The Dirty Truth About Pedals

December 23, 2016
Written By PGS Staff
Whether you like it sweet and sassy, hot and hairy or warm and fuzzy, chances are you’re using some kind of gain effect to push your sound into that sweet spot. As common and interchangeable as they seem to be, overdrive, distortion and fuzz are not necessarily the same thing, despite the blurry distinctions between them. To truly understand the difference between overdrive, distortion and fuzz, it is necessary to understand how each effect works with your guitar and your amp.
As you probably know, a guitar pickup works by inductance, the phenomenon of physics in which a change in a magnetic field creates changes in a conductor’s current, and vice versa. It is the actual physical phenomenon by which we transmit and receive radio, television, radar, satellite communications, and wi-fi, to name a few. In our guitar’s pickups, a coil of fine copper wire is wound carefully around a magnet and placed so that the guitar’s metal strings pass through its magnetic field. Whenever any of these elements changes position, the magnetic field changes, instantaneously inducing a small voltage in the copper wire. Each time a string vibrates back and forth, it creates an alternating current whose frequency and amplitude correspond directly to that string’s frequency and mass. The signal will resemble a sine wave that has been reshaped by the complex array of frequencies from all of the vibrating strings, as well as the natural acoustic properties of the guitar’s wood, hardware and electronics to reinforce some frequencies and dampen some others, creating a tone and timbre that is unique to each guitar.
The guitar’s signal is input directly into the first preamp stage in your amp. In any tube, like the ones in your preamp, a white hot emitter radiates electrons into the vacuum where they are absorbed by the negatively charged anode, creating a substantial current. Between the emitter and the anode is a control grid, whose variable electrical charge allows more or less conductivity, allowing more or less current to flow through the tube. When a guitar signal is channeled through the control grid to serve as the variable electrical charge, the output of the tube will recreate the frequencies and amplitudes of the guitar signal, modeled in the actual, much larger current of the tube. This is the amplified signal that is sent to the next preamp stage or to the power amp and then to the speakers. Every tube has a maximum and a minimum amount of current it can conduct. If the peaks and valleys of the guitar’s signal require the tube to exceed its maximum or its minimum, the tube will flatten out at its limit, effectively clipping off the top, bottom or both ends of its amplified signal. This is the naturally overdriven signal we all love.
At a high enough volume, any tube-driven guitar amp will deliver that overdriven sound. When you crank up your amp to get that sound, the high enough volume is often far too high for the enjoyment and well-being of your audience, since both your preamp and power amp are processing a lot more voltage. An overdrive pedal will work with your tube amp by boosting your guitar signal beyond the limits the preamp is designed to process. It will clip the signal naturally, regardless of the level at which your power amp is working, and let you bring that sweet spot down to a much more audience-friendly volume level. Overdrive effects are typically little more than a boost or a preamp with some mild clipping circuits. Most have some self-generated distortion, especially at higher gain levels, but they tend to preserve, or even enhance the natural tone of the guitar and amp. Unfortunately, overdrive pedals often lose their sonic charm when played through a solid state amp. Fortunately, there is an alternative.
Distortion pedals simulate the clipped signal of an overdriven tube amp. They can work with solid-state or tube amps, and the boost they offer can create some interesting sounds when used to push a tube preamp into overdrive, but they are designed to create a sound-in-a-box rather than a naturally enhanced tube sound. Because it is, essentially, a waveform-altering circuit, relatively free from the inherent design constraints imposed by the performance limits of a tube, there is a much broader range of “distortion” sounds available on the market, and they tend to create a much heavier sound, from a hard-clipped, raspy buzz to the high-gain, sonic apocalypse that is the signature sound of heavy metal.
Fuzz pedals were the original dirt boxes and one of the first effects of any kind (along with reverb and vibrato, of course). They were originally designed in the early ‘60s to lend texture to an amplified guitar tone, like the reedy rasp of a saxophone. The earliest designs worked maybe a little too well, the excessive clipping of germanium transistors creating a warm, enveloping sound that practically obscured the guitar’s natural tone beyond recognition. Later designs used more reliable, more efficient silicon semiconductors for their clipping circuits to create a brighter, edgier fuzz effect. Guitarists loved it, of course, since it remained responsive to the feel and dynamics of the player and opened up what many saw as a whole new world of creative possibilities. It was, perhaps, not the sole inspiration for some of the most memorable music yet recorded, but it is difficult to imagine “Satisfaction,” “Purple Haze,” or pretty much any classic ‘60s psychedelia without a generous coat of fuzz.
A word about pedal placement is in order (get it?). You are, of course, free to use your overdrive, distortion and fuzz pedals any way you like, but, you’ll probably find they sound better when placed as close to the beginning of your signal chain as possible, the output of the effect(s) going into the input of the amp. You’ll want to place lower-gain pedals before those with higher gain, overdrive into distortion into fuzz. And while there is always room for experimentation when it comes to the relationship between overdrive and wah pedals, most people prefer placing their wah pedal before their fuzz pedal for the best effect. What do you think?



  1. -jim says:

    WTF - if you don’t really know how tubes work you should ask somebody before publishing your article.

    posted on December 23, 2016 at 7:43 am
  2. Gabriel Aguirre says:

    Hey Andy,

    I’ve heard you talk about gain pedal order in this matter of fact way before and I still don’t think I am clear on why you do so. Is this just inference from your explanation of signal clipping? I think many of us know that stacking gain pedals seem to be in categories, ie fuzzes then overdrives and the orders within those groups.

    For example, which you touched upon, early fuzzes played most nicely with a direct guitar signal, meaning if you wanted to boost this fuzz the overdrive would be after the fuzz. This also just made logical sense to me, and it seems to make sense based on your explanations of what an overdriver is and what a distortion unit is, and I’m sure most know of people like Gilmour who boosted their fuzzes with overdrives, not vice-versa.

    Personally, on my portable board the Muff clone is the first gain effect (excluding the compressor for simplicity’s sake) then a transparent overdriver then a more mid-range overdrive. Can you clarify if you mean the order “should” be transparent, mid-range, muff? Again I know it ultimately is taste but like I said I’ve heard you say this a few times.

    posted on December 23, 2016 at 7:55 am
  3. Jim's an ass says:

    Jim, Andy’s text is a very simplified and completely correct description of how a tube works.  You, sir, are an ass.

    posted on December 23, 2016 at 8:05 am
  4. Christopher Nagy says:

    um i put my ocd before the muff, it seems to get the sound I want or is that backward>?

    posted on December 23, 2016 at 8:10 am
  5. Doug at Midknight Engineering says:

    Okay all.. simmer down.  Andy’s description is right (kinda) but his nomenclature is wrong.  The “emitter” as Andy calls it is a cathode in tubes and is negatively charged (most of the time at or near ground).  The anode is correctly named (more commonly called the plate), but is positively charged and attracts the free electrons that are emitted by the cathode.  In between is the control grid, similar to a window screen mesh, which follows the input (guitar) signal and controls how many free electrons get to the anode.  Think of it as an accelerator pedal for the flow of signal through the tube.  The more positive the input signal is, the more electrons are accelerated toward the anode, making the amplified signal larger.  The more negative the input is (or the smaller it is) means fewer electrons are drawn to the anode, resulting in a smaller amplified signal.

    Stomp boxes in general will provide some increase in signal over the standard guitar output so the input signal to the first gain stage of the amp will be somewhat higher.  Obviously, gain, overdrive and fuzz pedals are designed to add an amplification stage before the amp, making the tubes reach saturation in the preamp stages and get the sound everyone is after (to one degree or another).

    posted on December 23, 2016 at 8:37 am
  6. Geoff says:

    Usually, these articles are good. This one, however, is flawed with a complete misunderstanding or at very least, over generalization of how analogue frequencies are reproduced and transmitted. In no way are these analogous to satellite, radar or amd especially wi-fi. Check your science.

    posted on December 23, 2016 at 8:40 am
  7. Bruce Ishimatsu says:

    As for the signal chain, what does it mean when you say “early in the chain”?  Does the start of the chain begin with the first pedal that your guitar is plugged into?  And then the end of your effects chain goes into the amp, right?  That’s how I always understood it but then in Andy’s article, he says the following:
    ” you’ll probably find they sound better when placed as close to the beginning of your signal chain as possible, the output of the effect(s) going into the input of the amp.”
    That is opposite from my understanding.  I defer to Andy but can’t believe I’ve had it backwards all these years!

    posted on December 23, 2016 at 10:53 am
  8. Dave in S. Cal says:

    Geez Geoff, give the guy a break. Are you saying the phenomenon of electrical inductance is immaterial as concerns radio communication?

    posted on December 23, 2016 at 11:01 am
  9. Mac Leahy says:

    @ Bruce Ishimatsu; Basically, he’s saying to put fuzz/distortion/overdrive pedals as early as possibly in your signal path or “chain”; fuzz, then distortion, then overdrive.  If you use a “wah,” you’ll definitely want to put that first in the signal path or “chain.” 

    Personally, I prefer putting delay pedals as late in the signal path as possible, because I don’t want to distort the delay signal by putting it before any fuzz/distortion/overdrive pedals.  Most of my pedals are older Danelectro models, from before they started making their housings out of plastic, so my ideal signal path would be; Jim Dunlop “Cry Baby,” “Fab Tone” distortion, “Cool Cat” chorus and “PB&J” digital/analog delay. 

    If I’m using my “Free Speech” talk box, that would also go before the wah, though that’s more about my own personal preference than anything else.

    It couldn’t be any simpler than that.  (And yes, that means you’ve had it right all these years!)

    posted on December 23, 2016 at 11:42 am
  10. Luke Reiss says:

    some fuzzes (or fuzz boxes if you will) don’t like anything else between them and the guitar. That’s why, depending on the fuzz, it comes before anything else.

    distortions would go after every other gain pedal because their internal circuit has the clipping diodes after everything else.

    but you can change the order of things if the results please you.

    posted on December 23, 2016 at 11:47 am
  11. Rain says:

    Hey, you guys all know that PGS Andy doesn’t write this whole magazine all by himself every week, right?

    posted on December 23, 2016 at 12:14 pm
  12. Stringbender53 says:

      The “header” at the top says “Written by PGS Staff” while the e-mail it’s sent out under is “Andy’s Corner”. WHAT ever. No sense in anyone getting all butt hurt over it; just add your corrections,  observations, and two cents worth. That’s why there’s a “Leave a Comment”. 
      Everyone have a Merry Christmas, a Happy New Year, and hope to God after a year of the incoming “Trumpenfuhrer” we’re ALL still around here to bitch at this time next year!  :)

    posted on December 23, 2016 at 1:35 pm
  13. ken says:

    Hey guys, Doug at Midknight Engineering is right. The signal is as he says, from the cathode to the plate, with the grid acting as a control in the tube. Less is amplified the lighter you play, or the harder you hit the tube (pedal) more signal will pass until you reach its unlinear regions, which at that point you get distortion. How you guys want to set up your boards is your own personal taste. I think it is unfair to rip Andy the way you are. Me, I like it straight into the amp with it dimed, and I control everything with the volume. I may use a pedal for an effect, but that is it. I’m old school, but that’s the way I like it.

    posted on December 23, 2016 at 1:48 pm
  14. Michael B says:

    Hey Guys. don’t make personal attacks on contributors. it just highlights your own ignorance. Having said that there are a few flaws in the original article but the basic concepts are correct and for those not technically minded the explanations are adequate. Looking forward to more semi-technical articles as I believe they help us all understand the nuances of guitar amplifiers and effects pedals just a little better.

    posted on December 23, 2016 at 4:56 pm
  15. Stu says:

    A word about pedal placement…so many articles bring up pedal placement. I always have germanium fuzz first in line. I do not use wah pedals. As far as placement of all other pedals, I use a Loop-Master Reverse pedal to determine which sounds better before or after. From what I have determine with my collection of pedals is the order follows no rules. For instance, I have a boost pedal that sounds better before one of my OD pedals but for some reason sounds better after my other OD pedal

    posted on December 23, 2016 at 11:01 pm
  16. Joerg says:

    We are all sound designers, so the question is, how the amp interacts with a pedal. Sometimes it’s kinda cool, playing the amp, sometimes enrich with effects. My personal experience is, that sometimes you’ll get a FUZZ sound, by stacking pedals or add an OD to an overdriven amp.
    Our ear is the master, so it’s all about the taste. If we start here to create manuals how to setup the order for pedals and amps correctly, then creativity is dead. I like different kind of perspectives, then this is the essence to create something new. I like these statements, then it shows the right approach ! Merry Christmas and happy pedalboard building :-).

    posted on December 24, 2016 at 1:25 am
  17. Ernest Foss says:

    Dirt boxes.,Fuzz ,Overdrive and distortion. Overdrives the pre-amps tones, Pushed pre-amps tubes are affected by Dirt boxes,Tone goes to the amplifier with your taste in dirt boxes .Tones to the pre-amps tubes and Overdrive ,Fuzz and distortion add the essence!!

    posted on December 24, 2016 at 5:59 am
  18. Steve says:

    I think we should all cut Andy some slack. Tube terminology aside, he wrote a good article that’s of value to many guitarists. Andy, I want to thank you for your continuing contributions, especially the hands-on pedal demos that many of us look forward to.

    I would like to add one comment, as a layman guitarist : although I am not an EE and can’t necessarily back up my statement with science, it seems to me that the biggest difference between pedal clipping and amp clipping (especially when we’re talking about high volume vs “audience friendly” volume) is that most of the real “sweet spot” of REAL amp overdrive happens at the power stage, ie the output tubes - not in the preamp. Most pedals act as secondary preamps, and can only at best create a fairly convincing simulation. A Marshall combo running on “10” sounds quite different from, and IMO superior to, a typical $100 overdrive pedal.

    posted on December 28, 2016 at 12:55 am
  19. Joey Chickenskin says:

    I think pedal orders are useful as a starting point for experimenting and also making you think about why you might do things a different way.

    If the distorted sound is the focus of what you are doing but you’re using delay to fatten it up, then having it after keeps the distorted sound more in-tact. On the other hand if you come from, say, a rockabilly background where the percussive emphasis from a slapback is the focus then you’d lose some of that with the delay second.

    I have some sickly home made fuzzes (eg Fuzzwrite) that only just tolerate a cable before them without changing the sound and a buffer (either stand alone or from a Boss style bypass) renders them virtually uselsess so they ususlly need to go first.

    Interesting about Overdrive into Fuzz. I usually do it the other way on the understanding that the Overdrive is more like the front of an amplifier so it will be good to flip them. I’ve put a boost before a fuzz but not an Overdrive.

    It’s interesting coming from a pedal-building forum background where everyone is fairly gentle with opinion because there will always be someone with more actual electronics knowledge and it’s a joy to find people willing to talk about that stuff to remember how hilarious it is on gear forums when people bludgeon their way in like Donald Trump with their ‘WRONG!’ or ‘Everything they make SUCKS!’ opinions.

    I’m sure all of these articles are starting points for experimentation rather than additions to the ten commandments. i really enjoy reading them.

    posted on January 17, 2017 at 7:58 pm

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