and overdriven sounds.
  • Authentic valve modelling with good touch responsiveness.
  • Costs around the same as a regular amp plus a budget effects unit.


  • Limited effects controllability.


This Flextone amplifier really is the Rory Bremner of the guitar amp world, yet it's as easy to use as a regular amp and it looks just like a traditional guitar amp. The built‑in speaker‑simulated DI output makes it just as useful in the studio as on stage.