ThunderOhm Style

Welcome to the macro fab engineering podcast. I'm your guest Josh Rocher.

And we're your hosts Parker, Dolman.

And Steven Craig.

This is episode 221.

Topping the list of the most guest appearances on the Mac fab engineering podcast today we have Josh Roser, otherwise known as Roz Ross has appeared on two of the Star Wars specials and twice to discuss the dark secrets of hand winding transformers. Today Ross joins us to talk about his adventures and PCB design. Hello, gents. Welcome.

Hey, Ross, what's going on?

I appreciate the invite. Always a good time.

Yeah. So this is you, we got to make a trophy for you. Now trophy, five appearances,

gonna be like one of those like fantasy football trophies, where, like, the next person up etches their name in it or something? Yeah,

it's actually a good idea. Take it all out a PCB material.

There's plenty of like carcasses of failed PCBs lying around my house, probably. So

ah, so that's where we're gonna we're going to talk to you today. But that's a hallmark of basically any electrical engineers, like lab is the box of failed PCBs. I think mine weighs about 30 pounds at this point,

you know, okay, so there's a little caveat to that. I think because PCBs are so damn cheap nowadays, that like you don't, you don't normally buy, you know, if you're doing prototypes, you don't normally buy the quantity that you're getting, you get like, say you're building three, you end up with, like, 15. And so you it's actually not a box of failed PCBs. It's just a box of unpopulated PCBs that probably do work, you know? You some coasters,

no, mine are actually you like, these are all like prototypes and stuff that don't work, don't work.

Speaking of not working PCBs, no, no, we're not gonna go there just yet. But no, like, so Roz you, you've recently got into designing your own PCBs. And kind of the last time we had spoke to you about just general electronics, you were really digging into making your own transformers. And that was for the guitar amp world and building valve amplifiers. But you've sort of moved on, maybe moved on, it's not the right way of putting it, but you've sort of branched out a little bit of a different direction and started going towards smaller analog electronics, right? Yeah.

So mostly, like guitar pedals. So it's still in that music realm. So it started, nothing, I'm not to the point where I'm necessarily designing my own circuits, yet. I'm more like taking kind of classic tried and true ones, and then hacking them apart, putting kind of my own stuff into them. And, you know, what goes along with that is definitely, you know, I build my own PCBs with that as well. So yeah, it's been fun.

You know, something, I would be interested to hear from you. Because we've been asked this both on the podcast and off the podcast a handful of times. Sure. It's, where do you learn how and how do you learn? Like, where do you pick up this information, because there's, there's usually not someone holding your hand.

So I am very much the kind of person that you cannot put me in a classroom with a tutorial, or give me a video. Like, you literally have to hand me the thing and say, like, go screw it up for about, you know, three or four weeks. And then like, you might finally make something worthwhile, you know. So when it comes to PCB design, I literally, I was trying to find a, a web based EDA tool that I could use with basically any, anything that has a browser to it. So my wife and I have this little Chromebook. And it's, you know, I can log on to this EDA tool. I don't have to have it connected to any kind of Dropbox or any kind of cloud storage and really just pull up any of my designs and sit on the couch on a Saturday morning, while the kids are watching cartoons and, you know, just goof off on PCB design. So I literally so I was looking for a tool that had that browser. You know, it was native to a browser and I just Googled it. I was trying to find, you know, PCB layout tool, browser based free. Free. Yeah, that's the other big one. I'm, I didn't know what the hell I was getting myself into. And, you know, having looked at some of those programs, maybe years ago, when I was still dabbling in the guitar amp world and looking to branch out a little bit you know, they looked kind of calm. Located in scary, to be honest, and this one, this one looked relatively easy, so I started playing with it. And yeah, I mean, just get in there start pushing all the buttons like I was like a little kid, literally just flipping switches pushing buttons dropping things on the, you know, on the

schematic program ever asked you if it wanted to play a game

thermonuclear war?

You haven't mentioned what name of this EDA tool

Oh yeah, so it's, it's easy EDA, which is J LCS, you know, I guess proprietary tool. So that kind of made it easy to because JLC is actually Steve, you recommended them, and they're dirt cheap, obviously. And they make really high quality good stuff. So I ended up like, stumbling upon their tool, and actually not knowing it was JLC is like layout tool. And then, you know, they just make it nice and easy to give you time for you to give them the Your Money with a nice big button up at the side that says, you know, convert to PCB and, you know, and they just, you can order it all right through there, whatever, their, their tool, so I found it relatively, like, user friendly and idiot proof. As much as the EDA tool can be. I of course, I have my experience with like, one and a half I wouldn't even call it to. But, um, I don't have a lot of problems with it. Yeah, I'm sure it has its own finicky stuff that every piece of software probably has. But yeah, it's, it's, it's not bad. It gets the job done for what I'm doing.

And, you know, on the on the fairly regular since you found these, found this EDA tool, Parker, and I've been getting tech group text messages where it's just PCB showed up on a pretty regular basis. I kind of love it.

Yeah, it's, um, like, I so I nerd out a little, probably too much on the aesthetics of things that people will probably never see, which is like the layout of the board.

Now, that's exactly what we're here to talk about, though. So

it's probably probably like certifiable. If there's anybody with, you know, like psychology degrees, or psychiatrists that listen to your podcasts are probably like, here's my car, give me a call.

But yeah, if it's wrong, I don't want to be right.

Yeah, I don't. It's actually I blame Steve. He's the one that got me on that, like, that kick of making everything look good. I mean, it has to be functional, like top of the list, it has to do what it's supposed to do and do it well. But it's also got to look badass in the process. So

like, that's number one. But then one A is it's got to look good. Oh, yeah.

Almost to the point where, like, if I'm picking out a capacitor, and you know, one brand is brown and one brand is like red, which matches my resistors

fine gold caps. Oh, yes.

We've been down that road before.

I know. It's insane. I get it. I totally.

I did specify resistors. Before because they were blue. Guilty. So that's in the resistors that were blue. I think what was it? Kayo spear? K away spear? Or metal? For through hole or for surface mount? Oh, okay. There's,

I can't remember a company because because icons do blue through holes. Okay.

Now these were surface mount because I think like Panasonic so usually like black? Most of most, most of them are black ones. But I can't remember which one it was is they make blue ones?

You might have to send that to me.

Just gave them some more stuff to nerd out. I think I think you're in the right kind of audience for people who sweat the details. Let's put it out. Yeah,

you know what, it's kind of that like, I'm not designing cell phones here consumer electronics that are like cutting edge technology or, you know, something that I'm trying to squeeze fractions of percentage points of margin out of so I can I can do crazy things like put a giant silkscreen of my logo on the board and take up like half the board because it looks cool. You know? Totally, totally fine. Not a problem.

I mean, this makes a lot of sense from the person who winds His own transformers when you put it that way. Yeah. Yeah. Like have you have you tried putting graphics inside of the plates on your transformers? No, oh, no, I could do that. And if you flip them apart, it'd be like a flip book.

It'd be like, like me, a lead flip. They would say like, warranty void breed.

Did you know I kind of I really liked the concept of doing projects like this is for figuring out some of the more difficult details of electronics, which, okay, it's already hard enough to start with a blank piece of paper, and then say like, draw a schematic that does a thing. That's pretty difficult. Getting started. But if that's already kind of taken care of, in other words, like, like you mentioned, you picked some known operating pedals and projects to work on. So if you don't have to worry about the, the electronics generation side, then you can really get your feet wet and start digging through the concept of like, oh, what's good about picking this capacitor versus that capacitor? Or what's good about this style of layout? And not worry so much about just like, oh, my god, is this going to work?

Go one more step further. It's also learning the tool to design it as well, is a huge barrier.

Yeah. Well, yeah. And it's like, so the first pedal I built that worked was

sorry, no, no, quick tangent. That's like the Russians being like, the first person we sent to space that made it came back.

first man in space. Yeah, no. So yeah, my first pedal that went to space and came back was just a copy of a tube screamer, which is people have been copying since the 70s. Right? So there's all kinds of variations and mods and schematics all over the internet forum, there's circuit analyses out there, there's, you know, people have super special op amps. And, you know, you can get crazy in the weeds. So it was easy for me to just pick a schematic that's tried and true, you know, what it does, I know the parts are out there. I know all the Substitute Parts, if I need to go like three or four levels deep to make this thing work. Let's just, you know, lay one out, see if we can get it to work. And you know, it actually, that that one actually worked the first PCB I ever designed on a tool. It wasn't like the most optimized especially if it was something you wanted to like, scale up for a commercial. It took a while to sit there and kind of solder a couple of things on I can get into the details on later but it worked. Like I wired it up plug it in first go like it worked. So that that's kind of what got you hooked. Like if it was one of those things where I wired it up, plugged it in, and it didn't work. I don't I don't know what I have like gone to the next thing my ADHD probably would have made me like find another shiny object to go chew on or something but

enrolling capacitors baking a which

I haven't gotten there yet.

Aluminum foil in a wax paper and yeah, mineral oil,

special paper like, you know, made in like the type at and plateau by monks from some special tree or something dipped in Yak oil, or God knows what. Yeah, that sounds like something I would do.

You would take a pilgrimage to get that stuff though.

Yeah. And but research it for like three months in advance.

Yeah, and I would know, everything you need to know about like one very specific useless kind of

capacitor. We'll see you in about four months, then. Yeah, it probably be

about the size of a small tree, like hand rolled.

And you'd have five different Excel spreadsheets on how to actually calculate it all.

Yeah, and any of the five wouldn't work on its own. You'd have to have all five open at once. Which anyone who uses Excel? That's yeah, they can feel that pain.

That's a good that's a good Excel sheet. That's

it's working great. Like what do you want me to optimize? Optimize what

so what was the what was the name of the first pedal that you made? Because it wasn't a tube screamer? No, no, and

I didn't paint it green and like Yeah, and I didn't Yeah, so alright. I I'm a musician right and I my main I guess gig if you want to call it is I play at church and I my primary instrument instrument is drums. But you know a lot of people know that I design amps and you know, do electronic audio electronics for a hobby. And one of the guitar players you know, he was given me flack because he was from California. He knew I was from Texas, and he's just dog and on what a burger man I like talking about how in and out was far superior and like I'm not here to settle that fight but

you know hang on can we back up for just a quick yeah yeah so let's let's detail that real quick. There is a war that is between good and evil which fast food burger joint is better yes water burger, which is basically a Texas

pretty much chain yeah right.

Corporate Christian yeah in and out

right and in and out which is you know California I think specifically Southern California but I could be wrong about that please people from Southern California or Northern California don't send me hate mail but you know having lived in Dallas for a couple of years you know they've made their way east slowly from California. And I can I mean, in and outside great burger joint. I love their burgers i there fries are awesome. It's just not what a burger. So like I'm a native Texan and I'm gonna stick true to what a burger which is real burger, the white and orange striped number five with jalapenos man, you just can't go wrong with that. You know,

see, a burger needs to have mustard. Absolutely.

No ketchup. I know no in and out doesn't put ketchup on their burgers. But you know, they got that what they call it spread? Which, at what point does it stop becoming a sauce and start becoming a spread? Because I have a like, that's definitely a sauce in my mind. It has spread. It's a little bit too liquidy. But point is

that sort of that's sort of like the difference between saying tortilla or rap. I can't stand it when someone says rap. Good point. Like it's a tortilla.

Yeah, well, it's a tortilla. If you're, if grease leaks out of the end all over your hand, while whatever you're eating is covered in something really spicy. That's a tortilla. It's a wrap. If you put like avocado and tofu and

in lettuce, yeah, like surrounded by lesser wrap.

That's a wrap and if ranch dressing is anywhere near it, you better not call it a tortilla.

Okay, okay, so why why is there a connection between the fast food restaurant wars and your home?

Yeah, so this this guy there was like this ongoing like inside joke kind of half serious, but really serious feud between he would dog Whataburger and I'd have to I'd have to punch back. Right? So his birthday came up one weekend, and it was on a Saturday or no, it was on a Sunday and I knew I was going to see him that Sunday. Like Friday night, I had the stupid idea of oh, crap, I'll build them a paddle. And then had the idea of using it as a vehicle to Rasm about, you know, this, this whole feud. So I built a it was a two screamer clone. And I don't know, I guess I started designing it and laying it out and stuff. And it wasn't until I got all the parts in and and wired it up that it decided it dawned on me what I was going to call it. And I called it the water booster. And I painted it with orange and white stripes. And you know, repurpose the Whataburger logo. And, you know, it was basically just again, like a kind of a moto Tubescreamer. But you know, the best part was I took the in and out logo and put it in Inkscape and kind of sliced and diced it. And on the input and output Jack's repurpose their logo said input and output. And it was like stylized like the in and out logo. And I think I sent you some pictures that's probably not in there. But

it's gorgeous.

He thought it was hilarious. It wasn't it's not I wouldn't say I appreciate it, but you know, first thrown together and like 48 hours. It's pretty good. But you know, obviously copyright infringement and everything. It's nothing that you know, I could ever produce. It was just kind of for fun. So I

my favorite is how the knobs are labeled. Because they're labeled with so Whataburger when you get when you customize your burger, they put little stickers on them of like what you added onto the wrapper. Yeah, or bacon. And that's how you labeled the knobs.

Yeah, I can't I think one of them's like special and one of them's like jalapenos and one bacon.

And I love also how they're not like angle I mean they're not like straight across they're like angled like someone just slap just slap them

on there. Yeah, it's super great. I tried to match the colors and the font as best as I could to and yeah, I think special is is like the the drive or like the distortion level essentially the clipping in the circuit. So it's um Yeah and I think jalapenos like the tone knob or some nonsense I don't remember there was a there was like some rhyme or reason to it when I designed it But long story short he actually played it he said he kept it on his pedal board for a while you know that that particular pedal to be clear was not one of my PCB like one of my forays into PCB design I actually used an etched PCB I got you know, the copper clad fr four and, you know, a bunch of really dangerous chemicals in my shed and started doing, you know, black chemistry, magic alchemy in the backyard. Where my kids

fr for into gold.

Yes. But that, I think it was the struggle of that that really was like Screw this I'm designing my own from now on like, I This is horrible. I'm never doing this again, especially for like 299 from China in less than a week.

I think that was my experience too. When I first started building PCBs was i i started making them around the time where it was starting to get easy to get inexpensive. PCBs. Yeah. But it was so difficult. Like, I didn't have a credit card still. Like I was like, How do I pay people? So I'm like, oh, I'll just like, you know, at some in my backyard, but then you actually got to work in PCB, which is amazing. I did not I think

I only so to be to be fair, I had a little bit of experience etching PCBs prior to this like as I think Steve and I were when we were in either high school or college did some goofy stuff along the same lines,

I think yeah, I think we did one or two here in there.

To be perfectly honest, my very first pedal of all time, which is what got me into audio, like you know, electronics for audio is it was a phase 90 and MX or phase 90 clone and it didn't work. And I gave up on it and just like moved on to the next thing. So but yeah, it actually worked I was surprised now by worked I had caps like bent over and legs like soldered across the board and like this footprint was meant to take you know a six millimeter diameter cap and it was like I only had I don't know 10 millimeter laying around. So it's like laying down on top of other components and there's wires like it was it was it's not a pretty sight on the inside of the thing but hey, it worked.

Yeah, the outside is gorgeous. The inside is so yeah,

so little gross.

They got different names. We're building PCBs like there's dead bug style and Manhattan style. What would that style be called?

Mad Max. I don't know.

The Thunderdome Thunderdome style you know, it's funny, it's that style is actually like somewhere in the dead zone between Manhattan and dead bugs. Like it's like the worst of both of those

put together. So these are new terms to me I'm you gotta tell me what the what the hell okay

okay actually so the ridiculous anal side of you will really like Manhattan Go Go Google Manhattan style PCB like in terms of like guys like spending hours like bending legs of components to like perfect angles and soldering them all together like it like the radio guys the old Graybeard radio guys do it they're gorgeous. They're amazing. Wow. Yeah, they're they're ridiculous. And then what we said Man Oh dead bug style is when you

take a bunch of dead bugs crammed in there. Well dead bug.

If you get an IC incorrect or you build the footprint wrong, you can always flip it upside down glue it down and then run wires from each leg to the actual path that supposed to go so it's like a dead bug like a dead roach. Yep, yeah, like a dead road or a spider that you know is upside down. Yeah.

Okay, all right. Yeah, yeah. So Oh, wow.

Yeah, so yeah, we've created a new a dead dead bug Manhattan in Mad Mad

Mad Max. I liked Thunderdome style.

Thunderdome Yes.

Yeah, it's um it was definitely a good place to start from but not my not my best work I quickly progressed past that you know to laying out stuff and it's getting worse right so now I'm I'm I've gone from strictly using through hole components to starting to dabble with SMD stuff and you know, starting to play with that a little bit, which I'm really liking especially for paddles because you can get some really cram a lot of shit into a little footprint which which is nice because I don't you know real estate on pedal boards is valuable stuff and you know I want to make sure I can fit as all the goodies on the board as possible so it it's been kind of a there's been a few designs here lately that haven't gone super well but I'm figuring those out parts are on order

so what was the it's the water booster was the was the thunder homestyle but you went and redid that pedal and PCB? I did. Yeah.

And it's, um, I again, because of the whole Whataburger theme was kind of a gag, right? I redid it kind of in my own style. It's, it is still based off a TS 808 circuit, but it's pretty highly modified. And God knows how many people have cloned that circuit to where it's pretty much ubiquitous at this point. So I am I kind of did the same thing and I think I'm on Revision like three just kind of slowly tweaking, making things better, like layout wise, more compact, making the less noise stuff like that. It's the white, which is what I've kind of done dubbed it right now. So it's a pretty cool little pedal. I've had a couple people play on it. It's I'm not gonna say it's like, or let me Sorry, yes, it's super magical. I put, like, I rubbed the board massage the boards with the Virgin tears before sardine oil. Yes. And I only use solder that contains platinum. So mined from Chilean mines off the back of alpacas that have been phased in. No, I'm kidding. But it's a it's a pretty fun pedal plan.

So So you said you, you were kind of like developing your style, what would you say is your style?

Ah, so it's laughable. So a laughable if you're going to, sorry, I'm not an engineer. So the right and wrong way to do things that you guys probably deal with every day. I don't know those rules. So I kind of color outside the lines in a bad way most of the time. So, I don't know, going back to the aesthetic thing. The way the PCB looks means a lot to me. So I like to keep my capacitors as much as possible kind of lined up, I like to keep my resistors in a row and an array, I like to center, you know, op amps on the board, if I can, I like to, you know, keep switches and components in line with each other and color. I know it sounds insane, but color matters to me. So I use resistors from a company called PRP and they're red. So they have a red Jack, you know, epoxy coating on them. And then the caps I use are weima film caps and worth electrolytic caps. So they're all red, they're all red. And it's black PCB solder mask with white silkscreen on there. So they look good. If you were to pop one open, like the thing is, I know, I care what's inside of a pedal. And I know other people would too. I'm not planning on selling these really anytime soon, if at all. But you know, if I pop one open, you know, I want to be proud of what's inside. Not to say that you can't make an awesome pedal that looks like I mean, I, I made a pedal that looks like thunder dome style, but, and it works. And it sounds good. And a lot of people would rightly argue that it matters, like the sound is all that really matters. And, like 90% of the time that I would agree. But you know if it's going to have if I'm going to spend the time to actually do it, and it's going to have my name attached to it. I want it to look good. And I want it to be something I'm proud of. So I don't know. I don't know what I would dub that kind of style. Like, I don't know, Rain Man style, but it's it. It it's fun, like it's a way to kind of challenge myself and see if I can lay it out to where it looks good and sounds good. And oh, by the way, it has to work, you know, and not just work but work well. Like can't be noisy. Can't have cross talk. It needs to you know, though, I don't want to drill out any through holes because I screwed up the layout. You know, it's stuff like that, that it's a challenge, but it's kinda like You know, some people do crosswords or Sudoku or learn new language and I waste my time on 1970s technology. So

it was worse ways ago.

True. I think, sure, you may not have a piece of paper saying that you spent a bunch of money to go listen to some lectures at a school. But I think you use generally the same mindset that a lot of engineers also apply to these kinds of things. And you care. So I think, I think you're 99% of the way there.

Yeah, I mean, that's generous. I'd say I'm, I know, I know, enough to be dangerous about a couple of things. But I think so somebody put it, they were, we were talking about something completely different. But they used an analogy, once that I think it's a really, it's stuck with me, and I think it's, you know, kind of applies to a lot of different fields. And this is one of them, is, you know, if you hire somebody to paint your house, like, you can paint your house, and 95% of the work you can do. But it's, it's the little details, you know, that that really separates a professional from from a rookie. And it's those, you know, you can get the job done, anybody can get the job done, anybody can buy a kit, offline and build a pedal there, it's chill, people should do it, it's a lot of fun. And it's a great way to get involved in kind of starting those projects. But it it's like the small stuff that really separates, you know, the people who do it for a living from the hobbyists like me, right? So, it, there's a lot to learn. And I think anybody who's honest, would say that, that's one thing I've learned about the engineering kind of brain is, you're always constantly learning and well, and technology is constantly changing. And there's always new stuff out there to go get your hands dirty with. So I don't think anybody's anybody who's honest, would tell you that they're an expert in the field, right? We're always learning new stuff, and, and messing with new things and tweaking things and trying to make it better. And that's kind of half of the fun, is arguing over those little details or trying to figure out the right way to do you know, the smallest little thing that really doesn't necessarily matter in the grand scheme of thing. But just because you want it to you want it to be right, you want it to be as good as it can be, you know. So there's, there's a lot of stuff out there that I don't understand, like transistors, those things, or it's like, they, they drive me crazy. There's, I've just started dabbling in those things, and they're there. There's a lot to learn there. So I think I know, like, Ohms law, and that's even that, you know, I have to go Google, like that wheel that you see on Google all the time, most of the time, so

you know that, that 100% worth of house painting, and you were saying you could do 95% Sure, that last 5% sure you're paying for someone to do it. But of that last 5% 99% of that last 5% is the fact that that guy has that one really special tool that just does it quickly and perfectly.

Yeah, that's that's a lot of it. Right? And he's, you know, they've, they've dedicated their, you know, life or they're, you know, they make a living doing it. So, you know, that's, there's a lot of there's a lot of truth to that, for sure.

I think my entire garage is half specialty tools. I've used like twice, maybe three times.

Well, it's yeah, it's there's two

Bender, tube straightener through straightener

was born twice or three times. But yeah,

I have to sneak those in when my wife's not looking so my I don't quite have have quite as many as you do.

I can imagine you like trying to come through the back door and you have like an eight foot tall bandsaw underneath your shirt

Honey, have you gained some weight? 300. So what's what's more recent that you've been working on?

So like, most recent, like today, even I was messing with. So my dad played guitar way back in the day. Mostly acoustic, and this was like I think he stopped playing when I was probably not even driving yet. So when I was like a preteen or early teens, and then he just picked it back up this past year wanted to get back into playing guitar and he decided to go electric this time. So he bought himself a Les Paul and a nice Epiphone, Les Paul off the shelf I got him. I talked him into getting a legit, you know, tube amp. I tried to get him to let me but you know build him one but he refused. He's he wouldn't let me build them one because you know he's he's like yeah, that's that's a waste of a good amp like I'm not quite there yet you know. So he got a nice Marshall all tube you know five watt little lamp he bought a bunch of pedals and he's building he's into woodworking and he likes to do every you might start to see where I get this from here in a second. But he's into building woodworking by hand. So he tries not to use power tools if at all possible. So he's got like Japanese, like saws and chisels. And

so he's mentally insane is what you're telling me?

He's Yeah, pretty much. So he's hand building himself a pedal board, and once a power supply to go with it, and he's gonna build me a pedal board too. And, you know, he cuts the dovetail dovetails by hand, no power tools, and like, he's building his out of walnut. And we haven't really talked about materials all that deep on mine, but he wants a nice power supply on there. So I told him I build him a linear power supply. Now, can you go on Amazon and buy a perfectly usable? 99% perfect power supply? For like 60 bucks, probably yes. But where's

the fun in that, like, you're gonna spend $120 and make a

minimum of 120 Probably, because I'm going to probably screwed up a time or two and have to de solder some components and but I'm going to build them a, you know, an eight, it's got it's a linear power supply. I'm using PCV mount of transformers with dual secondaries on them. So they're eight isolated windings, you know, each with its own, you know, linear power supply circuit. So that there's, I want to try and isolate him from each other as much as possible, keep it super quiet. No noise, super stupid overkill. No one should ever do that. But I'm doing it. And so I was working on that today kind of laying out, you know, things like got a poly fuse in there. And when it trips, and goes off, if it trips, an LED indicator that will light up and like have a fault indicator or something on there, like just little things that you can kind of work into it when it's your own design that really don't add a ton of money, but are kind of cool little add ons. Right? So gizmos. Yeah, I was working on that today. So I'm using the LM 317. So it's got you can use that to do like variable voltage. So I've got a little trim pot on the board. So if it's a particular, you know, if I'm a little bit south and nine volts or a little bit too far above it, I can kind of, you know, dial it in exactly what I want it to be, but

gotta love it, there's this calibration points on it. Yeah, and

it's, you know, 30 cents for one of those little trim pots, so why not? Right,

you're gonna get the multi turn once

the 25 turns.

That's super granular. Like,

we actually use a ton of those at work. Just I mean, there's, there's applications where, especially for like tuning on a voltage controlled oscillator, to get it such that it does, you know, an octave for every volt input. Like, we use 25 turn, trim pots, and even on some of our more sensitive designs, even with 25 turns, we're still like barely nudging it to get it, you know, perfect on because to get, you know, 10 octaves of perfect tuning range. You got to have pretty tight resistances

Yeah, it's um, but they're more expensive.

Yeah, I'm just going with your off the shelf. 40 cent, like 30 cent, whatever, you know,

plenty, plenty good enough for an LM 317 style circuit.

Yeah, it's I'm kind of curious to see how it turns out I actually, I was starting on the bill of materials. This afternoon, I got the circuit more or less laid out. And, you know, I don't think it's going to be really all that bad. I think 120 bucks was actually probably pretty close. So you kind of hit it in the bucket, like right on the mark there but not too bad for the fun of being able to build something and you know, send my dad you know, he's building me this pedal board by hand and I'm kind of contributed into it in my way, too. So,

just out of curiosity, is it something where like, he gave you specs where he said, like, you know, it must fit within this envelope? It must be this big? Or is it more just something where it's like, yeah, just get it to me. And I'll just glue it to the back.

Oh, no, we spent, we spent three hours on Zoom last Friday, laying stuff out in, in a layout tool and talking about which enclosures will work for his PC, like, for his pedal board layout, and it needs to be this tall and like, yeah, so I had to kind of do a little bit of, you know, had to pick the right enclosure from Hammond. And, you know, the, the jacks had to come out the correct side otherwise, like, you wouldn't be able to route the cables, because it'd be pinched between the bottom of the board. And, yeah, so there was, it's a lot of fun, because, you know, I get to kind of do this, it's with my dad, now that we're 2000 or 1700 miles away, it's kind of a way to stay connected with them and do something that I really enjoy. And that turns out, you know, I probably where I get it from is, you know, his propensity to do things if it's worth doing. And so, you know, it's worth overdoing. So it's worth doing well. Yeah, so I, and again, not to say that something off the shelf wouldn't do perfectly fine, especially for, you know, our uses, which is just kind of sitting at home in the bedroom playing, I don't need some perfectly quiet output, you know, power supply, but why not, I want to give it a shot. And hey, I learned I've learned a thing or two about either PCB layout, or, you know, the linear power supply design are a little bit about transistors and stuff. So. So it's a way to kind of just keep learning and keep playing with stuff and have a little bit of fun in the process with music too, which is really one of my core passions. So

So actually, just, you know, if you could touch for just a quick second on, you knew you wanted a linear power supply. How did how did you learn to do it? Like where, like, what did you go search for to figure that out?

Yeah, so I know, you know, I've run across linear power supplies. In the guitar, amp space, right, so building like DC circuits, for, let's say, like filaments for for vacuum tubes, heaters, right. So it's rare, but it's, it's something that cuts down on noise, because you don't have that 660 cycle, hum, you know, bleeding into your, your audio circuit. But, so I was kind of aware of them there. And I was also, I mean, you can Google, I was I'm also, you know, have looked into trying to build like a benchtop DC power supply off a, like an ATX power supply from a computer. And though just like, you know, a list of everyone's kind of different flavor of linear power supplies out there, and everyone's kind of got their method. And, you know, so just kind of cobbled together ideas from a bunch of different ones, and looked at the manufacturing, you know, T eyes datasheet for the LM 317. And kind of played with that a little bit, and started incorporating a couple of different, there's lots of different discussion boards and blogs out there from people who know way more about electronics and engineering than I do. And, you know, also, it helps to have friends who know things too. So I talked to, you know, Steve a more than a handful of times about stuff like this, and this particular design a few times at least. So, you know, just slowly ironing things out. I'll get I'll get a couple of steps in and then kind of chew on something mentally for a while and then go back and do some more research and make a couple of tweaks. And then that'll lead to some more things that I need to kind of stop and chew on. But yeah, Google, there's, there's tons of information out there. But knowing how to sift through the stuff that you really need is the real, the thing that takes the real time, right, you can find 100 different linear power supply designs, but knowing which one will work for your particular application is where it gets, you know, that's where the hard part comes in. That's where it helps to have friends that you can bounce things off of,

you know, I think above and beyond that you can find 100 different linear power supply circuits and not only is it a troublesome Finding one that will work for your situation. It's sometimes a trouble finding one that will work just at all like I mean sometimes the when searching for circuits on the internet like you got to be really wary.

Yeah everybody you know comes off as an expert on a forum right you know,

on this want to say on podcasts

oh yeah what the hell like here I am on your podcast I you know, talking about engineering stuff I have no no right to be talking about but you know, it's a lot of you know, there's a lot of good information out there buried on a lot of mediocre information under a layer of just garden you know, with some garbage information sprinkled throughout so you gotta be careful the landmines for sure. So again, having friends and right in the right place to be able to bounce questions off of his key otherwise you you have to learn the hard way and you know, that's expensive and that's demotivating sometimes, you know, to blow up a board or have $100 worth of parts just become a pile of parts and not work so

they just go into that pile that we were talking about right at the beginning. Yeah,

the elephant graveyard

is a good name for elephant a PCB graveyard. You know, it's actually interesting is the one of the first circuits I ever designed and built and soldered together was a LM 317 power supply for my computer that controlled speeds on fans. Oh, no

kidding. Yeah.

I'm trying to find a picture but that was so long ago. I don't even have only ever known the camera back then.

The, the, what's the stir plate for my yeast? For beer brewing, I used an LM 317 and connected it to a fan, a DC fan and then glued magnets to the fan and you can just with a pot, you can control the speed of the fan and control the stir plate.

Mine's kind of similarly hacked together. Although I bought a pulse width modulator kind of circuit board off of Amazon or something. All fancy here. Oh, yeah. Yeah, no, I went super bougie and had somebody build it for me.

I went I went full thunder homestyle.

Yeah, well, I mean, I don't be too impressed. I still glued it onto a PC fan in a cigar box. So there is that?

Oh, that's the classic way of making a stir plate.

Yeah, I think still works to chugging right along. I was contemplating using it to culture yeast for bread making with this whole social distancing thing going on. Like, you'd be surprised bread yeast is is like, harder to find than you know toilet paper at this point. Yeah, yeah, it's nuts. So I thought about just starting a yeast culture. I got crap. I've got all the stuff to do it so I haven't quite pulled the trigger there yet because I was able to find some instant yeast at the little store down the road from our house. So

yeah, actually, this talk a Thunderdome style. I used to build a portable consoles, like put one in Windows and stuff. And this talk is reminding me a lot of how I built those back in the day where it is a bunch of PCBs hacked up and kind of hot glued into an enclosure. Yeah, function over form. You slapped a whole bunch of gloss on the on the top to make it look nice and inside is just like

him pray that that solder joint doesn't come in. If it breaks it, it's gonna stay broken. Because I have no clue. There's so many things that could go wrong.

I'm just looking at some old pictures. And I'm like, oh, man, actually used to build stuff like this.

Yeah, I mean, the, the latest project I've been working on, in addition to that power supply was a reverb pedal, which is just a clone of a, you know, famous, you know, like commercially produced pedal right now. So it's, it's, I wouldn't say a part for part clone. Like, I'm not specking the same, you know, part types or you know, the exact tone. It's exactly it's like, you know, film cap or a ceramic cap. Like I'm not kind of I'm just kind of paying attention to the

Yes, little c clone.

And so yeah, that's the one I've been laying out and Okay, so talking about EDA tools. I'm sure this is kind of, I don't know if you guys have struggled with this but so I have like a to 92 footprint. And you know how the pin outs on those things change depending on what exactly you're putting there. And the scrutiny pin Now it was like a What? Is it a 78? L oh five. Yeah, it was like a 75. And I Yeah, put it in basically backwards, right? Because my, my footprint got screwed up. And I just realized that the other day, and as I was desoldering it to try and flip it around, I ripped the trace up off of one of my PC boards. Not a problem, because JLC is minimum order is five. So I got four others to go with it. But you know, that was like the comedy of errors, because right after that my solder sucker broke. And you know, that I've had for 15 years. And so I had to order new parts. And I just basically threw it against the wall and just clicked reorder on Mauser. Just get out, get it all. I'm not I'm not going with that, again, starting fresh. So that's the one I've been messing with most recently.

That's how you start gaining a parts collection. Like you can see all those drawers behind me, as you usually order parts in order to have everything and you end up 90% Time only using one of them. Well, yeah, so

that I started using surface mount resistors on this guy, that was the main thing I wanted to do with this one, it was okay. And going back to your point about going with known designs, you can kind of throw one variable in there, that's a wild card. Right? So the first design was PCB layout for me, like that was the I had to learn the tool I had to learn like, what that was my wild card. I don't know what the hell I'm doing. Here. This should be fun. You know, a couple iterations. You know, next thing was like learning specific things around like, some of the footprints and a little bit more about the tool and, you know, construction, you know, principles and methodology on how to keep it quiet. And it's not a little buzz box that just you can't use. And this one this reverb pedal was alright. SMD, right. Like I've never used SMD so I use these little 10802 I think early 205 resistors oh, five, God, damn, those things are easy to lose. Nobody told me what like I was the pictures make them look so big. I ordered them and I take one out of the package and it falls and I'm like, I hate these, like fell into another dimension. I know we're obsessing with. Yes. So I should have ordered like five of everything. I know those in the type I was using. They were asumu which they weren't like the cheapest. So I think they're like 40 or 50 cents apiece, which isn't necessarily expensive. But you know, it adds up when you're starting to do like, a few dozen in a design. And then you do that like four or five times over. You know, it's not again, not going to complain, there's still relatively cheap, but I think next time I'm just going to link if it's on the bill of materials, it's going to get like multiplied by at least 1.5. And um, you know, or to just nice, big round number in case there's one.

But yeah, I was thinking suggested a few more SMT work is getting me a good, good pair of tweezers.

Oh, I got a set of 11. So I've got all kinds of different angles. Like I got the 90 degree I got the straight. I got like the hooked ones. I got the little needles. I got the big flat blade link needles. Yeah, I got everything.

Because that's the worst is if you use a a terrible piece. No, I've actually done that in a pinch before but I have some really crappy tweezers that I've had forever. And I use it mostly for automotive work. But one time I couldn't find my s&p Tweezers. So I tried to use these. i It's like they, the you pick up a resistor with it and they fling off at the speed of light.

I have those very ones that you're holding.

Yeah, but they make that that real high pitch like ping.

Yeah, hit something on the other side of the room. noise came from over there. Like do I want to waste an hour of my life on my hands and knees trying to figure out what it was? Or do I go down in the basement find a resistor a quarter watt, you know, through whole resistor and like solder it on the pads? Yeah,

so far, I figured out what it is that it goes the speed of light it instantly turns the energy. That's why you can never find them.

Well 40 cents for endless supply of energy. That's

you just gotta get tweezers to flick them.

Special, the special tweezers. That's our new power plants.

Yeah, those things go fly in. But yeah, it's

but they're not hard to solder, right? Like people are always like, super hard to find.

If you're probably certifiably like OCD like I am, they're hard to solder straight now. But they work like they work fine,

Roz, you're gonna lose your, your, your shit. When you find the Discover stencils, and paste and solder paste and reflow like your little toaster oven, you will be like, This is amazing

that, you know, there's another Hot Tip here, if as long as you don't mind heating your board up quite a bit, get a hot air gun, throw some flux on there and just heat it up until it until it melt and sucks right into place. And it's straight.

I'm probably gonna go down one of those roads next, because as easy, it's not hard, right? Put a dab of solder sticky resistor on there, heat it up. You're good, right? But again, we've already established that I'm psychotic enough to pick resistors based on their colors. So, you know, I think stencils and like I've seen that advertised on the PCB manufacturers website, but I've never really looked into it. But now you guys are making me want to go look into it.

JLC has a button that when you're ordering your boards, you click that button and a stencil comes along with it. And I think it's 15 bucks. No, it might even be

like, first ones like $1, probably with $17 shipping, like they always do.

Hey, you know, you know what's great about having all those extra PCBs we were talking about, what you can do is you you line up all those PCBs on your table and you make a little gap that's just wide enough to slide the one you want to paste under it. And then you have a perfect thickness that you can put the new stencil down on and wipe against. So having all those extra PCBs lying around, it's useful.

Yeah, that's um, yeah, there's a lot to learn. And that's one of the things on the list.

So I guess we can wrap up this podcast with that stuff. Oh, all right. That was the man I had to be the bad guy there.

What do you have to be the grown up that ended?

Ross you got I got Roger. Parents are here to take you home.

I'll just ramble. If you let me I think not only have I been on the show the long like the most times I think I probably hold the record for the longest podcast as well. No,

oh, God, no. Okay, good. Not even No, no, we've had some that aren't over to

God. There's people more interesting than me in this world. Because I mean, I've already been on the show five times. So I'm getting a little worried.

All right, on that note, that was the macro fab engineering podcast. I was your guest, Josh Rocher,

and we're your host Sparky Dolman.

Should we wait 40 seconds to make it a proper hour. I get

to do that all over again.

No, we're just gonna keep the tape rolling.

No, Steven Gregg. Later everyone. Take it easy.