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Using Guitar Amp Simulators 101, Part 2

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Read Time: 14 min
This post is part of a series called Using Guitar Amp Simulators 101.
Using Guitar Amp Simulators 101, Part 1
Using Guitar Amp Simulators 101, Part 3

In the first part of Guitar Amp Simulators 101, we looked at the fundamentals of choosing, setting up and getting started with an amplifier plugin. In this second part, we’re going to get our hands dirty and really get to grips with how to get the best out of our software amps.

As before, and largely for the sake of practicality, I’m working primarily in Guitar Rig, but many of the techniques we’ll look at can be applied to whatever software you’re using. Feel free to share your own software specific tips and tricks in the comments!

Getting Into the Ballpark

The easiest way to begin to find your own sound is by heading for what you know. If you’re used to a Marshall stack with a lovely old TS-808 in front of it, you’re bound to go for the closest approximation of that set-up your software will provide.

While that’s all well and good, your options in the digital world are much wider and, moreover, a model of, say, an old JCM800 and a matching 4x12 is just that – a model, an archetype – and so may not correspond exactly with what you’d expect from your own experience with the real world equivalents.

Mix and Match

With that idea in mind, it’s time well spent to cycle through all the available options to find out what kind of sounds they produce. Think of it like experimenting with colours in visual art: in that scenario, you’d be unlikely to get the best representation of the scene you’re trying to paint by using the colours right out of your paint box; you’re going to want to mix and match.

In doing this, you might encounter some unexpected results. Don’t be afraid to try some unholy alliances – say, a Triple Rectifier style high gain head with a tweed 2x12 cabinet; it just might be the sound you’re looking for, even if it might raise eyebrows if you tried it at your local rock club gig.

With amp simulation, it’s helpful to think of the cabinet not so much as a means of turning an electrical signal into something you can hear (indeed, in the virtual world, it definitely isn’t) and more as an additional layer of EQ. Each of the cabinet models is, essentially, just an EQ curve, and finding the right one can make or break your virtual amp sound.

As an example, here’s Guitar Rig 3’s representation of a Plexi style Marshall half stack into a matching 4x12 cabinet:

And here’s the exact same amp and settings into a Fender style 2x12:

Both are fine, but you can clearly hear how the different cabinet models are introducing a completely different EQ profile to the overall sound. So by doing this, we’re giving ourselves a whole new layer of EQ control beyond the amp’s standard bass, middle, treble and presence.

Go Expert

Having selected an amp and cabinet model with the right voicings for the tone you want, the first port of call for a little fine tuning is the amp’s standard controls – gain and EQ; but these will get you only so far. To really take control of the tonal properties of your amp sound, you need to get under the hood and get to grips with the “expert” settings.

In Guitar Rig, clicking on the expand button (+) at the left of the amp module will reveal a new panel, typically containing settings for power supply, Variac, sag, response and bias.

Each of these settings has an important part to play in defining the overall characteristics of the amplifier model, and to the way in which it responds to your guitar signal. For example, using these controls, you can choose between a loose, spongy sound and a tighter, hi-fi sound, or something between the two.

  • Power supply allows you to select between a 50 Hz or 60 Hz supply. The difference is subtle, but changing the supply to the same sort you're used to might just help!
  • Variac emulates changes to an amplifier’s supply voltage, a lower setting giving more of a vintage “brown” sound while higher settings are punchier and more modern sounding.
  • Sag does much as the name suggests, and is intended to emulate the differences between solid state and tube rectification. Tube rectification – more sag – has a softer, more saturated sound, and sounds particularly good for lead guitar tones, while the solid state end of the spectrum is harder, colder and well suited to punchy rhythm tones.
  • Bias is something tube amp owners will already be familiar with, and many will know that bias settings have a big impact on an amp’s sound. In Guitar Rig, a lower bias setting produces a loose grain, fuzzier kind of tone, whereas a higher setting is cleaner and more defined.
  • Response essentially changes the software’s response to the dynamics of your playing. Lower settings work well with more sag and lower bias to produce an organic, vintage sound; while higher settings will generally suit more hi-fi sounding modern tones.

Most of the effect modules, from distortions to delays, have these expert controls too, and are well worth getting to grips with to really fine tune your sound. We’ll touch on effects later, but for now, let’s have a quick look at what we can achieve with the amplifiers.

Here, I’ve taken Guitar Rig’s Ultrasonic amp model – a modern high gain amplifier along the lines of Bogner’s Uberschall – along with its matching cabinet, and tried to get two quite different high gain tones.

In this first clip, I’ve used the expert settings to give the amp an over the top, saturated, spitting sound by setting the bias, Variac and response parameters quite low with quite a bit of sag, producing a spongy sound reminiscent of a hot-rodded Marshall:

In this second clip, while the amp’s EQ remains the same, the expert settings are reversed – low sag, high variac, bias and response – giving the amp a faster, harder response and, consequently, a colder and stiffer sound, more along the lines of Engl or Fryette amps than Bogner or Mesa:

Same amp, same cabinet, very different vibe, and quite apart from the properties of the sound produced, each setting has a very different feel when you’re playing through it: equally, if not more important than the sound itself.

For example, the way a cranked up Marshall will saturate and sag can inspire you to really dig in to the strings, producing long, singing sustained notes – great for soloing, but not brilliant for pin sharp riffage. An Engl, on the other hand, with its rapid attack and relatively unsaturated sound is a dream come true for metal style rhythms, but not so great for those soaring, epic pentatonic widdle fests we all like to indulge in from time to time.

Where real world, physical amps are concerned, most of us have to find a compromise, but with software, we can completely change the way an amplifier works and sounds with a few mouse clicks: lots of potential! Peavey’s ReValver even allows you to completely alter its amp models with different tubes and circuit designs.

Mic and Air

Between all of the options and parameters we’ve looked at so far, you’d be hard pushed not to find something close to the tone you want, but we’re still only scratching the surface of what’s possible.

In Guitar Rig, you’ll notice a pair of slider controls on the cabinet’s front panel. The uppermost of the two allows you to switch or blend between two different types of microphone, while the bottom slider allows you to control the amount of “air” – basically room reverberations – in the sound.

If you’ve never had much opportunity to play around with real microphones in front of your amplifier, you may not be aware of the extent to which these factors – microphone choice and positioning – influence recorded sounds. For our purposes, it’s sufficient to say that microphone selection and positioning is an art in itself, and good studio engineers will often invest a lot of time and effort into finding the perfect method (methods they’ll often guard like a deep secret!).

Now, you can be sure they don’t go to all that effort for nothing, so let’s see what we can achieve with our microphones.

In this first example, I have a Fender Tweed style amplifier with a matching 4x10 cabinet, and I'm aiming for a nice, raw, bluesy kind of sound. There's a little gain boost in front of the amp, and some spring reverb between the head and cabinet. I’ve got the microphone slider set fully to the left, which means we’re only hearing Microphone A, with just a whisper (about 1.2, actually) of air:

And here’s the same thing again, but this time with the microphone slider fully right, so we’re hearing only Microphone B:

Conveniently enough for your intrepid guide, Microphone A is a little too dull and Microphone B is somewhat too harsh, so let’s see what happens when I blend the two by putting the slider right in the middle:

To me, that’s just the right balance of the fullness of A and the bite and clarity of B, but for my bluesy intentions, it’s still a little dead and lifeless, so let’s wind the air slider up to around two thirds full:

Much better. Now we’ve got more of a sense of the amp in a room, and it adds nicely to the dynamics of the riff.

All Together Now

So we’ve seen that there’s huge scope for tailoring and tweaking our sound beyond the limits of merely choosing an amp and dialling in the EQ. We’ve got at least two extra layers of EQing possibilities with our choice of cabinet and microphone, and more still if we blend the mics; we can alter the response and dynamics of the amp with the “expert” controls, and we can add some life into the sound (or, conversely, make things tighter more focussed) by varying the amount of room sound or “air” in the microphones.

Remember, too, that the effect modules have expert settings, too, so there’s a whole world of possibilities with our distortions, delays and modulations, too.

Van Shmalen

Let’s try to build a sound from the ground up using these techniques I’ve described, enabling you to see how you can apply these methods to your own projects. Conveniently enough, I just stumbled on some isolated guitar tracks from an early Van Halen record and, though I’m not a big fan of his music, you can't argue with his guitar tone, so let’s take that as something to aim for.

The Basic Rig

Here’s an appropriate Marshall Plexi style amp model, with matching cabinet, bass around 1 to keep out the flab, middle at 6, treble at 10 to add some bite, and presence at 6 for a dash of sparkle. All the expert controls are in the middle at 12 O’Clock and, in tribute to Van Halen, I tuned down a half-step… Without a tuner.

Not a bad approximation, if you allow for my rotten playing. But even with both volume controls at full tilt, it’s not got that smooth gain, and it’s lacking a little substance and excitement. It’s needs more bite, too, and some air.

Microphone Action

So, let’s put some more bite in there by mixing in a lot more of Microphone B. I’m going for 80% B and 20% A, as that sounds like as much bite as I can get without the sound becoming too harsh. In addition, I’m backing the middle off to around 4 to help put an edge on the sound, and I’m also adding some air, around 3.7, to help give it that vintage rock liveness.

Closer, but the quality of the distortion is still bothering me. It needs a juicier, fatter feel, and still more bite.

More Juice!

I’m going to back off the Warm Volume control to leave me with just the “bright” sound, and I’ll pop out the expert panel and make the following adjustments:

  • Bump up the Variac to 150. The Plexi model has a warm and rounded tone, so doing this is going to give it just a dash more attack
  • Bring the sag down to around 3.0, again giving a little more immediacy to the tone
  • Lower the response setting to around 2.0, adding just a touch more life and complimenting the added bite of the other settings
  • Up the bias to around 6.0, again giving just a tad more edge and bite

Much closer! Now it really sounds alive, but I still want more juice in there.

Still More Juice!

I’ll add the Skreamer overdrive module – a digital homage to the Ibanez Tube Screamer – with volume at 6.2 and tone at 5 and drive at 2. The extra overdrive is quite low, but the higher volume setting will push the front end of the amp harder; these combined should give me that saturated sound.

I’m also going to open the expert panel to take out a little bass to cut the flab, and set the clean control to 0 so that all of the processed signal from the Skreamer goes into the amp.

That’s really not bad! The quality of the gain sounds about right, and it feels responsive to play through, but it’s definitely still too warm sounding. I still want more edge.

Bite Without Fizz

I’ll try a Fender style 2x12 cabinet model with the same microphone blend, but I’ll back the amp’s treble off a hair to 8 to keep it from getting fizzy.

Now we’re really in the right neighbourhood, but too much of the body and oomph has gone.

More Balls!

I’m going to back the microphone mix down a little towards Microphone A, to a level of 60/40, in order to introduce more of Mic A’s warmth, offsetting the brighter tone of this cabinet. I’ll also bump the amp’s bass EQ and warm volume up to 4, and drop the Skreamer’s tone to 0, for the same reason.

Finally, just to add some interest and thicken things up, I’m going to put the Phaser Nine model in front of the amp and set it to 13% wet; low enough that you can’t really hear the phaser’s sweep, but high enough that you get a sense of a fatter, more organic sound.

Close Enough for the Blues

Well, I’d say that’s about right. I’d maybe play around with the level of drive on the Skreamer, depending on what I was playing, but the tone and response of this model sounds pretty much like what I was aiming for.

So to recap, even before we’ve sprinkled any production fairy dust with compression, EQ or reverb, we’ve gone from this:

To this:

But Wait, There’s More

Yes, this is only the beginning. The more advanced tweakers among you may have noticed some glaring omissions in this article: What about blending multiple cabinets? Blending multiple amps? Third party cabinet impulses? All will be covered in the next and final part of this series.

In the meantime, I hope this article has given you some ideas and inspiration to start learning how to get more out of your amp plugin, and please feel free to share your own thoughts, tips and tricks in the comments section.

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