Fuzz face schematic

Breadboarding A Plastic Fuzz Face

© 2015 By Small Bear Electronics LLC

This short article accumulates immediately in the finish ofUsing A Solderless Breadboard. If this sounds like the first project, please browse the intro article before you decide to continue and make certain that you're confident with the concepts and methods. If you're already acquainted with breadboarding, observe that the amount of detail in the following paragraphs is supposed to guide complete beginners, so be just a little patient.

I'll take you step-by-step through the setup of the complete circuit. When you're done, you'll have something that may be dedicated to a soldered develop perfboard or perhaps a PC board.

Here's the fundamental circuit that we'll setup:

Fuzz face schematic

This can be a more complicated schem compared to Brought demo within the intro, but it is still merely a dozen parts such as the battery. not very tough. I've intentionally not incorporated jacks, stomp switch or power switching to keep it easier we'll add individuals later. The only real items to note at this time are:

Where wires mix inside a schematic try not to connect, you will see this:

Where wires mix or participate in a schematic and Do connect, you will see this:

The Floor symbol isn't a link with our planet it is the reference that all voltages within the circuit are measured. Every point within the circuit which have or share the floor symbol are connected. If this isn't obvious yet, you will get the concept when i take you step-by-step through the build.

So let us go! Trim and make up the leads of the 2.2 mf. ("microfarad") electrolytic capacitor, following a convention of departing 1/4" to fiveOrsixteen" of lead length for insertion within the board. Electrolytic caps are most frequently polarized on radial-situation types such as this one, a black band marks the gloomy (Fig. 18.) I created the results in span five holes, however, this really is arbitrary. You might want to follow my directions and layout now after you have the concept, you are liberated to do whatever works. Similarly, I'm working from left to directly on the board, but that is not engraved in stone, either. Connect the cap using the gloomy toward the ability rails, since this is where your guitar input jack will connect later (Fig. 19.) I've it located between indexes E-1 and G-1. It's not necessary to use the identical locations I actually do. However, if following my actions (bear tracks?) helps you to construct your confidence and steer clear of mistakes, do it now.

Now add transistor Q1. It's three leads: Collector, Base and Emitter, recognized as C, B and E within the schem. I would recommend whether 2N2222A or perhaps a BC108, each of which are available in metallic can known as a TO-18 package. In this fashion, the leads form a triangular, and also the can includes a tab near the Emitter (Fig. 20.)

Fuzz face schematicFuzz face schematic

I plugged this product into indexes J-4, I-5 and J-6 using the tab around the can left (Fig.21.) The selection was arbitrary, however it switched to be perfectly workable when i added more parts and connections. When you are getting to "moving your personal," in case your first selection of an area does not pan out, support and check out elsewhere! Now bend a brief, bare-wire jumper to span five holes and plug it into indexes H-1 and H-5 (Fig. 22.) Fig. 23 shows the bond you have made. Got the concept?

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Now complete the connections to the bottom of the transistor with the addition of a 100K resistor between indices F-5 and F-9 (Fig. 24.) The colour code is Brown, Black, Yellow, Gold. The Emitter of transistor Q1 needs to get at the floor bus, so add two jumpers from indices E-4 to F-4 along with a-4 to ground (Fig. 25.) Figure 26 shows these connections.

Fuzz face schematic

A 33K (Orange, Orange, Orange, Gold) resistor must connect in the Collector of Q1 towards the positive power bus. Hook it up after that to index B-10 and add two jumpers, E-10 to F-10 and H-10 to H-6 (Fig. 27). Transistor Q2 gets into next. Since its Emitter needs to connect with one for reds from the 100K resistor, that pin (the main one close to the tab) logically gets into at index J-9 (Fig. 28). Putting the bottom Q2 within the next column connects it towards the Collector of Q1. Figure 29 shows where we're.

Fuzz face schematicFuzz face schematicFuzz face schematic

Last components before we add some containers: The 8.2K (Grey, Red, Red, Gold) connects towards the Collector of Q2. Yes, it will come across with one for reds from the 330 ohm, and so i run it horizontally beginning from index H-11. This is not the tightest utilization of space, however it does keep your layout neat and easily visible. 330 ohms (Orange, Orange, Brown, Gold) ranges from the positive supply bus to index B-17 and 2 jumpers hook it up to index G-15. A .01 mf. film capacitor (marked "103") starts at H-17 and really should terminate at index H-19. It's not polarized and may use in either case (Fig. 30). We're getting close (Fig. 31.)

Fuzz face schematic

Prepare the fuzz and volume potentiometers allowing you to connect towards the breadboard by soldering results in them. A couple of inches of insulated breadboarding wire to every terminal is okay. By convention, we make reference to the terminals from the containers as CCW (counter-clockwise), W (wiper, for that moving contact) and CW (clockwise) (Figure 32).

Add three jumpers: G-4 to G-7, G-9 to G-14 and E-12 to F-12. Then your connections towards the fuzz pot are:

CCW down bus

CW to index J-14

Wiper to index J-12

Adding the 22 mf. electrolytic capacitor from index A-12 down bus. Gloomy to ground, please! Check all this in Figure 33. Now add some level pot as proven in figure 34.

CCW down bus. This needs two jumpers.

Wiper to index J-18

CW to index J-19

Figure 35 shows the additions.

Fuzz face schematic

For testing purposes, you want to install input and output jacks as proven in Figure 36. The schematic shows mono jacks for input and output. This kind has two contacts: tip and sleeve. Figure 37 shows the connection between your schematic symbol and 2 styles that you'll probably see, shrouded and open-frame. Figure 38 will the same factor for any stereo jack, that has three contacts: tip, ring and sleeve. The stereo jack proven is really a Switchcraft #12B observe that the arrangement from the contacts might be different on other makes.

Fuzz face schematicFuzz face schematicFuzz face schematic

Inside a typical pedal build, we'd make use of a stereo jack for that input and fasten the ring contact to change electric batteries. To help keep things simple here, we only use the end and sleeve. Connect short lengths of wire to every jack. The sleeves of both jacks are plugged down bus. Input tip would go to index D-1, output tip to index D-18. That last connection requires a jumper towards the wiper from the level pot. Things need to look like Figure 39.

Fuzz face schematic

Isn't It Time?? Connect your amp and fasten battery power. Show up the amount control and switch in the fuzz pot until you hear fuzz. Try having fun with it a little.

Does not work? Return with the pics and evaluate which is not connected right. Also make sure that:

All component values are correct

Polarities from the electrolytic caps are observed

Transistor pinouts are correct

I've built just as proven, and also the instructions happen to be vetted by my assistant too, therefore we are certain that your build works if everything matches the instructions.

I Love The Actual Way It Sounds. Ok Now What?

You've gone far enough to construct it on perfboard or PCB and set it within an enclosure for gigging! Or continue below if

You're dealing with the SBE package, And therefore are sure you've wired properly, however the tone is poor.

You're moving-your-own and/or dealing with components that aren't within the package.

You need to try some mods, just like a tone stack.

It really works, However It Sounds Terrible!

If you're working in the package, this shouldn't be the situation since the components happen to be pre-selected. Look at your wiring!

Presuming there aren't any wiring errors, let us take a look at possible tweaks. In older days, Fuzz Faces were built with a deserved status to be variable in tone quality, and just what you hear might be what many guitarists heard when giving them a shot. They'd try many pedals till they found "the main one" that sounded good. Since that time, numerous those who are way smarter than I'm (Thanks, R. G. Keen, Mark Hammer, and many more!) determined how the circuit works, and the way to tweak it to ensure that every build sounds consistently good.

How Come The Fuzz Only Happen Within The Last 10% from the Rotation?

"Taper" in potentiometers may be the relationship between percent rotation and percent alternation in resistance. The 1K fuzz pot within the original Fuzz Faces was straight line taper a tenPercent alternation in rotation gives in regards to a 10% alternation in resistance. With time, numerous people observed that the audio (left-hands logarithmic) taper gave far better charge of the fuzz. However the direction of control was reversed, and thus not intuitive the finest distortion what food was in the counterclockwise finish. A pot having a reverse audio taper straightens this out, and that is what you'll get within my package. If you work with a straight line ("B") taper pot, put it back.

OK. However the Fuzz is Harsh or The Seem is Limp/Sputtery.

Normally, this is since the transistors have been in the incorrect gain buckets, not properly biased or both. Transistors are as individual as snowflakes no two are precisely alike. Even among devices that have a similar type number, an alternative in gain of three to a number of isn't unusual. The BC108, for instance, which i've seen specified by many elderly schematics for that plastic Fuzz Face, may have an increase of between 80 to in excess of 200 based on what factory managed to get so when. The issue is similar with the other NPN plastic devices which are generally substituted with it.

Without entering the mathematics that describes precisely why, apparently ,, for that standard resistor values that you'll end up finding within the Fuzz Face circuit, many people such as the resulting seem when Q1 includes a gain of roughly 70 to 90 and Q2 an increase of roughly 120 to 140. If both products are really low in gain, the circuit will probably seem lifeless if both devices have gains of countless hundred, it's prone to seem harsh. Area of the answer to getting smooth clipping in the Fuzz Face circuit is selecting transistors which are in workable gain buckets. So.

Appraise The Gains of the Devices and Understand What You've!

Today, even affordable multimeters will often have a scale for calculating transistor gain. The size is generally labeled "Hfe", and it is plug-and-play. My first setup with two 2N2222A above did not seem right, with no question one device were built with a grow in the 50s and yet another within the low 100s. This mixture can really be produced to operate, as we'll see later whenever we take a look at biasing. For the time being though, let us focus on locating a better match of gains.

The factory-specified gain range for that 2N2222A is 100 to 300 one of these simple falls in the actual middle. At low 100s, it may be used. for Q1 or Q2. For test purposes, I stuck it within the Q2 position and searched for another for Q1. Instead of looking for a 2N2222A by having an abnormally low gain, I fished for any different NPN transistor that typically runs reduced gain based on the factory specs. One which I discovered I love may be the 2N4123 I tested six samples from my stock while using gain proportions of my multi meter, plus they all measured between 80 and 90. Using the 2N4123 within the Q1 position, the circuit sounded better, but nonetheless not "right". We are dirty need to set up the bias, and I'll reach that in a moment.

Fuzz face schematic

So where do you turn if you're moving your personal? The good thing is that lots of transistor type figures works within this circuit. They're also very affordable and easily available from many sources, both local and catalog shopping. If you purchase a couple of of countless types, you'll certainly find a minimum of two devices which will work nicely together. The fundamental specs are:


  • Plastic, NPN
  • Small signal
  • low- to medium-gain, refer to it as 60 or 70 to low 200s


The part figures I would recommend are: BC108, 2N2222A, 2N3904, 2N4123, 2N4401. You will find other recommendations in the past threads at diystompboxes.com. Browse on "plastic fuzz face." For puroses of testing and setup, here are a few typical pinouts which you may encounter:

Fuzz face schematic

FAQ: Let's say I really desire to use germanium transistors?

Everything I stated above about selecting devices pertains to germanium too. However, a multi meter Hfe scale will not read germanium devices precisely. Browse the way of testing grow in my article about Fuzz Face transistors. Also remember that while NPN germanium appropriate for that Fuzz Face can be obtained, it's fairly scarce and thus costly. If you are using PNP devices, polarities of battery and electrolytic capacitors should be reversed.

Modifying The Bias

Permanently results, this circuit wants the collector of Q2 to become at approximately half the availability current, or roughly 4.5 volts. See figure 43. To create this measurement, set your meter to the low-current scale. It's not necessary to possess the guitar connected, need battery connected. Connect the gloomy from the meter anywhere on the floor bus, positive side to collector from the transistor. Figure 44 shows things i saw.

Fuzz face schematicFuzz face schematic

This really is far too low, and it is no question the seem is limp and unfocused. To place the collector current where it must be, you want to reduce the need for the 8.2K Collector load. This makes a lot of supply current to decrease over the Collector-Emitter of Q2. I began substituting standard resistor values, and Figure 45 shows what things appeared as if with 5.1K instead of the initial 8.2K.

Fuzz face schematic

If you have the bias near to 4.5 volts, try playing through circuit again. Now it may sound just like a Fuzz Face, right?

Tweaking Having a Trimpot

Sometimes you would like so that you can tweak just a little, play just a little, etc., to determine what difference a little alternation in bias makes. Trimmer potentiometers ("trimpots") are great for this. They come in a number of situation styles and an array of resistances. Figure 46 shows bottom and top views of 1 of my SKU 1015 cermet types (10K resistance) and its schematic symbol. Figure 47 shows a trimpot established to switch the resistor. When setting it up around the breadboard, it doesn't matter regardless of whether you connect with pins 1 and two or three and a pair of. Begin with the modifying screw at approximately the midway point before you apply power.

Fuzz face schematic

Some builders just tweak the trimpot till that they like the end result others connect the multi meter to determine the bias as before, set the trimpot to obtain exactly 4.5 volts, after which experiment after that. You may then appraise the resistance from the trimpot making use of your multi meter and substitute the nearest value fixed resistor, 1% tolerance if you wish to get really rectal. Or leave the trimpot in. It is your build.

One further suggestion, that one from Phil Bryant's Fuzz Central: a little capacitor, from 100 to 500 pf., between your Base and Collector of Q1 or Q2 tames raspiness but does not decrease definition. It's especially helpful when you're using high gain transistors. I am not photographing this, since you will be able to add it by yourself now.

At this time, even if you're moving-your-own, you ought to have an effect around the breadboard that is a good example to invest in solder. Now construct it on perfboard or PCB. I am intentionally stopping lacking suggesting mods, because I wish to bare this version as easy as possible. Future builds includes features just like a tone stack, pre-gain control, yet others. I think you'll have enjoyed understanding how to breadboard the Fuzz Face. Comments and suggestions are welcome at smallbearelec@ix.netcom.com.

Here's delicately to complete all things i have described, such as the Brought demo within the intro article. A package that contains all this can be obtained as SKU 0010.

Fuzz Face Germanium Transistor Shootout

  • Oqsy: GTs were my favorites.

    Transistors charge “hate cha fees”?

  • Paul B: To my ear, the ASX12D sounded the most interesting. Apparently these are NKT275 clones.
  • Zen: Interesting video, just wondering, using different transistors like that, wouldnt they sound different because of different biasing requirements?
  • jupiter moongauge: What's the point of testing a fuzz face with a guitar with shitty high output pickups ? Everything is going to sound the same because the source signal is too high and undynamic. Waste of time
  • 3jasom: I have some germanium tranzistors made by Tesla and russia. Some of them are on video. I am planning made some effects 🙂 (sorry, but my english is terrible :D)
  • Steven Griffin: I wonder if a 12 o'clock position would have been a better test than 'flat-out'… Just wondering..?
  • davidscl casares: AC125k all road
  • Super BEE: Not sure if it is the recording, but they all sound similarly shitty, sorry.
  • Britt Rossman: Thanks for the great tip re: the fargility of the GT308b. I too think they sound pretty good, so it's nice to have a heads up on being a bit more careful with them.
  • looptheloops: Almost positive that the reason they all sound relatively the same, and not that great, is because the hfe's for q1 and q2 are too close in value to one another
  • Andy Betts: I'm sure Eric Johnson could tell the difference but i could only tell a slight difference in bottom end on a couple of them…
  • Fiasco Seven: 128. fuller and more articulate.
  • Francois Dastardly: all sounds practically equal
  • JOOODYJOOODY: all equally terrible
  • Stewart Atkin: My ears have long been Marshall-mellowed but I hardly hear any difference. I have used old Japanese germaniums and they too sound pretty much alike.
  • Cass Virgillo: Hi Paul, I hope your having a good Winter, almost over, and you and yours are doing good. I know it's a 3 year old video, but, still relevant as I have been experimenting with my 7 minute Fuzz kit I got from you, working great. At some point I will get a few Ge Transistors and experiment with those. I had 3 different pedals on my bread boards, getting ready to perf one. Fun new addition to my hobby electronics range of circuits, devises. You gotta switch it up once in a while. I would really like to hear your Fender Amp sometime. Uncle Doug & Rusty, on YouTube, the best in amp videos, would too. Be good, Cheers, C.
  • Максим Мороз: 128
  • Galova: what is the real meaning of germanium transistor use? Do they behave somewhat "tube-like"? I just wonder. I have no experience with these so I wish to know
  • MrCacciLLo: I really like the sound of the AC125k | AC128 | CV5416 ,
    they all sound similar to me with a nice fat tone without being muddy.
    I didn't like at all the ASX12D | GT2308 | GT308B, sound a little bit thin and harsh ugly top end that I dont really like, sound a little bit plastic to me. I compared them by going back in the video really fast, doing A/B between the different parts.
  • Enotik Poloskun: There no ussr GT2308B transistors, i think correct name was – GT308B / ГТ308 / 1T308, radio frequency transistor (why ppl put them in audio circuits)
  • Jesse Juup: Thanks for this, very nice comparison and very clear differences between the sound of the nice germanium transistors! None is "best", they all could serve ther purpose on different material, but for guitar I would pick the AC128. Were those guitar pickups Seymoir Duncan Super Distortions? Seemed like they had crazy hot output indeed!
  • Kenny M: Very informative, I've used AC125s,  AC128s, Russian MP-25s, and Si's for Q2.  I like AC128s with about -2.5V on the collector of Q2 the best.  They also sound the best with the fuzz control at some intermediate setting.
  • ToothyGus: they all sound the same. crap
  • Pavel Himin: Help. What effect you use in intro?
  • pleximanic: Why use a high output pickup with a Fuzz Face, and a Humbucker?
  • DIY Guitar Pedals: Dam I forgot! I keep looking for uses for this garbage full of nkt275's I keep tripping over 😀
  • Jakeneverwins: Come on Paul, how could you have done this without some NTK275s!! 🙂
  • DIY Guitar Pedals: No problem Matthew, glad you liked it!
  • DIY Guitar Pedals: It benefits myself doing these comparisons as well. I can hear a direct comparison when I watch the video back. YOu have to have minor space between each sample to hear the difference. Its not the most scientific test, but a bit of fun all the same!
  • Fred Garvin: A very interesting comparison. The first I have ever seen. I gravitate towards the brighter tones myself. I'm not a fan of the muddy fuzz tones, I think the 308 was pretty nice.
  • David Robinson: Hugely greatful for the channel you have created, thank you.
  • Cortexturizer: GT2308 all the way. Best sound in my opinion and best note decay.
  • DIY Guitar Pedals: Thanks Darron! This sort of sound test definitely has to be closely spaced. Well…when the differences are subtle, I personally just cant notice the difference otherwise.
  • Darron Thornbury: i'm glad you only left a small gap between the demos, made it useful 🙂 reckon we could spend a whole day doing this so cool to condense it
  • DIY Guitar Pedals: Thanks! Glad you liked it!
  • Ariel Nonamë: very helpful videos man, very nice channel.. always grateful for your work greets from Chile
  • DIY Guitar Pedals: Thanks! The 308 is the perfect example of why hfe isnt everything, imo.
  • Aint1S: I like the 308, the tone sounds a bit fatter and more full. All would be dine, but only the 308 for my little project. Thx for a great comparison.
  • DIY Guitar Pedals: Difficult to do a controlled test for this sort of thing, but hopefully some of the tonal characteristics can be heard. The results in tone in the russian vs european in a rangemaster test video i made a few months back, were much more polarised. Anyway interesting stuff 😀
  • KyleCarrington: Thanks,, it was a cool vid. Takes a while to do these experiments and its always cool to hear someone else do something you'd also like to do, but haven't found the time for! I can hear, I would say 3 different tonalities, amongst the whole works. Thats what my ears are saying, anyway.
  • DIY Guitar Pedals: Hey Kyle. Biasing the collector on q2 at 5v's is the generally accepted way of setting up a fuzz face. q2 is the second germanium transistor in the circuit. They are PNP BJT's. Hoped you like the video!
  • KyleCarrington: They are all pretty close. When you say you biased each to 5V… are they all NPN or JFET, or? Were you dealing with gates in some cases, and bases, in others — or were they all one type of transistor. Thanks for sharing.