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  • Distortion… Clean and Simple

    By hcadmin |


    Understanding Those Magic Boxes of Doom


    By Jon Chappell


    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 OverDrive SD-1. Both feature similarly named controls. The key to t he pedals’ tonal character lies in their model 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 (Fig. 2) 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.


    Overdrive, Distortion, and Fuzz

    Fig. 2. It’s pretty clear what you’d use the Ibanez Tube King for. And many of the controls are intuitive. But what’s “Void”?


    These terms are all used loosely to describe distortion, but discriminating tone freaks will make distinctions between them. Overdrive is what happens as a signal is pushed beyond the limits of the circuitry’s ability to reproduce the sound faithfully. A slight overdrive has a warm, smooth, and somewhat dull sound that is musically pleasing on a guitar signal. The next category, distortion, covers the widest tonal area, because it includes everything from “just beyond tube warmth” to the brittle buzz saw effect of System of a Down. Within this range is all manner of metal, alternative, hardcore, and industrial timbres. Fuzz is almost a caricature distortion effect, producing a nasally, buzz saw tone that is generally useful only on single node lead lines. It was made famous by Jimi Hendrix (who played a Fuzz Face), and is now called for by name, though many producers use the word generically described any distortion beyond the warm blues furriness. There’s no accepted category for “beyond fuzz,” but certain hardcore adjectives are making their way into the nomenclature, notable metal (see Fig. 3).


    5318ee7b46dd0.gif.38cf8bb8b2fcc2e860d18f6cae896ef5.gifFig. 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 narrowed the sonic field to blues, metal, or subterranean death knell, and are fairly clear on the naming conventions of distortion’s controls, it’s time to check out some pedals. You can do this by going to friends’ houses or visiting the local music shop. But you must be systematic when using your “testing instruments.” You can’t go into a store and try Seymour Duncan’s Lava Box with a Les Paul through the Marshall and expect the unit to behave the same way when you try it in Store B’s Strat and Fender Vibrolux. The best way would be to bring your own rig to the shop. But if that’s not practical, work to get the closest setup at the store to the one you have at home. Hint: approach the store during their downtime so the salespeople will be in a better position to set you up.


    Bench Test

    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?



    5318ee7b4798b.jpg.421c5a429d02c126bb73d10373ab3691.jpgJon Chappell is a guitarist and the Senior Editor of Harmony Central. He has contributed numerous musical pieces to film and TV, including Northern Exposure, Walker, Texas Ranger, All My Children,  and the feature film Bleeding Hearts, directed by actor-dancer Gregory Hines. He is the author of  The Recording Guitarist: A Guide for Home and Studio (Hal Leonard), Essential Scales & Modes (Backbeat Books), and Build Your Own PC Recording Studio (McGraw-Hill), and has written six books in the popular For Dummies series (Wiley Publishing).

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    i beg to differ on fuzz.. while some do have the buzzsaw effect (particularly if the guitarist doesn't know why there's knobs on their guitar) a fuzz can be far more versatile than an overdrive or a distortion, because it's interactive with the guitar. most dirt boxes will just get muddy when you turn your guitar down, and the distortion change is minimal. do it with a decent fuzzface, and you will get myriad shades of tonal colors, from "cleaner than clean" to all out filth. of course it is relative to the player, but tho distortion and overdrive pretty much sound like what they are, fuzz is a completely different animal. peace. ;)

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    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.

    Distortion creates high frequencies which are not there, which have to be carefully controlled. The more distortion, the more highs there are.

    Fuzz-type distortion can cut out high frequencies that were present in the clean signal, but that happens because the high frequencies are basically ripple that rides on much larger low frequency waves. When these big low-frequency waveforms are clipped flat by the fuzz, much of the ripple which is riding on them is cut away too.

    Non-fuzz type chunky distortion prevents this problem by high-pass filtering the clean signal first to diminish the low frequencies. Then the higher frequencies in the signal can cut through (resulting in that property that we call "chunk"), and can get louder with more distortion. Bass can be boosted after the distortion to recover the bass response that was rolled off on input.

    Distortion requires a careful EQ of the high frequencies. Enough high end has to be retained so that the tone has definition and brilliance, without being harsh and fizzy. A lot of this critical action takes place in the 6 kHz to 16 kHz range.

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