AF’s Weblog

June 28, 2012

Distortion… Clean and Simple

To read the full detailed article see:  Distortion…Clean and Simple

Most outboard effects behave in predictable ways as you move from manufacturer to manufacturer. For example, you can pick up any brand of digital delay, set at the delay time to 125 ms, the feedback to one repeat and the level to 50%, and get essentially the same, expected sound. Quality issues aside, you can also get predictable results from an EQ. This is a good thing, as it helps you set up the sound you hear in your head on different rigs. But guitar distortion pedals are the “black boxes” of the effects world; they are all unique, inscrutable, and adhere to no known standards for parameter definition. You don’t know how the Tone control is voiced, which harmonics are emphasized as the Distortion knob is cranked, or even what effect the Level control has (such as whether it works dynamically with the other controls or just boosts the existing signal to a louder level). Often the manuals are no help either, preferring not to reveal the mystery of what goes on inside their magic boxes.

So the bad news is, it’s virtually impossible to tell what the distortion pedal sounds like without auditioning it personally. There are no shortcuts, like reading reviews or scanning spec sheets. You just gotta drag yourself down to the local emporium and plug in. The good news is, it gives you an excuse to go shopping! And you can evaluate these disparate mystical contraptions—and even compare and contrast them— by using some basic common sense.

What’s in a Name

Fig. 1. Behringer’s Blues Overdrive BO100 and the Boss Super Over Drive SD-1. Both feature similarly named controls. The key to the pedals’ tonal character lies in their names.

If you’re seeking a warm bluesy overdrive, you can pretty much a eliminate anything with the word “metal” in the title. Conversely, if you’re trying to make Slipknot’s James Root look like a tone wimp, don’t limit yourself to mere “overdrive” pedals or effects with the word blue or tube in them. Often the best clue to pedals’ sounds are in their names, even if they feature controls that are similarly named, as shown in Fig. 1. You’ll find it’s tough to get any hard information from ads, because companies try to outdo each other with descriptive superlatives.

Also compounding the confusion is that some companies name their controls in a completely nonscientific way. Witness one company that released a pedal with controls called “Butt” and “Face.” The Ibanez Tube King’s Void control is perhaps not as flip, but it’s equally mystifying. Remember though, as odd as these names might strike you, it doesn’t mean the sound is necessarily worse (or better) than a pedal with more conventional named controls. Again, you can’t determine the quality of a pedal sound by looking at it, but you can get clues to its category.

Now let’s take a closer look…

Bench Test

Fig. 3. Though the DigiTech Death Metal has conventionally named controls—Level, Low, Mid, High—the name (not to mention the color scheme!) tells you its tone will be anything but conventional.

Once you have the prospective pedal set up and under your feet, the first thing you should do is establish the pedal’s unity gain setting. That’s the point that produces the same volume level when the pedal is active as when it’s bypassed. This will let you hear the pedal’s effect without the influence of psychoacoustics—that is, the ear responding differently to the same frequencies at varying loudness levels. Typically, your starting levels will look like those in Fig. 4. Kick the panel on and off a couple of times to hear what the pedal does to your tone in its most neutral state. Then slowly crank the distortion control from leftmost to rightmost position, noting not only the differences but how the unit is calibrated—how drastically the unit changes from low to high. Make sure to play real-world examples: lead lines, rhythm figures, arpeggios, percussive, and sustained passages. Then try touching up the sound with the pedal’s tone control. That’s part of the pedal’s character too—how its E.Q interacts with the distortion.

Using EQ with distortion is an important element in tailoring your sound. Generally, the higher the distortion setting, the more treble you’ll need to add. The reason is that the more distorted your signal, the more compressed it becomes, and compression rolls off high frequencies. But should you use the pedal’s EQ or your amp’s? Or an outboard EQ? And if you use an outboard EQ, should it come before or after the distortion? Only your ear can decide. Just remember this paraphrase from Woody Allen: If it’s not done dirty, it’s not done right. He was talking about guitar tone, right?

To read the full detailed article see:  Distortion…Clean and Simple

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December 22, 2010

A Guitarist’s Guide to Multiband Distortion

If you’re a guitarist and you’re not into multiband distortion…well, you should be. Just as multiband compression delivers a smoother, more transparent form of dynamics control, multiband distortion delivers a “dirty” sound like no other.

Not only does it give a smoother effect with guitar, it’s a useful tool for drums, bass, and believe it or not, program material – some people (you know who you are!) have even used it with mastering to add a distinctive, unique “edge.”

As far as I know, the first example of multiband distortion was a do-it-yourself project, the Quadrafuzz, that I wrote up in the mid-’80s for Guitar Player magazine. It remains available from PAiA Electronics (www.paia.com), and is described in the book “Do It Yourself Projects for Guitarists” (BackBeat Books, ISBN #0-87930-359-X).

I came up with the idea because I had heard hex fuzz effects with MIDI guitar, where each string was distorted individually, and liked the sound. But it was almost too clean, yet I wasn’t a fan of all the intermodulation problems with conventional distortion. Multiband distortion was the answer. However, we’ve come a long way since the mid-’80s, and now there are a number of ways to achieve this effect with software.

How it Works

Like multiband compression, the first step is to split the incoming signal into multiple frequency bands (typically three or four). These usually have variable crossover points, so each band can cover a variable frequency range. This is particularly important with drums, as it’s common to have the low band zero in on the kick and distort it a bit, while leaving higher frequencies (cymbals etc.) untouched.

Then, each band is distorted individually (incidentally, this is where major differences show up among units). Then, each band will usually have a volume control so you can adjust the relative levels among bands. For example, it’s common to pull back on the highs a bit to avoid “screech,” or boost the upper midrange so the guitar “speaks” a little better.

With guitar, you can hit a power chord and the low strings will have minimal intermodulation with the high strings, or bend a chord’s higher strings without causing beating with the lower ones.

Now let’s take a closer look at some plugins…

Rolling Your Own

You’re not constrained to dedicated plug-ins. For example, Native Instruments’ Guitar Rig has enough options to let you create your own multiband distortion. A Crossover module allows splitting a signal into two bands; placing a Split module before two Crossover modules gives the required four bands. Of course, you can go nuts with more splits and create more bands. You can then apply a variety of amp and/or distortion modules to each frequency split.

Yet another option is to copy a track in your DAW for as many times as you want bands of distortion. For each track, insert the filter and distortion plug-ins of your choice. On advantage to this approach is each band can have its own aux send controls, as well as panning. Spreading the various bands from left to right (or all around you, for surround fans!) adds yet another level of satisfying mayhem.

Here a guitar track has been “cloned” three extra times in Sonar, with each instance feeding an EQ and distortion plug-in. These have been adjusted, along with panning, to create multi-band distortion.

And Best of All….

Thanks to today’s fast computers, sound cards, and drivers, you can play guitar through plug-ins in near-real time, so you can tweak away while playing crunchy power chords that rattle the walls. Happy distorting!

To read the full detailed article see:  A Guitarist’s Guide to Multiband Distortion

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