Designing your own?

[Jberg]

Can someone give me information about designing my own distortion/fuzz circuits?  This sort of stuff has really peaked my interest! 

[R.G.]

Read Geofex. All of it. Then come back and ask more focused questions about the things that it didn't make clear.

[CynicalMan]

Distortion relies generally on three elements: boosting, clipping, and filtering. How you combine them and what type of each you use determines the sound of the distortion. There are various circuits for each that you can use, and often circuit stages combine multiple elements. Ask a generic question, get a generic answer.

Hopefully we can help to narrow down your question. What kind of distortion do you like? What circuits do you like? What are some design specs you'd like to follow (complexity, part types, controls, etc.)? There are some guides out there to help design a specific kind of distortion, but there are so many ways to use and abuse electronics that no guide can cover everything. Really, you just need to get experience with loads of different circuits and design concepts. Time to pull out the breadboard and get your hands dirty!

[petemoore]

  There is already distortion in your electric guitar/amplifier sound.
  The guitar pickup has very little output current, and the AC voltage produced by the strings wiggling a magnetic field are also quite small, the pickup output is weak.
  You'll need a voltage booster, building this will involve an active component and a power supply for it to produce another signal output.
  This type of amplifier is quite simple in terms of using an active component, and required if any signal processing [if it is not an active component with a DC power supply it is 'passive', passive components in a circuit cause losses.
  Losses subtracted from a guitar pickup can cause signifigant signal degradation, a booster provides the current needed to do any-much processing beyond what the guitars tone control does [an adjustable LP filter = trims the highs].
  Getting the booster going will increase the distortion you now have.
  The next stage is where actual processing [could be tone control, another active/distortion stage] starts occuring.
  Though more than one job can be done with an active stage [distortion plus is example of boost/voice/distort using 1 active stage], the booster focuses on..boosting. By the time it is boosting, you will understand a great deal more about active stages.
  It can then be used as a booster, frequency shaping booster, distortion 1rst stage...etc.

[Processaurus]

The most common ways of making musical clipping in pedals are the transistor fuzzes (like the 60's fuzzes Fuzz Face, superfuzz, tonebender, etc), diode clipping (big muff, rat, distortion+), and those based on a misuse of unbuffered 4049 logic inverter gates (Red Llama/ Anderton Tube Sound Fuzz).

Distortion relies generally on three elements: boosting, clipping, and filtering. How you combine them and what type of each you use determines the sound of the distortion. There are various circuits for each that you can use, and often circuit stages combine multiple elements. Ask a generic question, get a generic answer.

Hopefully we can help to narrow down your question. What kind of distortion do you like? What circuits do you like? What are some design specs you'd like to follow (complexity, part types, controls, etc.)? There are some guides out there to help design a specific kind of distortion, but there are so many ways to use and abuse electronics that no guide can cover everything. Really, you just need to get experience with loads of different circuits and design concepts. Time to pull out the breadboard and get your hands dirty!

Good answer, definitely use a breadboard for trying out different component values quickly to dial in the sound.

Read Geofex. All of it.

Well, duh  !  Geofex (and a few other sites I can think of off the top of my head, like JC Maillet's site, AMZ and the Tone God's site, and here, of course) are great resources for pedal building because beyond the scope of constructing projects, they have articles about what makes designs tick, and how to tailor them to your own needs and work in bits as modules into your larger, unique designs.

My own 2 cents is to really get how opamps work fundamentally.  It is really handy.  That and a community college beginning electronics class, and reading here, and I've been able to branch out from building clones to designing new weirdo pedals and extensive, unique mods.

[dukie]

How about read this page for references....Cook your Own Distortion

Cheers!

[Mark Hammer]

At this point in "distortion pedal history", what some might call "design" consists essentially of little tweaks and mods to one of the many, many, many, MANY existing things. 

I don't say this dismissively, since improvements to products that were never completely thought through or tested with enough consumer feedback, are always welcome and appreciated.  There is no end to the number of options, add-ons, or strategic component-value changes that could be made to suit a given player's needs or tastes.

But the notion of "design" suggests a need which has yet to be filled in any manner.  And when you multiply the number of distortions that are produced in any given year, both commercial and DIY, times the number of countries where these things are being generated (many of which we tend not to know about here because of the Anglo-centric nature of the web), times the number of years that such things have been being explored.....well, the likelihood that there are ANY niches left unfilled is pretty dang small.

So, once again, I'm not saying this as a polite version of "piss off you poser!".  Rather, at this stage in the game, what you REALLY want is to understand the basic platforms that exist out there and what makes them do what they do and sound how they sound.  Buy yourself a ream of paper, and make yourself a great big old binder chock full of schematics.  Print them up double sided if you can, with as many different ones on a page as you can while still being able to see the details.  Then flip through that binder whenever you have the chance: on the can, waiting for the dryer at the laundromat, waiting for the movie to start in the theatre, waiting for a friend to show up at Starbuck's or wherever, before classes start in the lecture hall, during classes that are boring, over lunch at work, etc.  Learn to see them all in your mind, and be able to recognize the patterns the same way you can hear a song and think "Oh, slow blues in A minor", or "Standard I-IV-V folk progression in D".

Eventually, the mods will suggest themselves, the same way you can pour yourself a bowl of soup and think "Yeah, this needs a bit of salt/hot sauce/vinegar/cumin".  Ultimately, what gets you to that point is to have a deep intuitive feel for what already exists.

[smallbearelec]

One answer to this is that before you can design your own, you need some understanding of how distortion is created, which components influence the result, and how. A way to begin is to breadboard one of the many vetted designs, make it work, and then read past threads here for information on mods and bits of theory about the design.

Yes, a breadboard will be an essential tool. This article covers

http://www.smallbearelec.com/HowTos/Breadboarding/BreadboardIntro.htm

the basics of how to use one, and there are a couple of follow-up pieces in the same secion that I know have been useful to other beginners.

[liquids]

Mark, I love your analogies!

Steve, I love seeing the wise and learned, such as yourself, encouraging others to start this endeavor with a breadboard and focused listening (in addition to all the important tools Mark laid out)! 

   Those posts made my day.

[petemoore]

 What is AC ?
  What is DC ?
How is Dc used to 'amplify' [create a larger voltage recreation of] an AC signal?
  If capacitors always follow the same rule of increasing impedance as frequency through them is longer wavelength [bassier], how is it the same capacitor can be used to LP filter and HP filter [see AMZ labs notebook].
  Understanding how to set up DC bias on...whatever it is that needs DC bias...how resistors can be used as voltage divider or pots as variable voltage dividers.
  What is a floating voltage potential ?

[Jberg]

I have read and read and come up with this basic idea: the basis for distortion is to bias a transistor and use it to amplify the signal then add clipping diodes.  Is this correct?

Also, I'm not out to come up with my own brand new idea for a circuit, just be able to draw up my own schematic and not have to rely on someone else.

[Gurner]

I have read and read and come up with this basic idea: the basis for distortion is to bias a transistor and use it to amplify the signal then add clipping diodes.  Is this correct?

Depends on what you call distoprtion...I would call distortion is any difference in the output signal vs the original......I guess it's then down to how extreme you want that difference to be!

How is Dc used to 'amplify' [create a larger voltage recreation of] an AC signal?

You modulate a DC level with an AC signal ........ do I get the job?

[petemoore]

  Mark is right about design, people have asked: "What do you do, sit around all day and look at schematics?" [Yeaah. Fine tooth comb is what these compromises have seen, and weak spots, tweeks and errors have been fixed, or made variable, or...if you find a simpler or easier to way to accomplish the same thing I'd notch that as a design accomplishment.
  As far as the artwork...how good are you at painting/finishing ?
  The see design two ways:
  1 Using TS as example is designed to be used by everyone.
  2 An 'equation' which requires much greater understanding and background than 'I use a TS', which raises more questions than it answers or asks...
  TS through what ? or is it just to look at.
  Moving right along...2: is a design from ground up, top to bottom, cabinet, speakers, cables, output section, preamplifier, more cables...everything else and last or first but not least, the guitar ! {Depends on which end of the chain you're starting from.
  Most of it can just be bought, and that can be excellent and excessively affordable [just get used to plastic], understanding what actually does what and how to fix, debug, de-noise, tweek, dial in, cause adequate reproduction equipment [amp/speaker/cabinet/room] to be placed...then things tend to really start shining.
  Can you practice and solder at the same time ?...lol !
  Welcome to the forum, be sure to check out the links and do lots of reading. It all gets explained again here but it takes more time and there aren't as many diagrams and pictures, the text can be very rich and a good deal of it is in the links/forum options.
  Many resourceful members have sites with excellent articles detailing their circuit experiences.
  For a 'steer', recent favoritism for having multiple links in the chain contribute to overall sound character have popped up, it's all about controlling softer clipping through mutliple stages which achieves a more complex sounding clipped signal than a hardclipped once circuit, a booster with guitar signal input is often an example of 'sorta distorted' signal. Of course the input of the second booster in a chain [say you want even more distorted signal] would see the first boosters output [much hotter than guitar output] so some attenuation might be in order between the stages...or before both. Might be a good time to attenuate certain frequencies if they 'grew', boosters don't boost all frequencies evenly..necessarily, highs and bass might get out of hand...who knows depends on the guitar PU, and then of course the speaker that is expected to deal with all this boosting...anything else inbetween ?
  Design is mostly about choosing options, intuition and further understanding through trial and testing [reading has been known to help].
  More than one page, usually it takes already knowing what's on one page...or having all the pages handy in case they need to be referenced.

[smallbearelec]

...basis for distortion is to bias a transistor...to amplify the signal then add clipping diodes.

That's A way. Other ways involve deliberately mis-biasing an amplifier stage and feeding your signal through that. Depending on the kind of amplifying device and how you mis-bias it, you can get numerous flavors of distortion, krunch, etc.

[petemoore]

  Greater than 99.2% of the information you read about electronics will be good within a few days after it appears, everybody makes mistakes, patience has it's virtues !
  You can trust that now is now and that 'it' always worked as intended, and that it's perfectly natural to be able to infinitely repeat electron tricks whether they be a thousand nice sounding Fuzzfaces a year or popping capacitors, the trick is to learn how to make mother nature's natural energies to work for you as best you can.
 Time is a funny thing, it often seems like it always worked this way.