 It's a great search brought to you by Digi-Key, and you get free to every single week. Lady Aida uses her powers of engineering to help you find things on digikey.com. Lady Aida, what is a great search of the week? This week. Okay. This week, we're going to build on last week's NPI, which was that headphone amp. This week, I'm going to get the headphone connector, because I realized a lot of people actually have been emailing asking like, where do you get these headphone connectors that you're using? This one's quite nice. Let's go to the overhead and I'll show it off real fast. So, for the little gamer board prototype, underneath here is the headphone amp. That's the maximum part that we showed off last week, and then this is the little headphone jack. And I really like this style headphone jack, because it's quite slim. It's surface mount only, but it's TRS, which can be nice, because you can get the microphone output, and it's not that much bigger than the jack itself. Sometimes these are really kind of chunky, but these are very slim. And they're slim enough that they fit between the headers on this board. So let's find this jack. This one actually in particular does not have the through hole pads. I found that you don't need them, but it does have a cutout on the PCB. So this is actually kind of nice, I think, because usually the most string comes from pushing into the board. You don't want people to push and shear at the same time. So there's a little bit of a cutout. You can kind of barely see the u. There's a little piece of plastic that goes into the board that just kind of gives it a little bit of mechanical strength. So let's go to dig.com. And let's search for... So these are weird. You'd think that they're called headphone jacks. And they kind of are, but they're called phone jacks, right? Because just historically, if you look at all like videos or photos, these were used for telephone systems. That's kind of what they were. The quarter inch type were used for plugging into a switchboard. So they're called phone jacks or barrel audio jacks. So we're going to go to barrel audio connectors. And it's funny is like, there's a lot, but somehow there's less than I expect. So you can get kind of anything and sockets and RCA type and panel mount and all that. What we're looking for specifically is like this industry-recognized diameter. We want three and a half, which is, sorry, 3.5 millimeter, otherwise known as quarter inch, sorry, eighth inch. Quarter inch is 0.25 inches, 6.35 millimeters. Eighth inch is not actually eighth inch. It's 0.14. So it's like a nominal, right? One thing you learn as an engineer is like, everything's exact until it's nominal. Eighth inch nominal is not 1.25, it's 1.4. Just keep that in mind. So searching for that. Okay. So let's see what we got. Okay. So we got four, reasonable, so there's all sorts of types. There's wire, inline, there's this, which is actually kind of close to what we're looking for, through-hole, more panel mount or inline. So let's go for, we want active, and we want jack, and we don't want dual or triple where you have three to where we want singular, and we don't want RCA, so that's fine. Let's apply that filter. And then one thing that I looked at was, some of these are called cut out style, and I was like, what is this? So let me show you. So let's do not panel mount, let's do surface mount, right angle, and there's board cutout, and there's non-board cutout, and apply all. So board cutout type is interesting. It looks like, hold on, let me find one, because it was unusual, I was like, oh, what is this? Surface mount, surface mount, surface mount. Board cutout. Okay. So this is board cutout, and here's something interesting about this design. You see how the legs kind of come out from the side? So this is something where you want to have the jack be centered on the PCB, not rising above it. Usually, if you want to have a very elegant design, you want to have the USB jack come out through the center, so it's kind of floating in the middle of the circuit board. You can do the same with headphone jacks, let me find, this is another one. So you can see it's kind of like, it's weird, like it sinks into the PCB, it goes in upside down so that it's centered on a 16-inch PCB. Anyways, I'm not going to use this, but I thought it was interesting for people who were like, oh, I want to have that really elegant, you know, the hole is centered in the product, and the product has the PCB centered in the enclosure. Because otherwise, you know, it's kind of apple sort of popularized this, like beforehand it was like, eh, fuck it, like, all the characters are like uneven and they're wherever you want, but if you want them to have a really elegant straight line of all the connectors, you might have to have them sunken into the PCB. Anyhow, so let's just do surface mat right angle, and then the next thing is you can get ones with switches inside of them. And so, you know, at this point, I sort of, there's a couple that are very similar in style, so the style I use, which is this, there's quite a few of them, but I sort it by price, and so I also want to look at ones that are in stock right now. And I found this one, so this one you can tell by the rendering, this is upside down, but you can see that there's more than four contacts or six contacts in the bottom. So, if you have three contacts, you know, it's almost certainly going to be left, right, and ground. If it's four contacts, it's usually ground, microphone, left, right. And if there's more than that, it means there's internal switches, and internal switches can be used to, like, you know, when you plug in, it disconnects the speaker, or you can use it with a very light pull down to indicate whether, you know, something has been plugged in to either turn it on or to, you know, enable audio output at all, and there's no point in turning on the audio subsystem, maybe if the headphone isn't plugged in. So, you can check out the data sheet, and yeah, it has a bunch of contacts, and this is what it looks like. So, you know, normally you plug in, and you get ground, mic, left, and right, and when it's unconnected, the left and right are connected through to five and six, which lets you, you know, have an internal speaker or against some detection that says, like, okay, the headphone's not plugged in. You know, it would be really great if headphones had, like, a separate switch that was not routed, like, it wasn't going through the audio line, like, line path, but I actually, you know, once I found a jack that did that, but since then it's been, I always find it this way. So, even though this doesn't seem like it can be used to detect a headphone, like, it looks like it's only good for switching the audio line through speakers or not, you can use it for detection of whether a speaker's plugged in and if their headphone is plugged in, and in fact, the headphone amplifier we talked about last week does have in the app note section a circuit to show how to disable the headphone amplifier when these switches are opened. So, it's a very cute headphone jack. It's got the mounting holes, so it's kind of nice. I don't know if you need a board cutout. Oh, yeah, you do. You can kind of see it goes a little bit underneath. So, you know, either you have it up against the edge of the board or you do a little bit of a cutout. If you don't want it to be sticking out past. And it's very affordable. It's like 88 cents for singles, you know, 60, 55 cents in a reel. And I like it's gold-plated and it's from Tensility. So, this is my pick for the great search. And that's a great search.