/diy/ - Do It Yourself

>>803704
Oh shiz, you're totally right, they're facing opposite directions. I must've missed that. (I was probably drinking and working at my breadboard again.)

Anyways, those clip both sides of the signal, provided you use the same diode type for both diodes it will clip both sides (which you already know.) If you're the anon studying that guide, have you built it yet?

>>802900
Wow, that sounds pretty damn good for a noisy 386. I usually use LM358's because they've got a lower THD (I think) but considering how well that came out, that makes me rethink the 386. If you end up building one, be sure to share pictures and audio tests!

>>802462
Oh it's much more simple than you think actually: The zener is to limit incoming voltage from an AC/DC adapter, not a 9V battery. You wouldn't have any crazy voltage spikes from a battery, but an unreliable AC supply and a less-than-perfect AC/DC wall-wort could end up passing a surge into the pedals' voltage supply, possibly fucking it up. So, hopefully, the zener plus capacitors (which you wonderfully clarified for me, very sharp thinking anon) can mitigate any damage.

>pic is my last breadboard build of >>801753, the project I am currently working on.

>>802183
BTW, in this picture the diode is facing ground, in your PDF the diode is facing the signal, so if you built it as your schematic shows, it would clip the "bottom" half of the wave instead of the top half.

>>802059
Heyo, you guessed it, the Zener diode is there to catch any excessive voltage, which is a rare occurrence with nicely made power supplies, but in the event of a slight ripple, it would prevent anything serious from happening.

As for the capacitors, to the best of my understanding, those exist for the same purpose. If you take them out of the schematic you'll find that the effect sounds the same.

>PDF Guide
WOW! That is one really useful guide! I'm saving that link. If we had a sticky for guitar effect pedal building, that would need to go in it.

Anyways, to answer your question, there isn't any good reason to go connecting random components from the audio signal to the ground signal, but what that design is doing on page 15 is creating what's known as overdrive distortion. It's created by clipping the edges of the wavelength of your audio signal. This happens by the direction the diode is arranged in. There are many, many arrangements to diode clipping, they mention the standard, two diodes from signal to ground in opposite orientations in the PDF, but that is just the tip of the iceberg.

This sounds rather complex I'm sure, but I can dig up a guide to explain, to be honest, this is rather common and is used in many, many designs.
Here's an example of several kinds of diode clipping set ups.
>http://www.muzique.com/lab/sat2.htm

Also: a picture attached to give a rough description of what is happening here.

>>801902
>>801210
J201, eh? Nifty, I have all of the parts laying around then. I sometimes wonder why designers leave out crucial component names, I like to assume it's to coax hobbyists like us to experiment.

As for the PT2399, I too have heard it's hard to work as a chorus because of the long echo, the fellow in the link I mentioned >>801753
at >http://sound.westhost.com/project26a.htm
found a way to minimize the delay for resistors below 1-2k by delaying the startup of the PT2399 by about 25ms so that it doesn't latch up upon turning on. I'll link the picture.

The part that confuses me is the output labeled "timing circuit", I haven't tried it but I think that connects to pin 6's resistor.

No worries about audio clips.
Lastly, you're completely right, there's only one way to find out for sure! Good luck, and happy tinkering!

>>801168
>saved
Whoa, 555s can sound really dirty in the signal line, looks like that thing can make some serious ATPesque waves.

How's your build? I've always wanted to build an envelope filter to play around with the LFO.

>>801210
Njfet preamp to a 386 amplifier? Talk about lo-fi, that's really cool. You wouldn't happen to have any audio clips of these in action would you?

>>801522
It doesn't label it in the schem (or perhaps I'm blind) but that must be a PT2399. I'm tinkering with a PT2399 right now, trying to get a good sounding digital delay/echo out of it.

My suggestion with that schematic is put a potentiometer on Pin 6.
There's a great article on the PT2399 at this webpage I read that explained a lot:
>http://www.diyaudiocircuits.com/tutorials/pt2399-digital-delay-analog-echo/
And here:
This one has a lot of text, but it explains a lot of really good things about the chip:
>http://sound.westhost.com/project26a.htm

>>801631
Rick Holt must have a sense of humor.

>>801663
Good luck, right on about the coffee though, I always drink coffee or beer (or both) when I sit at my breadboard.

This is the design I'm tinkering with currently.

>>801089
They're made of germanium, which is a vintage material for transistors, they have specific qualities (which aren't relevant to hobbyist level work) that make them sound unique, even with vary differences among themselves. So they're sold in matched sets that are similar. It's vintage, less supply, the potential for NOS and niche market drives up the price.

Pedal works fine if you substitute silicon PNPs instead. Just sounds different.

tl;dr they're old and they sound funny.

>>801149
>>801152
No worries, with all the transistor part numbers out there these days it's hard to keep track.
I used 2N5087s on a whim and it sounds fine, but honestly you could 2N3906s or any general purpose silicon PNP.

>>801149
I did change some of the resistor values, but that was only for taste, the pedal still sounds wild even if you directly substitute silicon for germanium.

>>801092
I totally agree, ICs take a lot out a lot of guess work and are very reliable IMO.

>>801637
>>801155
Like a schematic or an enclosure?
Mammoth Electronics / Ebay sell enclosures and wah pots to make those.
I'll link a schem, and a schematics vault for the curious.

>pic crybaby

Schem vault:
>http://tonepad.com/projects.asp?projectType=fx

>>801077
FYI AC128s are germanium PNP transistors, you can build this with silicon transistors if you prefer. It sounds harsher, but it's not bad at all.

Next up, how about an omnidrive? That's a cool design, really smart guy who invented this piece of work.

>>801074
For those of you who don't care so much for vero/stripboards, I'll post some other designs.

Here's a GREAT design for anyone who's looking for an interesting distortion to play around with.

This design is extremely flexible, and can do many different things by experimenting with part values. I built a bass-guitar modification of it recently for a friend.

How about some schematics?
I'm always building pedals, and collect a lot of schematics.
I'll post some.

>>798523
>Taydaelectronics.com
>Bitcheslovemyswitches.com

Try these places for cheap and effective parts.

>>799399
Electrical experience is not necessary for building pedals. Honestly there are plenty of simple "my first pedal" guides on instructables.com, "Randofo" has a lot of great instructables personally. Any trained monkey can assemble a pedal from solder-by-numbers guides.

To design pedals, as I do however, I would strongly recommend electrical experience. I would suggest reading those books in the beginner's section of the /ohm/ thread.

All in all, there are advanced concepts in some pedals, but there are also plenty of simple pedals that a beginner could easily understand.

>>799463
Ordering online is much more cost effective, there is indeed a waiting period, but I definitely believe it to be worth it. But take note of >>800638, some places will want you to order at least $10 or so. Like Mouser.com.
Tayda is pretty good for shipping.

>Schematic: A clever PT2399 (digital delay IC) that functions as a lo-fi distortion.

>>799710
I second >>799713, I use it for a minor basis of my guitar effect pedal designs and testing filters. It gets the job done, it's not cheap, and I only get to use it through my college, but it's effective.

I've heard good things about Spice, but it "doesn't play well with others IMO."

Have you considered breadboards? I know it involves ordering components but you may end up grasping a better understanding of the project if you can physically handle the parts yourself.

>>799731
Would you kindly fuck off?
Tripping is fine, being a dickhead is another

>>777514
Get yourself a PCB program, like EAGLE.
>>777519 This anon knows what's up.

Draw your circuit like the picture in your OP.
Be very careful, put junction nets where every joint meets.

Then transfer it to the built in PCB making side. Be careful to arrange everything very carefully, lovingly even.

Print it out on transfer paper and iron that shit onto a copper board.

Etch that motherfucker, drill holes for through hole components, apply paste + bake on your SMDs, wire and solder.

>>759791
I drilled it by hand, no clamps, just freehanding on the press. It was a really rough job, but it works! I'll give that a shot though, if EAGLE supports that.

>>758860
I found one of those in a goodwill in Florida with a Canadian battery.

I think a snowbird died and it ended up there. It has been doing great work for me. I love it.
I'd recommend one.

>>758613
Any motivation is good motivation. Especially if it's a positive outcome, like making some cool rose that you can win a valentine over with!

>>758848
>>758845
Here's the bad monkey schematic too, btw.

>>758845
Ah, so it's true? A larger emphasis on Kirchoff's laws and Coulombs electrical fields instead of circuit design and application? Shame, oh well, you'll have to learn somehow!

Well digital delays are interesting, but the real guts and meat of them exist in the BBD (Bucket Brigade Device)
>http://www.electrosmash.com/mn3007-bucket-brigade-devices
BBDs are pretty cool things, basically gigantic chains of capacitors, the longer the chain, the longer delay.
Definitely potential to mod that thing for some kicks, though I wouldn't know much about how, I've never touched my digital delay pedal.

The Tube Overdrive however might be a good place to start. That's going to have an interesting clipping / distortion system to create it's effect, so you might learn a thing or two playing around with that.
Looks like someone else out there has taken a knack to modding them, they complain about it being largely surface mount (which bothers me too, hard to play with SMDs) but you might figure out a thing or two if you give it a look-see!
>http://www.ultimate-guitar.com/forum/showthread.php?t=1034068&highlight=bad+monkey+mods

I would be wary of the do-it-all pedals, that one might be a big SMDfest, but the only way to find out would be to crack it open!

I think the professor in The Magic School bus had something to say about taking chances, so uh, get messy! But try not to burn yourself with a soldering iron, it's not pretty.

Here are a few LFO designs too, just as a FYI!

>>758837
Thank you very much, Schematic is free to use if anyone is curious.

To be honest, I'm still finishing my AA, I used to be a psych major when I first entered college in '10, but a lot of partying and failed classes later, I reconsidered that learning a practical skill would be wiser.

I started working at Radioshack, and reading books in my time off, eventually I began making my own circuits, and somehow I ran into the joy of making wacky noises with guitars.

I read a bunch of really helpful books, like The Engineers' Handbook, and Getting Started in Electronics by Forrest Mims, and a eventually started poking through "The Art of Electronics".

In short, I'm self taught, I have been working this hobby and learning new things all of the time for the past 2 1/2 years now.


But to get back to what you said: I would strongly suggest opening up your old pedals.

A good pedal that a lot of people play with on their first run is the Boss DS-1. You can usually find them at pawn shops used for about $20, or buy them online for maybe more/less.

If you have one, you're in luck, I've messed around with them before, and noted up a schematic I dug up one day.

>>758834
Part 6: Pray that everything works and you don't need to debug it! So far so good, this pedal will be going for sale after I polish it off and whatnot.

If anyone needs a hand or a tutorial, post away! I'll be popping in the thread daily to post my latest builds so it doesn't 404!

>>758830
Part 5: Put the board in the box, mount everything and stick knobs on it. (I skipped taking pictures of Part 4: offboard wiring because I had a brain fart and forgot.)

>>758833
I'm an EE student too, it's a hell of a cool field, I really wish I had access to a PCB engraver, but I cant afford it on my budget, so I just use PCB etchant and blank boards for everything.

One day...

Either way, I really dig your ambitious spirit, nothing great would be accomplished if everyone was too deterred by hardship, so rock on, good luck, and if you need a hand, /gebpg/ is here!

>>758829
Part 3: Populate the board.

>>757098
I did some sniffing around, and from what I can gather, it's an expression pedal (think wah) with more than one axis of movement.

http://www.rig-talk.com/forum/viewtopic.php?f=3&t=92215

It's being talked about there. Personally I'm sort of confused, especially since I cant find a picture of it. Cool machine. I would guess it's some combination of tone control like a wah, a delay, and a phaser with an LFO that can be sped/slowed by manipulating the footpad.

Kudos to you for being adventurous, but you may need to read into the characteristics of an LFO before you try to build one, here are some links that I hope will help:
>http://www.play-hookey.com/oscillators/
>http://electro-music.com/wiki/pmwiki.php?n=Schematics.Schematics

Good luck!

Part 2: Prepare the box.

>>756948
/gepbg/? Sign me up!

I've got tons of links to share for all of the curious builders out there! While I'm at it, I'll bump the thread with my latest build, a design of mine I dubbed: "The Fuzzy Caterpillar."

First step: design and etch your own boards.

>LINKS:
>http://www.muzique.com/lab/main.htm
Muzique is run by the genius of guitar pedal designers named Jack Orman, this page has a bunch of helpful tutorials on how to construct different elements of guitar effect pedals, like tone control, diode clipping, etc...

>http://home-wrecker.com/articles.html
>http://www.diystompboxes.com/pedals/schematics.html
>http://www.runoffgroove.com/articles.html
These are schematic vaults, many and some unknown authors contributed to the creation of these websites, some circuits come with explanations and helpful tips for construction.

>http://www.mif.pg.gda.pl/homepages/tom/schematics.htm
This is a gigantic schematics vaults, circuits/diagrams may not be in english or have explanations for their construction, however you will find a plethora of designs here, enough to keep you building for years to come.
If you need help understanding a circuit that comes from here, post it here, I, or perhaps another poster may be able to help you decipher what is happening on the schematic in question.

>http://www.geofex.com/
Geofex is a website run by another guitar pedal building master, named R.G. Keen, he will cover nearly all aspects of pedal construction on his website, from designing, to painting.

>>758267
I like it, good job OP.

>>748977
I've got a lot on my plate now, but I really like that design, especially considering how dirty the LM386 sounds, I think it's interesting that the 386 doesn't have the gain capacitor in between pins 1 and 8, but instead is jumpered, also, optoisolator, hilarious. I ought to build one sometime. I'm building a drill press:
http://www.instructables.com/id/Easy-Mini-Drill-Press/

I figured in the true DIY spirit I would make my own instead of buying one. I also came to this decision because the difference between nice drill presses and cheap ones is too large for me to settle for a cheap model.