Step 4: Important Step: diodes!

http://www.allaboutcircuits.com/vol_3/chpt_3/1.htmlI will not go into detail with the diodes as you do not really need to know much about them other than what they do, how to connect them and some other stuff.

Diodes are used in circuits to stop electricity from flowing back into the circuit. They only let current through in one direction. The diodes in the distortion pedal are what make the distortion. Diode-clipping distortion is what this called!

There is a certain way to connect diodes. It is pretty straight foreward.
There is always some sort of line on a diode (except for LED's) but on regular diodes there is always a line. Like in the picture below on the left side of the diode is a line.

The schematic symbol for a diode is shown below:

You connect the diode with the line facing the direction the arow is pointing.

Reccomend u read this
More on diodes: http://www.allaboutcircuits.com/vol_3/chpt_3/1.html


<p>I did it, and sounds great BUT:<br>-first cap, used a 102 (0.001uF), distortion will be clear and bright<br>-gain pot didn't work there, instead I putted between emitter and ground, works great<br>-volume was low so I changed R1 for a 1.5 Mohm that had around<br>-NPN was a 8050 or S8050, diodes a pair of 1n4148</p><p>this was my first pedal and it's great for experimenting, I'll keep doing it until I have no more ideas!<br> volume pot worked until I did my gain version, if I put C2 before the output will work?</p><p>sounds nice alone in clean amp, for boosting the amps distortion is great!</p><p>P.D: if it doesn't work, try other NPN, I did it three times because the first 2 shorted or something. <br>also check if yours is ECB or EBC</p>
<p>The link to the video is broken :(</p>
<p>where do put the tone pot? can anyone suggest me please!?</p>
<p>where do put the tone pot? can anyone suggest me please!?</p>
<p>Here's a pic if anyone wants to take a gander, C1 is 100uf, C2 is 10uf, I have checked and rechecked polarities, etc.</p><p>Power supply is 6V right now, but I've tried everything from 3V to 12V. And again, a good few different diodes.</p>
<p>oh and I did have the emitter grounded, just had it removed while messing around for the picture lol</p>
<p>I've breadboarded this circuit 3 separate times, same thing each time: it lowers the strength of the signal, no distortion. When I disconnect the power source, it allows the louder, clean original signal through? </p><p>This is driving me crazy! I've also tried lowering R1 impedance, and different diodes...any idea what's going on?</p>
<p>The Youtube video is not working.</p><p>Is there a video or an audio clip somewhere where we can hear what this pedal sounds like...?</p><p>Does the type of resistor matter...? I went on eBay to order some resistors and all of a sudden I see there are a few different types of resistorrs (Carbon Film, Metal Film, Carbon Comp, Metal Oxide Film). I know from dealing with high end audio that some components (like capacitors) sound better, are more silent, and are more musical than others. Does it make any difference what kind of resistor you use in this circuit...?</p><p>How about capacitors. Are there certain capacitor types you recommend...?</p><p>I'm very interested to hear what this sounds like....</p>
<p>I have had alredy built one of these. I can tell you it will sound like a sharp low-gain distortion, down to mild overdrive. </p><p>Go for carbon/metal film resistors. Metal film are better, but they are more expensive, but as we are not working with high voltages you won't see the difference. For capacitors, im not sure, but for these circuits i think polyester are the best.</p><p>If this is your first pedal build, go for it. But if you some more specific tones, i can recomend you better ones.</p>
Thanks Miguel, <br>That's good info about the resistors and caps....<br>I'd certainly be interested in other distortion pedals...<br>I've been playing for over 40 years now, and am familiar with a lot of the brand name pro units, which is what I would be comparing the sound to, I just can't afford the price of the pedals these days, so I'd be willing to put the time and effort into building my own. So, yeah, if you know of some better sounding, more feature laden DIY boxes, I'd really appreciate if you could turn me on to them... ;-)
<p>So, i would recommend you to check these three websites:</p><p>runoffgroove.com</p><p>tonepad.com</p><p>sabrotone.com</p><p>Both have great schematics and layouts to build pro pedals. There is also the: bigmuffpage.com which is specialized only in the electro harmonix big muff Pi. It would be helpful to know your tastes so i could recommend you more specific pedals. As i am more into metal, i have more layouts of marshall, mesa boogie and other amps' preamp to use as a distortion pedal.</p>
<p>Thanks, Miguel, I'll certainly be checking those sites out. You know, I like a guitar tone that can &quot;sing&quot;, which basically means it has good sustain, so I do tend to like a compressed sound. As far as distortion goes, I like a number of types of distortion. The first being the kind of distortion that is touch sensitive, for playing blues, so when you strike the string hard, it breaks up, but when you pick softer its not hardly there. So, there's blues distortion. Then, there's the distortion that sounds like an overdriven Marshall, again, with sustain, but not harsh at all. I like a warm, tube kind of distortion. A distortion with a tone control to dial in the amount of mids and treble works best for me, as I don't like a muffled sound at all. Leslie West had a great distortion on Mississippi Queen. Randy Bachman had a great distortion, Mark Farner, Hendrix, and so on, for Classic Rock distortion. Though I tend to listen a lot more to virtuoso players now, like John Petrucci, Steve Morse, Joe Satriani, Steve Vai, Etc. and again, what all these players have in common with their tone is clarity, warmth, and sustain. So, I cover a range from Blues based, Classic Rock, into more modern progressive music. I don't do metal at all, although I'll listen to metal and especially check out the soloing. Metal technique is awesome, but it's just not what I play, ya know? I grew up in 60's, in the era of classic rock, and my ear has always been drawn to players with great technique, and while I do play blues occassionally, I'm not a 3 chord blues kind of guy, I'm more like a 12 Chord blues kind of player, as I like harmonic complexity and music that interesting, and not repetitive. </p>
<p>Then you will definitely love to build a EH Big Muff pi for your solos and some Marshall preamp for crunchy tones. These are way more complex circuits than the one in this instructable, that's why i recommend you to have some experience in soldering first. </p><p><br>Marshall JCM800: <a href="http://www.sabrotone.com/?p=1895" rel="nofollow">http://www.sabrotone.com/?p=1895</a></p><p>Big Muff: <a href="http://www.sabrotone.com/?attachment_id=4177" rel="nofollow">http://www.sabrotone.com/?attachment_id=4177</a>, <a href="http://www.kitrae.net/music/Images_Secret_Music_Page/BIG%20MUFF%20CIRCUIT%20GUIDE.pdf" rel="nofollow">http://www.kitrae.net/music/Images_Secret_Music_Pa...</a></p>
<p>To my amazement, it worked despite the fact that I used no structure and only a few wires, soldering most components directly to each other.</p>
<p>What am I doing wrong?</p>
<p>Could someone show me this project on a breadboard?</p>
<p>I made it haha This project is really simple and perfect to learn offboard wiring (for beginners) ;) </p>
<p>just find out how rectifier diodes look like, i was so wrong xD.</p>
<p>Works for me - made on a business card because no perf board available - will add a gain pot , volume pot and tone pot (I must have some knocking about .</p><p>The capacitors should be nf values not uf in my opinion.</p>
<p>actually it looks good with business card :) </p>
<p>Cheers - was fun and it works well and its still on the card</p>
Could I use a 1000uf capacitor for some super bassy sound or would that just not work?
<p>hi! with another transistor and correct resistors it works so fine on my bassline synthesizer!!! sounds so nasty!!! will build other trying some variations based on other projects ;)</p>
<p>hi! i'm trying a random transistor and no distortion, just a little less volume and bass ... trying to build with parts found in some broken hardware i have around... this will be the mission of the month :P</p>
<p>You are genius! I bought online an amplifier and it doesnt have distortion, you save with it. Its first one I can complete. The pther two diodes was my first attemp with materials I had. Dindt work, but I could listen to the radio with it.</p><p>Than you very very much.</p>
<p>What diods did you use? Will it work good with a bass guitar?</p>
<p>Different diodes will give you a slightly different sound so try what you can and choose what you like best! In other words: it doesn't matter as long as they are diodes.<br>As for using the circuit for a bass guitar, just make sure you use a large value for the input capacitor (where your guitar signal goes).<br>At the end of the day all that matters is that you like the sound; there is nothing that needs to very specifically be a certain value in the circuit. Swapping the 100k feedback resistor out for a larger one will give you more gain (equals more distortion + more volume), for instance.</p><p>I'll end with a jelly bean recommendation: go with an input capacitor larger than or equal to 10uF (whatever you can find) and use 1N4148 diodes as they are cheap and widely available.</p>
<p>hi!!! do you think that we can use speaker directly (outpout) </p>
<p>You could try it but it probably won't work very well (depending on the type of speaker you use). I would recommend adding a buffer or feeding it into an amplifier (best option).<br>Experimentation should be encouraged, however, and is the best way to find out. Just don't expect too much.</p><p>There are quite a few simple circuits to make amplifiers that can be found online that cost less than a buck in parts. Look on google for the smokey or noisey cricket amplifier.</p>
<p>what is the Wattage of the resistors?and the voltage of the capacitors?</p>
<p>This is a low power circuit so you can just use standard 1/4 Watt resistors. 1/8 Watt resistors would be fine too but are a bit less commonly used. For the capacitors; your power supply is 9V so anything above that will be fine. Electrolytics usually come in 15, 25, 35 and 50 Volt variations so you will be safe either way. For most other types of capacitors (particularly the low values) the voltage ratings usually start at 50V.</p>
How would you add a tone pot ? Would you use a variable capacitor for c1?
<p>Jack Orman has a page on the tone circuit inside a big muff pi:</p><p><a href="http://www.muzique.com/lab/dtone.htm" rel="nofollow">http://www.muzique.com/lab/dtone.htm</a></p><p>If you want a foolproof circuit just build that one, if you are a bit more experimental just look around at schematics for different effect pedals and copy/modify their tone circuitry.<br>Variable capacitors are somewhat expensive and generally not supplied in convenient-to-use packages. (Not to mention they are usually only available in the pF to low nF range) This is why variable resistors (potentiometers) are usually used.<br></p>
Will a 10k ohm linear work for distortion knob
<p>A 10k pot will work but it will give you a little less volume on the lower distortion settings. As for using it for bass, I'm sure it will work to an extent. In the end it's all about what you like so try it! If it doesn't sound good to you just add some filtering.<br>A tip you could probably use off the bat is to increase the capacitance (value) of the input capacitor as doing so will allow lower frequencies to pass more. Another useful idea is to use sockets instead of permanently mounting components so you can toy around with some values. This would be an alternative to using a breadboard (which I'm going to assume you don't have).<br>Hope that helps!</p>
<p>Hey Guys! So I decided to make this my first project and it came out sounding amazing! Here's my layout if you want to use it! Thanks for this awesome Tutorial!</p>
<p>Would be really helpful if someone could show me how to connect the Indication LED please :) Thanks</p>
<p>To add a power indication LED just put an LED in series with a resistor across the battery. You can determine the resistor value you need by using:<br>(Vsupply-Vled)/0.020<br>If you find the LED is too bright, just use 0.010 instead of 0.020; LEDs are bright these days! Oh yes, just some very approximate common forward voltages of LEDs (Vled):<br>Red - 1.5V<br>Blue - 3V<br>Green - 1.5V<br>Yellow - 1.5V<br><br>Please not these values are just vanilla values that will work and might be out by hundreds of millivolts, but they will get you on the way without needing you to know much (LEDs don't actually have a &quot;forward voltage&quot;, this is just a value we use to characterize the LED in it's linear-ish region where it's usually used).</p>
<p>I made mine, and it works. made it with 1n4007 diods, 47nF as 1c and 1m for 1r. but I can't get the distortion potentiometer work:/ great distortion, but I can't control it. anyone has the idea why? </p>
<p>okay, made another one and it works great! </p>
I tried this project 4 different times already using store bought stuff and stuff I pulled from a old radio and not one of the builds have yet to make any distortion ...lol First I used the 2n3904 with all the resistors and caps as in the schem..Lined up everything as shown and nothing only fart sounds as if a battery was drained tried a different battery tested the other and still the same even though both batts was tested on multimeter and shown good . I then tried adding a series of different resisters 100k then 220k with a few odds and ends together that could wrap around the sun 2 times ...lol They brought up the volume when the battery was connected but still no distortion . I have tried assorted diodes from radioshack ones pulled from a old stereo ...2 different sets of leds and yet no distortion . I did the no pots then tried the pots schematic then scrapped the 2n3904 and found a old transistor marked d1387 and I still get no distortion it will push a tiny bit of distortion out but only because its very bass heavy I used a cap marked 184k for c1 in my search to get this thing working
Try raising the impedance of r1
thanks man it works great!!<br>I put a 1uF capacitor instead of the 100uF and<br>a 4.7MOhm resistor for ultra gain
<p>can you tell me wich components did you use?</p>
<p>Sure: I used the same circuit as the one above but I added a third diode, I put a 2,2 MOhm resistor as R1 to get a lot of distortion and replaced C1 for a 47nF capacitor. I tried several diodes and found out that the best sounding combination was these three diodes in parallel and inverting their &quot;polarity&quot;: 1N4003 (or 1N4001), 1N5819, 1N4003 (or 1N4001). By inverting the polarity I mean that, just like in the diagram above, every diode's mark (the little line thy have) should be facing away from the marks of the diodes on their sides. I hope I explained it decently.</p>
Would the middle diode have the line up or the line down?
<p>Oh and I did all this because the distortion coming out of the pedal above was too little and it didn't sound great..:)</p>

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