How fuzz pedals work

[ReeceAblaze]

Hello everyone I recently built my first pedal kit and it was a clone of the Fuzz War by Death By Audio. It sounded good and really got me interested in making a fuzz pedal of my own. I am gonna get hold of a breadboard and some components at some point. I was wondering if someone could explain to me when looking at a schematic what each section does to the audio signal from in up until out and also what changing parts of the circuit will do and how to manipulate it to something I myself like.

Thanks, Reece

[GGBB]

Start here: http://www.geofex.com/Article_Folders/fuzzface/fffram.htm.

[ReeceAblaze]

I will read through it now thanks!

[Mark Hammer]

It s a time-honoured reference, for all the right reasons.  Just note that it explores only one of the many recipes for producing fuzz.

[Rob Strand]

I was wondering if someone could explain to me when looking at a schematic what each section does to the audio signal from in up until out and also what changing parts of the circuit will do and how to manipulate it to something I myself like.

There's a lot of factors.

For transistors and FETS you probably need to understand DC biasing.  DC biasing is where you set the DC currents and voltages of a circuit.  This is more to do with electronics than sound.   However, it has a large impact on the sound.   To get an idea of the sound you are best building a circuit with a variable collector resistor, like a fuzz face with the "R2" value variable.   You will get the effect straight away.

The other common ideas are rolling off the bass before stages to even out the distortion and post low-pass filtering to smooth out the sound.  To understand these electronics you need to understand simple low-pass and high-pass filters.   Again if you build a circuit and play with these parameters you will see what it does straight away.

Beyond that it starts to get hard to explain with words or even with maths.  Like you can write down many words or equations but it doesn't help the cause too much.

[PRR]

How fuzz pedals work

[Rob Strand]

How fuzz pedals work

Personally I'd add a mouse wheel with a mouse running away from the cats which drives a small generator which then powers the LED on the front of the enclosure.

The Transistor Man shows what is inside a transistor,

[R.G.]

Mark is correct, as usual. The Fuzz Face is only one way.

I went into a few of the other ways in "A Musical Distortion Primer" here: http://www.geofex.com/effxfaq/distn101.htm

Pretty much, anything that mucks with the wave shape of the signal causes distortion, which amounts to adding in harmonics and sum-and-difference products with the original signal. The math of Fourier transforms describes this process in a rigorous, if abstract, fashion.

As a caution to purely eyeballing waveforms, filters affect both the distribution of the array of harmonic products as well as the phasing of the partials, and that can change the waveforms on an oscilloscope a lot after the initial distortion process.

[Kennt82]

     If it's the four transistor version, then it's a modded Big Muff. There are some tone stack and clipping diode differences.
     Compare your kit's schematic to this: http://www.kitrae.net/music/big_muff_guts.html

[pinkjimiphoton]

getcherself a breadboard, and a mess of caps and resistors and pots and transistors and have at it.

distortion/fuzz isn't something for engineers, its more for geeks who wanna let the magic smoke out.

start by plugging a q in the board. add an input cap and an output cap. play with some resistors from the + rail to the base, and from ground to the same point. mess with the resistors until it passes sound. mess with it more til it sounds ok. wango. instant dirt box.

its only slightly more complex than that, really... just look at everything you can, take the time to dream, and experiment. 10,000 monkeys in 10,000 years optional.

once ya get a stage that fuzzes, add another one. before ya know it, you'll be z vex

[Mark Hammer]

Normally, it takes care and attention to detail to amplify an audio signal cleanly, contributing nothing to the output other than a whole lot more of the input.  And because of that, there is an infinity of ways to produce an output that has more than simply the input, amplified.  The question is whether it produces additional harmonics of the input signal, which ones, how much of each, and for how long. 

The "how long" is more important than many might think.  Guitar strings are NOT signal generators, producing a signal of fixed waveform and amplitude.  A picked string starts out ever so slightly above-pitch, due to stretching, with the most harmonic content it's going to have, and shortly afterwards dies down quite a bit, and loses the majority of its harmonic content.  The nature of the bridge can play a role in how all of that progresses.  Big jazzboxes with floating wooden bridges sound like they have greater dynamics, but that's primarily because they produce a big contrast between the initial attack, and what the string settles down to, as the body and bridge absorb a lot of the energy.

Because the signal produced at the pickup is a changing beast, the proximity to whatever clipping threshold a distortion pedal may have can change.  If the guitar signal falls below that threshold quickly, most of the additional harmonic content produced by the pedal will occur early on, and then disappear as the string dies out.  For my money, that's what "overdrive" is.  If the additional harmonic content last for a while, that's "distortion", and if it lasts for a really long time (i.e., the input signal is amplified to remain above some clipping threshold for much of the note's lifespan), that's "fuzz".

Which harmonics are added to the output can be played around with, independent of how long such harmonics are produced, leading to different-sounding kinds of fuzz.

[pinkjimiphoton]

all that mark says, but....

you have to understand, at least if you're a working musician, that the envelope of the guitar accoustically matters far less than i believe mark thinks it does due to changes in the sound from distortion. feedback assisted sustain. harmonic bloom a couple octaves above the fundamentals of the guitar. the compression added by squarewaving the living @#$% out of a signal all change note duration, sustain, intensity. there's a LOT more going on than a "simple" analysis of how the strings may act <he's 100% right> accoustically.

but electronically? completely different animal as soon as you plug in and play at actual stage levels.

i used to test everything thru tiny diy amps, as i did in many of my pedal videos of days of yore, but they give a seriously skewed result as to what the device, no matter how attractive it may be, and what it does and how it reacts.

to me, its easy as pie to make anything sound good thru a tiny amp. it ain't about tiny amps tho at a certtain point, it comes down ultimately not to a line 666 in your bedroom either,,,


its all about pushing a stage amp in a live environment. that is a completely different situation, and the fuzz and guitar signals are completely unrelated in almost any way to the accoustic aspects of the attack sustain decay release aspects of a plucked guitar string.

the compression completely changes the sustain ration and envelope. all fuzzes compress the signal significantly.  this makes it more like an organ. notes shapes change drastically in the process <they don't HAVE to, but.... that comes down to the player and his touch and experience and ability to control subtle shadings>

this compression adds to feedback assisted sustain. you don't need to play any louder than it takes to feedback, really. but as many fuzz guys will tell ya, once ya feedback a note, you can literally sustain that son of a gun til the cows come home or the amp is shut off if you want to.

your fundamentals, which run out about 4-6k on a guitar unamplified are suddenly more like 12-15k with the addition of harmonics. these harmonics air mix with the guitar in the feedback assisted sustain loop too, which allows you to do pinch harmonics that are easily a couple octaves above the 12k.

there's a lot to it.

but ya gotta decide, grasshoppahs, are you an accoustic guitar player playing an electric guitar with effects?

or are you an electronic guitarist, using the guitar and amp as a generator to drive your fx and amp to create the sounds you hear in your head?

very few of us are both; i am firmly in the second category. i never bothered with chords until years after i started playing, <yes, i started playing lead, one of them guys you hear about that sucks lol...> and i'm the first guy to pass if someone offers me an accoustic guitar. i am an AMP player, not a GUITAR player.

its like.... you can be a typewriter operator.... or you can be an author. both are equally valid in their own right, but the two actions... performing the physical task, and creating original data.... are two vastly different things.

so to me? adding in the physics of the accoustic guitar and its response matter far less than they would to a more traditional "guitar player".

i'm not looking to replicate my guitars accoustic sound louder. i am looking to @#$% that shit up, give it huge hairy endless balls from hell, and in general completely @#$% up the sound, and hard.

that said, that's why i am a fuzz guy. because i can control it with my guitar to get whatever sounds i may choose, from crystaline bright cleans to crunchy middy rhythms to the muddy roar of too much.

for me, it literally takes much of the "accoustic" aspect of my guitars and their sounds and chucks 'em out the windows. that ain't for everybody, but for me, its hip.

i can literally take almost any guitar in my collection at any time and get completely different sounds out of them... or sounds so close, you'd be hard put to tell a les paul from a strat. and not cuz its a solid wall of doomy velcroy big muffy doom... but because the fundamental tones can be bent to my ear's sonic preferences.

there's no right and wrong usually.

but in electronics, ya got the right way, or the wrong way

<man, i miss dave.... huge shoutout to Lucifer's Trip, a fellow fuzzahollic>

electronic engineering has problems with distortion. they can design stuff, and make it great, but first they have to learn how to @#$% it all up.

they don't teach distortion in electronics class.

that comes down to idiots like me who could give a shit about the rules, looking for something thats on a road far less traveled.

so to me,  the aspects of ohms law, and the aspects of filtering and voltage division etc to gain access to gain ranges and biasing and voicing, are all valid and important...

and useable, in fuzz tech

but the most important aspect is using your ears, and being willing to bend or break rules in search of The PerfectFuzz...

and to me, the accoustic aspects don't really need to come into play much for that to happen. ymmv, and probably should.

but once you electrify, its a completely different animal in every way.

soon, i gotta new one i'll lay on ya. nothing spectacular, and straight from the fuzzface school... but with a couple twists to make it sound a bit more like "a dead rock star" in a box.  not that its really relevant to this convo.
but ya can take literally all you learn  and use it, or sometimes, you can be flying blind and lummox into something really cool.

anybody can make a transistor amplify with very little thought or research.

anybody can take snippets and bake sonic cookies.

but to create a good fuzz thats versatile and can be used for almost any situation?

that can take time and work, and will likely do better with some hands on breadboard time than perusing TAOE.

jmo, with no dis meant to anyone, but man, theres a lot of ways to skin this cat.

[Mark Hammer]

Good start to the year, Jimi.  I think that is the longest post I have ever seen from you.  GIVE THOSE FINGERS A BIT OF A REST! YOU HAVE PLAYING TO DO. 

But the notion of an electric vs an acoustic player is a useful distinction.  And the notion of how volume and processed/amplified dynamics also play a role in the way that distortion works is also important.  One of my own points was that the signal provided by a guitar string through a pickup is not a steady state, but rather a changing quantity.  Indeed, it is the manner in which the necessary transformations would have to be recomputed, millisecond by millisecond, BECAUSE of that constantly fluctuating signal, that have made distortion the last frontier of digital effects.

And when we consider that "how fuzz pedals work" ALSO has to consider "how guitars work when amplified...loudly", it is no wonder that digital FX don't nail it quite as well as they do for reverb or phasers.

Happy New Year to ya, bro.

[pinkjimiphoton]

thanks mark, happy new years to you and yours, too!

yeah, i think the whole thing changes when they're plugged in. maybe i did too much lds with spock at berklee, but i swear electric guitars come to some form of life when plugged in.

and, as promised, YAFF

https://www.diystompboxes.com/smfforum/index.php?topic=121645.new#new

rock on bro!

i gotta go, gotta gig tonite. man. i feel like methuselah and look like satan claws and party like i'm  keith richards. when will the train slow down? lol

peace out!!