Guitar Amp Modeling

Faster computers + better modeling algorithms = great guitar recordings.

Over ten years ago Line 6 introduced Amp Farm, the first widely used amp-modeling software. It was greeted with open arms by some, skepticism by others, and derision by a few. While purists scoffed, session guitarists—accustomed to years of rushed setups, badly miked (or worn-out) studio amps, and/or baffling and volume problems—found it a godsend. At last, you could quickly dial in a fine guitar tone for myriad recording situations where miking and recording a real amp properly was problematic— or not even an option.

Unfortunately, Amp Farm was available only for Digidesign’s Pro Tools TDM system. But then IK Multimedia introduced AmpliTube, a native solution for multiple platforms. Even non-guitarists found amp modelers useful for crunching up drum tracks, adding grit to vocals, or enhancing conventionally-recorded guitar tracks. Still, until recently software amp modeling remained largely the province of a few studio rats.

Today, reduced memory costs and faster computers have led to greatly improved sound quality. IK Multimedia is up to AmpliTube 2, and also offers a Jimi Hendrix package that comes frighteningly close to matching the analog sounds of the rock legend himself; Native Instruments’ Guitar Rig 3 goes beyond emulating vintage gear to add sequencing, filtering, and modulating tools previously available only to synth players. Meanwhile, Waves’ GTR3 expands considerably on their existing roster of amps and processors, and Line 6’s GearBox software is now available in plug-in form as well as being part of products that use their ultra-low latency ToneDirect monitoring system. Just as analog tape is being abandoned for the convenience and cost savings of DAWs, more guitarists are availing themselves of the convenience and sound-sculpting capabilities of software modelers.


Having previously reviewed AmpliTube2, GTR3, Guitar Rig 3, and GearBox software (see sidebars “Encore!” on page 56 and “Amp Sim Update” on page 58), we’ll look at four recently-released amp modeling software packages—two high-end products and two budget bargains.

Digidesign now offers their own modeler, Eleven; Scotland’s db audioware, an audio technology company that specializes in designing high performance audio engines and plug-ins, makes Flying Haggis; and from Brooklyn comes DSP engineer Marc Gallo’s Studio Devil. The fourth newbie is ReValver, from a company perhaps best known for its guitars and amps rather than software—the Mississippi-based giant Peavey. But before getting into each model’s particulars, let’s look at some concepts shared by all amp modeling software.


As musicians and recordists, we want software that will help us replace the drudgery of hauling a heavy combo or 4x12 stack, shorten the tedium of trying to find a “sweet spot” for the right mic on the best speaker, and not have to deal with matching an amp sound for an overdub after the head has warmed up and sounds totally different compared to the original track. Toward this end, every amp modeling software company begins by modeling the interaction of a stack or combo’s components, to varying degrees. All of the available software offers a choice of amp heads that you can combine with various speaker configurations. Some also let you mix and match preamps and/or tone stacks with power amps. Many versions offer a choice of virtual microphones and mic placement, as well as “guitar pedal” effects.

The criteria for judging modeling software are the same as for a “real” amplifier. For clean tones, does the amp exhibit the slight sag of real tubes, or does it sound like we’re plugging directly into the board? For crunch applications, does the sound go from clean to distorted in a gradual, smooth manner and “cleans up” when you lower the guitar volume? How does it respond to pick attack—and is the overdriven sound “fizzy” or “warm”? We also have a standard of comparison when modeling vintage classics: Do the Vox emulations have both the “Beatle clean” and “dirty Queen” thing happening? Do the Marshalls make us want to play AC/DC and Zeppelin? Do we get that Pantera vibe from the modern high-gain monster models?

Part of the digital advantage is that software gives options that are difficult or impossible to achieve with hardware. And thanks to MIDI, we can automate parameters so sounds change drastically, or gradually, as the mix progresses.

Amp modeling is also useful for “re-amping.” In the past, guitarists have recorded a direct signal along with the sound from miking a physical amp, and then later sent the direct signal out through a different amp if needed. Now you can simply record a direct signal, and run it through various amp models—you can even dispense with the physical amp entirely, and run the direct signal through as many amp models as you care to, re-structuring your tone at any point in the mix.


Amps are just the beginning with some modeling packages, as they also include anything from stomp box and rack effect models to studio gear and synthesizer-style modifiers. As with the amp models, these vary from accurate representations of well-known vintage pieces to generic sound modification gear. Here too MIDI allows a high level of control. You can modify your tremolo speed with a continuous controller pedal, or change your analog delay blend from verse to chorus with track automation. Some software allows you to experiment easily with device chaining in new ways, like placing a spring reverb and then a fuzz pedal after your speaker cabinet.


Each of the four modelers under consideration offers an array of different amp sounds, various speaker configurations, and a noise gate, as well as MIDI control over multiple parameters. And, all four include presets to get you started. Most amp modelers, for legal reasons, only allude to the amps, cabs, and mics being modeled by a clever name or GUI representation in the actual software; the exact models are often listed more directly on the website or in the manual.

There the similarities end, and the differences begin, so let’s explore these four different approaches to amp modeling software. For testing, I used a 1965 Fender rosewood-neck Strat, Strat-style Fernandes maple-neck, and Danelectro Pro guitars. The software was installed in a Macintosh Power PC G5, a Macbook Pro laptop, or both. I ran the program in both standalone mode when possible (ReValver MkIII and Flying Haggis), and as a plug-in (all) in Ableton Live 7 and Pro Tools M-powered. For the G5 I interfaced with an M-Audio 1814 (FireWire), and entered the laptop through a Native Instruments USB Audio Konnect.


Eleven works with Digidesign’s Pro Tools (TDM, LE, and M-Powered versions), Venue, and Avid systems. It comes with no pedals, rack effects, file players, or tuners; what you get are guitar amps, cabinets, and miking options. In that respect it provides a wide array, including a ’59 Tweed Lux, ’59 Tweed Bass, ’64 Black Panel Lux, ’66 Hi AC Boost, ’67 Black Duo, ’69 Plexiglass-100W, ’82 Lead 800, ’85 M-2 Lead (Mesa/Boogie Mark IIc), ’92 Treadplate Modern and Vintage models (Dual Rectifier Head), ’89 SL-100 Drive (Soldano), and DC Modern models (Digidesign Custom).

Each model loads with its appropriate cabinet, but any cabinet can be matched with any head. One of Eleven’s selling points is that the heads react in a realistically different fashion with different cabinets—e.g., evidencing less headroom when matched with a higher impedance speaker set. Unlike the real thing, the head will not burn up if matched with a lower impedance cab. The eight mic models available can be set on- or off-axis. Eleven offers a Speaker Breakup adjustment control that simulates the distortion created by a speaker when playing an amp at high volume.

You adjust input to Eleven on your interface; the knob labeled Input actually causes a clean line boost or cut of –18dB to +18dB, so you can customize how hard your guitar drives the amp. The Output knob helps match preset levels. Although factory presets can often leave you scratching your head and wondering, “Who thought this sounded good?,” Eleven’s list of over a hundred had nary a dud in the bunch. You can create and save your own presets as well.

You can switch off both the amp and cabinet sections, which is helpful when using Eleven with other amp modeling software, using multiple cabinets with one head, or running an Eleven head signal out into a live room, where you can set up and mic a physical cabinet.

Running your guitar through multiple amp models at once can be problematic with some software, as modelers often eat up considerable CPU power. Whether because Eleven is designed to work specifically with Digidesign products, or because it doesn’t include effects, Eleven is extremely CPU-friendly—I was able to run five tracks worth on my 2.5GHz Mac G5. Eleven also has the lowest latency I have experienced to date.

Digidesign went to extreme lengths to achieve accuracy in their modeling, “It had to be the original speaker cones, original transformers, everything matching the date of what we claim was modeled in the product,” says Senior Project Developer Bobby Lombardi. Of course, anyone who knows vintage amps will tell you that no two old amps sound exactly alike, so the real question is do the Eleven models sound good—and the answer is yes. You will definitely hear a recognizable version of the legendary Vox, Marshall, or Fender sound in their respective clones. Eleven also responds realistically, cleaning up when the guitar volume or picking dynamics are dialed down. The software also responds well to hardware pedals (or other software plug-ins) run into its front end, which is Digi’s rationale for not offering effects. Unfortunately the one effect available—amp tremolo—is all-too-realistically not syncable to the DAW.

If you run Pro Tools or Avid and are looking for software that does a great job of modeling amps, and only amps, with low CPU drain, Eleven is for you.

PRODUCT TYPE: Amplifier simulation software plug-in.
TARGET MARKET: Pro Tools users who want realistic amp sounds and don’t need to have “stomp box” type effects built into their amp sim plug-in.
STRENGTHS: Realistic sound and feel. Works well with pedals. Low latency. Low CPU usage.
LIMITATIONS: No effects other than tremolo, which doesn’t do tempo sync. Pricey.


Until now, any amp modeling software you installed in your Mac or PC was developed by a company more used to ones and zeros than 12AX7s and EL34s. Not so with Peavey: A company that cut its teeth on actual tube amps has taken the leap into the software realm.

Like most other modeler developers, Peavey mimics the interaction among amp components. Unlike other companies, Peavey lets you get “under the hood” yourself—no screwdriver, soldering iron, or programming skills required. After you load any of the software’s brand name amps, preamps, or power amps into the virtual rack, clicking on that module’s plus (+) sign allows you to alter the specs of the plate loads, cathode resistors, bias time shift constants, power supply, transformers, negative feedback loop, and more.

The speakers that load with the preset amps are modeled by a “convolution speaker simulation” module; that is to say, from recordings of the actual speaker cabinets, using a specific mic and miking location. Options of the same cabinet with a different mic choice and placement are available. Convolution is CPU-hungry, so a Resample button reduces the module’s appetite while retaining sonic detail. Unfortunately the Convolution module groups cabinet options by the sources from which they were recorded, so if you want to try out, say, different 1x12 combos, you need to jump around among multiple categories; I find this slows down workflow. The less CPU-intensive, more tweakable, “Speaker Construction Set” module allows adjusting the cabinet’s width, height, and depth (without woodworking tools!), the type and number of speakers, the mic model, its distance, radius, and angle.

All the typical amp clones are available—Marshall, Fender, Vox, and Boogie, as well as six different Peavey amp models (hey, it’s their software, and some of these models are coming up on classic status themselves). The usual effect suspects are on hand as well: distortions/ overdrives, compressor/limiters, delays, reverbs, chorus, flanger, phaser, vibrato, attack decay, wah/filter, noise gate, EQs, and octave divider. ReValver also supplies some extras, like stereo widening and channel delay.

A unique feature is the “VST host,” a module that can host the VST plug-ins in your collection, allowing you to load them into the ReValver rack. Some plugs work better than others; my free plug-ins and Cycling ’74 Pluggo effects functioned, while Native Instruments’ Reaktor and Guitar Rig crashed the software. [Editor’s note: With the latest rev of ReValver, we could load not only Reaktor and Guitar Rig, but any VST effects we threw at it—including the processing sections of software synthesizers. So it seems this bug has been fixed.] Being able to use your favorite VST plugs with ReValver in standalone mode is a great feature.

In terms of sounding and feeling like a real amp, ReValver is easily the best software I’ve tried. You can always argue whether the Marshall, Vox, Fender, or Peavey model sounds exactly like the amp that you own, but in terms of just great amp tone, I will stack (no pun intended) ReValver against any other software, and more than a few boutique amps. You can really feel the “tubes” sagging when you dig in, and the depth and richness of many of the tones makes reverb superfluous.

This alone makes ReValver worth getting, but all that tweak power is not just a gimmick—it really works in a musical way. ReValver doesn’t come with a Fender Deluxe model, but by swapping out the 6L6s in the “Bassic 100” for 6V6s I was able to make my own. Really! Single triode tube and tone stack modules can be racked up to build your own amps and preamps. By joining a Bluesmaker 62 tone stack with three 12AX7s and a KT66, then adding a 4x12 cabinet, I created my own personal Marshall, and it sure sounded good.

Peavey’s 43 years of experience building tube amps has translated remarkably well into the digital world; ReValver MkIII could sweep the competition with its great tone and outstanding price.

PRODUCT TYPE: Amp, cabinet, and effect modeling software.
TARGET MARKET: Those who want an amp sim that comes as close as possible to the real thing.
STRENGTHS: Amazingly lifelike tone. Massive tweak factor. Great price.


You say you don’t have $300+ bills to drop for software that you will just use to sketch in some ideas when you are too lazy to mic your Marshall? No need—you’ll be amazed what you can get for under $100.

Like Digi’s Eleven, the Studio Devil Virtual Guitar Amp offers only amp and cabinet models—but lists for way less. Why the difference? For starters, Studio Devil has only three generic amp types: Modern, British, and Classic (read Soldano, Marshall/Vox, and Fender). Each of these can be set to Lead, Crunch, or Clean, and Boosted or not. Gain, Tone (Treble, Bass, Middle, Presence), Power Amp Drive, and Noise Gate amount are all adjustable with virtual knobs. You have a choice of a combo cabinet, a stack sound, or a D.I. box—that’s it. Although the manual doesn’t mention it, there are presets accessible through standard VST preset save/load functions—but not in the GUI of the software itself.

It’s possible to get some really good sounds out of this budget product, but you won’t get the same dynamic response and richness as Eleven. The clean tones sound fine but the slight breakup area is where Studio Devil seems somewhat weak compared to the high-priced spread. The midrange-heavy Combo speaker setting doesn’t work well with most of the clean settings, but fleshes out the higher gain sounds for a fat, old school distortion vibe. Using the Stack setting brings us into more modern overdrive territory, and adds sparkle on the clean settings. The D.I. box comes in handy if you already have a speaker modeler of some sort or want to send the sound out to a speaker in the room. Running Studio Devil’s amp sounds into speaker simulations by Guitar Rig or ReValver improved the tone dramatically; with a little work on the speaker algorithms, Studio Devil could edge up on the big boys.

PRODUCT TYPE: Amp/cabinet modeler.
TARGET MARKET: Recordists on a budget.
STRENGTHS: Surprisingly good and varied sounds for the money.
LIMITATIONS: Lacks realism and options of the more expensive software.


Haggis is a traditional pudding made of the heart, liver, etc., of a sheep or calf, minced with suet and oatmeal, seasoned, and boiled in the stomach of the animal. While it helps to be from Glasgow to fully appreciate the thought of such a repast soaring through the air, the amp modeling software that bears this name has charms that will appeal to many.

Flying Haggis appears onscreen as a retro-style amp head, complete with virtual gauges to indicate input and output levels (but no attenuators). On the left side are knobs for Drive, Distortion, Compression, Bass, Midrange, and Treble. On the right side are the controls for Master volume and Reverb, as well as virtual pushbuttons to choose six cabinet configurations (sorry no D.I.), and four mic placement choices. One switch in the middle allows toggling between the controls and the presets. The software comes with only about 50 presets but all of them are actually usable, and you can save your own. Another switch turns the software on and off.

Below the head is a line of stomp boxes: noisegate, auto-wah, phaser, tremolo, echo (delay), and chorus. Effect positions are fixed—what do you want for a hundred bucks? Amp and effect parameters are MIDI-controllable in both standalone and plug-in modes.

Like Studio Devil, Flying Haggis delivers a surprising array of musical, usable sounds for the price of a heavy date. Don’t expect ultra-realism, or sensitive finger dynamics, but you do get perfectly usable clean and distorted tones that are fun to play and easy to set up. These sounds will serve you well for song ideas, or even as additions to real amps or more expensive software. The effects sound better than the amps; the Auto Filter effect and the Echo’s comb filtering effects are practically worth the asking price. If you want stomp boxes to go with your amps but are on a wee budget, check out Flying Haggis.

PRODUCT TYPE: Amp, cabinet, and effect modeling software.
TARGET MARKET: Recordists on a budget who want some effects with their models.
STRENGTHS: Surprisingly good and varied sounds for the money.
LIMITATIONS: Lacks dynamic response and depth. Limited effects tweaking.


Digital amp modeling, whether virtual or embedded in hardware, has come a long way in the decade since the first versions of Amp Farm and POD. The computing power necessary to make ReValver MkIII sound as realistic as it does would have been unavailable outside of a military mainframe back then; now you can have it on your lap. And whether you’re looking for a simple, quick way to get some guitar sounds into your computer for songwriting and recording, or are ready to take the leap into performing live with just a Tele and a laptop, there’s an amp modeling program out there that will fit your needs.


This article doesn’t review Native Instruments Guitar Rig 3, IK Multimedia AmpliTube 2, Line 6 GearBox software, or Waves GTR3, because we already reviewed them (see sidebar “Encore!” below). But all four companies have had significant new announcements since those reviews; here’s the latest.

NI’s latest guitar products, Guitar Rig XE ($119) and Guitar Rig Session ($249), further democratize the process of using guitars with computers. Guitar Rig XE software offers five amps, 21 effect modules, and 12 speaker types, as well as two “tape decks” (scratchpad recorders), metronome, and tuner. The software comes with 178 presets and also incorporates “Live View,” which displays the most crucial parameters for live use in a large window with a minimum of clutter.

But there’s also a hardware issue if you’re playing guitar, as a passive guitar output is not happy feeding a typical audio interface. Enter Guitar Rig Session, which bundles XE software with Session I/O, an audio interface designed specifically for guitarists (which also bundles Cubase 4 LE and the Kore Player, with the Pop Drums soundpack). It provides low-latency operation via USB 2.0, but also includes a line input (feed in a drum machine, for example), mic input for recording vocals along with guitar, stereo line outs, and headphone out. The enclosure is aluminum, further emphasizing the “use it on stage, use it in the studio” vibe.

Only a few years ago, using guitars and computers was a minefield of latency, hardware issues, compatibility, and other problems. Products like Guitar Rig Session show how far the technology has progressed.

There are two big items from IK Multimedia. The first is Stomp I/O, a full-fledged pedalboard for their AmpliTube-based amp/effects simulator software. You can hook it up to a laptop and forget you’re even using a computer, as you can control just about everything you’ll need from the pedalboard; Stomp I/O is slated for more coverage in a future issue of EQ.

The second is X-Gear, a “shell” program that lets you mix and match modules from any “powered by AmpliTube” products (AmpliTube 2, AmpliTube Jimi Hendrix, Ampeg SVX, and the upcoming AmpliTube Metal) installed on your computer. Prior to X-Gear, there was no real way to integrate these programs; now when choosing, for example, an amp model, you can select any amp model from any compatible program. The same goes for stompbox effects, cabinets, and studio-type “rack” effects. www.

If GTR3 hits the checkbook too hard, how about a “greatest hits” package with the best of GTR3 for $140 list? That’s GTR Solo, which includes ten amp models, ten cabinets, and 13 stomp boxes (overdrive, distortion, phaser, flanger, chorus, delay, wah wah, spring reverb, pitch shifter, vibrolo, gatecomp, EQ, and volume). There’s even a tuner—with alternate tunings.

Having used GTR Solo quite a bit, I must say it doesn’t feel like a “lite” program. The amp section offers several settings: bass, clean amps (2), drive amps (3), and high-gain (4) sounds, including two based on amps from Paul Reed Smith’s personal collection . . . who has about as good a set of ears as you’ll find in this industry.

There are four slots for effects, and you can move them pre- or post-amp, as well as control them via MIDI. When you remember that these effects are based on Waves’ big-bucks effects algorithms, the package value goes up another notch. Waves Solo also works in stand-alone mode with ASIO drivers for Windows or Core Audio on Mac OS X.

In addition to covering the GearBox Gold plug-ins, we also covered the UX8 TonePort interface in the May issue—but because the focus was on the hardware, it’s worth emphasizing that the UX8 not only includes the GearBox software suitable for use with their ToneDirect monitoring process, but also GearBox versions in VST, RTAS, and AU plug-in formats. Furthermore, you can expand the UX8 roster of models with Model Packs, which include the Power Pack (36 amp models and 50 effects), Metal Shop (18 high-gain models), Collector Classics (18 models based on boutique combos), FX Junkie (30 effects models), and Bass (28 amp models with 22 cabinets). Line 6 offers a 30-day money-back guarantee on these so you can try them, and if you don’t like them, no problem.

In other news, Line 6 is developing 64-bit drivers for the TonePort line. Regardless of what you think of Vista or Leopard, the 64-bit OS is the wave of the future, particularly for music applications because of the ability to address huge amounts of RAM.
—Craig Anderton


You want more? Of course you do, and EQ has done lots of articles and reviews on amp simulators. Go to and search for the following:

05/08 McDSP Chrome Tone review (as part of Emerald Pack Native bundle)
04/08 Native Instruments Guitar Rig 3 review
03/08 Waves GTR3 review
08/07 Guitar Amp Sim Power User Tips. Tips for NI Guitar Rig, IK Multimedia Amplitube, Line 6 GearBox, and Waves GTR
04/07 Line 6 GearBox Gold Plug-Ins review
01/07 Power App Alley: Using Waves GTR as a vocal processing strip.
12/06 IK Multimedia Amplitube2 review
09/06 Power App Alley: Creating multi-band distortion with Guitar Rig.
08/06 AmpliTube2 Meets Drums. Techniques-oriented piece on using AmpliTube2 with drums.
07/05 Myths Revealed: Guitar Amp Plug-Ins. Separating fact from fiction about guitar amp plug-ins, with some fascinating insights from their developers.
07/05 Creative Combos. Tips for using Native Instruments’ Guitar Combo plug-ins.
12/03 The Complete Guide to Re-Amping. Includes tips on “virtual re-amping” with plug-ins.
07/02 Four Guitar Amp Plug-Ins (Steinberg Warp, UA Nigel, IK AmpliTube, Alien Connections ReValver)

EQ, Keyboard, and Guitar Player magazines have collaborated to create a mega-source of vital amp sim info. The article you’re reading emphasizes recording, guitar, and applications. The July ’08 issue of Keyboard also covers amp sims, but from a more review-intensive standpoint, with an emphasis on non-guitar uses. So pick it up at your local newsstand.

If you want to use amp sims as a “producer” to recapture classic guitar tones in the absence of a physical amp, we also have a special treat for you. “Five Essential Guitar Tones,” penned by Guitar Player associate editor Matt Blackett, is available as a special extra article online here.