"Me am play 'Rain Song' again, okay?"
Here are the instructions for Part 2 of our first DIY Club project: building a bad-ass distortion pedal.
Not to spoil any surprises, but in this installment, we take the loud, raw sound we arrived at in Project 1, Part 1:
…and refine it by adding diode distortion, and customizing it to taste. Here are four possible results:
We’ll also add a variable gain control:
…plus a master volume. Along the way, you’ll encounter cool tricks, wicked sounds, boring theory, and a friendly but foul-smelling sasquatch who can play most of Led Zeppelin’s “Rain Song.” And only one of these statements is a lie!
Joe,
I’m finally getting chance to go after part 2. The Diodes and the gain pot sure calm this thing down. I think I found an error in the instructions. You have us put black wires on lugs 1 and 2 on the C10k pot. But on the installation page you reference the white wire on lug one.
LOL — you only found ONE error?!
You are absolutely right, of course. The reference of page 14 of the PDF should have said “Connect lug 3’s white wire to the transistor’s emitter.” It’s fixed now. 🙂
I only want to report one error at a time. I don’t want to pile on.
thanks joe, for what so far is a really informative and thourough introduction to this (what i think) is an extremely interesting and rewarding subject.. especially for gear techs like me 🙂 sometimes going back to basics reveals new insights, which is where all this is benefiting me (and no doubt, everyone else) the most.
questions – the step between distortion and fuzz is fairly minimal, will there be a fuzz project? and you mentioned the uglyface before, is that later on in your evil plans for us?
great work man, loving it
LOL — the difference between distortion and fuzz can be minimal, but not in this case!
No Uglyface this time, though now that you mention it, it WOULD be a cool build. But the fuzz we’re do is a variant on a popular DIY design often called the Bazz Fuss. I don’t believe it’s available commercially. It’s an extreme, fat, modern-sounding fuzz, and you will definitely hear a difference compared to Project 1!
So I’m pulling my hair out trying to figure out why my gain pot doesn’t do anything. I put a meter across the lugs. 10 K from 1 to 3. 1 to 2 open. 2 to 3 open. Seems I’ve got a big pretty 10 k resistor. The guy in Beijing forgot to connect the wiper. Guess it’s time to run to Rat Shack!!
Yeah, I think it’s my fault. I said these components almost never fail, so naturally they do. 😉
Ok,
I’ll blame you.
I have not started on the diode modes but looking forward to messing with it.
It’s the FUN part! 🙂
Question: Joe how do you think old strings affect the guitar tone? How often do you change strings? Do you use any string cleaner product?
If your sound sound dull change them. I would change them instead of just trying to clean them. strings are nto that much.
Awesome question — that I can’t really answer! : )
When I was young, I totally fetishized fresh strings. I’d change them every couple of days, usually with money begged from my folks. Then when I was in my 20s, I started playing with a lot of African guys, and I’d hear all those stories about players from that part of the world tying knots in broken strings to extend their life, or unravelling bike cables for strings, and since then, it’s always felt uncomfortably decadent to change them that often. But yeah, I probably ask my tech to change them every other show when I’m on tour.
But when I’m not on the road, I can play the same set of string on a guitar for months and months. Or years, in the case of bass strings. But bear in mind that 1) aesthetically, I just sort of like the darker sound of older strings, 2) I only use a pick about 10% of the time, so strings don’t wear as quickly, and 3) I’d way rather record with a set of strings that’s too old than one that’s too new.
It’s a funny coincidence that you asked about string cleaners, because I JUST bought a can of that GHS Fast Fret stuff, which I used to use DECADES ago. It seems to work pretty well. Though a lot of times, I just grab a microfiber cloth (got tons of them around for cleaning iCrap) and give the strings a rub. But most of the time, I just play the filthy strings and don’t think about it much. 🙂
Great answer Joe. I ordered the GHS Fast Fret when I wrote my comment too 😛 Coincidence? I recorded an album 2 weeks ago, and when I picked the guitar and recorded a new song after some days the sound were pretty different in a bad way. Maybe I should try coated strings. They say they last longer.
I use Cleartones and they last a lot longer sounding “new” but of course at 13 bucks a pack they damn well better!
Finished this part last night. It was fun! I feel like a mad scientist.
My 9-year old son and I disagreed on which transistor to go with, but we went with my choice, the one in the original design.
I’ll help him build his own pedals soon, so he can have exactly what he wants (and so he’ll leave my stuff alone). 🙂
Joe, these step-by-step instructions are great, and really lessen the intimidation factor of doing this for someone who’s not handy at all.
I might be beating Joe to the punch, but which transistor did your son like?
Whatever it was, he was right. 😉
lol, he wanted the most distorted one, of course.
After he gets his own guitar for x-mas, then we’ll work on owning HIS tone.
Re: string cleaners and whatnots, I used to go through strings waaaaay too often- I dunno if my hand sweat was just super-caustic or what, but yuck.
What I started doing- and continue to do since it works so well- is to spray a little Caig DeOxit DN5 contact cleaner on a rag and pull the strings through a time or two before I put ’em on. This seems to keep them from corroding for a really long time. Added bonus is that they retain just enough of that “new string feeling” well after they’re broken in to my satisfaction, without being painfully bright. And of course, a can lasts a loooooong time and this stuff rules for cleaning pots, switches, etc. One of my favorite tricks, but be sure to turn the nozzle to the “low” setting before spraying, and only do so in a well-ventilated area- whatever magical juice D5 is made of can’t be good for you.
Really cool tip, el reclusa. Thanks for the share. I’m gonna try that, especially after having been a slave to Finger-Sleaze for the last few years.
Try the Graphtech Preplay hand conditioner it helps a ton, my bass player swears by the stuff. Made for evil yucky hand issues !
Hi Joe. When can we expect Part 3?
Hi! Hope to finish it up over the weekend. 🙂
My pleasure, BroKen. I like that the D5 works so well, but doesn’t leave anything behind that you can feel ten minutes after you’ve applied it. I’m telling you, that stuff is MAGIC IN A CAN!
playing catch up – any aussies (like me) keen on kicking on with these awesome projects, but still need bits, i’ve done some research into local suppliers that we can order components from.
locally, we have a ‘radio shack’ like supplier, called Jaycar (jaycar.com.au), that can provide most things, various dpdt, tpdt, LED’s, all sorts of values and sizes of ‘alpha’ brand pots, aluminium enclosures, breadboards, pcb materials, and a limited range of diodes, capacitors and resistors necessary to gather most of the items stated in Joe’s shopping list in his initial entry about the projects. Be aware though – pricing is quite high on some items, especially switches ($12aus for a 3dpdt stomp switch, for example).
Dick Smith Electronics have less range (even though they promote themselves as an electronics superstore), and pricing is similar to Jaycar (dicksmith.com.au).
In the direct guitar parts related dealers, the only one out of all I have found anywhere close to being helpful (outside of general guitar accessories and retail items) is Tym Guitars in Brisbane (tymguitars.com.au). Some great gear and prices, and I am going to hit him up to see if he’ll share a couple of his local suppliers (for the purposes of our projects – keep you updated).
FutureLec (futurelec.com) is a much faster option here than with the US, especially since FutureLec has 2 suppliers here in Aus, so we can get bits much faster.
Pedal Parts Australia (pedalpartsaustralia.com) has a growing but at the moment limited supply of various shopping list components.
I’ve found there is barely a handful of ‘commercial boutique’ pedal builders here in Aus, so there isn’t a lot going on, and suppliers a few. I’ve also found getting specific values of ic’s, germanium diodes, and certain types of capacitors/resistors difficult to come by (quickly I mean – of course, we can order from the US, but it takes weeks to arrive).
If anyone else local wants to share suppliers, help a brother out!
btw Joe – ever tried soldering on a bouncy castle? 😀
not to spam the comments, but the other local pedal builders (actually selling items) are (as previously referenced) Tym Guitars (tymguitars.com.au) in Brisbane (specialty is Fuzz – big Dinosaur Jr. fan), Toy Room Effects (toyroomguitareffects.com) in Sydney, and CubistEffects (cubisteffects.com – more guitar pedal mods and circuit bending though).
Know anyone else? I hit forums across a wide range of guitar tech and building related site here, and I have found very few people interested in pedal building.
On (i promise) one last note – I just signed up at https://www.guitarpcb.com/ – there seems to be a rich community there for people to engage with beyond Joe’s projects, for those with the thirst for more knowledge!
Hi, Dr. Soda — thanks for all your great comments,
I haven’t tried the Guitar PCB stuff myself, but I hear great things about it. As mentioned previously, I’m a great fan of the BYOC projects too.
Hehe — haven’t tried soldering in a bouncy castle, but I HAVE had my eye on a butane-powered iron, so I can solder outside on the one or two days per year when the weather here in San Francisco is nice enough. 🙂
Joe, I have been working on part 2. I have noticed that I get a lot of interfeance or what could be called a load hum, while the circut is engaged.
I have tried the 2N3904 and the 2N5088. I have also tried a couple of diodes. I noticed the glassiness of the LED. and I am trying three diodes. However, it is hard to hear the difference with the load hum not playing the guitar. I’m running the circut through my IKMedia Amplitube 3 software. Could it be because it is not in a case?
Actually, I think Suspect #1 is the proximity to your computer monitor. Can you move the two further apart and see if that helps?
I’d also double-check the ground connections on you input and output jacks.
Finally, try putting a 22uF cap with its long leg on the positive bus, and its short leg on the negative. (You may need a jumper cable, depending how you’ve laid out your breadboard.)
Any of that make a difference?
well it was not the computer monitor. You guys are going to laugh very hard.
The problem was I had the jacks wired with black going to the tip and white to the ground. I had the signal going in through the ground!
I have reversed the wires and it is sounding a lot better.
It takes a lot more than that to get me to laugh! I generally don’t start smiling till the emergency sprinklers go off.
I screwed up and bought a linear taper 10K pot to replace my bad gain pot. So now all the dirt is in the last 1/8th of a turn of the knob. I found this article on pots by RG Keen. He talks about using a tapering resistor. My coffee hasn’t kicked in yet. Will throwing one of these across the lugs save me a trip to rat shack?
https://www.geofex.com/Article_Folders/potsecrets/potscret.htm
Thanks,
Swen
As screw-ups go, that one is pretty minor. In fact. most of the commercial pedals based on the circuit use the linear pot, and I’d even suggested that as an alternate in my plans.
But yes, as you’ve seen for yourself, the reverse-taper, C-series pot just seems to distribute more of the tones you’ll want more evenly across its range.
The only problem with reverse-taper pots is, they can be really, really hard to find! You definitely won’t encounter any at Radio Shack, and even giant suppliers like Mouser don’t carry them. The only reliable sources are the stompbox specialists like Mammoth and Small Bear. Also, until recently, they cost several times the price of other comparable pots, though Mammoth now sells them for the same prices as A- and B-series pots. Hurray!
Yes, you can try some of the taper tricks in the Keen article, though even THINKING about thinking about the math makes my little brain hurt. I experimented a bit with these when I first started building, but don’t anymore, thanks to the relatively ready availability of reverse-taper pots. If you’re altering the taper with resistors, you generally need to start with a higher-value pot than your target range. I don’t believe you can convert a B10K pot into a workalike for a C10K. (Correct me if I’m wrong on this, math-and-science people!)
I say go with the B10Ks, and order some C10Ks. It’s easy to swap it out later.
Thanks Joe,
Keen gives a formula to pick different log tapers. I think I’ll start with a 1.5k and play with it from there. I’ll let you know what kind of results I get.
here’s a link to a soundclip of the circuit … ( if the link doesn’t show up, can someone tell me how to post the link ? thanks … )
https://soundclick.com/share.cfm?id=11146630
i used germanium diodes and a 47nF input cap … 1st chorus: straight guitar, no effect … 2nd and 3rd chorus: distortion with low gain … 3rd chorus overdub: distortion with high gain …
Ooh, that’s so cool! Thanks for posting. I totally encourage anyone to post audio links, anytime! 🙂
I came across the schematic for the Beavis Trotsky. A single transistor OD with diode clipping, very similar to our circuit. But on the Trotsky the gain pot is on the collector side rather than the emitter side. Since we’re controlling the EC voltage with the gain pot does it make any difference where you place the Pot?
Oops. Here’s a link to the schematic.
https://www.beavisaudio.com/projects/TrotskyDrive/Trotsky_Build_Guide_1_5.pdf
I’ve built a few Trotsky Drives. They sound fab. I suggest breadboarding, and seeing whether you prefer it to the circuit we’ve been working on.
hi joe, big fan, used to read ya in gp back in the day…
definitely reccomend building the uglyface…i think you can handle it.
😉
but…if you do, i reccomend building the variant with the lfo in it..much more versatile. check https://diystompboxes.com for various layouts, including the vero version i built.
here’s a youtube: https://www.youtube.com/watch?v=DeD1jQ3Cu_s
Oh, I’ve built a half-dozen or so, with and without the LFO mod. Yes, a cool addition, especially if you’re into using the pedal in self-oscillation mode.
Hey, I love the circuit. I put in a 3rd diode. Not sure what it is but it tightened up the distortion a bunch. Made it really smooth.
What I was wondering is, how can I add a tone circuit? I tried to add in the tone circuit from the Fuzz project but it doesn’t seem to be making a huge change. Or am I asking too much from this project?
Hey Derick — so glad you’re digging it! The diode thing is kind of a mystery. Despite what anyone claims, I think most designers don’t really know exactly how a particular diode combo will work till they try it out. There are few generalities (germanium = softer, LED = crunchier), but you just have to experiment. Like you did!
Okay, tone stacks (that’s what they call the tone control section of a circuit) are a pretty huge topic, and one about which I’m extremely biased (no pun intended). So prepare for a very personal rant…
I think most stompbox tone controls sounds really crappy. That’s because use a passive tone control that robs the signal of volume, then add an additional transistor stage to make up for the lost signal. To my ear, almost any distortion pedal sounds better when you strip out the tone stack, especially in circuits that use discrete transistors, as opposed to op amps. A lot of people disagree with me, but my take is, if you want to modify the tone, start with your fingers or pick, then your pickup selection, then your amp setting, then post-amp EQ. 🙂
Another alternative is to add an active tone control — that is, a more complex circuit with an integrated boost. This sometimes sounds a bit better.
It’s a matter of taste, obviously. But I prefer getting tone adjustments by other means, such as varying the voltages to the transistors, or filtering the signal on the input before it hits the first transistor. (These methods are used in Project 2.)
But a great way to learn how a typical tone control works is to build a Big Muff kit. That’s a good example of the “cut the signal, then boost it again” approach. But even here, I think the circuit sounds better if you nix the tone control.
Here’s a test: Compare the pedal you just built to some fave distortion pedals. If the one you made seems livelier, more dynamic, and just more exciting than the others, you’re hearing exactly what I’m talking about. If the tone-control pedals sound as good as or better than the one you built, you can officially consider me full of crap. 🙂
Thanks for the reply!
The control that I added from project 2 sounds like more of a bass boost. It’s nice, I was just hoping for a little more control on the high end. I would like to make the pedal a bit brighter.
Interestingly enough, I just got a Suhr Riot in the mail today and tried it out. The tone control adds body and brightness to the tone.
I understand what you are saying though. I am all about changing the tone of everything else before messing with effects tone. That’s one of the reasons that I don’t have an on-board eq. I have something like 8 pedals on my board and use small tone adjustments to make them play nicely together.
Yeah, the Riot is a real cool pedal. It’s a derivative of the Marshall Guv’nor pedal, and uses a pair is op amps. For whatever reasons, I find the tone controls less problematic in circuits of these types. Again, just me and my crank ideas.
Oh — and Madbean makes a PCB clone of the Riot called the Uproar. This PDF includes a schematic, if you want to see what makes it tick: https://www.madbeanpedals.com/projects/Uproar/docs/Uproar.pdf
I just looked up a schematic for a big muff. I see what you are saying and actually did try that with this pedal last night as I was trying to find something… it sucked. I think I’m going to mess with the diodes a bit more and see if that doesn’t make a difference. Perhaps I’ll try adding a 4th as an led then put the pot between it and the others… I love this trial and error stuff.
Hehe — check out the front page for a cool diode trick.
Oh — and it would be super-cool if you shared the results of your diode experiments. Just sayin’. 🙂
I ended up doing the tone control from project 2 but I moved it to the output cap. It’s more of a body control than a tone control but I like it. I used a 102 and a 104 cap for it. I tried adjusting the diodes but everything I did differently only made for a more dirty distortion. I really like the smooth sound I’m getting so I left diode changes out.
Thanks again!
Hey, I noticed that Project 2 has a Diode from the + bus to ground and also has a resistor from the audio in to ground. Should this project have those as well?
Yeah, that might be a good idea. But probably not essential. The resistor is to prevent switch popping, and sometimes makes a difference. The diode is to guard against damage in case you plug the wrong of power supply into the pedal. (The diode fries, instead of the whole circuit.) I usually put both components into all builds, unless I, like, forget, or don’t feel like it.
I put them in. Wired up the box yesterday. This thing is BEASTLY! Can’t wait to move on to project 2!
So glad you dig it. It sounds like a cliché, but it tends to be true: Simple guitar circuits usually sound the best. 🙂
Hey
So, I was trying to figure out in my head how, conceptually, the diode part of the circuit actually works.. I mean, just putting diodes between the signal and ground looks like a short circuit.. Anyway, after a tiny bit of searching I came across this article:
https://www.instructables.com/id/Add-Diode-Clipping-Distortion-to-your-Guitar-Amp/
Thought it might be useful for people. So, essentially all diodes (unlike the perfect model of a diode I had in my head) have a forward voltage that needs to be reached before it will start conducting. This results in only the peaks of the signal being clipped, giving the distortion. Awesome.
Anyway, thought it’s worth reading, because that part of the circuit was bothering me.
Thanks for these Joe!
Hi all! I just got part 1 together and working nicely. Don’t know if any sound improvements are even needed! I got stuck on part 2 with the diodes, and was going to ask for advice here, but I just figured out my problem: I was connecting the diodes *before* the output cap, and not *after* the output cap. (I had tried a LED during my experimentations, and the LED lit up. So of course, it was getting DC, meaning it was before the cap!). Now I’ll have to go back and try the diodes after the output cap.
But, it’s worth noting that I stumbled upon a cool “fuzz” this way (it was some combination and orientation of 2 diodes before the output cap). The main problems are that you need to turn your guitar and amp way up in order to hear it, and it kind of lacks sustain. But it’s a wicked fuzz! Maybe it you take that weak “fuzz” signal and then amplify it with another transistor circuit, you’d gain a cool fuzz pedal.
I couldn’t decide if liked the sound better with or without the diodes. Each one is great: Without them, a nice boost that really enhanced the tone of my guitar. With them, a distortion that when dialed back is very touch sensitive. So in the end, I built my pedal with the toggle switch that was supplied with the kit, to bring the diodes in and out. I left them connected to ground, and the toggle switch connects them to the output signal. I just had to drill an extra hole to accommodate the switch, but I got a couple of new drill bits at the hardware store and it was no problem even with just using my hand hell drill. I used a slow setting on the drill, drilled a smaller pilot hole first, and then enlarged it enough to accommodate the switch.
That makes me happy! That’s EXACTLY the build-to-taste attitude that I hope these projects inspire. Well done!
One thing I noticed with my switch for the diodes: When the master volume is turned down, there is almost no difference between having the diodes on or off. As the master volume is turned up, the effect of the diodes becomes more and more noticeable. Is this a limitation of the circuit? And how could it be solved (guess: after the clipping stage, add another gain stage, and then then the volume control)?
Yes, but . . . (and this is very much my subjective opinion) . . .
I’ve really soured on the methodology of adding make-up gain stages in overdrive and fuzz pedals. Obviously, many disagree with me, since it’s a very common method. But to my ear, it takes away way too much of the immediacy and exciting “crackle” of these sorts of effects.
Since the master volume is downstream from the diodes, it theoretically has no effect on how they behave. But clearly, with your particular amp and settings, it’s clearly altering the response.
If I were building one of these for my personal use, I would a) add a diode-changing switch rather than a diode-nixing switch, and b) omit the master volume and control the level from the guitar.
Hi Joe,
Thanks so much for taking the time to teach us all dummies the magic of electronics. After having read the first part, I couldn’t find the link to the second part of the article anywhere.
Any help?
thanks
The reason the volume control behaves the way Yonatan describes it comes basically as a result of the clipping effect the diodes have on the signal. Without the diodes, you have full signal. But when you add the diodes, they chop off (“clip”) the peaks of the signal waveform. Basically, you have less signal to amplify.
The difference in signal voltage isn’t huge, and when you subject both conditions diodes on / diodes off) to a large amount of resistance by turning the volume pot down, the effect on the output is pretty much the same. But as you decrease resistance by turning the volume up, that tiny difference in signal voltage becomes more and more apparent.
It’s kind of like noticing the age difference between a couple of eighty-somethings versus a couple of kids. There are noticeable differences between newborns and 5-year olds. A couple of old people, not so much.
Yikes… I didn’t notice how late to the party I was until just now. 😛
The DIY party NEVER ends. 😉
This may have already been addressed but i don’t like to read a lot so…. Where would a tone pot go into this circuit? :shiftyeyes:
Or any circuit like drive or boost?
Well, not to start a big tech argument, but one reason this circuit sounds good is because it doesn’t HAVE a tone control. The most common way to add one is to stick a passive filter at the end of the circuit, and then add ANOTHER boost stage to make up for the lost sound. That’s how a Big Muff works for example — though some players, including me, prefer a streamlined circuit without a tone control.
This is 100% subjective, but . . . your best tone controls are your pick and fingers. Next best are your amp and mixer settings. Adding a crappy little tone control to an overdrive pedal is a distant third-best.
As if there were any doubt, I’m being an opinionated crank here. 🙂
++++!!!!!!
Ok. I am going to build the cicuit but I was just curious how tto do it for further tweakability and experimentation. When you say “passive filter” what are you referring to? I assumed that a tone control was simply a variable resistor/pot in place of a fixed value resistor at a crucial point in the circuit. I must be over-thinking it…..or am I under-thinking it? :cuckoo:
Just a little…
You need to add a capacitor. Simple filters like these are usually capacitor/resistor networks, with, as you correctly note, the tone pot working as a variable resistor. It’s called a passive circuit because it has no battery. (The pedal has a battery, but the filters in question don’t draw current from it.) And it cuts a LOT of gain and impact from the signal — which is why these are often followed by a boost stage.
These images may help you understand it.
It’s starting to make sense…i suppose from here on out, experimentation shall become my teacher! Thanks!
Cool. And really, use your ears, which is something a shockingly large number of engineers fail to do. If it sounds good and there’s no smoke coming out of it, it’s probably just fine.
Seriously: Get a breadboard and try out this circuit. Then add a tone control before the last capacitor in the circuit, and see what YOU think. If you’re playing real high-gain pickups, for example, maybe the volume drop won’t bug you. (I pretty much always use vintage-output pickups, unless the guitar is pink and has Hello Kitty! on it.)
:satansmoking:
Well joe, you were right! The tone control circuit did kill my gain. I built the circuit and with the gain at max with no control it sounded more like a fuzz on the low end. There was a lot of compression and heavy sag when digging into the low E. once I added the gain control(I used a B10K) i was able to get a desirable sound to my ear. I like the 2N3904 for it’s brighter tone. I also added a combo of two diodes and two LED’s one LED in series with each diode to ground and it sounds great. I also added a 5k resistor in series with my gain pot to contain the max level of gain to stay away from the woofyness! It sounds more like a good boost/overdrive now…which is what i like.
The tone circuit worked but all it really did was roll off the treble and kill my gain. How do I brighten up the circuit(add high end)? I like it a little bright for the praise and worship stuff that I play. If I change to a lower value cap on the input would that brighten things up? Would that work in the tone circuit if I were to lower the value of the cap that is tied to ground?
Sounds like a very cool pedal! Don’t suppose you could share any audio clips? 🙂
Hmm — I’m thinking you may end up with something a lot more like a Muff. You’re heading in that direction already with your diodes. That circuit has a dramatic tone control (a super-scooped curve that’s defined bedroom punk and adolescent metal since the ’70s). Then there’s a fourth-transistor boost to restore the level lost in the EQ stage.
Even if you covered up the words “Big Muff Pi” with tape, that pedal may be too nasty for the gig. But I’m wondering . . . has anyone ever done anything like a lower-gain version of a Muff? With or without a re-voiced tone stack? I’m not up on the last few years’ worth of Electro-Harmonix stuff. Do they do anything like that?
Just finished up Part 2 this evening, and I must say I have enjoyed the education and creation process more than I anticipated. Everything seems to be working well, although I do have some noticeable hum coming through wih the circuit engaged. I’ll have to check my grounds, although I am using a rather noisy guitar and a not ideal bass amp for testing, so that may not be helping matters.
Thanks again for the great material!
Yay! I’m so glad it’s working. One quick thing to try: if you’re using a power supply rather than batteries either with the breadboard or stompbox build, try switching to battery power, and see if it’s quieter.
Hi, Joe. I am having a problem with my diodes. No matter how I arrange them or what kind I use, they are having absolutely no effect on the sound of the pedal. The only thing I did differently than you is use a stereo inout instead of mono. Any ideas what could be wrong?
I’m having the same issue. Even orienting them incorrectly doesn’t kill the signal as the pdf describes. Any ideas? It does sound pretty wicked without diodes though!
Same problem here. Diodes don’t seem to have any affect for me. I’ve gone through the part one several times now to see if I made a mistake, which I’m still assuming I did, but I can’t find any errors.
Added a pic of my layout.
Rick,
Any diode will only have an obvious effect if the signal level across the diode is larger than the diodes forward voltage drop. For silicon diodes this voltage drop is often taken to be 0.6 volts and for germanium around 0.3 to 0.4 volts. This means that for a pair of back to back silicon diodes the peak to peak signal swing must exceed 1.2 volts for any effect to be heard.
The possibilities are that either the preceding transistor circuit is not working correctly and therefore not producing enough signal across the diodes, or you are running into a very low impedance audio input. This would load the signal and could cause it to be reduced below the level where the diodes have any effect.
Most (not all) guitar amplifiers have a 1 Megohm input impedance. Other audio amplifiers can have much lower input impedance’s.
Wow- what a great pedal! After a year or so of hemming and hawing I finally took the plunge and ordered the 1st three projects. I finished the 1st one and I have learned a lot- most notably that I need glasses. I also became better at reading schematics, and knowing what these components do. I had issues in part 1 when I didn’t remove the jumper that was installed on page 12. Once I took that out it roared! I recorded a tune:
https://soundcloud.com/user-655467882/bumpkin
This is without any mods, all I did was roll the gain back a bit. I will post other versions of the same song with some of the mods just to compare, but I am going to live with it the way it before a mod it and box it up.
Skot, I can’t tell how delighted I am to hear that. (Sorry for the slow-ass reply. I was traveling.) Your tune sounds awesome — thanks for sharing. It’s so cool, getting to hear how something I soldered together on my filthy workbench winds up inspiring another player! 🙂
No worries at all about the late reply- I know you are a busy guy. I will say, that after boxing this pedal up, I like it all the more. It looks like I stuffed an ostrich nest inside this tiny box, but it worked on the first try, which is amazing! I hope to do a cleaner job next time, now that I know a bit more what I am doing. I don’t have a need for a “distortion” box, but this thing works great as a boost- it has plenty of volume, and as a great overdrive. It kicks a tube amp already on the edge of breakup, into awesome, dynamic overdrive. And even more important- I tend to play very quietly , while my family is sleeping early in the morning- and this pedal is able to approximate the sound of a tube amp overdriving so much better than any other pedal- most notably tube screamer types, than I have played. That has always been difficult: getting that tube amp breakup sound at low volumes, or on a clean amp. I like tube screamer types for pushing an already overdriven amp, but to make that sound from the pedal, has always sucked (for me)- too nasally and thin. I can’t wait to box up the bazz fuzz, and go to town on the other projects. I have really learned a lot- I breadboarded the circuit, took it apart, did it again, and then attempted to do it by only reading the schematic, in which I was successful. The I moved on to the fuzz project, only using the schematic, and checking my work according to your instructions after. Very cool stuff you have given us!
How exciting is that!?! My pair of diodes for tonight is 1N4007 (cathode into ground) and 1N34A (anode into ground), plenty of gain… Playing with these diodes is not a game for the indecisive…
Hee hee. I beg to differ, Jakub! My Gross Distortion pedal incorporates 25 diodes for 158 possible combinations. It’s hard to get more indecisive than that! 🙂
Having said that, I think you’ve selected a great-sounding pair of clipping diodes. I predict fine results from that mixed pair of silicon and germanium diodes. Let me know how it goes! 🙂
Joe, that truly has to be tweaker’s delight!
I ended up with 1N4001 and 1N34A. I have no idea whether it sounds different than the pair including 1N4007 and 1N34A, it’s a bit like smelling perfume samples, after a few I’m confused. But this must remain the choice for now. The impression I have is that if I use 1N34A in my pair, the sound is more distinct than in any other combination of two diodes (I tried). Otherwise, the difference can be really subtle, but my perception may be affected by number of factors: really quiet bedroom amp, or using headphones from the amp or into old POD XT.
At some point I recalled I want to check what the regular 3mm red LED will sound like paired with silicon diode, and I have to say that — apart from the fact it lit up nicely when the signal flows through it — the sound seems to stay unaltered when compared to one without a pair of clipping diodes.
I am thinking of having two pairs of diodes or one plus mode without diodes and switching between them… I have no idea how to do it… yet! I haven’t used higher gain pedals for so long that I also installed 2N5088… out of urge for noise 🙂
Thanks for this AWESOME tutorial, moving on to part three!
Thanks! I’m delighted you found the info useful!
In my experiences, all the 1N400x-series diodes sound about the same. If you want to push the gain even further, try a 2N5089 transistor, or an MPSA18.
My first ever pedal attempt. So far at the breadboard stage. I love the “chewy” sound it gets! 😀
https://www.youtube.com/watch?v=ycHZJuSiY7k
Congrats! I love the camera angle, through the components. 🙂
Thanks – totally by accident – but it does look cool 🙂
Hi Joe, thanks for putting together these articles. They are great!
I”m working on step 2 for this layout. I’ve got the loud, violent distortion going just fine but when I add in the diodes, nothing changes. I made sure they are oriented correctly and I tried the other possible combinations, but nothing changes. Any suggestions? I suspect that there is something obvious that I am doing wrong here.
Thanks
Dylan
Portland, OR
Just an update – I was having issues getting the diodes to work. I found out that it was a breadboard issue – I was working with the diodes at the other end of the breadboard, and on my breadboard the busses aren’t connected along the whole board. I jumpered the negative bus to connect the two halves of the bus and voila, diodes were a go! This was a while back, and I just built it up on the board and tested it out – works perfectly and sounds great. Thanks Joe!
built it up on the perfboard, that is.