In Summary

Guitar amp simulators are one marvel in the DAW that some cannot live without. Some guitar heavy productions will always need to move some air, but others rely on virtual amplification. Here we round up some of our favourite ways to turn the realism up to 11…

Going Deeper

Some engineers will remember a time when “guitar amp simulator” meant a box of some kind with a speaker simulation circuit and some distortion thrown in if it was really fancy! Armed with just a handful of tricks such as low pass filtering and one flavour of fizz, these boxes had their uses, but ultimately trying to use one for any prominent part was being optimistic.

Towards the end of last century, later digital units such as Line 6’s kidney bean-shaped Pod desktop amp simulator, along with systems such as Roland/Boss’ COSM virtual tech started to make convincing amp tones within closer reach for bedroom warriors and guerrilla recordists the world over.

Convincing virtual guitar amp audio plugins are now the tool of choice for many mix engineers, thanks to their infinite instances of multiple amp models, and everyone’s favourite feature: Recall. That said, even the very best of these can benefit from a little enhancement in the DAW mixer to elevate guitar sounds and more. Here we round up some of our favourite tools and techniques to make simulated guitar amp sounds that really convince.

Double Up

Recording and stacking identical parts is a classic production trick, with double tracking parts perhaps being the best known technique. The effect of the subtle differences between two takes is well known, and there can be a tendency to use identical instances of amp for this trick, just like when working with a single rig.

Although imposing the same ‘restriction’ with a virtual amp can suggest a real setup, using two different plugin amps that work in the context of the song is a simple trick that most studios can do. For the ultimate in authenticity, using the same virtual mic or pair of mics is often what happens on the studio floor, so why not tap into that as well?

Or for ultra-tight doubles, why not use exactly the same take to feed two different amps? This spin on the classic live sound principle of ‘one player, many amps’ creates a sense of size to parts without any raggedness or inconsistencies. Extra chunkiness can be added by introducing a slight delay to any duplicates - anything between around 25 - 75 milliseconds can work but of course that’s just a suggestion.

Doubles or any number of duplicates can be fanned out across the mix, but for the ultimate quick way to open out guitar tracks’ panorama, using a dedicated tool such as Softube’s Widener can broaden the horizon for guitars and more.

Align To Impress

Using two virtual mics should mean that signals arrive properly aligned out the amp sim plugin, however, if things sound amiss with no adjustment available, there are ways to improve things. Solo-ing one mic at a time and printing or bouncing the result allows mics to have their time and/or phase relationships adjusted to get things hitting as they should.

That’s not to say that there is a ‘right’ way to do this; many guitar sounds get their character from imperfect time alignment or phasiness from placements that were nearly just right. In fact, ‘breaking’ the alignment from your sim in this way can be the ultimate way to convey the sound of real mics’ interactions.

For those engineers who like to check that everything is hitting as it should, virtual mics’ bounced waveforms can be aligned by eye or ear (especially when polarity is used). Going further, using a tool such as Sound Radix’s Auto Align 2 can take multiple signals and rotate, slip, or otherwise fix many mics (real or virtual) on guitars or anything else.

Get A Room

For all of the realism many guitar amp simulators provide, some of them can benefit from a little virtual ambience to sell the effect. While many do have their own reverberators, or ambient mic perspectives built-in, using a dedicated audio plugin reverb further downstream can guarantee sounds that convince. This can be simply a matter of control; many built-in ambiences that land with guitar amp sims are designed to be simple enough for musicians themselves to get the best out. Although this can be an advantage for creators, ‘engineering’ virtual sounds needs more parameters to be available.

With real amps, pulling the mic(s) back a little to get a sense of space around guitar sounds can really add some life to banish the one-dimensional sound of close-up sounds. Using a dedicated reverb can let engineers do the same to dry virtual sounds to give virtual amps a sense of place. Luckily, getting some welcome air around virtual guitar amps is now easier than ever thanks to a whole new generation of advanced audio plugin reverbs such as many post mixers’ favourite LiquidSonics Cinematic Rooms.

Build-In Some Character

Could it be that even our beloved crunchy guitar sounds have become a little sanitised? Gone are the days of guitar amps with more cigarette burns and beer stains than a dive bar’s floor. Also absent are some of the more characterful vibrations coming from guitar amps (and were not talking about that loose change or old guitar strings rattling around in the back). The effects that come in stomp box form, and the DSP effects built into many modern amps have a common ancestor. Some of the oldest guitar effects around were built into classic amplifier heads and combos from the days of blues, surf, and rock’n’roll. Of these, tremolo and spring reverb were the most common flavours on tap.

Using these in front of your amp sim will give tones a vintage twist with an authenticity that straight-edged modern sounds cannot match. For extra realism, why not plugin into your interface after you press record for some unmistakable retro-glitchiness!

Supercharge Speaker Movement

So far we’ve talked about tools and techniques that can help transform sounds artistically, but recently we came across something that actually sets out to address some of the technical limitations of conventional amp modelling and the use of impulse responses to mimic speaker behaviour. Many will be aware of the latter for measuring and replicating the characteristics of various gear and acoustic spaces, however the ‘classical’ approach to this kind of technique is to use sine waves as opposed to musical input. Coupled with amplifier behaviour that also differs depending on the input, it’s easy to see how idealised IR’s through real guitar amps might not be the same as the results from real playing.

Bogren Digital’s IRDX Core uses their virtual amplifier technology. This uses “advanced machine learning methods” to reconstruct the difference between a real cab and an impulse response. It's been developed to be used downstream of existing cab emulations or impulse responses for a guitar amp sim that reacts like a real amp. This means that engineers can simply put it at the end of their plugin chain for a different way to supercharge the realism of the virtual amp itself. Having recently tried it out for ourselves, we liked the subtle but noticeable difference IRDX Core made to our guitars, as well as its nice big GUI that has the Bogren Digital family look: zoomed in on one part of the amp panel just where you need it.

Bogren Digital on IRDX Core:

“It is not only useful to rock guitarists but really for anyone who ever works with tracks that include guitar cabinet impulse responses — which is pretty much every recording engineer these days.”

• With IRDX Core disabled, every stroke on the guitar sounds similar, and the guitar seems somewhat two-dimensional and lifeless.

• With IRDX activated, differences between the individual strokes are more discernible, the sound wakes up, and you get all the changes over time that are so important to keep the listeners’ attention.

• Using IRDX Core in a mixing situation adds width, movement, and excitement to guitar tracks. It also helps guitars sit better with the other instruments.

• With IRDX Core activated, the guitar sound reacts more realistically to your playing when you play through an amp sim in real time.

Final Thoughts

In the DAW age more than ever, even basic guitar amp simulator plugins can sound a lot like the real thing, especially when planted in a mix with real sources to further sell their effect. There’s a lot to like about these new contenders for virtual amp supremacy. Not least are their infinite instances, recall, and automation that make grid-perfect channel changes and other fancy footwork a reality.

Despite many tools being mix-ready from the start, sometimes sounds can benefit from a extra little push to make that virtual air move as nature intended. Along with some classic production techniques such as tracking-up parts for monster sounds, or placing sounds in stunning virtual spaces, engineers can even concentrate on the finer points of IR-measured speaker movements as well. Zooming back out for a second, if the all-important music is right, we have the technology to do it justice!