Parker talks about his Embedded System Design process and Stephen explains his 20 band EQ design!
Stephen finishes his Synth and jams some tunes!
On this episode, Stephen gives an update on the FX Dev board and Parker talks about his MacroDuino project.
Parker is an Electrical Engineer with backgrounds in Embedded System Design and Digital Signal Processing. He got his start in 2005 by hacking Nintendo consoles into portable gaming units. The following year he designed and produced an Atari 2600 video mod to allow the Atari to display a crisp, RF fuzz free picture on newer TVs. Over a thousand Atari video mods where produced by Parker from 2006 to 2011 and the mod is still made by other enthusiasts in the Atari community.
In 2006, Parker enrolled at The University of Texas at Austin as a Petroleum Engineer. After realizing electronics was his passion he switched majors in 2007 to Electrical and Computer Engineering. Following his previous background in making the Atari 2600 video mod, Parker decided to take more board layout classes and circuit design classes. Other areas of study include robotics, microcontroller theory and design, FPGA development with VHDL and Verilog, and image and signal processing with DSPs. In 2010, Parker won a Ti sponsored Launchpad programming and design contest that was held by the IEEE CS chapter at the University. Parker graduated with a BS in Electrical and Computer Engineering in the Spring of 2012.
In the Summer of 2012, Parker was hired on as an Electrical Engineer at Dynamic Perception to design and prototype new electronic products. Here, Parker learned about full product development cycles and honed his board layout skills. Seeing the difficulties in managing operations and FCC/CE compliance testing, Parker thought there had to be a better way for small electronic companies to get their product out in customer's hands.
Parker also runs the blog, longhornengineer.com, where he posts his personal projects, technical guides, and appnotes about board layout design and components.
Stephen Kraig began his electronics career by building musical oriented circuits in 2003. Stephen is an avid guitar player and, in his down time, manufactures audio electronics including guitar amplifiers, pedals, and pro audio gear. Stephen graduated with a BS in Electrical Engineering from Texas A&M University.
Special thanks to whixr over at Tymkrs for the intro and outro!
Hello, and welcome to the macro fab engineering podcast. We're your hosts Parker Dolan
and Steven Gregg.
And this is episode 35.
Yeah, so we're working on Parker,
A, the Silicon Labs, if I may, right. Yeah. I've been talking about it for a bit. I think last time I talked about it, I was trying to figure out how to make the bootloader work. Yeah, cuz it's kind of funky. Yeah, it's not really funky. It's more the fact that you had the app the proper date code chips, Mickey or?
Well, that's kind of in general, the standard? Yeah,
well, usually, you don't have urato Is that take out entire functions of chips? Um, so yeah, if you, you basically look for 16 01 bit code for on the chips. And so far, everything I've pulled from, like Mouser is the correct date code.
Okay, so we just had some old chips, we just had old chips, what what's different, they just don't,
they don't have the the you can load the bootloader on them. And that all that stuff works. But they don't have the failsafe to get into the bootloader. Via hardware wise. So what we do is you pull one pin down low, and then reset and that pin is held low during the reset events. It goes into bootloader. Now, that doesn't exist on the older chips. Okay, yeah. So the newer chips basically have a, they probably have a couple pieces of you know, transistor in there boot into bootloader. Yeah, well, it's part of that software. It's just some piece of hardware that enables that the power on reset or por circuitry. Has that part in there. That betcha it was just like adding in just a couple flip flops and crap like that in there probably. So I got that working. Hopefully that article will come out next week, about EFI. mates. Yeah, how to use them, why they're awesome.
What to look out for?
What to look out for? Yeah. All that good stuff. And I've been investigating their bootloader stuff, like how to upload all this stuff. Because basically, you have to do you know, you have to do the reset dance when you want to use the bootloader loader kind of sucks. It's not like Arduino where it goes right into bootloader. Yeah, from the default. So I was trying to figure out how to make that work. And I can just actually code it in so on, it would go into the bootloader. Right? I can just change the bootloader to make that work. Yeah. But then you lose the fast boot up. Because now you have to basically wait for like three seconds on boot.
How fast is fast boot up?
Well, it basically just says is this pin low, no, go straight the operation. So it's like, so it's real fast. That's really fast. But if it's by Arduinos, they wait for bit. There's a wait period as it's waiting to see the interfaces talking to him or not. Yeah. And so what I want to do is add in the fast boot loading stuff, where it's basically a toggle of the pin to their loader software that's on the computer. Because open source they have when you download the package Upload link in the description is like a n nine for something. Is there. Like app note for it? Yeah. They actually have a Python script that you can run. And so and it uses pi serial, or five serial or however you want to pronounce that. And so you can actually toggle like the RTS pin and all that other stuff through that library, that Python library. So you then you can basically you can say hey, hold this pin down, reset the microcontroller with the reset line, or RST which is not actually reset. It's um return something something Why would
you name it RST if it's not reset?
I don't know. It's old, old modem stuff. It's like return something terminal. Is what RST from like, like a ft 232 RL. Yeah, that's not reset. That's actually return something terminal. Anyways, that's getting off topic. But I use the rst signal as a reset. That's what a lot of people use on like adrenals and stuff. So use that three, set the microcontroller, and then use one of the auxiliary pins like DTR which is something's terminal something I whatever that signal Behold, hold the pin down, toggle reset. And now the minute controller's in bootloader mode. All right, so you basically automatically go to bootloader without having to do the button dance on the on the dev board.
Okay, so it makes a little bit easier. Yeah, it makes a little easier. A little less manual. Yeah,
yeah. Sorry, I got a look into that. I think it's very doable. It just gonna take some work because I had no idea what I'm doing in Python. Perl, I'm actually not bad at But Python for some reason, looked at the code. And I'm like, I have no idea what is structured.
I'm sure there's a lot of people listening right now are like, Ah, I thought so easy.
Yeah. No. Not to see guy. Yeah. Cuz I'll put this way is, and at least for for me and see is see, you can walk through most programs, even like highly convoluted programs. And you can just walk through step by step and know exactly what's going on this Python code, I have no idea what's going on half the time.
Python, I've found has a lot more inherently built in functions that you just kind of have to know. Yeah. Whereas she's just like, No, these like six rules. And you can walk there anything. I love C. C is awesome.
Yeah, I think that's what it is. It's, it's using some functions that had no idea what one does. Yeah, exactly. Yeah. So I have to sit there and look everything up? Well, it's like, it's like when you're like fourth grade, and you read a book, and you have to have like the dictionary right next to you.
Right, right. Or like when you read, like when you read somebody's really well done, but yet still convoluted. Pick code, that's part C and picks nomenclature and stuff. Oh, it's so foreign. Because they're using all these register names and crap. Yeah. And it looks like it is looks like C but not Yeah, it's using
some registers. I have no idea. You don't want to be great. This would be great. If if someone can make their IDE, right. Where if there's a register? Yeah, you click on it, and opens up the datasheet to the page that describes what the fuck that thing does.
Oh, come on, come on. No, that's way too smart. They couldn't do that.
Someone do that in that? Yeah, that'd be awesome.
That would be that would be so killer. But do you realize how many like permutations that would
take and you can go the opposite way is in in the IDE? Yeah, you can find what you need. Click it. And it brings the code the code in the initialize that thing? And
it also wait, if it was an integrated data sheet and IDE together? Yeah, they were one in the
same. Yes. Oh, that would be so reliable, almost does this? Well, they do that with their config. But yeah, they have the they have the hardware config thing in their ID, which is cool. It's really cool. It's just, it's graphical. And I don't really like how Silicon Labs kind of hide stuff from you. So you're like, you have no idea what you're actually doing it with. The thing is that when it makes the configuration code, it actually shoves that code somewhere else in your project. So you can't actually look at it. And this should go digging for it. What Yeah,
it shouldn't have put it at the top of well, it doesn't put it in
Maine. Why? No, it just it throws in some other C file. No. Yeah. So well, why did you fail there? You can go get it. It's just it just makes it less obvious what's going on? Yeah. Cuz I'm like, like, oh, I need to set this one bit the turning some competitors off. And this pig 16.
So, np lab. Gosh, the last time I was really messing with it, I've done some MP lebackes. What icon was it? It was not x. It was MP lab eight. I think it was just a big MP or something like that. MP lab changes there icon like every day. Yeah. But ever released MP lead eight, I was doing some projects in that. And they had sort of the proto beginnings of what you were talking about where instead of writing your own config bits, you could go into this like, sort of graphical it was it was more like you choose the your pic name, then I had a whole bunch of pulldown lists. And it was like selector, what kind of oscillator how fast it is. And you know, do you want watchdog and blah, blah, blah, all this crap. And then all it did was you press OK. And it would spit out one line of code at the top of your main was just your config bits. And what's funny is it took longer to go through their wizard than it would to just write the config bits. Yep. But it would mean it was cool.
Yeah. Um, so yeah, that's almost done. And then I got my macro Duino today. Yeah. And what is your macro Duino macro Gino is a basically better version of the Arduino. Oh, but other Arduino Uno? I guess is a good way to put it. Yeah. So uses the 320 P Yeah. But it has USB type C has a proper USB bridge chip, it has proper power management and management except that the power is not working right now. So at the figure that out the power to the USB bridge chip is getting there. And then the USB bridge chip, which is a ft 230 x by FTDI it's actually talking to the computer, but nothing on the on the serial stream on the on basically the the aprm Yeah, nothing's talking. So it's all stopping
at the FTD
Yeah, so something is wrong with I think I basically hooked up the VCs, the VC C I O pin, is I tried to do something really funky because I wanted the I wanted this board to be able to be five volts and 3.3 volt compliant. Yeah, so all you have to do is move a jumper and bam, you have a 3.3 volt board to make that work is yet to talk to your you have to change the the voltage IO on the bridge chip. Okay. And the the great thing about using, you know, most FTDI devices is they have a pin that you say this is the voltage that your I O is going to be so you can make it whatever you want within the range. Sure, right. Which is really cool. So I'm like, okay, cool. I'll just pipe in that voltage that I'm using for Vcc into that pin. Right. But I forgot that I'm using a I'm using proper USB implement input that
yeah, that word. It's I'm using a p channel MOSFET on the USB voltage line. So basically, it has to wait till it gets enumerated before it opens. Right? That's all handy it's getting is it's talking to the computer. It's a numerating. But the pin that controls that MOSFET needs voltage from the pin that's not being driven because there's a MOSFET blocking it. So it's this make sense. The chip is is kind of confused
in a way?
Well, the the pin doesn't have any voltage to drive the gate that needs it that doesn't have any voltage to drive the gate that's turning on its own voltage for the eye. Oh,
this is this is the chicken a Yeah, the electrical engineers version of chicken.
Definitely post like, I'll post the schematic you can download it on on our GitHub, but I post schematic with like, arrows and stuff showing like what's actually not working.
Yeah. Sounds like sounds like there's I don't know there's there might be a unique, easy solution to it. I
hope so because I really want to keep that chip to be five volt or 3.3 volt like
a master commander kind of thing. Yeah.
I really want to be able to build switch between those voltage levels. Yeah. But at the moment, I can't figure that out. Maybe, maybe, I think I think a diode might work.
Wait, no, no, this is like, electrical engineers just like train of thought. It's just like, there's got to be a diode somewhere.
It's like, I need something to go somewhere but not go back the other way. Diode died
more testing tomorrow. And I'll yeah, I'll post a picture. On on
the below. On the below. Well, whatever we
call the text, podcast notes. We're going to be doing this 34 times before.
On the below people.
Oh, awesome. Okay. See?
That's hard to follow that. So, as you know, Parker, I was out the majority of this week. That's why it was so quiet. Monday. Yes, it was out earlier this week. Actually, my wife was having surgery. And we were out in Austin, Texas. Your old stomping grounds out there. Yeah, it was. So yeah, we were out there taking care of health issues. But and the reason why I kind of bring that up is when when people have been asking me about you know, the surgery and what's been going on. I'm super excited to tell them that that my wife got to have a surgery done using the Da Vinci machine.
Yeah, so this thing's crazy. The Da Vinci machine is this
like ridiculous? Medical like robot anime Mecca. Crazy. I don't even know like, we need to post links to it because it's super cool. And I'm all like, you know, my wife is doing fine. And it's worth saying that But I'm geeking out about that. So So it's this. It's this ridiculous robot that has like four arms that are all like, infinitely configurable. And they have a bunch of different attachments and like saws and grippers and knives and all kinds of crazy stuff. And the surgeon sits inside of this like, crazy, like 3d pod. And he sticks his face inside this pod. And he's got two controller arms. And he can do the most crazy stuff with this like he was he was showing us images of the inside of my wife's, like, cavity, I guess is the right word to say Edna, and it was just like, Wow, that's crazy that you could do with that machine.
He didn't let you drive.
Oh my gosh. My wife No, no, it's super cool. We need to post some some stuff. I've been geeking out about it for like a week now.
Yeah, you showed me that stuff today. I think I watched like a 10 minute video on that. Today. Oh,
yeah. There's there's a great video. Well, I think a couple of them on YouTube of this machine, skinning an apple. And like the surgeon's totally, like sitting there and just just delicately and very gently, just slicing just the skin and peeling the skin off the apple. And he's of course sitting like 10 feet away from the Apple inside this, like video game apparatus kind of thing. It's super cool. Super cool. So I was out doing that. Yeah. But
so could you I guess in futures, there could be like, the doctor can just do surgeries while he's at home in his slippers.
Yeah, as long as he doesn't have like crappy internet. Damn, you calm. The lag on this is terrible. No, ma'am. So I had a lot of downtime, waiting, waiting in the office and whatnot. So actually, while I was while I was waiting, of course, I'm sitting there designing stuff. It's so funny, because proper engineer. Yeah, like my sister actually came to hang out with us in the in the waiting room. And we were sitting there and I'm totally like, drawing away on my little notebook. She's like, Oh, what are you working on? And I'm like, I'm helping design a synthesizer for my, from my buddy. And she's like, your wife is having surgery and you're designing a synthesizer. I'm sorry, this is just who I am. So let's talk about synthesizers real quick. Yeah. Actually designed a voltage controlled amplifier. This past couple days. Super cool. So I found a company that is called that. Like, tha t. The name of the company is that corporation. I work for that company. Yeah, yeah. And tha t is all capitalized. Go check them out. They have a bunch of like, they call them audio engines and audio processors and
oh, I Okay, that I remember this company now. Yeah, they got audio engine definitely click that bit over my head.
Oh, yeah. You know, they have things like you know, just digitally controlled preamplifiers all in one package and you know, just simple stuff like that, but they have a line of voltage controlled amplifiers in single chip that is just absolutely killer. So it's the whole amplifier plus a linear to logarithmic converter inside the chip. So you provide a linear voltage ramp to it and it logarithmically controls the volume. So I actually have a an amplifier right now. That is, it only takes two chips to dual op amp and one of the that chips I guess one of their things and it it can go from zero dB or just unity gain all the way down to negative 120 decibels all with just some simple control voltage stuff so it's actually really cool now that you know, making a VCA in the past was not particularly easy. Now it's just two chips so pretty cool. I'm gonna try to throw that together and play around with a modular synth
this amplifier right
and that VCA Yeah. Oh my gosh, that's awesome.
Ah, yeah, so yeah, go check those guys out. They make some pretty cool stuff. Yep. Just ignore all the fancy audio words they use jargon that's a good way to put it
find gold capacitors find gold.
We actually gonna talk about capacitors and a little bit o RFA section and our first section. And this is gonna sound like we are the Silicon Labs fanboys engineering podcast but we're not slept so last week with with Michael Lyons we talked about how Silicon Labs had a teaser for like, their new thing,
right? Oh, yeah.
So apparently it's it's cool but not as cool as talking for like a new sleep be a sensor be angry be or an angry yeah angry you like turn it on and
that's all it does turning silicon um so it's
not as cool as that but it's pretty cool. So they had this line called Thunder boards. Okay, so like their development board line, you know, whatever. So they came up with this new board called the thunder board sense. And it's basically their FM 32 line that's got like built in wireless, all that crazy stuff
I believe you have written down on our sheet 24 gigahertz wireless, blah, blah, blah, oh, yeah,
it's an IoT thing. And every IoT thing has 2.4 gigahertz, right? So it's like, who cares at this point?
It's not special. It's not
special. But what is special is it got a crap ton of sensors on this thing. It's got a it's got humidity and temperature sensors, UV and regular ambient light sensor. It's got a pressure sensor, that indoor air quality sensor, which I didn't know existed more on that in a little bit. Then it's got six axis like IMU. And then it's got a means microphone, which I didn't know existed either. So it's got an awesome, so it's got a silicone, silicone based dye microphone. And so
I've actually used those before. They they work. They don't have a lot of bass,
but they will Yeah, you vibrate something that's like, you know, a couple atoms thick.
Yeah, right. Right. And the diaphragm is, you know, half a millimeter by half a millimeter if that Yeah, right.
Um, so yeah, this cool thing is indoor air quality sensor thing. All right. Part number Si, si es 811. Unfortunately, we can't buy this at Mouser DigiKey. I think future has some. So basically, you have to talk to the company probably buy some. And they don't they have some evaluation boards, but they're kind of hard to get. Yeah, it seems like and they don't have like, I want a board that just has this chip on it. That's broken out. Right? They don't sell that.
People would actually, I bet you if you made a little IoT device that you stick somewhere in your house, that just tells you your air quality. People would
eat that a lot. And that's what the same does the Sunday board. And it actually hasn't. They actually wrote an app that already works with the board and just gives you all the raw data. So wait,
wait, this is actually this. What they've created is an indoor weather station. Yes. Yeah. That's awesome.
Yeah. So and the great thing is the price is 30 bucks. For all that all in Yeah, it's power. You can power it with a coin cell or over USB killer. And it's got all the demo code. Really cool. I'm going to pick up some from the for the fab. Oh, yeah, you can play around with them. I'm actually kind of excited. I wish it was like a sensor B that was like a mic. Like they took all this stuff and put it on one die. Nothing ginormous. But it'd be cool. Yeah, that would be
CEVO systems. See if they can make a System on Package
system on port weather station on package. Ah, or environment alarm mental unpackage something like that.
Environmental package. Yeah, that would Okay, so that would actually be really cool. If you just got all the big stuff. And it could just coin sale goes go anywhere. Yep. Oh, that would be so awesome.
And so this is what I want to use at the our new shop. Right? Yeah, cuz at the new shop, I want to put light towers on the outside of all the bathrooms. Because we were so light so for people who don't know a light tower on a production machine, it's got usually has three colors on it. Do you have a green? A yellow and a red? Yeah, so green means a everything's good with the machine. It's working really? Well. Yep. Yellow means there's some kind of issue what's not stopping production? Yeah, red means line stopped. Something's something bad happen. Right? Usually, it's like, I have no idea why this parts out stuff like that.
Yeah, yeah. They we actually, a lot of places put those on, like manual working benches to green saying I'm okay. Yellow says I need something and red meaning I can't go forward. Exactly.
Yeah. That's all we can do is get some of those permanent outside of the bathrooms. And so when someone's inside the red, right, when someone's left, for x period of time they're yellow because someone You know, no, had taken number two in it. And then and then green means it's all fresh ready to go.
And you have Silicon Labs to help you out
with it. Yeah, I can buy one of these, one of these has enough IO drive some, you know, solid state relays,
and you got an air quality and gas sensor. Exactly.
And it can control like the lights and it's got a it's got a light sensor on it. So you can detect when the door got opened when when the door opened. Sure. Turn on the light. Yeah, right. Yeah, yeah. And then turn on the fan. Yeah, right. And then when someone leaves you can detect you just time out. Gotcha. Yeah. And it can control the fan. So you can run the fan after someone leaves, but turn the light off to save electricity. It's perfect.
Yeah, yeah. Well, and you gotta you got a microphone. So if someone needs to use an intercom they need to get with somebody real quick. They could just Oh, no.
D solder that part.
You could have you could have conference meetings right from the bat. Oh. Awesome.
Yeah. It's gonna be cold. But the first tower? Oh. That's perfect. Yeah.
All in one package for 30 bucks. Yeah.
Well, plus the light tower. I think add a fruit cells was like terrorists, too.
I think they do. Yeah. Yeah.
All right. So next on the list. You might not have seen this article since you were up in Austin. But Snapchat is they rebranded themselves Snap Inc. I think snap something. And that's not that doesn't matter. They're in a hardware game. Now. They are building hardware. Snapchat, Snapchat, the app that's on maybe on your phone? I don't know if it's on your phone.
Depends on how cool you are.
Yeah, I guess anyways, the called spectacles. Okay. They're like the most hipster looking sunglasses I've ever seen. Up there. And basically what they do is they have a camera in them. Right? And a little LED that turns on when they're when you're recording and take basically touch them. They record for like 10 seconds, and then you have the option to upload them to Snapchat.
How was that a game?
Well, it's not a game. It's not a game. Hmm. Snapchat is a like, texting. chat program.
I don't I haven't used it, but I'm aware of it.
clearly didn't know what it was.
In the oh, I apologize. I read it wrong. You said they're in the hardware game now. Yeah, I thought you were meaning they were making a hard No, not making a heartbroken. Okay. Okay. Okay, so they're making hardware now. Yeah, totally makes more sense. I'm a bit slow
at making Google glasses without the augmented reality part.
Gotcha. Okay. This all makes so much more sense now.
And so that some interesting things. Okay, maybe only one interesting. It's gonna have wireless. They don't say what kind of wireless it's gonna have. Yeah, I think Google Glasses actually had a SIM card in it and actually connected to cell towers, right?
Oh, shoot. I
don't know. I don't know if it paired with your phone. I don't remember.
I mean, it might have.
So I'm gonna bet you it's wireless. It's going to be Bluetooth, probably. And so it will pair with your phone and then use your phone as the interface. It will make a lot more sense because it doesn't have a display like the Google Glass did. Yeah. It's interesting that someone else is finally trying this idea. Because I always thought Google Glass work was a really cool idea. Except it the form factor was wrong.
Yeah, it looked. It looked out of place. It
looked out of place. Oh, it was designed. Whereas this looks like I mean, granted hipster sunglasses, but it's just all wrong. Ray Bans, right? With ginormous plastic frames. The only thing that looks out of place is the fact that right up on your you know, your upper I think upper left or whatever it is. There's all you know, around dots that shared the lenses that Sure. So it's not too crazy, huh? So it looks like normal sunglasses. For the most part. Yeah.
Yeah, it's got a it's got a sync up with your phone. Yeah. via something. Yeah,
I think it's cool idea. I can't wait to see I probably would never own one. But it's actually kind of cool. Seems kind of jump from a, you know, strictly software app company to hardware.
Yeah, I can I wonder if they're gonna offer like a prescription version. You might buy one. Maybe she's a Snapchat.
Hey, yo. And as I said earlier, we're gonna talk about capacitors. This is more of like a Oh, that's interesting. Seeing a weird kind of thing not really an RFO Yeah, but someone was taking some Hot Wheels apart yeah and I didn't know that made electrical hardware Hot Wheels
like they have motors when you see like Hot Wheels You mean like the toy car
yes torque car
okay yeah yeah
um made by Mattel
yeah so they have some some hot wheels that are actually have motors in them and you charge them up with this like little dock thing and they you know go around your track sure whatever Yeah, um, so one someone took one apart at least recently I guess and took a picture and they have hot wheel brand capacitors
inside Yeah, that's awesome. Yeah, that is so awesome. Yeah, we'll bring Kratz we'll capacitors Yeah,
exactly. I want to do I'm like do you know what we always talk about your Nikki con fine gold? Yeah. Hot Wheel capacitors and your amp. Oh my god. Make your amp go. Like if you have like 10 more horsepower.
Your amp sounds so awesome. Badass. Oh, they don't care if they're bad caps. I would totally once
like make a Yeah, you know what? I want to I wish to go check out and see how much our wheels cost.
Let's make a hot wheel. stompbox Yeah, exactly. Yes. Let's do this. That is so awesome.
I'm gonna bet you they are the cheapest electrolytics you can buy well
know they've run a motor. I wonder if they're super caps. Yeah, I doubt it. They're small
like the size see your first digit on your pinky. Right so as the motor Yeah, but they go for like, you know, a minute, huh? Until like a normal electrolytic is going to like burn that all up in the ESR
Bray. Well, no burn up real fast anyway. Yeah, let's look because I saw a picture. I think I saw a picture of him earlier. They look like regular cats that just kind of have hot wheel heat shrink on.
Each Other took the heat shrink wrap and just slammed it over it. But why? Yeah, exactly. That was the thing is no one's supposed to open these things up. Why?
Well, thumbs up Mattel. Attention to detail. That's super cool. No, I'm now I'm on a mission. I have to get some hot wheels.
So I think we have to figure out how much they cost. Okay, I don't know if they make them anymore or not. So I had to go on eBay, whatever. And just pull some get some pull them out and actually measure them. I bet you if we sliced the the Hot Wheel covering Oh, it'd
be like lead lawn or something. Or
Find silver. What are what are they? Like? There's so many like, like fine Chinese New Han or whatever. Like they have this shows loves. It's one of those brands? If you don't if you've never heard of it, it's bad.
Yeah, basically, yeah. When it comes to those electrolytics. It's like
the one that burned down a bunch of Samsung TVs while back. Oh, yeah, I know what you're talking about huge recall about them, too.
Yeah, kind of. So actually, funny enough, a customer dropped off an amp at my shop the other day, get this. This is this was really interesting. He dropped off the amp, and he's like, Hey, I've got this weird issue. If I play a note on my guitar, you hear my note? And you also hear another note with it. And usually, so else notes a ghost note. Yeah, exactly what it is. And it's not it wasn't due to distortion because we we set it up such that it was clean tone. And literally, it would play an overtone that was either in phase or out of phase with the the tone you were playing. So sometimes it actually sounded cool. Sometimes it sounded crappy. It sounded like a if you've ever heard a ring modulator Yeah, a ring modulator takes your signal and it breaks it up into a like adds and subtracts and basically guarantees dissonance. In a way, regardless, ces did the same thing. So I start I start with obvious things, like replacing these tubes and blah, blah, blah, a couple other things, nothing works. I check to make sure the polarity on his output transformers correct because if that's wrong, you can get note doubling and things of that sort all of that's fine. So I said, Hey, screwed, okay, I throw my scope on it. I start probing around and I looked at the main high voltage line. Yeah. And it's got just a ridiculous amount of ripple on it. And the ripple is just disgusting. It's like 40 volts of garbage ripple on a 300 volt line, and it has tons of overtones on it and Lo and behold I look at the main rectifier cap and it's just some just wacko just crappy brand or like hey that there we go great caps
Inc great. Yeah so super caps
by good caps people just just spend the extra money and buy good caps it because this amp is is was fairly new
to high it's just replacing the cat fix it
I haven't done that yet. I'm getting on an order so but I hopefully it is we
were just slandered great caps Inc. Oh.
Such a good company. So yeah, cool. Yep.
And that was the macro fab engineering podcast. We were your hosts Parker Dolman and Steven
Craig. Later guys, take it easy.
On this episode, Stephen gives an update on the FX Dev board and Parker talks about his MacroDuino project.
Parker talks about his Embedded System Design process and Stephen explains his 20 band EQ design!