Distortion Classifications

[WGTP]

http://www.bosscorp.co.jp/products/en/OS-2/images/intro_R_L.jpg

This is the coolest (and only) chart I have seen "placing" distortions in comparison to each other.

Where would some of the classic favorites be located?   

Fuzz Face, Tone Bender, Distortion Plus, Tube Screamer, BMP, Rat, ... Bazz Fuss, BSIAB, Vulcan, Obsidian, BlackFire, Shaka series, etc...

Maybe this will help.  A cleaned up version with the SD-1 and DS-1 left for reference.

http://aronnelson.com/gallery/WGTP/Distortion_Chart

[Vsat]

Thanks for posting that WGTP!
Wonder where Roland would place the 5 individual sections of the ROD-10 (since they built it...)?
Cheers, Mike

[R.G.]

Given the murdering of the language describing distortion that has gone on for the last half-century in the name of shameless commerce, and the lack of any real measurable way to say that "overdrive is from 3.24 to 7.45 while soft distortion is 7.46 to 8.54", it is useless sophistry to assign strict meanings or a hierarchy to the words describing distortion.

In the words of one of my euphemistic heroes, William Jefferson Clinton, "... it all depends on what your definintion of "is" is..."

When you can put a number or other independently verifiable classifier against them, then you can do meaningful taxonomy. Otherwise, it's all lost in opinion and advert-speak.

[Mark Hammer]

Don't be so quick to dismiss.  While I suspect we could all have some quibbles about the absolute ratingsor placement of their pedals along the two dimensions, the dimensions themselves aren't that bad a way of classifying things.  Along the one dimension (natural to metallic) we likely have the amount of gain applied.  Along the other dimension we have essentially the amount of stridency vs  lowpass filtering applied to whatever got boosted.  Now, admittedly, you can stick a lowpass filter on ANYTHING, but the notion is essentially "How much of the harmonic content is beling 'released' in this pedal?".

[LoudGreg]

Sorry to but in but I'm with RG more on this.

I remember reading that Vai had a producer ask him one time to find a sound that was close to sounding like a vanilla shake. (so they miked the sweet spot !!!! of the speaker)

But describing distortion is either very basic (TS, Marshall, Boogie, moddern Hi-Gain ) or down right totally subjective. I don't think stats or measurments tell the whole story.  They help but when it comes down to laying out the cash for another distortion box, you can't go by measured numbers or a graph. You go by what you hear or what someone else has heard and then wrote about. Then you hear what others have to say about it as well.

But one mans perfect vanilla shake is another mans glass of milk.

[toneman]

I agree with RG *and* Hammer

MayB a start would be to list the type of circuits that produces the sound(?)
Certainly "overdrive" is a term used to emulate the sound of an overdriven tube amp.
And "distortion", from an audiofile's point of view, is unwanted.
Most distortion pedals usually use diode clipping, or overdrive a transistor, or a pair of transistors,
that usually are not biased for linear operation.   All have filtering afterwards.
Hard clipping, softclipping are subjective terms, but they relate to  germanium clipping, LED clipping, & on & on.
The thread on the ROD blew me away!
Never heard/saw that box B4.   What an eyeopener!!   
Lot of differentially connected trannys... 
I remember someone making an "AmericanPedal" that had FF, BMP, TS9 & one other, i think,
ALL in one box.   Switchable, one at a time.
The overall sound still depends on your guitar,
the type of pickups, and the amplifier, and one last thing....
the Musician.....

stayplaying that R&R
tone

[R.G.]

I understand your point Mark. Soft taxonomy is possible even without numbers - that's a formal tenet of the project management body of knowledge.

However, to really do justice to this, you need more axes. F'rinstance, how about the amount of harmonic to intermodulation distortion? That's a big discriminator of the subjective sound of a distortion. I guess properly, you'd put THD on one additional axis and IMD on another. Three axes takes some careful squinting to see useful data in, and four is out of hand.

I just think that by the time you wade through it, you could have built another couple of boxes.

[Mark Hammer]

I just think that by the time you wade through it, you could have built another couple of boxes.

Agreed.  I guess the only point to keep in the back of one's mind here is that this is a 2 x 2 matrix of Boss pedals, rather than any attempt to classify all distortion.  It may work fine for them, but obviously there are no Scramblers, or Tone Benders, or Fuzz Factorys, or Shin-Ei's in there anywhere.  Within those constraints, I'm comfortable with the diagram, but recognize its limitations.

Me, I'm just happy that I found a terrific balsa wood tea box at the discount store the other day that can probably house a quartet of those cute high-compliance 2" 32 ohm MacIntosh speakers* AND an 8-pack of AA cells.  Two bucks, and I got all that Earl Grey tea to boot!  This is gonna be the T-tone ( http://ampage.org/hammer/files/T-tone.jpg ) mini-stack.  Probably try a TEA2025 in mono bridge mode.

(* A computer "rendering" place near me has piles of speakers pulled from old monochrome Macs.  These are small but they have magnets of speakers 4 times the size and a foam surround on the cone to get more bass than you'd expect for such a small speaker.)

[Harry]

Nice one Hammer. I used to use empty soup cans and mount speakers where the lids used to be, Speaker Cans.

[WGTP]

Thanks for your responses, they were more or less what I expected and all valid IMHO.  Probably the engineers will have more problems with this than the social scientists.  I have an engineer friend who denies any validity to psychological measurements (or couse it is convenient because he is ***).

I don't know the correct scientific technique or terminology, but let's try and break this down and take it a small step at a time.  This won't be the first or last stupid thing I've tried.

I left the 2 commonly used/known Boss distortions on the chart as reference points.  This will be a very "soft" approximation, of course, no numbers.  As usual, I like Mark's and R.G.'s comments about the axis (is this what Hendrix was talking about)? I can barely think in terms of 2 dimensions, although a multi-dimensional matrix might be good for the next go round.  Maybe would could rank the classics on a variety of parameters 1-5 or something.

Let's start at the beginning with the Fuzz Face.  Of course the first problem is GE or SI or a combination.  Let's see if both can be lumped within the same "oval".

I forgot, how are the quadrants numbered? North South East West?  What are your thoughts. 

[phaeton]

Given the murdering of the language describing distortion that has gone on for the last half-century in the name of shameless commerce

I think R.G.'s right here... we need an axis for things like "Searing Leads"<------>"Dripping Honey".  There's a whole swath of pedals that "Sound just like tubes" and yet some more that "Sound just like a Marshall Stack".  Not to mention "Sound like Eric" and "Sound Like Jimi".

And besides, how would you classify my all-time favourite description: "This pedal should be called THE ANNIHILATOR, because it annihilates the tone of any amp and infuses it with its very own molten metal, thrashing death tone."  I forget which pedal that was in the old Musician's Friend catalogue but this is one of those descriptions that you pull out of the back of your head every now and again and chuckle.

[WGTP]

Interactive Virtual Distortion Grid.  Check that out at the boss site.

Annihilator sounds like it belongs top left corner of grid.   

[bwanasonic]

I notice Boss *disowned* the HM2 for that chart!  Or maybe it's just *off the charts*! The black sheep of the family?

Kerry M

[tiges_ tendres]

the way I see this is the same as fast food.  You can compare the burgers from mcdonalds, burger king, in n out etc, because they share common values, meat and a bun.  

But when you add in to the mix a $200 fois gras burger from a swanky so-ho eatery, you've got an entirely different set of values to judge from, and probably 3 different new scales to judge from.

I can see why you would want some kind of comparison, but where do the more harmonically complex circuits fit?  If we judge them only on their "meat" and "bun" what about the other facets that make up their "burger-ness"!   It's a raw deal, and I like my burgers well done

[WGTP]

OK, lets try this.  Is a Fuzz Face natural or metallic?

[Steben]

Soft vs hard clipping can be translated into "Dynamic" and "Flat Edge" etc... The way the distortion breaks up is certainly an important point.
The other Axis should be Bassy distortion (lo impedance; eg FuzzFace) vs Trebly distortion (eg Tube amp with treble booster) which explains the pregain EQ.
      Dynamic
            |
Bassy--+--trebly
            |
     Flat Edge

Examples:

           Tube amp
                  |   Amp w Treble boost
               SD-1
Fuzz F ----DS-1---- MT-2
                  |
              Superfuzz

[Gilles C]

I notice Boss *disowned* the HM2 for that chart!  Or maybe it's just *off the charts*! The black sheep of the family?

Kerry M

This is where Boss place the HM-2 in their printed book "The Boss Book", (for Boss lovers only  ) which includes 20 distortions in place of only 8.



The original chart seems to be coming from this online book http://www.rolandus.com/specs_brochures/3884_GuitarEffects_US_200.pdf

Gilles

[bwanasonic]

Hard clipping, softclipping are subjective terms, but they relate to  germanium clipping, LED clipping, & on & on.

I was under the impression this had more to do with where the clipping was going on, i.e. diodes to ground on output = hard, diodes in feedback loop = soft? Maybe I need to read that distortion cookbook article again.

As for the Boss chart, I think it's only designed as a very loose buyer's guide for marketing their pedals, not a taxonomy of all distortion effects. But following the chart, I'd be curious to what circuit(s) would fall in the lower left (Rough/Natural)?

Kerry M

[R.G.]

--Hard clipping, softclipping are subjective terms, but they relate to  germanium clipping, LED clipping, & on & on.--
I was under the impression this had more to do with where the clipping was going on, i.e. diodes to ground on output = hard, diodes in feedback loop = soft? Maybe I need to read that distortion cookbook article again.

Hard or soft distortion have to do with the relative signal level compared to the clipping threshold and with the abruptness of clipping, not where the signal is clipped. It is true that the conditions that the clippers are used under may vary the abruptness of their clipping knee a bit, but this is not the primary determinant of the hardness of clipping. That is, how you place the clippers may affect their clipping abruptness a bit, but it's the clipping abruptness that matters. Swapping devices  - e.g. schottky diode versus germanium - fundamentally changes the clipping abruptness.

As for the Boss chart, I think it's only designed as a very loose buyer's guide for marketing their pedals, not a taxonomy of all distortion effects. But following the chart, I'd be curious to what circuit(s) would fall in the lower left (Rough/Natural)?

Your first sentence here is absolutely correct, and your second sentence is a very reasonable one.

The problem with charts like this is that they engender endless fruitless discussions of exactly which and where and what and...

[WGTP]

Guess I'm going to have to concede defeat.  I can't even figure out where to put the Fuzz Face.  I tend to think of fuzz as metallic and unatural, but none of these things can be "evaluated" out of context.  I'm always amazed how much adding a big old cap to ground at the end of a distortion/fuzz smooths things out and changes the "character".  My amp tends to be Dark making things smoother and less metallic.  Hit the bright switch and there you go.

Correct me if I'm wrong, but R.G. and others have said the EQ is as important, if not more so, than the method of clipping. The more I mess with this stuff, the more I agree.  It's like we keep trying different methods of clipping to disprove this.

Still, I spent a lot of time trying to get a 3 transistor Tone Bender to sound like a distortion, rather than fuzz, and reducing the input cap's was the main thing.  But it never lost that Fuzz Face sort of "twisted inerds" sort of tone that my old 2 (farting sounding) transistor Vox Tone Bender had.  I guess is the highly asymmetrical nature of the distortion. 

Anyway, that defines FUZZ and metallic and unatural sounding to me.  And that is why I focus on overdrives/distortions and not fuzzes, although they are way fun to play with.

The THD at 100hz vs. the THD at 1000hz.

EQ - Ts - Dist+ - EQ = I guess I'm done.   

Not really.  The Vulcan has the mojo for me.   

Thanks for the discussion.