Simple Complexity
The Catalyst has plenty of bells and whistles. On the surface, though, it looks a lot like a simple, conventional 2-channel amp. There are knobs for boost, gain, bass, mid, treble, presence, channel volume, effect, reverb, and master volume. There’s also a knob that lets you choose from six original amp models: clean, boutique, chime, crunch, dynamic, and hi gain. Mini buttons let you save and choose between two channel presets or engage manual mode, where what you see is what you get. Other mini buttons allow you to engage boost, tap tempo, and select effects and a tuner. On the back panel is an output power knob that lets you choose from mute, ½ watt, 50 watts, and 100 watts. There’s also a USB jack, a DI out, and an effects loop.
Six Amps in One
There’s not enough space in this review to cover all the amp models in depth. And I suspect that for many players even just a few used through the full range of their clean and dirty variations will be everything they ever need. Still, the Catalyst’s abilities and potential—especially relative to its price—will excite any potential user.
I started my own experiments with the boutique voicing at the ½-watt output setting. Predictably, there’s not a lot of output in this mode, though it’s a lot of fun as a practice amp. At the 50-watt output setting, though, I could hear and feel the amp in a more complete way. There was headroom to spare and it’s impressively dynamic and responsive to picking nuance. And it was surprisingly easy to get SRV-style bite out of otherwise clean, blues-tinged phrases—again, very impressive. The useful boost knob lets you dial in extra kick, and, thoughtfully, each amp model has a specifically tailored boost voicing. In boutique mode higher boost settings added a lot more gain to the amp model’s cleanish sound, and the saturation sounded and felt organic.
The chime model, loosely inspired by a Vox amp, is warmer and thicker than the boutique model in cleaner settings. But when I engaged the boost (with the knob at noon) and set the gain knob around 11 o’clock, the amp positively screamed—generating an aggressive and at times piercing sound that would reward a player with a commanding approach like Eric Gales or a 1960s-influenced guitarist who loves the potency of single-note lines.
The high-gain model, meanwhile, is a fire-breathing beast. With the gain at 11 o’clock, there is plenty of bottom end, and the sensation of the amp moving air becomes more apparent. Engaging the boost softened the attack slightly, which made soloing more liquid. But there wasn’t much of a difference through the range of the boost knob from noon to max. The amp model is pretty saturated to begin with.
There was headroom to spare and it’s impressively dynamic and responsive to picking nuances.
No Jumping Through Hoops Running Loops
Using the clean model, I ran my Yamaha UD Stomp delay through the effects loop. The results were dimensional and often sublime. The power-amp-in feature lets you plug in a pedalboard and play it directly into the Catalyst 100’s power amp. I used another setup, with a Mesa/Boogie V-Twin preamp pedal, directly through the Catalyst’s power amp and it sounded phenomenal. And even though the preamp is bypassed in this mode, the boost function is still active. Set at 10 o’clock, it added a nice final touch to the Mesa/Boogie preamp’s clean channel, making it sound discernibly richer. In my humble opinion, just the power amp and speaker cabinet alone are worth the $399 price.
Though Line 6’s acclaimed HX technology is embedded in the Catalyst, the company did a good job of keeping options easy to manage and navigate. There isn’t an endless buffet of effects, as you might expect. There’s a standalone reverb, and apart from that you can only use one additional effect simultaneously, unless you bring your pedalboard to the party.
In total there are 18 effects, grouped into three categories: delay, modulation, and pitch/filter—each with a corresponding LED in green, blue, or purple, respectively. If you’ve used Line 6 products before, many of these excellent effects (and the color coding) will be familiar. There’s the fabulous dynamic “ducking” delay, some modulation models based on iconic pedals like the MXR Phase 90 and others, and some classic Line 6 pitch/filter effects like growler synth and synth strings. If you do want to use more effects simultaneously, the effects loop is an excellent way to patch in external effects.
The USB hookup, by the way, enables connection to a computer so you can use Line 6’s editing software, which allows you to dive deep into tone editing or just fine tune a few things. I imagine that, in reality, most users will just figure out how to get a couple of core sounds directly from the amp, save them, and just go with that. But it’s always great to have options, and if you’re someone that actually maximizes the capabilities of modelers and editors, you’ll have a field day with the app.
The Verdict
For any guitarist looking for an all-in-one, plug-and-play setup for practice sessions, live shows, and recording (you can record directly using both USB and the built-in DI with cab simulation), the Catalyst, at $399, is pretty tough to beat. It’s got more features than many players will need, but what will count for most of the target audience is how much you can accomplish without diving too deep. And though the price might suggest otherwise, Catalyst isn’t just for beginners or intermediate players. Any professional guitarist that’s tired of dealing with tube related maintenance and expenses will be happy with many of the sounds here.
If you are into processing, pedals might be plenty for you, especially in this era of stompboxes that do things even top studio gear couldn’t manage a decade ago. Still, there is a portal to another world of sound available for live use—a world explored by guitarists like Adrian Belew, John McLaughlin, Eivind Aarset, Fennesz, Dan Phelps, the late Andy Gill, and others. It’s a portal you may be looking at as you read this. I am talking about a laptop computer.
I was introduced to the concept of guitar and laptop performance through the series of Warper parties— gatherings dedicated to computer-based music—I attended in New York City. At the very first one, I encountered a guitarist with a computer built into his guitar and another playing jazz fusion through his laptop to backing tracks, also on computer. Yet a third player was performing arrangements of TV themes, playing guitar with one hand and keyboards with the other—all through a laptop.
Plug-ins offer sonic shaping and effect routing that is difficult or impossible to achieve with pedals. Even if you could, it would require a pedalboard the size of the entire stage and a router/switching system of NASA-level complexity.
For me, performing solo with a laptop let me privilege the kind of sonic fairy dust I had been offering as a side musician, shifting the lush pads and textures I had delivered to singer/songwriters for years out from the background and into the focus of attention. Plus, as someone who does not sing or play typical solo guitar, playing through a laptop let me take control of my performance opportunities: no pesky bandmate schedules to consider for rehearsal or booking.
Many guitarists already use a laptop to record everything from demos to final releases. These days, all it takes is a guitar, an audio interface, a DAW (Digital Audio Workstation), and a pair of speakers or even good headphones, and you are ready to make your next masterpiece. If you have worked this way, you have likely discovered plug-ins. Instantiated in a DAW, plug-ins offer sonic shaping and effect routing that is difficult or impossible to achieve with pedals. Even if you could, it would require a pedalboard the size of the entire stage and a router/switching system of NASA-level complexity. Multi-effects units might get you part of the way there but as yet cannot offer the range of potential sounds available with a computer.
With a wealth of creative software, a laptop lets you easily take lush reverbs and mangle them with filters or distortion. You can sequence effects to automatically appear and disappear over the course of a song or composition. If that sounds interesting, you might want to consider transporting your laptop, DAW, and plug-ins to the stage, either as your sole processing system or in conjunction with pedals. Here’s what you’ll need to get started.
Hardware
A MIDI controller, like the Novation Launch Control ($159 street) seen here, isn’t necessary to use Ableton Live, but using one increases interactive functionality.
Because live performance has different requirements than recording, ultra-high audio specs are not quite as important, but portability, reliability, build quality, and low latency are crucial. Latency is the time it takes for your signal to go into the audio interface, pass through the software on the laptop, go back into the interface, and travel out to the speakers, as measured in milliseconds. You will want the latency low enough that you don’t hear the sound reaching your ears noticeably after you hear/feel your pick hit the strings. Ideally, you will want the most powerful laptop you can afford in order to have access to the fastest processor possible. Plenty of RAM and a solid-state drive will contribute to the computer’s speed.
There are factors that affect latency. One is buffer size, delineated in samples. Without getting too technical, the lower you can set the buffer in your DAW, the less latency you will hear. How low you can set it, without getting dropouts and other unwanted glitches, is determined by the number of plug-ins you are running and the power of your computer. With virtually any of the current Apple M1 powered laptops you should be good to go. If you can’t afford a new computer, don’t worry. I was performing with a MacBook Pro over a decade ago with no problems. You can attempt this with a non-Apple computer, but virtually every major touring act uses Macs thanks to their reputation for reliability.
Here I have the buffer size set to 128, where I find I can record tracks without latency issues. With modern computer power and minimal plug-ins, you can probably set this even lower.
To plug your guitar into your computer, you will need an interface, which converts your signal from analog to digital. There are many available options, including the Universal Audio Arrow (available used for $350-$399) or Focusrite Scarlett ($179 street). You only need one input, unless you use both electric and acoustic guitars, which have different input requirements. The number of outputs will depend on your signal chain.
A MIDI controller of some sort—foot switcher, tabletop controller, or both—is a good idea because, as with pedals, you will want to turn effects on and off and have access to parameters. Akai, Korg, and others make a variety of tabletop controllers, ranging from $119 street and up, with knobs and switches that will let you turn on, blend, and manipulate the parameters of the plug-ins in your DAW.
Eivind Aarset is among the group of creative guitarists who bring a laptop into the mix for all gigs.
Photo by soukizy.com
You might be thinking, “Aren’t my hands otherwise occupied playing my guitar?” That’s true, but one of the advantages of laptop guitar is advanced looping. Once a loop is created, a tabletop controller lets you easily route that loop through myriad effects—filters, resonators, delays, reverbs—in ways that are impossible with hardware loopers. A footswitch-style MIDI controller is helpful if you want to do sync’d rhythmic loops, though it’s not as necessary for ambient looping.
Software
To process your guitar in the computer, you can use any software that hosts plug-ins: Logic, Pro Tools, GarageBand, Logic MainStage, and others. As a performing tool, Ableton Live (starting at $99 street for an introductory version) is the most ideal and offers a number of unique features. With Ableton, you can tap in tempo, easily syncing all your effects and loops at once, and there are “nudge” buttons that let you move the tempo of loops slightly up or down to match a drummer’s shifting time without changing their pitch. The “link” feature lets you wirelessly sync your effects with your keyboard player’s laptop, your drummer’s loops, and even the computer running the show’s backing tracks and light show.
This is my performance setup in Ableton Live. It includes the Jam Origin MIDI Guitar plug-in ($149 street) that lets me control spoken-word recordings in a sampler without any kind of MIDI pickup on my guitar. Also shown is a great granular processing plugin, Stream, from Delta Sound Labs ($49 street).
Live’s native plug-ins will let you create a custom amp-modeling system; emulate digital, analog, and tape delays; and add stutter, granular, or bit-crushing effects. Plus, if you are performing solo using backing tracks and running through a PA, you can easily set a dedicated track to resampling and it will record your entire evening’s performance.
Live lets you loop in two different ways via the looper plug-in and “clip” system. The looper plug-in is great for overdubbing ambient soundscapes, but can also provide timed rhythmic parts, while the clip system is perfect for making multiple rhythmic-based loops that can then be triggered by a MIDI footswitch and/or tabletop controller. While you can’t overdub on a clip, you can set up multiple clip loop tracks where you are able to, for example, record all your verse parts in one row, your chorus parts in a second row just below, and create a third row for the bridge. You can then trigger these rows as scenes.
Here is a dummy clip set to raise and lower the feedback of the Ableton echo plug-in.
Live also lets you make “dummy” clips with no audio that can be set to modify effects parameters over time. For example, you could set a dummy clip to increase a delay plug-in’s feedback to just under runaway levels while simultaneously shortening the delay over a period of two bars, and then reverse the process over the next two bars. Try that with pedals!
Would you like to hear two great examples of guitarists using Ableton Live onstage? Check out any video with Eivind Aarset performing. Aarset uses it for a variety of sounds, including ambient reverbs and delays and looping. John Scofield collaborator Avi Bortnick also uses Live for myriad sounds and textures, one of which includes using his guitar to open a noise gate that lets rap vocals cut through only when he plays.
Signal Path
Fig. 1 (*Magenta cables indicate additional or alternative signal path.)
There are multiple ways to insert a laptop into your signal chain. You can run everything through your computer, employing amp modeling software—like Bias FX 2 ($49 street), Guitar Rig ($199 street), or AmpliTube ($99 street)—and running the signal from your audio interface to the house PA or a pair of powered monitors (Fig. 1).
Fig. 2
You might instead eschew the amp modeling software and run the signal into a pair of guitar amplifiers (Fig. 2). This offers a way to keep your favorite tube amps as part of your rig. But be careful: Some effects plug-ins can put out low frequencies that don’t work well with guitar amps and speakers.
For both of those methods, all you need is an interface with one input and two outputs. You run your guitar signal into the interface, which converts your analog signal to digital, and then sends that digital info through USB, Lightning, or Thunderbolt cables into the laptop and the software. Next, a stereo digital signal is sent back to the interface, where it is converted to stereo analog and sent out to the amps, powered speakers, or PA using standard guitar cables or XLR-style microphone cables.
Fig. 3
A more complicated method is a version of the wet-dry-wet setup. Here you would split your guitar signal between a mono signal going directly into a guitar amplifier and the laptop’s stereo output to two full-range powered speakers or the PA. This setup can be achieved in a few ways. You can use an interface with one input and three or more outputs that can be routed inside the interface. This allows you to send your guitar signal from the interface simultaneously to the laptop and directly to a guitar amplifier (Fig. 3).
Fig. 4
Alternately, you could use a splitter box before the audio interface that sends one signal to your interface and computer, and one to the amp (Fig. 4).
Fig. 5
If you don’t want to use modeling software in the computer for the wet signal, you can use a reactive load box, like the Universal Audio OX ($1,499 street) or Fryette’s Power Station ($899 street) or Power Load ($699 street), which gets placed between your amplifier and its speaker (Fig. 5). You run your guitar into the amp, and two outputs on the load box simultaneously send your amp signal to the speaker and, with speaker emulation, to the computer interface. Sending the sound of your amplifier to the DAW means there is no need for amp modeling within the computer. Once the sound is processed, it is sent to powered speakers or the PA, as in Fig. 2. In this method, your amplifier signal can remain dry and present, while processed sounds will emanate from the powered speakers or PA.
If you don’t want your amplifier signal completely dry or just want to place some of your effects pre-computer, you may want to use pedals in front of your amp. Which brings us to.…
Pedals and Laptop
As much as a computer can do, there are plenty of good reasons to combine pedals with laptop sounds. Digital modeling software sounds excellent these days, but adding a mild overdrive pedal before your interface can lend some analog warmth to the sound. In addition, a drive pedal set for just a little breakup can make the playing experience feel more organic. As you play harder and softer, the “give” of the pedal can often feel more expressive than even the best amp modeling software.
Plus, just as many plug-ins are not yet duplicated in pedal form, likewise there are pedals that perform functions not available as plug-ins. Glitchy, digital micro-looping pedals like the Red Panda Tensor, Hologram Electronics Dream Sequence, Chase Bliss’ Blooper and Mood, and the Hexe FX Revolver do not yet have any direct analogs in the plug-in world. If you want to learn a programming language like Max MSP, you might be able create something like these pedals inside your computer. Ableton includes Max for Live with the purchase of their suite and a plethora of pre-programmed plug-ins are available using Max as their basis, but these pedals still offer something special.
Taking the Stage
You now have all your hardware and software and are ready to perform. Depending on how you use the laptop in your signal chain, you might be able to place it out of the way and use a foot switcher, as if you were using a standard multi-effects unit. But if you want to maximize the advantages of using a computer live, you will likely want it at hand.
In almost two decades of performing with this setup, I have had fewer computer crashes than pedal malfunctions.
You can normally rely on the venue to provide a table of some sort, or you could try Eivind Aarset’s solution. He brings a keyboard stand and places his guitar’s hard case on it, creating a perfect platform for controller, computer, interface, and some of his hardware pedals. I haven’t used a hard case in years, so I just screwed some handles onto a painted piece of plywood and place that on a keyboard stand.
As with any performance, hearing yourself is crucial. If you are using guitar amps or powered speakers, they will act as monitors. Some powered speakers may have XLR outs to send to the house PA. If you are only running through the PA, you may want to use headphones plugged into your interface to be assured of hearing the same thing as the audience.
Some guitarists have trepidation about reliability when using a laptop. All I can say is that in almost two decades of performing with this setup I have had fewer computer crashes than pedal malfunctions. It is also easier to bring a backup laptop and interface than a second pedalboard and amp.
A laptop dedicated to only music is ideal, but if you don’t have that luxury, make sure to quit any programs other than the performing software in use. Turning off WiFi during your set will prevent notifications from interrupting and provide a little extra processing power. And speaking of power, while it is best to keep your laptop plugged in while performing, if there is ever an issue with clean power or a faulty socket, unlike with pedals, your laptop battery will take over and the show will go on.
Is It for You?
Playing through a laptop is not for everyone. You probably won’t be welcome at your local blues jam if you say, “Hang on a minute while I boot up my Mac.” But if your music involves a world of sounds that go well beyond those offered by hardware pedals and multi-effects, or you’re just seeking a more portable way of producing interesting tones, taking the stage with a computer might be an option. And, with tubes becoming harder to get, who knows? Someday it may be the best option.
Kemper Profiler Stage, Nueral DSP Quad Cortex & Line 6 HX Stomp (clockwise from top)
That democratization of pro-level workflows has opened new and exciting paths for guitarists to explore. Barry O’ Neal, who is the chief puzzle solver for Xact Tone Solutions in Nashville, has built rigs for some of the biggest acts in the world, including Taylor Swift, Bon Iver, and Peter Frampton. “In the beginning, all gear was pro gear, to an extent,” he says. “There is a line of demarcation between pro-grade gear and consumer gear. And there used to be a lot clustered around that line. Now, they are all either way above or way below.”
At this point, the difference between modeling technology mainly has to do with features. Do you need more inputs and outputs? Is direct recording via USB a priority? Are there certain one-off effects or sounds you need on a gig? All the top-level units have a somewhat similar set of core features, but each one also branches off into more specialized realms. Let’s dig in and discuss choosing a modeler, break down some myths that surround these units, and help novice users get just a little bit more out of their chosen processor.
Which One is For You?
Kemper Profiler Stage
Ah, the eternal question—as a guitar journalist, this might be one of the most frequent questions I get asked. There are many ways to tackle this. One element of this puzzle that I’ll leave for others to debate is how these different units compare in terms of tone. From my perspective, you need to figure out what you’re missing in your current setup and how a digital rig would make your life easier. As we’ve seen in literally hundreds of Rig Rundowns over the years, these units have passed the test both onstage and in the studio. Even when you have Dumbles and vintage high-powered tweed Twins at your disposal, having a modeler in the rack can still be useful. (Hi, Keith Urban!) “Go online and watch videos on how you program and use the unit. If those don't make immediate and visceral sense to you, bail,” says O’Neal.
Fractal Audio FM9
I usually point people to two different camps: the all-in-one units (Line 6 Helix, Fractal Axe-Fx, Neural DSP Quad Cortex, Kemper, etc.) or the smaller stomp-sized boxes that have a narrower focus on amp, cab, and mic emulation (Strymon Iridium, Walrus ACS1, or the Boss IR-200). This is an important fork in the road because both types of units offer their own solutions. Plus, price can vary widely. Although there will be some overlap, this article will focus mostly on the all-in-one units. However, the stomp-sized amp emulators have their place. Simply place one at the end of your board for an easy analog-digital hybrid setup or keep one within arm’s reach in case a tube goes out on the gig.
Neural DSP Quad Cortex
One of the bigger conceptual things to think about when choosing a modeler is the difference between an open ecosystem and a closed one. The Line 6 Helix and Fractal Axe-Fx units (and their various spinoffs) are what I consider closed systems, because you can’t create an entirely new amp model within their space. (The Axe-Fx III has an incredibly powerful ToneMatch feature, but that’s more based on deep customization of a pre-existing amp.) Both offer regular firmware updates with new amps, cabs, effects, and features. On the other side of things, you have Kemper and Neural’s Quad Cortex, which allow you to “profile” or“capture” digital versions of your amps and effects. This is really the defining feature of these units. With a simple recording setup, you can get extremely accurate versions of your prized—and fragile—tube amp and leave the original at home. The one caveat is that the quality of the result is only as good as your engineering skills, which is why a cottage industry of purchasable, professionally made profiles has popped up.
Start With What You Know
A piece of advice that I always recommend to anyone getting into modeling is to create your own presets. Yeah, it might take more time than just tweaking a factory or purchased preset, but in the end, you will learn much more about the features of your unit, as well as how the various elements of your signal chain interact with each other. For example, let’s say you’re a country-rock player who prefers a Vox-style amp.
With a simple recording setup, you can get extremely accurate versions your prized—and fragile—tube amp and leave the original at home.
Put aside the bells and whistles for the moment and focus on how to create a good base tone. Carter suggests a similar route: “Start simple with just an amp and cab. Get used to the interface and GUI [graphical user interface]. If you’re a Bassman player, it doesn’t make sense to just jump in and start tweaking a Mesa/Boogie.” Depending on your modeler, the various parameters for amps and effects might be different—or nonexistent—but at least you will have a point of reference before jumping into the deep end with experimentation.
Once you have the basics down, a prime place to start branching out is in routing. Gone are the days of needing a huge amount of rack gear to experiment with pre- and post-effects, parallel solutions, and MIDI. With a virtual playground, you can emulate nearly any imaginable signal flow and even design some that would be impossible in the analog realm.
Fig. 1
Most of the digital “boards” that guitarist and PG contributor Joe Gore designs are subversive, inspiring, and far from the mainstream. (He offers 13 different meticulously crafted Helix presets through the Line 6 marketplace.) Gore’s presets taught me invaluable lessons about using expression pedals when I tried to reverse-engineer them. Each scene or snapshot change has up to 60 different parameter changes, which alone is quite the feat. I would highly recommend his Blood & Pasta and Psych presets—they are simply mind-blowingly creative. In Fig. 1 you can see an example of how extensive this can get. Don’t be afraid to push the limits and reverse-engineer something from a more complicated setup.
“This is really the first time in a while where you can have bar bands playing the exact same gear as stadium acts.” —Cooper Carter
If you’re at least considering a digital unit, you likely don’t get the cold sweats when you think about learning your way around various menus and options. Each of us has our own specific tolerance of those, but in my experience the better you learn the ins and outs of your gear, the better you will sound. Although these are very, very tech-heavy units, you can get incredible results with simple setups. Going “digital” isn’t an all-or-nothing proposal. If you really dig your amp or pedals you can easily integrate those with any digital modeler. Let’s look at a few options that allow you to hold on to a bit of the analog.
4 Cables or 7?
Fig. 2
The easiest way to combine digital control with analog pedals is to take advantage of the effects loop. Here’s a scenario: You want to use your modeler simply for effects alongside your trusty tube amp, but you don’t want to run everything in front. This is where the “4-Cable Method” comes in. In this arrangement, you’re able to run all your compression and drive pedals directly into the preamp and move all your modulation and time-based effects to after the preamp. In Fig. 2 you can see a diagram of how to hook everything up. Here are the steps:
- Arrange you signal chain in your modeler so that the effects loop insert is at the point where everything before it will go in front of your amp and everything after will go directly to the power amp.
- Connect your guitar to the input of your modeler (cable 1).
- Connect the effects send of your modeler to the input of your amp (cable 2).
- Connect the effects send of your amp to the effects return of your modeler (cable 3).
- Connect the output of your modeler to the effects return of your amp (cable 4).
This results in a hybrid setup that allows an incredible amount of flexibility with routing your digital effects within a traditional tube amp. (One tip: Check the global settings on your unit and make sure the effects loop is set to instrument level rather than line level.) Not sure if a certain effect works better before or after the preamp? Simply move them around in your modeler.
In Clip 1 you can hear what it sounds like with distortion, delay, and reverb running directly into the front of the amp.
And in Clip 2 I used the 4-cable method to clean things up.
Fig. 3
But what if you’re running a stereo rig? That’s where the 7-cable method comes in. There are a few more things you’ll need (other than cables) to pull this off. First, your modeler must have two effects loops and dual outputs. Let’s pretend that the 4-cable setup described above is for amp #1 via output 1 of your modeler (Fig. 3). Now, follow the steps below for the second amp:
- Connect effects send 2 from your modeler to the input of amp #2 (cable 5).
- Connect the effects send from amp #2 to effects return 2 of the modeler (cable 6).
- Connect the main right output of the modeler to the effects return of amp #2 (cable 7).
It always helps me to sketch out how I envision everything working before diving into editing a patch.
The signal flow in the modeler will also become a bit more complicated. It always helps me to sketch out how I envision everything working before diving into editing a patch. If you think of these two as simply two parallel signal paths that come from a single source, it helps to keep everything straight.
Monitor This!
Fig. 4
On major tours, there’s an army of talented engineers that help craft the best sound possible, both onstage and out front. For most of us, that’s a real luxury. One routing setup that Carter suggests helps with both your monitor mix and getting a bit of that amp-in-the-room feel onstage. “The most practical application would be to run your fully processed signal to FOH and then a separate signal to a powered cabinet on stage,” he says. “From there, you can insert a split before the delay and reverb and feed that to your monitor or in-ears.” In Fig. 4 you can see an example of how to feed FOH, an onstage cabinet, and your in-ears. Tweaking the level of delay and reverb in your ears separately from FOH will allow you to better shape the reverb for the room without affecting what you’re hearing. “Whatever sounds best to you will make you play better,” says Carter.
Impulses Galore
One of the easiest ways to level up the realism of a preset is to use an impulse response (IR). This is where the all-in-one units and smaller stomp-sized modelers cross paths. Remember, the speaker and cab configuration in a traditional setup is basically an EQ—different cabinets and speakers treat the signal differently and therefore match better with certain amps and guitars. An impulse response is a digital version of everything after the amp, which would include the mic pre, mic, cab, and speaker. With a digital modeler, these would run in place of a cabinet block and before any time-based effects or reverbs.
Creating an impulse response isn’t too complicated. There is a wealth of tutorial videos on YouTube detailing the process, and some DAWs come with a built-in IR creator. In short, you sample ambient sound around a core tone and then the modeler uses that to treat your guitar tone.
In Clip 3 you can hear a Vox-style amp with a closed 2x12 cab IR.
And in Clip 4 you can hear that exact same tone with a larger 4x12 cab IR.
There are a host of ways to use IRs in your signal chain, but often it can be a somewhat paralyzing notion to try and wade through dozens of options to find the right one. Most IR packs come with loads of different WAV files that that can be separated by either cab, mic, or, for acoustic settings, guitar type. One way to quickly parse through them would be to set up a simple template with your preferred signal chain and then insert a split after the amp block to two separate IR blocks. Then map those IR blocks to different footswitches. This allows you to A/B a pair of IRs without taking your hands off the guitar.
Acoustic amplification can be a tougher road. Brian Wahl and Bradford Mitchell are behind Worship Tutorials, a website that offers various presets and IRs for many types of modelers including Helix, Kemper, and Axe-Fx. A few years ago, Wahl purchased a few acoustic IRs but never really connected with them. So, he decided to make his own. “One of the big myths I see is that people think you need to get an IR pack that closely matches their guitar type. That’s not true,” he says. “It’s like thinking you can’t put Telecaster pickups in a different guitar,” adds Mitchell. The purpose of the IR is to help shape the tone of your instrument in ways that EQ can’t quite reach since there’s a bit of reverb and possibly delay packed into each one. Another myth that Wahl hears is that if you have a really good pickup system, you don’t need an IR. “My response to that is we’ve found that guitars with higher-end pickup systems actually benefit more by using an IR,” he says.
“One of the big myths I see is that people think you need to get an IR pack that closely matches their guitar type. That’s not true.” —Brian Wahl
The process for Wahl and Mitchell starts with making a high-quality recording of the miked acoustic. Then, they will match the recording across six different pickup systems and 10 different mic options. Once you factor in different sample rates and WAV lengths, the process can become quite intense. “When deciding which IR is for you, I typically recommend staring with a mic you’re familiar with and cycle through the different pickup options,” says Wahl. Trust your ears at this point in the process above all else. “Most of them actually might sound bad,” he adds, “but once the correct IR clicks, you’ll know it.”
Talking with Wahl and Mitchell inspired me to dig up a few acoustic IRs and test his theory. I plugged my Córdoba Acero straight into my HX Stomp and recorded into Logic Pro X via USB.
In Clip 5 you can hear my completely unaffected signal. The Acero’s pickup system combines a piezo and under-saddle mic, so I kept the blend at noon. It’s not a bad tone, but enough of the piezo quack is coming through to warrant a better solution.
For Clip 6 I loaded up an AKG C12 dreadnought IR. The result sounds better. There’s more air around the sound, but the high end is a bit thin.
Clip 7 is an IR from the same mic, but I chose a different pickup option. It’s not as good as Clip 6, but still has that ambience that I dig.
Finally, we have Clip 8, which is a combo of a piezo pickup and a Neumann U67-style microphone. It’s kind of gross and thin but could serve a purpose in the right mix. I think recording examples like this is essential to finding the right IR match. Taking an objective listen will help you decide between options that could be quite subtle.
State of Expression
One of the most fun—and interactive—parts of using a modeler is exploring the absolutely endless options that expression pedals can offer. In most units, nearly any parameter you can think of can be assigned to an expression pedal for real-time tweaking. One player who really opened my eyes to what’s possible with expression pedals is John Nathan Cordy, a British guitarist who specializes in jazz-fusion styles and has a YouTube channel that explores most of the modern modelers. One of his favorite expression pedal tricks was inspired by the ambient pads Eric Johnson would play on the intro to live versions of “Cliffs of Dover.”
Fig. 5 shows the diagram, but here’s how you set it up:
- Arrange a basic signal path and then add a parallel path.
- Place a digital delay on the parallel path. Digital works better because with analog emulations you can dip into self-oscillation, and we don’t want that.
- Within the delay, assign your expression pedal to the feedback control so that when the heel is down you’re at about 10 percent and toe down is 100 percent.
- Put a volume pedal block before the delay and assign the expression pedal so when the toe is down it mutes the input.
- Add reverb to taste after the delay.
- Connect the parallel path back to the main path after the amp and cab block.
I’d recommend saving this as a template and then experimenting with loopers, compression, multiple outputs, and more.
Next Steps
Ultimately, the better you know any piece of gear, the better it will sound. Once you find a modeler that you connect with, invest the time to learn and explore the features and effects that you can put into practice. Understand its strengths and weaknesses and make sure those align with the goals you have for your rig. And don’t be too bashful to ask questions online—each of these units has a robust community of users, which means there’s a ton of info out there. Chances are if you run into a roadblock, someone else has too.
Finally, do what inspires you. Don’t overthink things or get distracted from the big picture, which is to enjoy making music.