Why Amp Sims Make Your Sound Degrade, and the Right Settings | Signal Order, Gain and Your Interface

"I loaded an amp simulator, but the sound is somehow thin."
"It's full of noise and unusable."

This is where people who come into DTM from guitar first stumble.

Most of the causes aren't the performance of your gear.
It's that the signal order and gain settings are still in the habit of a real amp.

What's scarier is using it wrong. It degrades your guitar's sound.

Even with expensive gear, one setting can ruin it.

This article sorts out the basics of amp simulators, written from a guitarist's point of view.

By the time you finish reading, you should know why your sound is thin. The reason will become visible.

ryo

To be honest, I was using it wrong at first too. I was degrading my guitar's sound myself.

What, can settings alone change it that much?

Reader

ryo

They can. In fact, using it wrongly makes the sound worse. I'd like to tell my past self.

What Is an Amp Simulator?

An amp simulator is a system that recreates the sound of a real guitar amp in software.

Even without buying a real amp, you can run an amp inside your computer.

You can rearrange tube amps, cabinets and even mic positions on screen. That's its strength.

Typical ones include IK Multimedia's AmpliTube and TONEX.

Bundled DAWs like Logic Pro also include a built-in amp simulator.

ryo

I was using it with a real-amp mindset and missed the idea of building the path the sound travels. That's why everything sounded thin.

The Biggest Difference from a Real Amp

A real amp has the amp and speaker as one unit.

When you make sound, it reaches your ears as it is.

An amp simulator is different.
You have to build the sound's path yourself.

This "path" is exactly the signal order I explain next.

Understand the Basic Signal Order

An amp simulator is divided into several parts.

Connecting them in the right order is the shortcut to a good sound.

The most basic order is as follows.

step
1Guitar (input)

First, the guitar's signal comes in. The level here is the foundation for everything.

step
2Compact-type effects (drive, wah, etc.)

These are effects placed before the amp. They're in the same position as the pedals at your feet with real gear.

step
3Amp (pre and power)

This is the center of sound design. The gain here decides the amount of distortion.

step
4Cabinet (speaker)

This is the part where the amp's sound is played through a speaker. The thickness and air of the sound change a lot here.

step
5Time-based effects (reverb, delay)

Finally, add reverb. The basic rule is to put it after the amp.

I'd never cared about the order...

Reader

ryo

I lined things up carelessly at first too, and put the reverb before the amp. Looking back, that was one cause of my muddy sound.

What Happens If You Get the Order Wrong

For example, suppose you put the reverb before the amp.

Then even the reverb tail gets distorted.

The result is a sound with a blurred outline. A muffled sound.

It's the same reason few people put reverb at their feet with real gear.

How to Think About Gain

After signal order, the next stumbling block is gain.

It should be the word guitarists are most familiar with.

But gain in an amp simulator is a little deeper.

Gain Is Not Only "the Amount of Distortion"

Many people think of gain as "the distortion knob."

That's half right.

But an amp simulator has another important gain.

That is the input gain.

The signal coming in from the guitar must not be too strong or too weak.

If this isn't right, no amount of amp adjusting gives a good sound.

A Guideline for the Right Input Level

Adjust while watching your DAW's meter.

Aim for peaks around minus 12 dB.

There's no need to raise it until it lights red.

Leaving a little headroom is just right.

I thought it was fine to just record loud.

Reader

ryo

That's exactly how I used to be. I pushed it until the meter went red, and even though the sound was clipping, I only fiddled with the amp side. The cause of the degradation was the input level.

Don't Raise the Amp's Gain Too Much

A common mistake in home recording is raising the gain too much.

If you remember playing a real amp at full blast, you want to add more distortion.

But a recorded sound overlaps with other instruments in the mix.

A sound that's too distorted loses its outline. It gets buried in the band.

A "good sound" live and a "good sound" in a recording are different things.

3 Tips to Prevent a "Thin or Harsh" Sound

Once you have signal order and gain down, here's the final touch.

Here are three tips to prevent thinness and harshness.

The cabinet's mic position in particular changes the sound dramatically.

The closer to the center, the stronger the highs; the more you shift it outward, the rounder it gets.

If it feels "harsh," first move the mic slightly outward.

ryo

Mic position really works. When I was struggling with a harsh sound, just shifting the mic slightly outward solved it at once. It felt like a lie that I'd been forcing it down with EQ until then.

So just reviewing the settings changes it that much.

Reader

The Input Settings on Your Audio Interface Change the Sound Too

So far it was about the software side.

But the settings on the audio interface side, where you plug in the guitar, change the sound a lot too.

In fact, get this wrong and the sound is already degraded at the entrance.

However much you adjust the amp simulator, you can't get back a source sound that's already thin.

Even before the software, how I plug in changes the sound?

Reader

ryo

It does. And this applies to every interface. If you remember it, you can use it for life.

The Difference Between INST (Hi-Z) and LINE

Many interfaces have a switch for changing the input.

It's labeled something like "INST," "Hi-Z" or "LINE."

This switching is to match the signal's impedance.

It's a difficult word, but think of it roughly as "how hard it is for the signal to flow."

When you plug the guitar in directly, set it to INST (Hi-Z).

A passive guitar's signal has high impedance. If you leave it on LINE, the highs drop and you get a muffled, thin sound.

Conversely, sound that has gone through pedals at your feet or a multi-effects unit is different. The level is already set.

In that case, receive it on LINE as the basic rule.

ryo

At first I recorded with the guitar plugged straight in but left on LINE. No wonder the sound was thin. The moment I switched to INST, the thickness of the sound became something else, and I was surprised.

+48V (Phantom Power) Should Basically Be OFF

Another important switch is +48V.

This is power dedicated to condenser mics.

When plugging in a guitar or pedals, always turn it OFF.

If you leave it ON when it isn't needed, you could damage your gear.

The Labels Differ by Maker but the Roles Are the Same

These switches are on almost every interface.

Only the labels differ a little by maker.

For example, the Apollo Twin Solo I use also has these four lined up as they are.

Once you know the label differences, you won't be lost even when your model changes.

Only the labels differ, and what to do is the same. That's a relief.

Reader

ryo

Exactly. Once you learn it, it applies to any interface.

Summary

Let's review the basics of amp simulators once more.

Just keeping these in mind changes your home-recorded guitar sound a lot.

Before you buy more gear, review your settings first.

With your current setup, you should be able to get a sound a step better.

ryo

If you use it wrong, even a good guitar is ruined. But conversely, if you just fix the settings, it transforms with the gear you already have. Just like it did for me.