How EXACTLY does a fuzz pedal work?

[nieh]

Just for shits and giggles, can somebody explain to me exactly how a fuzz pedal works? Like what the capacitor and transistors do as the signal goes through them.

[eatyourguitar]

capacitors are like resistors except the resistance increases as the frequency decreases. this is why low frequencies dont pass through caps. DC has a frequency of zero or approaching zero. so the resistance is approaching infinity or just a really high number that keeps the dc from getting through the capacitor. thats why you have caps on the in and out of every pedal. keeps the power in the pedal. transistors are a long topic and its already been written by people smarter and more educated.
explanation of how transistors work

you might want to click on bipolar transistors since they are way more common in fuzz pedals. there are many different ways you can get clipping and fuzz. sometimes its done with diodes so you might want to read about diodes or diode clipping. because there are so many ways, its hard to really say how a fuzz works. depends on the fuzz. almost everything you change affects the sound. when you think of it like that, you realize that its much easier to focus on what you want to do and talk to people about what pedal to build and what to change. its mostly not needed to know exactly what is going on everywhere all the time. but if thats your thing you should take a college course and get your hands on simulation software. colleges usually have a lab with an expensive oscilloscope. that alone is worth the price of admission both for what it can do for a guy building pedals and what you can learn from it by actually testing all you've learned.

[moose23]

Probably the best article on how a fuzz face works:

http://www.geofex.com/article_folders/f ... fffram.htm

For big muffs it's mostly the diodes doing the clipping so just read up on diode clipping on wikipedia. If you want more info there's a thread on diystompboxes detailing all teh workings on a big muff.

Once you understand those two you're well on your way to understanding the majority of (but far from all) fuzzes.

[culturejam]

All circuits that distort (fuzz, drive, distortion) do so through signal clipping.

This is done a couple of ways, but the results are similar.

The input signal (from a guitar or another pedal or whatever) is amplified until either one of two things happen, and sometimes both: 1) The circuit runs out of headroom (voltage) and can't accurately amplify the entire original signal anymore and clips the peaks; 2) diodes are used to force the signal to clip at a given voltage.

The Big Muff does both; Rat does both; King of Tone does both; etc. The Fuzz Face only does the first type; so does the Hot Cake and Tonebender MKII and Super Hard On, and many others. The Bazz Fuss I'm not so sure about, but I think it's doing some of 1 and a lot of 2.

So if you have a circuit that is clipping hard at 9v, upping to 18v effectively doubles the amount of signal amplification that can happen before a transistor or op amp runs out of headroom and clips. Of course, if there are diodes in play, they will still clip at their rated forward voltage, but there will be less clipping from the the active semiconductors (op amps and transistors).

Granted, I didn't cover what the caps and resistors do, but I was going for the big picture.

[The4455]

basically germanium adn silicon are incomplete elements so when sound passes through them not all of what youplayed hets through which makes it "fuzzy," therefore: Fuzz.

[eatyourguitar]

All circuits that distort (fuzz, drive, distortion) do so through signal clipping.

This is done a couple of ways, but the results are similar.

The input signal (from a guitar or another pedal or whatever) is amplified until either one of two things happen, and sometimes both: 1) The circuit runs out of headroom (voltage) and can't accurately amplify the entire original signal anymore and clips the peaks; 2) diodes are used to force the signal to clip at a given voltage.

The Big Muff does both; Rat does both; King of Tone does both; etc. The Fuzz Face only does the first type; so does the Hot Cake and Tonebender MKII and Super Hard On, and many others. The Bazz Fuss I'm not so sure about, but I think it's doing some of 1 and a lot of 2.

So if you have a circuit that is clipping hard at 9v, upping to 18v effectively doubles the amount of signal amplification that can happen before a transistor or op amp runs out of headroom and clips. Of course, if there are diodes in play, they will still clip at their rated forward voltage, but there will be less clipping from the the active semiconductors (op amps and transistors).

Granted, I didn't cover what the caps and resistors do, but I was going for the big picture.

all good information but leaves out additive synthesis that happens in some fuzz pedals. like PWM fuzz. or flip flop fuzz. some pedals even have square wave oscillators in them. no clipping involved but I guess the sounds can all be considered fuzz. they sound similar since they all have a very noticeable square wave on the oscilloscope. also foldover distortion is different too but can still get some fuzzy sounds just before the octave up. it also looks like a square but not as sharp. thats why it sounds fuzzy.

[AC128]

very good info here.

thanks guys!

[culturejam]

all good information but leaves out additive synthesis that happens in some fuzz pedals. like PWM fuzz. or flip flop fuzz. some pedals even have square wave oscillators in them. no clipping involved but I guess the sounds can all be considered fuzz. they sound similar since they all have a very noticeable square wave on the oscilloscope. also foldover distortion is different too but can still get some fuzzy sounds just before the octave up. it also looks like a square but not as sharp. thats why it sounds fuzzy.

I forgot what forum I was on. You guys like things that sound broken.

[theavondon]

basically germanium adn silicon are incomplete elements so when sound passes through them not all of what youplayed hets through which makes it "fuzzy," therefore: Fuzz.

Erm, well, uhh...erm...well...uhh....ermm...

[The4455]

basically germanium adn silicon are incomplete elements so when sound passes through them not all of what youplayed hets through which makes it "fuzzy," therefore: Fuzz.

Erm, well, uhh...erm...well...uhh....ermm...

Word, to put really simply, I know how a fuzz "actually" works, but it doesn't matter to me as long as it does work.

[eatyourguitar]

basically germanium adn silicon are incomplete elements so when sound passes through them not all of what youplayed hets through which makes it "fuzzy," therefore: Fuzz.

Erm, well, uhh...erm...well...uhh....ermm...

Word, to put really simply, I know how a fuzz "actually" works, but it doesn't matter to me as long as it does work.

While your here, maybe you could tell everyone what an incomplete element is

[theavondon]

basically germanium adn silicon are incomplete elements so when sound passes through them not all of what youplayed hets through which makes it "fuzzy," therefore: Fuzz.

Erm, well, uhh...erm...well...uhh....ermm...

Word, to put really simply, I know how a fuzz "actually" works, but it doesn't matter to me as long as it does work.

While your here, maybe you could tell everyone what an incomplete element is

As someone studying chemistry, I did indeed wonder what that is.

[morange]

Maybe it's a solid state crystal lattice?
[youtube]http://www.youtube.com/watch?v=iVTj08qTwGw[/youtube]

[eatyourguitar]

But how EXACTLY does a solid state crystal lattice work?

[McSpunckle]

I find this one to be far more informative:

[youtube]http://www.youtube.com/watch?v=nr8EcKe4p0w[/youtube]