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Distortion-related pedal categories: Overdrive/Booster, Fuzz, Distortion, Metal/Grunge, Power-tube saturation, Compressor/Sustainer, Mid-boost



Overdrive pedals
Fuzz pedals
Distortion pedals, "crunch"
Metal/Grunge pedals
Power-tube saturation pedals


There are several categories or types of saturation pedals, and several other pedals for establishing Basic Tone as opposed to Special Effects. You can generally categorize distortion pedals. These are sound, reliable principles for identifying types of distortion boxes. These all have to do with establishing Basic Tone. You might think this is too broad a scope for "distortion-related boxes", but notice that I have left out many effects: echo, reverb, chorus, flanger, harmonizer, multitracking (multi-tapped delay), pitch shift, modulated delay, envelope filter, wah, phaser, tremolo, panning, digital whammy, talk box, and many others. None of the following have any cycles or variability involved; they are stationary or static effects and the end sonic result is distortion/saturation processing.

I have a name and a concept for a distortion box: the Frequalizer. It has very low-noise eq, then dist, then eq. Maybe even additional eq between gain stages.

Combinations: compressor/sustainer, overdrive/distortion, sustainer/overdrive, etc.

I do not establish major categories for "solid state distortion vs. preamp tube distortion". Like Craig Anderton, I maintain that the distortion voicing is overwhelmingly more important than the device used for preamp clipping. The preamp tube distortion revolution is a hoax, self-delusion of the industry, and of practically no significance compared to saturating power tubes, output transformers, and speakers.

Ryan A. O'Hara wrote:

>I constantly see pedal manufacturers like DOD and BOSS coming out with more and more different type of distortion pedals. I call this 31 flavors of distortion. There are so many kinds. What are the major differences in the overdrive, distortion, fuzz, etc. pedals? I do recognize different styles of distortion, I am just confused about which pedals make which effect.


The 3 primary saturation/distortion types are:
o The "distortion" tone and the gear setup to get this tone
o The "overdrive" tone and the gear setup to get this tone
o The "fuzz" tone and the gear setup to get this tone

My 4th category, "saturation" of a power tube, is pretty closely related to the tone produced by an "overdrive" type pedal placed in a standard configuration to produce the overdrive tone. (Or, bypassing the amp's preamp by connecting the overdrive or booster pedal straight into the tube power amp section via the amp's Effects Return jack.)

Compression and equalizers also work well in conjunction with good amp saturation. You can try all sequences, such as compression after the mic'd speaker, and eq before distortion.

Boosted bass before distortion produces fuzz or crust.
Cut bass before distortion produces glassy or liquidy clipping.

Cranking a solid state amp is better than playing purely with preamp

Almost all the rock guitar you hear on the radio is played through
tube amps, using significant power amp saturation.

Must-read: Guitar Player Oct 1992: The Distortion Issue. Page 40: The Grunge & The Glory: A Celebration of Distortion. Tom Wheeler. [Distortion/Tone] Tips from the Loud & Mighty. Decoding Distortion: What It Is and How It Works. (Must-read: The sidebar about Tips for shred vs. blues tone is the best amp-distortion summary ever; this article is also in the "Guitar Gear" special GP issue; see my books page). Fuzz Tone User's Guide: 31 distortion pedals. Rats in the Cellar: gallery of classic grunge - Art Thompson. Dialing for Distortion: sound advice from producers.

Overdrive pedals

Overdrive adds a little grit, to put some edge on what would be just power-tube saturation, because saturation by itself could be too sweet, without any biting edge. For example, a MESA/Boogie Blue Angel's power amp, in Class A rather than A/B, with Triode rather than Pentode, and with reduced plate voltage, would sound so sweet, it would be pretty and chimey and bell-like, but would not be good, on its own, for searing rock leads. Also, one principle of saturation/distortion is to avoid getting all your saturation/distortion from a single gain stage. So actually, it could be sweeter or better sounding to not push your power tubes with a dynamic spike as when you strike a note and send it through a straight booster then to the cranked power tubes; instead of so overwhelming the power tubes, you can control that spike first by clipping it a little, or by using a compressor first. The compressor would preserve purely power tube saturation sweetness, while an overdrive would add gritty edge.

I prefer using a Booster pedal rather than an Overdrive-with-clipping pedal. I like this chain, for hearing *only* power tube and speaker saturation:

Compressor pedal
EQ pedal with bass cut, mid boost, treble boost
Booster pedal that outputs a high voltage span without clipping
Power tubes (bypassing any preamp that might introduce preamp clipping); can usually go in through the effects return jack.
Low-wattage guitar speaker, driven directly with no attenuator, and mic
EQ pedal

Overdrive can be thought of as some clean signal mixed with some distortion signal, and is used to directly drive the input of an all-tube amp. Definitive example: Ibanez Tube Screamer. (This is my way of thinking of it and Keen disagrees as far as how, technically, the TS-9 achieves its characteristic clipping.) Particularly good for emphasizing power-tube saturation such as in the live Led Zeppelin album and their album _Presence_, and Vaughan's signature tone. Overdrive emphasizes power tube clipping; it preserves the direct guitar sound more than distortion. It's volume boost with a little grit. The overdrive exists to get more power tube saturation than possible by just cranking the power amp. It is not intended to generate more preamp-type distortion.

Depending on your amp's circuitry, boosting the signal before the input might cause the preamp tubes to distort, or might make it through the preamp without causing the preamp to clip, thus causing just the power tubes to saturate. One trick when you want to avoid preamp clipping and only hit the power tubes hard: guitar, booster, effects loop in. This avoids the risk of overdriving the preamp tubes in the amp's preamp section.

What I've read implies that the Marshall amps with no master volume can be hit harder, at the input jack, without causing much clipping in the amp's preamp tubes, while master volume amps tend to clip in the preamp tubes, to a greater proportion relative to the power tubes, when hit with a high signal coming in from the input jack. Thus with master volume amps, you can never hit the power tubes as hard as you might like -- the preamp tubes get in the way and completely clip, while the power tubes don't clip much. That's definitely the implication of what I've read, though I don't know if the circuits really do result in this difference.


No alteration of the signal; plain amplification. See the Overdrive pages at this site. Overdrive adds a little grit, to put some edge on what would be just power-tube saturation, because saturation by itself could be too sweet, without any biting edge.

Fuzz pedals

Keen's Distortion 101 page lists different ways of producing a square wave or other hard-clipped signals, but I still think that boosted bass and cut midrange before the clipping device is the fundamental recipe for fuzz.
Hendrix has some good examples of fuzz. I'm going to create a fuzz examples thread.

Some early Zeppelin might require this type of clipping.

Fuzz is a distortion box with boosted bass before clipping. You can simulate fuzz on any rig by playing the neck pickup, with the tone control down all the way, picking near the neck -- these produce the most bass and least treble prior to the clipping stage. Definitive example: Electro-Harmonix Big Muff Pi (big muff pie).

Distortion pedals, "crunch"

Distortion emphasizes preamp transistor or preamp tube clipping, and is not usually combined with flat-out cranking of the power amp. Distortion is a tonally balanced clipping, with the eq carefully shaped before the first clipping stage, between the stages, and after the clipping stages. Distortion sounds best before an all-tube amp pushing a real guitar speaker.

>Crunch is over-the-top distortion, combined with some power tube saturation. This is the type of sound you can hear all over Van Halen 1.

I think of Crunch as a 50/50 combination of preamp and power tube clipping.

excellent thinking style and analysis techniques - already at my links page, add desc. Awesome 1996 article about preamp distortion history.

I'm getting into preamp distortion and will provide more coverage of preamp distortion products. I have my eye on: Line 6 Distortion Modeller, deluxe Tube Driver, Lee Jackson preamp, Sonny Boy and Red Rooster amp-modelling distortion boxes.

To assess distortion box quality, don't think of a dist box alone; think of it as between two EQs. To compare two EQs, put them both between EQs and ask, which dist box supports a wider, better, more musical range of distortion sounds when used this way. The Metal Zone and Daddy-O, I could not get clear, present Tones from them even with this EQ sandwiching. You might have a great potential dist box that just happens to be presented with less than ideal pre or post Eq. This method normalizes away that deceiving limitation. What's more important is the dist box's potential when bracketed - and you *can* compare different dist boxes this way and judge one as a reject and the other as superior. Good dist boxes are generous and friendly to many pre and post EQ curves. Others are hostile to just about all EQ curves. You cannot control the interstage EQ inside a dist box - that's why distortion modelling boxes and multiple dist boxes in your collection makes sense, even if you sandwich dist with eq.

With MP3s, I will demonstrate that assessment technique with preamp dist and with power-tube saturation products.

Metal/Grunge pedals

Voicing: pre, post, and inter-stage EQ is set up for a dry, scooped-mids sound, with a lot of clipping. I found that no matter how much pre and post EQ I did around the Metal Zone pedal, I could not get a convincing liquidy neck-pickup tone like I could by using the same technique with the Chandler Tube Driver, a standard distortion box.

Power-tube saturation pedals

Most of the enthusiasm about preamp tubes is really misguided enthusiasm that should be directed toward power tubes. There is little difference between preamp tube distortion and preamp transistor distortion. Power tubes, on the other hand, sound obviously different than power transistors. Preamp tubes have been greatly oversold. Everyone wishes they could add a preamp tube to their rig and instantly have tube amp tone. Do preamp tubes really make a significant difference, compared to power tubes?

The "saturation pedal" design idea: use a high-level non-distorting preamp inside the pedal casing. Have a tube set up as a power tube, driving an inductive load. Have two outputs -- one straight off the inductive load, and the other after a low-pass filter for speaker simulation. For this type of modular pedal, you should *not* provide preamp clipping -- leave that to a dedicated clipping pedal. (If you insist on bundling preamp clipping in this box, provide an "effects loop" between the preamp and power tube, so that the preamp stage can be bypassed.) "Saturation pedal" or "power-tube saturation pedal" is my term for the new wave of power-tube overdrive pedals I'm predicting, such as the H&K Crunch Master and the ADA Ampulator, to a degree.

Overly high expectations from tube distortion boxes led people down a naive, false path of trying to get "amp distortion" using just a preamp tube and not a power tube or output transformer or guitar speaker. To this day, in 1998, 13 years later, people are still naive, and it's time the entire industry to realize that a preamp tube is of no significance compared to the power tube, output transformer, and guitar speaker. Tube preamps are somewhat of an advance, but will really blossom when a power tube and well-designed load are added (before the time-effects stage).

My site does not cover tube distortion pedals much, because there are many reviews in the magazines, and I am against the overemphasis of preamp tubes, at the expense of power tubes. Preamp tube distortion sounds just slightly better than solid-state distortion; inter-stage EQ voicing and levels are more important than whether a preamp tube or solid-state device is used. *Power* tubes, however, sound *vastly* better than a solid-state *power* amp. It's wishful thinking to equate "tube amp" with mere preamp tube distortion. A distorting preamp tube obviously sounds *nothing* like a saturating tube power amp interacting directly with a hard-driven guitar speaker. It is possible to use a preamp tube as a power tube; the Ampulator and the Cream Machine, with 12AX7 or ECC82 in a power-amp configuration into a load, sound entirely different than using a 12AX7 as a preamp gain stage.

>Saturation is when your signal is always distorted/clipped, like AC/DC. That's a typical power-amp distortion sound.

A really good combination to achieve a sound that the amp emulators can only wish for, would be to package a tube compressor with a low-wattage, Class A, tube power amp, into a sweet, low-wattage guitar speaker -- with levels defaulting such that there is no preamp clipping. This would generate 100% power tube saturation, in the sweet spot of the power tubes. This would *not* be a searing rock lead tone; this would be super-sweet and ultra-round and liquidy, to make the simulator users scratch their head, like I used to -- "Huh? it's distorted, yet it's clean. No matter how I tweak my EQ and compression, I can't get that sound." Like a neck single-coil pickup played into a cranked Vox amp with no preamp clipping.

I am thus proposing a "Compressor/Saturation pedal". I am wondering if the Peavey VC/L-2 Valve Compressor with EL84 can be used as such a device, or modified to be one. These two effects are very closely related because they work together to produce pure, sweet-spot, power-tube saturation, with no preamp clipping.

A big question with cascading power tube saturation & load stages is, whether to mic a speaker. You can cascade multiples of: power tube, speaker, spk isolation cabinet, mic, eq. I expect results similar to, but better than, multiples of: TS9 overdrive pedal, eq, or multiples of: power tube, dummy load, eq.

I bought a Hot Plate. Driving only 1 guitar speaker, at 1 watt minimum, works great - will A/B playback mic test re: dynamic depth. Don't less than 1 watt per spk - that's not enough to get speaker rounding. 4x12 cab? Disconnect 3 spks. 2x12? wire as stereo, use only 1 spk.


See Compression as part of Basic Tone or search home page for "compres".


These are probably a combination of compression, overdrive, and/or distortion. Mostly, same as compressors.


This affects the distortion voicing, just like changing to a different pickup, by doing EQ before the preamp distortion; certain frequencies get clipped harder than others and dominate the clipping behavior, to establish the distortion voicing. This is completely, absolutely different than the sound of adjusting the EQ *after* the distortion pedal. In between distortion/clipping stages -- within the pedal -- there is an resistor/capacitor network, which establishes the inter-stage voicing. I thought I saw a Metal head, perhaps a Wizard, which had Gain stage 1 level, bass, and treble, *and* Gain stage 2 level, bass, and treble. This would enable user control of distortion voicing; almost all distortion units prevent you from adjusting the interstage EQ. However, you could run through two distortion pedals, with just a little gain on each, with an EQ in between them, to study distortion voicing.

A common technique for a sort of mid-boost is to set a wah pedal to halfway, before any clipping device. This has very limited control, however, compared to an EQ. The thing to watch out for with eq before distortion is self-hiss of the EQ, which gets amplified. So a good rackmount EQ is best for this pre-distortion placement. And a parametric EQ -- of which just a couple pedals are available -- enables you to design your own mid-boost flavoring.

For specific mid-boost products, find "eq" on the home page.

Amptone.com ultra gear-search page

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