Systm: DIY Headphone amplifier: Tech Culture
Tech Culture: Systm: DIY Headphone amplifier27:30 /
Learn to solder by building yourself the most excellent Chu Moy headphone amp. It sounds great but cheap enough to give away as holiday stocking stuffers.
[ Music ] >> This episode of Systm is brought to you by NetFlix, GoDaddy.com and the United States Air Force. Want to make your headphone sound amazing? Wanna have a great holiday gift you can build for a friend, then try building a headphone amp. Sure you can buy some really cool HeadRoom amps. We love 'em, I own a couple of them third grade, but they're not so cheap. For 20 or 50 bucks, we can help you turn an Altoids tin into an outstanding headphone amp on this episode of Systm. ^M00:00:30 [ Music ] ^M00:00:51 >> Welcome to today's episode of Systm, I'm Dave Calkins and Patrick is tired of listening to me so-- >> Hi, Patrick Norton here. >> Does your dad use to do that too? >> What? >> My dad would use to talk loud when he had headphones on. Headphones are great, great for listening, big headphones actually. Actually the more expensive headphones get or even earbuds get, they tend to wanna be driven harder, right? They want-- >> More amps. >> More amps, more voltage, more power! Scotty. >> I should say monovolts but-- >> Then the problem with like an iPhone or an iPod or a Zune or any of those devices, these little tiny surface mounted amplifiers that are like the size of-- >> So, why don't I just, you know, go out and buy one of these special headphone amplifiers here. >> Absolutely no reason not to, except they tend to be a little pricy and we're not gonna build one of those on the show. >> Yeah. >> Yeah, so actually what we have here is [inaudible] actually there's another one that's already pre-built. You can build something like this. It's called a Chu Moy amplifier and the idea is that, you know, much like one of these headroom amplifiers. You're going to use a little tiny Burr Brown op-amp, and this one's actually designed with a stereo op-amp to amplify the signal coming out of your portable audio device before it goes into your headphones or your high-end earbuds. It's pretty easy. Some people have built them for as little as 25, 30 bucks, around 50 dollars in parts is more typical. If you go for super cool guy parts, we'll talk about that a little later on like 'cause you need audio file grim sisters, man. You can get it up to around 100 bucks, but this is a really easy project and it's a great holiday project you wanna build for somebody as a gift. >> It's a good stocking stuff earning. >> And you can certainly personalize them unlike an off-the-shelf form where you can paint your all play tune or your penguin pin. Put a little [inaudible] if you can think of it. >> I like that thought. So what's your favorite part about--like anytime you build a new project, is it getting the parts or mapping up the circuit? >> It's the smell of the solder as the lead enters my bloodstream. That would explain a lot actually. >> What's--we should point out though is you're not gonna find most of the part. Well actually some--a bunch of the parts for this, you can't find it on local Radio Shack. >> Your local Radio Shack, I prefer to use Jameco or Mouser online-- >> Digi-Key is one of my favorite. >> Digi-Key, all 3 of these companies are excellent companies. They all are interesting in that if you're looking for a whole bunch of parts between the 3, Digi-Key, Jameco and Mouser, you'll find not one of them is the cheapest. >> Right. >> Part A will be cheaper at one-- >> The resistors are cheaper here. >> B will be cheaper at the other so on and so forth. So, the core of this is an op-amp. Burr Brown was the original designer for this. This is the OPA2132 and this are little anti-static packaging on this, and it's a pretty cool, pretty simple 8-pin IC that sounds actually pretty phenomenal and cost like 4 bucks which is a great start to the project and the original ones are actually built with a single channel one. They don't have a double channel part which is the 2132P and 2132PA and that means you can actually do stereo off of a single chip and means you have a somewhat smaller board, again, which is gonna look like that. >> And for those who are curious Chu Moy is just-- >> --a guy >> --a guy who sort of a DIY guru. The nice thing about this project is not only is it cheap, but it's very simple. >> Yeah, I'm like 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 components on the board and 14, 15, 16, if you count the jacks and the switch. >> So we'll actually try and time how long it takes to make this, you know, and it's really--it's a insert doodad into slot A, insert other doodad into slot B. But you don't need to have an electrical engineering degree, it's pretty straightforward. >> One of the nice things about how popular this particular project has been is the gentleman behind tangentsoft.net has done an extraordinary tutorial and this is something that's incredibly invaluable because instead of having you puzzle out how to lay this thing out yourself, he gives you a part number for a Radio Shack proto board. The ever popular grid style PC board which looks like that and tells you how to lay this out, which I can actually say is pretty awesome because having have to figure out how to turn a schematic into an actual physical product. I suck at that, I usually end up putting it out on a proto board or-- >> Actually proto boards are very useful. So if you are doing your own project, I have many hundreds of these at home that I use all the time and we'll talk about that a little bit more in the lab. So, should we head into the lab and start soldering things together? >> Let's do that. >> Alright. [ Background Music ] >> Let's take a moment to thank one of the sponsors in today's episode of Systm, GoDaddy.com. You wanna make an impact online? GoDaddy.com has what you need starting in less than 5 dollars a month. Web hosting for the GoDaddy.com includes 99.9 percent up time, 24/7 support and free access to the GoDaddy hosting connection. That is the place to quickly install over 53 applications like WordPress, Juma, Drupal, osCommerce and quite a few more. And don't miss the GoDaddy.com holiday shopping spree. Between now and December 15th, every purchase of 50 dollars or more automatically qualifies you for a chance to win a 1,000-dollar cash price. Now, you're watching Systms, you know there's a hookup, right? You enter in code SYS6, that's S-Y-S-6. When you check out, you're gonna score an additional 20 percent off on any 12 or 24-month hosting plan. Some restrictions do apply, please see the site for details and get your piece of the internet at GoDaddy.com. Support us by supporting GoDaddy.com [ Music ] >> Alright, so we're back in the workshop and we're gonna solder our miniature amplifier together. So, a lot of people have had a lot of questions about how to solder, so this is a really good time for us to get into soldering. So, if you're gonna start soldering, the first thing you wanna do is get a good soldering iron. You know those dumb little Radio Shack black plastic soldering irons, they're crap, don't buy those. What you want is you want a good Weller brand soldering irons orange. You can get them to plug in directly to the wall or you can get little soldering stations like this with actual temperature controls. Either way, whether it's plugged into the wall or a temperature controlled soldering station, they're both very good. They come in lots of different wattages. Generally, if you get a 35-watt plugged into the wall, you'll be okay for most of your soldering purposes. Once you got a good soldering iron, then it's a good thing to practice soldering. And this particular project is really good for that, so you can buy lots of practice what are called prototyping boards such as this one and you'll notice on these prototyping boards you have copper on one side and nothing on the other side. That's basically so the components actually go in on the nothing side and then the wires come out of the copper side and that's actually where you solder, which is what we're gonna be doing today. Now when soldering, what you wanna do is you wanna take all your components and you wanna solder from the most shallow component to the deepest component. So, for today's little experiment, what we'll be doing is we'll be taking this jumper pins which are actually part of the project and we're gonna be soldering iron the jumper pins. Since they are so shallow, it's really easy for them to fall out. So if you put in a larger object here, then we're gonna put in, the jumpers would just fall out. So what I'm gonna do is I've pre-drawn all of the places where I'm gonna put my jumpers on this board, so now I don't have to look back at the paper. I can just push it in through my little black sharpie points and now I lay it flat on the table. Because it's still the shallow object, it's not gonna fall through. It's gonna be almost flushed with the board. When soldering, this is really important, you have 4 points of contact. Point number 1 is the board, whether it's a PCB board or whether it's a prototyping board. Point number 2 is your actual object to the component that's coming though, and that's the wire. Number 3 is your soldering iron. We put your soldering iron, you want it to hit right at the joint, right where that wire is coming up through the hole and you're gonna hold it there for about 3 seconds. And then point number 4 is the solder which you are then gonna bring in from above, usually from the opposite, and you're just gonna barely touch it so you just get a little bit of solder on there. Now, a good solder point is what I like to refer to as were called volcanoes because it actually looks like there's a volcano coming up from the board, okay. A bad solder joint looks like the death star because you haven't hit the board, so basically then what you have is a big blob of solder that's just stuck to the wire but it's not actually making a connection for the board. So, this is a really good opportunity for you to practice your soldering on this board and just go through and put in all of your jumpers and solder. Now, sometimes when you do this and you're using lots of pins, by trying to flip this over, I'm gonna lose a lot of them. Don't worry about it, just pick it back up and redo it. But yeah, see, I lost about 3 of them there. Always remember when soldering that too little solder is much better than too much solder. If you use too little, you can always add a little bit. If you use too much solder, it's really hard to get the extra solder off. There's lots of products that allow you to do that. But if you're an inexperienced soldering person, it will take you a while to figure out how to use those products to make it work right. ^M00:09:57 [ Music ] ^M00:10:12 >> So now I've got all my jumper and soldered iron on, you'll see that there's lots of little wires sticking up. So the wires--they're not really bad in the sense that they're gonna poke you in the fingers or anything but it's gonna make it difficult to work with when your soldering other things on. So now you're gonna use what's called a diagonal cutters which is a wire cutters but it comes in a well, a diagonal and you just wanna go in and you wanna cut off all those elements and watch out your eyes, you may wanna use some protective eyewear when doing this. ^M00:10:38 [ Music ] ^M00:10:44 >> When soldering microchips you've never actually solder a microchip. The heat or static electricity is very easy to destroy an EPROM or any other microchip. So what you use is you use what's called a socket. And basically what that is, is it's something that will hold the microchip in place but this is what you solder on so you don't actually destroy the microchip and then once this is soldered on, then you slide it in the microchip into what's called the socket or you can also call it seat. They also have little polarity knobs. So if you look on this particular one what you'll see is on one side there's a little hole, a little notch and that tells you which way is up or the microchip. It's very important to pay attention to the microchips because they're even on the left and the right. So they have the same number of pins coming out. But there is a top and there is a bottom, so they're not polarity independent which means you can just turn them around and it will work just fine. So you have to be very careful knowing which way the chip goes in. Sometimes when soldering you'll find that your soldering iron gets clogged and has excess solder on it that's left over. It can be really pain to use soldering iron like that so basically most soldering stations come with sponges. If yours didn't come with a sponge just grab a regular sponge, make sure you're not touching the tip of the soldering iron and actually if you just wipe across the very wet sponge, most of that excess solder will just come off and it will bead up into cute little silvery balls on the sponge that you can see there little silvery balls on. If you happen to make a solder bridge which is basically two rows of solder end up getting too close together and they actually join then actually oddly enough a simple razor blade will usually cut it open and you'll always wanna use a continuity tester after you're done to make sure that they're still not touching. This is what's called a multimeter. If you don't happen to have one this big you can get smaller ones generally. A good one just measures DC voltage, AC voltage, resistance, and continuity which is basically, is something touching. The better ones actually have a little speaker. So when you touch the lens together you can hear it to chirp. So now that I've cut away my solder bridge I'm just gonna test it to make sure that it's not actually connecting. And it's not. So now I'm done soldering on both my jumpers as well as my IC socket. So the next step is to solder on your resistors. Always pay attention to the worksheet when you're making a kit or following directions like this so that you know exactly which resistor you're soldering on and things like that because it's very easy to confuse them. They all look very similar. [Music] There are two ways to put resistors on board such as this. You can place them vertically or horizontally. For this it's gonna be a little bit easier to note the resistors vertically. What that means is the resistors actually poke up a little bit off of the board. ^M00:13:57 [ Music ] ^M00:14:18 >> It's time now for our Netflix sponsored movie pick of the week. This week it's Frequency. Dennis Quaid stars as a New York firefighter who manages to use his shortwave radio to communicate 30 years in the future with his son. They soon find out that you can't change history without unforeseen consequences providing plenty of thrills and surprises. Its unique twist on the familiar altering the past premise and definitely belongs in your geekly Netflix queue, and don't forget to check out the other 90,000 titles Netflix has to offer including an amazing selection of Blu-ray Discs. You're bound to find anything you're looking for plus with 40 shipping centers almost all deliveries happen in a single business day and shipping, both ways, free. Now if you're an Xbox Live Gold member, you can receive Netflix on [inaudible] viewing on your Xbox 360. That's right, no disc, no mailbox, no waiting. Your movie is instantly streamed over your broadband connection straight to your TV through your Xbox 360. Plan start at 4 dollars and 99 cents but we got the hook up for you, it concert a system viewer. Sign up today at www.NetFlix.com/systm and get your very own free trial. Please support Systm by supporting our sponsors. [ Music ] >> It's important to remember when we're making a pocket amplifier. If you're looking at this exact instruction guide that well it looks mirrored left to right, it's not actually mirrored. So it's very important to follow the guides extremely closely. For instance, in the second resistor, here it's on the first row of the amp whereas on this flip side it's on the second row. So it looks kind of like they're mirrored but they're not. So pay close attention to make sure that you're not actually soldering resistors on to the wrong row. If you plan on making a lot of projects such as this one and things you wanna invest and when we say invest this is like a 10 dollar investment, is a set of jumper cables. Now all of these jumpers are--come in different lengths and they're color coded based on the size and things like this. If you're one of those people who doesn't follow directions and doesn't read the whole thing, one of the things with the mini semware project amp is, is that resistor 5 isn't actually used. So it's shown in the illustration but resistor 5 is actually one of those things that if you're having problems with the amp, you could put what's called a pull down resistor in one of the positions but they don't actually list what resistor 5 is supposed to be. So you might just idly fill it in with another thing but in fact what the directions say is that you're supposed to use a jumper pin. Now since this is so long you wouldn't wanna use a short jumper pin. So I'm gonna use one of these jumper pins for where it says resistor 5. Now if I'm having problems, if there's a lot of static and things like that, I'm gonna replace this pin with a resistor. When talking about capacitors for projects like this, you have two kinds of capacitors. You have polarized and nonpolarized. Much like electrical plugs or even batteries, you know you have a positive end to a battery and you have a negative end to a battery. Well, capacitors which are vaguely sort of kinda not really like batteries, only [inaudible] they store energy. Have, some of them have negative and positive leads, some of them do not. So some of them are called polarized and some of them are called nonpolarized. They come in lots of different looks and designs and things like this. So in the case of this one, it is polarized and you can tell that two different ways. First of all the negative side is usually colored differently. So there's a little stripe down the negative side. There's actually a little negative mark on there. The second way to tell is if you actually look at the metallic leads, one of them is shorter than the other. And so the shorter one which has been cut off is the minus side and the longer one is the plus side. In the case of the other capacitors that we're using this one is considered a nonpolarized capacitor. So the polarized capacitor distinctly matters which way you put in the board. The nonpolarized capacitor can go in either way. It should be noted that the capacitor C2 on the right side is jumping across three holes rather than two like it is in the left side. It's very hard to get that in. So if you were just following the visual guides on the pocket amp guide for now, you're gonna find it's almost nearly impossible to do, so you may wanna move it over one and then just wrap a wire around just as long as you're making contact. The last components that you're gonna solder on is the capacitors marked C1 for both. Be very careful because it is very hard to understand if you're just glancing at their sheet because again these look nonpolarized like you can put them on either way, and the right one and the left one are inverted in how you put it on the board. So if you're just gonna duplicate it you're gonna put the left one on the same way that you put the right one on, you're amplifier is not gonna work. So be very careful to make sure you know which side is negative and which side is positive. Okay, in making my mini amplifier, I'm gonna go a little bit off the charts here. Two of the big differences here is one, they say that you can have a potentiometer on your amplifier, which basically means it's a second volume control. When basically or you have volume control on your iPhone or whatever else you're using for iPod. Secondly, you have an in and an out female plug for your mini jacks. So basically, one would be a plug to your iPhone and then the other one would be to your headphones. Well this can be confusing as far as which goes to which and it also means that you have to have a second plug always coming in. So what I wanna do is on mine, I'm actually gonna run a male mini plug out so that the plug is always there to plug directly into the iPhone or whatever, and that way it's obvious which the headphones always goes into and I'm also not gonna use the potentiometer, I'm just gonna use the volume control on my iPhone. So to do all of these, basically if you happen to have a dead set of headphones, the best way to do this is to use a dead headphone jack and just cut off the headphone aspect of it. The only headphones I could find around here were Patrick's and he wouldn't let me use his, so I'm actually going to use-- >> Roger's >> Roger's instead. I'm actually going to use a little mini headphone jack plug that you can buy and then I'm gonna run the wires to it. But nonetheless we'll still end up having an actual male plug coming out of it. So it's always obvious which plug is which. So now we're gonna drill a few holes in our Altoids' tin so that we can put our component where basically our circuit is all done, soldered together and we just have to mold it in there and once we do that we're gonna test it and see if it works. Now if this is your first electronics product one of thing you're gonna know that you might not notice is that if you just put your board in like this, you might not notice that now all of the components on the other side are touching each other because this is a metal object. So we wanna insulate the Altoids' can and since this is very cheap project you can use all sorts of things like metal standoffs, rubber standoffs, all sorts of things, but we're just gonna use regular old [inaudible] mil electrical tape and we'll line the inside of this twice with electrical tape and that will basically insulate it so that we put all of our components in, they're not shorting each other out. So for those of you who've never inserted a microchip into a chip socket before, you're gonna notice that the little pins are too wide to fit in the socket. So what I tend to do is I tend to just take it and squeeze just a little and again, too little is better than too much, 'cause if you don't squeeze it enough you can always redo it, but it's hard to bend back. And then always check the polarity, that little davit on one end and make sure that that davit matches up with the davit in the socket. [Music] Okay, once you've got everything soldered together and placed in your box, it should look something like this. You can see the electrical tape in the background to insulate everything. I've got my little LED right here to find out if it's on or off, my on-off switch, my headphone's jack, and like I said before, I prefer to use a male plug so that I can plug this right into my iPhone or whatever it is that I'm amplifying rather than using two female plugs and so this is one of those things where you can do lots of different designs. For instance, you don't have to have the LED on this or you can put the LED on the front, other different things. There's lots of different ways of doing this. Also be careful when you're putting together your 9 volt battery adaptors and make sure you have enough lead so that your two adaptors can fit both batteries in but not so much since you got wires everywhere. Because if you have too much wiring in it, it's actually gonna be hard to close. So now this is gonna be our test. We haven't actually done this before so I have no idea if this is gonna work or not. I'm gonna plug my batteries in-- ^M00:23:00 [ Pause ] ^M00:23:15 >> --close it up, turn it on, my LED does go on so I know that there's something coming out there and I'm going to plug this into the headphone jack of my iPhone and then plug in my earbuds and see what we get. This sounds a lot better than the amplifier in my iPhone, just my regular old pods that I use every single day plugged in through this and it sounds a lot better. It's a lot louder. It's a lot cleaner even. And I really don't think that this is more than about 20, 30 dollars of parts at the most. It takes a little bit longer than I actually thought it was gonna take and mostly that is because it's a very tiny little compartment so if you're building a big old robot, you've got lots of room to work with. It goes faster because there's more slop room whereas because of the size of the board that we're working on this did not go nearly as fast as I anticipated. There is of course one fringe benefit to making an Altoids' tin box, fresh breath. [ Music] >> We'd like to take a moment now for a short message from United States Air Force. >> I'm Lt. Col. John Wagner, United States Air Force. I'm the commander of 45th Force Support Squadron. You know I've always wanted to be a part of the space program and the Air Force is an exciting place to do just that. What I did realize the Air Force space program is equivalent to NASA in size and scope and mostly it's larger. Now the shuttle launches about once a month and I've got three launches here in the next 30 days so if you wanna be in the space program, the Air Force is a great way to do it. ^M00:24:56 [ Music ] ^M00:25:03 >> Mr. Pearly [phonetic] the camera's back on. So what do you think? >> This is good. >> Sound pretty good? >> It sounds great. >> Pretty cheap? >> Dirt cheap. >> Easy to assemble? >> And painfully easy to assemble. >> Yeah, first time you're doing it, if you're not really good at soldering, if something's not soldered right, if you burnt out a component maybe you could spend 8 hours on this if you spread it out over few nights. >> But basically if you pay attention to the instructions-- >> Four hours. >> Not even. >> Three? Yeah but your like super robot assembler cool guy dude. 'Cause you know what it looked to me like it took you 2-and-a-half hours to do that and I can't. >> Well, that's because you leave the room for an hour and a half at a time. It's true. >> Yeah, like you don't. >> Anybody with [inaudible], anybody without his attention span, I really think could honestly do this in 2 hours. >> ADD boy just told me I have attention issues, that's scary, yeah. >> If you have any ideas, comments or suggestions, please email us at firstname.lastname@example.org. We do get several good ideas from your email so we do read them. >> And don't forget to visit the forms at revision3.com/forum and you can visit all of our episodes full of cool projects at revision3.com/systm. That's it for this week I'm Patrick Norton. >> And I'm Dave Calkins. >> We'll see you next week, oh, Dave one last thing. [ Background Music ] >> Never gonna let you down, never gonna run around and desert you. >> Here's a party of one people. ^M00:26:30 [ Laughter ] [ Music ] ^M00:26:42 [ Background Music ] >> They put the words in the teleprompter for me. [Singing] >> So now we're actually gonna make some test. Now the nice thing about this particular pocket amplifier is you have lots of Patrick's in the studio and Patrick will destroy any pocket amplifier. So remember when using your soldering iron always be very, very careful and always grab it from the nice foamy rubber grip because if you're slow and careless, you might put a good second degree burn right into your thumb. >> That is Dave and I am white, I can't rap but that's all right. I got no class and I got no style but I can out rap you by a country mile. [ Door Closing ] >> Oh my god!