Several years ago, I did a summer tour of Europe and the UK, during which we played a few of the large outdoor festivals including Graspop, HellFest, Retro C Trop, and Barcelona Rock Fest. In addition to seminal hard rock acts such as Deep Purple, UFO, Alice Cooper, Saxon and Aerosmith, there were some really heavy acts with names like Lucifer’s Friend, Killcode, Night Demon and Gotthard. Much to my surprise, many of these acts — including the heaviest of the heavy — were using guitar amp simulators in lieu of miked amplifiers. Yes, there were stacks and stacks of Marshall 4x12s, but most of them were for show. The guitar sounds were coming in direct.
At that time, one of our guitar players (Richie Castellano) had already been playing through a Line 6 Helix (shown in Fig. 1), so using an amp modeler as opposed to a traditional guitar amp head/cabinet was already part of our routine. As I recall, one of the reasons Richie went to the Helix was consistency: the majority of the shows we play (then and now) are fly dates where we use rental backline. Sometimes that backline is amazing, and sometimes it’s beat to hell — even when supplied by the major backline players (which is a discussion for another time). The Helix gave us consistency regardless of where we were playing and what gear was supplied. Richie had already done “preproduction” at home, but the Helix sounds needed some tweaks when heard through a large-format P.A. system. Lucky for me, he was willing to spend time fine-tuning the sounds and I think we achieved excellent results.
Here are some of the advantages that amp modelers or simulators have over miked guitar amplifiers:
- You can play softly while sounding like the amp is cranked (great for low-volume situations).
- Traveling with a simulator is much easier.
- It’s possible to carry a spare or rent one in an emergency.
- The guitar will be sonically isolated from the rest of the stage.
- Amp modelers offer endless possibilities of amp/cabinet combinations, and those combinations can be instantly recalled.
- Though initial programming may take some time, the signal path is simplified.
- It’s easier to change the sequence of effects, which may be impossible on a pedalboard.
- You won’t get a backache from lifting an amp simulator.
- Some amp modelers (e.g., the Kemper Profiler) can capture the sound of your own guitar rig.
Two quick tips: (1) Connecting the output of a simulator into a guitar amp will probably sound bad because the simulator is already creating the sound of the amp/cabinet. (2) Make sure that the simulator’s cabinet emulation is turned on when patching it into a mixing desk.
Leave the Microphone Home
There are a few things to be aware of when switching to an amp simulator, the most obvious of which is that you’ll need one less microphone and one more DI. Some amp simulators (the Helix Floor for example) feature a built-in DI, but you may find that the onboard DI doesn’t have a ground lift switch like you’d find on a dedicated DI. It’s a good idea to carry an audio ground lift such as the Lifter from Whirlwind (Fig. 2), a device that isolates the ground of a balanced audio signal without forcing you to hack apart an XLR cable to cut the shield (and Murphy’s Law dictates that this cable will inevitably make its way back into the cable trunk, where it will cause all sorts of trouble).
Situations may arise when an audio ground lift doesn’t solve a hum issue, and that’s where a device like the Morley Hum Exterminator™ (Fig. 3) comes in handy. Such devices filter unwanted voltage on the ground line that could otherwise cause ground loop hum, and make it possible to solve hum problems without using an AC ground lift.
One thing that you should never do when trying to solve a ground issue is remove the ground pin from the AC cable because doing so can cause hazardous conditions.
I Can’t Hear You
A big issue that comes up when using an amp simulator is figuring out how the musicians will hear the instrument onstage. Our solution has been to patch the ¼-inch TS output of the Helix to an external DI, then feed the balanced XLR out from the DI to the house audio split. We also connect the ¼-inch output of the DI to a powered monitor such as a QSC K12. The K12 is set upright alongside the backline where the guitar amps live, not in the usual downstage wedge position. The monitor is there really just to move a bit of air and provide some onstage presence, but it’s not blasting out like a guitar amplifier normally would. The majority of what the band hears is the DI feed from the Helix into the monitor desk, which of course means they can have it as loud or as low in their IEM mixes as they like, without need for an amp raging on stage. BTW, this also helps clean up the FOH mix.
Use the Cloud
A lot of amp modelers provide a USB connection that can be used for firmware updates, to load new IRs (Impulse Responses), and for interfacing with offline editing software. Be sure to carry a backup file for the device, and leave a copy of that file in the cloud. Not only is this a good idea as backup for the unit you own, it also enables you to load your sounds into a rented unit in the event that the airline loses your gear on the way to a gig — which of course never happens…
Steve “Woody” La Cerra is the tour manager and front of house engineer for Blue Öyster Cult.
