Difference between revisions of "Dialing in Distortion Tone"

Revision as of 00:01, 15 August 2014

Types of Distortion

I like to lump distortion tones into 3 broad categories. This is a bit different than the distortion pedal types listed earlier. Distortion pedals tend to be designed to distort only a certain way. This is more about how tube overdrive can be tweaked to sound different ways. While pedals also have flexibility, they tend to get quite nasty outside their "comfort zone", while tubes are a bit more versatile. That's not to say that tubes trump solid state pedals outright - in fact, they can be combined to get the best of both worlds as seen below.

Also, tubes are not universal - some amps can be dialed in for nice-sounding distortion in one (or two) type(s) below, but not the others. And this is not about distortion levels - there can be mild distortion or extra-saturated distortion in any of the types below.

Leads higher up the fretboard tend to sound nice on all kinds of distortion, although the response can vary significantly.

Fuzz

Fuzz sounds are marked by an emphasis on distorted bass frequencies. The tone is rumbly (or muddy) and tends to turn to complete mush whenever intervals beyond perfect 4ths or 5ths (or chords) are played. When transitioning between two notes with slight overlap, the notes sound almost like they are fighting each other. The response is quite loose, making it difficult to play fast passages clearly, especially in lower registers. Palm mutes are particularly muddy, with the percussive attack extremely muffled and tone rather noisy.

Crunch

Crunch has an emphasis on midrange frequencies distortion. It can sound a lot like a vintage-style overdrive (although depending on the amp or pedal model, it may be much smoother and cleaner). This is often the default type of distortion that an amp will provide, requiring a boost or pre-EQ to dial in others. The attack retains most of its dynamics, being able to hear accents and strums. Lower registers can get a little rough and loose, but it's generally clear enough for rock riffing. Chords can get a little nasty, but come through well enough as long as they aren't too complex. Palm mutes are clear but rather percussive, sounding similar to how a clean tone sounds on palm mutes.

Metal

Metal is based on distorted treble frequencies over others. The bass comes through clean and tight, only compressed, while the high-end is filled with saturated, harmonic overtones. Notes and power chords in riffs have a tight response - all the notes can be fairly clearly distinguished, even when playing at fast tempos. Chords have most notes come through well enough to be distinguished, but can get too harsh and noisy for bigger chords. Palm mutes sound thick and rattle the walls, while having the signature djent sound in the upper mids and highs, emphasizing each stroke.

Pre-EQ

The simplest way to experience the different types of distortion mentioned above is to take a relatively balanced sounding distortion from a tube pre-amp that has a bit of all the aspects described above, then use a parametric or graphic EQ in front the amp to boost a hump in the frequency spectrum. Sweep the center frequency of the boost - as you sweep from low to high, you'll hear the distortion turn from fuzzy to crunchy to metallic. Pre-EQ can be used to crudely change the overall nature of the distortion as such.

I find EQ gives you more control, though. Rather than aim for a general distortion type, I like to use EQ to fine-tune the distortion tone, focusing in not only the sweet spot of the spectrum but also trimming frequencies here and there to avoid any nastiness. For a metal tone, I will find the exact spot in the low end where the bass gets farty and dial it back just enough to clean it up. If there's some raspy noisiness in the high end, I'll trim or dial it back so it blends into the rest of the tone. I may dial down some mids to make the tone more djenty and less percussive, or the opposite to sweeten it up.

This chart sums up how the tone will likely sound if the given frequency is the peak (loudest) part of the signal before distortion, as well as what will happen if those frequencies are overly deficient. Generally, you want all the frequencies to be balanced, but emphasize a peak for the tone you want. Your peak can span several of these zones, however. Or your signal could be relatively flat for a more even distortion.

For Pre-EQ, usually there's no need to make large, narrow cuts/boosts - they tend to sound bad. I like larger cuts/boosts. The first thing I'll adjust is bass. If the distortion is a bit too rough and has a muddy, low-end breakup, I like to reduce bass. I like to use a low sheft, with about -2 db and start with frequency around 300 HZ. This should mildly clean up the low end. Then I reduce the gain further and try to notice when the bass gets totally clear and tight. You don't want to cut too much or you lose tone. Then I start to reduce the frequency, trying to see where I get the most punch without losing tightness. Usually this is around 150 HZ, but it depends.

You can do the same thing for the highs but in reverse. Do a high shelf +4 db boost and slowly move the frequency downwards from 5 kHZ to around 1 kHZ. You should find a sweet spot that adds extra harmonic richness to the tone but isn't too sharp and harsh.

You can also use parametric bands. Some suggestions are to cut around 500-800 HZ - this should make the distortion a little rougher, but too much will make the mids too weak. Or boost around 1 kHZ to 1.5 kHZ. This gives the tone a Tube Screamer-like effect, getting a bit more djent to the tone, but can sound a bit like a cocked wah pedal if overdone. You can also try the exact reverse to getter a smoother, creamy, liquid-lead tone.

I don't have a preference of parametric EQ vs. graphic EQ here. Usually you can make settings on either one for the exact same effect, because I'm not doing any narrow or extreme boosts/cuts. I just find it generally easier to find the sweet spots using a parametric EQ - trying to adjust the graphic means moving more sliders (or turning more knobs), but it does have the advantage that you can visually see how you're impacting the signal.

Boosts

Boosts generally do exactly what I describe above: emphasize a peak frequency range to focus the distortion. They are often used for metal to "tighten up" an amp by boosting the upper-midrange and treble frequencies, while often dialing back the muddier bass frequencies.

Additionally, however, boosts can add their own tone, adding compression or certain resonances or other weird stuff. Most players will tell you there's a bit of magic or mojo in their preferred boosts. Personally, I prefer straight up EQ and would prefer to change the amp (model) for the mojo. I find some boosts can "wash out" the signal a bit. But of course it depends on your preference and the actual pedal/device being used. The only way to really tell is to experiment.

The standard for boosts is the Ibanez Tube Screamer; however, due to the variety of both the number of "Tube Screamer" product lines and variances in components used over the years, I think a more accurate standard is the Maxon OD808. Maxon actually produced the original Tube Screamer for Ibanez and claims its OD808 is true to the original circuit. Another that seems to get lots of praise is the MXR Zakk Wylde Overdrive. While I haven't used one myself, I have lots of awesome profiles on my Kemper where it was part of the profiled signal chain.

Another type of boost used more in classic rock and sometimes for leads is a cocked wah - this clearly emphasizes a specific frequency range for the amp to distort, moreso than a typical boost pedal or pre-EQ settings. You'll have to find the right wah and the right position for the sweet spot to emerge.

Some pedals are purely called boosters, or treble boosters. These are more common in vintage rigs, used to overdrive amps with a rather bright tone. I tend to find they can overemphasize treble for modern purposes; however, they are simpler to use.

Mixing Multiple Distortions

The key to a great distortion tone involves mixing multiple gain stages to a get a rich distortion throughout the frequency spectrum without the signal turning into a noisy, chaotic mess. Modern high-gain amps have been hip to this technique since the late 70's, using multiple distorted pre-amp tubes in series (aka cascading gain stages). These use different biases or frequency treatments between stages to layer the distortion in a controlled manner, where each one adds to the tone rather than mucks it up.

However, there are cases where we want to utilize different methods of distortion other than overdriving preamp tubes. This can be quite difficult, as mixing distortion can often result in lots of noise, squeals, harshness, and rough edges. Here's some general rules:

• Only one distortion stage should be heavily distorted at most. Generally, its best to mix two or three mild distortions to get one big distortion tone. When using one saturated gain stage, any others should be very mild. Otherwise, you will get a mushy, noisy tone.
• The big advantage is to mix different types of distortion. Chaining several similar distortions is likely to get a similar tone as just one of them, but with less control and more noise. You can often get a better tone simply by turning up the gain on just one distortion stage and removing the others.

Pre-Amp and Power Amp

Power amps are usually difficult to drive into heavy distortion and distort in a rough, somewhat nasty manner. Sometimes this is all you need to give your tone that edge that a smoother preamp doesn't provide. Unfortunately, it can be very difficult to control, requiring loud volumes to achieve. Also, distortion is frequency response dependent, but you don't have much wiggle room here. If you use the pre-amp's EQ or an EQ in the effects loop after the pre-amp distortion to prep the signal for power amp distortion, you may get the distortion tone you want, but the frequency response after the power amp may need some EQ tweaks. Yet it's impossible to EQ after the power amp and before the speakers. You can EQ post-mic'ing, but this won't help for practice/gigging applications.

Distortion Pedal and Amp

Multiple Distortion Pedals