Bringing Back the iPhone Headphone Jack – in China

I’ve spent the past four months in Shenzhen, China, modifying an iPhone 7 to add a fully functional headphone jack. To the best of my knowledge, this is the first time anyone has done anything like this.

In April, I decided to finally upgrade my iPhone 6s to an iPhone7 to get better camera quality for the videos I was shooting when I was out on adventures in the industrial markets and manufacturing world. But I was super annoyed that it doesn’t have a headphone jack! I already have headphones I really liked, and I didn’t like the idea of having to keep track of an adapter just to use them.

So I figured I’d add my own – after all, how hard could it be?

It turns out, really really hard. But possible.

I went through a ton of iterations and debugging to get this to work. The hardest parts were the electrical design and getting everything to fit inside the phone. Specifically, because I was using the logic from an Apple headphone adapter and a headphone jack from an iPhone 5, I had to find space to put them without breaking anything else. I feel like I got extremely lucky about finding space inside the phone. There was inexplicably a lot of extra room in the lower left hand corner, right where I wanted to put the headphone jack. And because I was connecting the headphone adapter to the lightning jack, I needed to figure out how to make the lightning jack still work for things like charging and syncing to a computer.

I ended up designing lots of circuit boards that were more complex than anything I’ve ever done. I had three iterations of PCB designs manufactured, and 4 different flexible PCB designs.

I also ended up having to buy lots, and lots, and lots of spare parts. I went through 3 complete iPhone 7s, a handful of screens, and countless internal components (mostly bottom cable assemblies and taptic engines).

And I had to buy some new tools. I got a fancy binocular microscope for tiny soldering work (including hand soldering my own BGAs), and had to seriously level up my soldering equipment.

The nitty gritty

I’m pretty proud of the final implementation. I took apart an Apple lightning to headphone adapter, put that inside the phone, and hooked it up by man in the middling the lightning jack with a flexible PCB. The PCB has a switching chip that switches between connecting the headphone adapter to the phone by default, and then disconnecting it and connecting the lightning jack when something is plugged into it. I have a couple other timer chips that briefly disconnect everything from the phone when something is connected/disconnected to improve the reliability of the phone detecting when something is plugged/unplugged (otherwise it sometimes gets confused).

The final flexible PCB uses 5 mil/5mil traces and 0.5mm pitch BGAs. Which is pretty darn tiny. I managed to hand solder these under the microscope, and it turned out to be much easier than I expected, despite being my first time really doing any surface mount design or soldering. If surface mount scares you, buy a microscope! It’s a total game changer.

You can get the kicad files and gerbers here: github.com/strangeparts/niubi-headphones

This design is open source under an MIT license, and you’re very welcome to modify and improve on this design, and even manufacture it yourself. If you do, I’d love to hear about it.

This isn’t just about a headphone jack though – I think this design can be adapted to put other lightning based adapters inside an iPhone, while still allowing the lightning jack to function. It’s mostly just a matter of finding room inside the phone!

FAQ

Q: Who are you?

A: I’m Scotty Allen. I’m an American engineer, entrepreneur, and hacker. I’ve worked at Google and several other prominent Silicon Valley startups. I’ve been traveling the world full time for the past 3 years. I’m a nomad, which means I don’t have an apartment or house anywhere that I rent full time.

I’ve spent about half of the past two years in Shenzhen, China, learning about the electronics manufacturing scene – the industrial markets, factories, and back alleys where the world’s electronics are made. I started Strange Parts as a way to start telling stories about my adventures.

Earlier this year, I made my own iPhone 6s from parts I bought in the market.

Q: Where did you get the parts?

A: I bought most of them from the cell phone repair markets in Huaqiangbei in Shenzhen, China. These are public wholesale markets that target cell phone repair businesses all over the world.  I also purchased some official Apple headphone adapters from the Apple stores in Shenzhen and Hong Kong.

Q: Couldn’t you just buy a $10 headphone adapter instead?

A: Yes.  But that’s less fun.

Q: How much did it cost?

A: I haven’t kept perfect track, but I’ve spent easily thousands of dollars on this project.  I’ve bought 3 iPhone 7s to take apart, a handful of new screens, several handfuls of backs I mutilated, and countless other parts I broke.  I paid a factory to do 7 manufacturing runs of circuit boards.  And oh god the headphone adapters.  I bought lots and lots of official Apple headphone adapters to take apart.

Q: Why didn’t you use a chinese copy headphone adapter?

Believe me, I tried.  I couldn’t find any that fully worked.  Either the buttons on an apple headset wouldn’t work, or they didn’t detect when I unplugged the headphones.  Or they just didn’t work at all.  But I wish I’d been able to, as it would likely have been much cheaper.

Q: Does this work on iPhone 8?

I don’t know – I haven’t seen one yet!  But I’d like to take a closer look at that once they’re available.

Q: Can you charge the phone and listen to music at the same time?

A: Sadly, no, because of the way the circuit is designed.  Either the headphone jack is connected to the phone, or the lightning jack is, but never both at the same time.  To fix this would require a pretty serious engineering effort, that would require a much deeper understanding of the lightning protocol than I currently have.

Q: Where can I get my own iPhone with a headphone jack?

A: Sadly, this design isn’t quite ready for mass manufacture just yet.  It was really hard for me to put together a single working phone without breaking any internal parts.  I hope that others build upon my design to make it easier to manufacture, or that Apple brings back the headphone jack into their phones.

However, for the diehard Strange Parts fans, I made some special circuit boards just for them.  You can find out more in the _Strange Parts Store_.

Q: I want to manufacture your design.  Is that ok?

A: Yes, please do!  The design is open source.  I hope that you can improve on what I’ve done, and make it available to more people.  And if you decide to do this, send me an _email_.  I’d love to hear from you!

57 Comments

  • Tony
    Reply

    one thing that i still dont understand is: what happens when you plug headphones and a changer on your phone? Does just one thing work? Do both not work? Does the phone explode?

    I would love to know your answers for that, because thats the only thing that bothered me in your video.

    Have a nice day anyway 🙂

    Tony

  • Radovan
    Reply

    Why didn’t you try to wire headphone jack to speaker? There is probably some way to make automatic switch between jack and speaker. I know it would be harder because of placement, but then you could charge phone and use headphones.

  • Bryn Curran
    Reply

    Great video Scott! Had to grab that sweet swag as soon as the video finished! Keep up the good work!

    Bryn, UK

    P.S You thought about starting a Patreon? I imagine there would be loads of people that would take part in one (Me included! ☺️)

  • Vince Pale
    Reply

    I understand that you don’t have the exact costs, but, could you give a rough estimate on costs of having your normal board manufactured, having the flex board manufactured, and the price of the cool microscope?

  • rephlo
    Reply

    So you waste thousands of dollars for multiple iPhones and parts but you still can’t charge and listen to music in the same time.

  • jackriot
    Reply

    I don’t have any engineering background but your work is absolutely an inspiration. Thank you so much for doing this. AMAZING!!

  • Humaam
    Reply

    This is the best thing i have seen on YouTube.. All i can say is keep up the good work and you’re Awesome and i admire you a lot!

  • exikyut
    Reply

    In case you are not aware of https://ramtin-amin.fr/#tristar , I’ll just leave this here. No affiliation, I discovered it via Hacker News a while back (by the way, your post is at https://news.ycombinator.com/item?id=15190199).

    One of this person’s other projects (the iPhone NVMe exploit) required a custom FPGA board for PCIe sniffing. This guy clearly likes digging into protocols. Would be very very interesting to see what you could collaborate on together.

    PS. You might want to adjust the theme so the textbox font color is black / #000. It’s *very* hard to type with the very light shade of grey it is right now.

  • Ajay
    Reply

    Hi, I loved this video – really impressed with what you did.. I was just wondering what Microscope you ended up buying and whether you have a link to the supplier and cost?

  • Vishwanath
    Reply

    I wish I could be in Shenzhen for two years exploring all the back alleys and other small factories that churn out countless gadgets .I would love to work with you for a couple of months in Shenzhen for some cool projects .

  • Bullwinkle J Moose
    Reply

    I think this conclusively demonstrates the real reason Apple did away with the headphone jack.

    There is plenty of room, and a headphone jack can be made 100% waterproof. So Apple’s excuses were merely lies. The true reason was to boost Apple profits by selling unnecessary and overpriced wireless AirPods, and by no longer providing wired earbuds with every iPhone. Of course this means Apple will never–ever–restore the headphone jack. They have finally shown, once and for all, that profits are number one. (And their customers aren’t.)

  • arjun
    Reply

    hey brother I want to learn hacking and smartphone technology so plz can you help meepleaseat lastधन्यवाद मेरो देश खोज्नु होला by this letters you can know my country

  • Beldar
    Reply

    Really cool video man! I know it will sound very geeky, but it was very exciting to watch, like an action movie or something like that. Keep doing videos!

  • Ilya
    Reply

    Hi! You are God damn cool! Only one question: did you try to compare 6s lightning connector with iphone 7? It seems to be the easiest way. Copy 6s structure and make it in a form factor of iphone 7s. If this works you can charge and use headphones at the same time

  • Darlin Hidalgo
    Reply

    hello, first of all I would like to congratulate you for your projects, the truth is it is fascinating to see your videos and see what you can do, really congratulations, secondly is that I would like to know what is the make and model of the microscope used in this video, I would be interesting to get one. thanks in advance and success in your next project.

  • Marcus Azur
    Reply

    It’d be nice if you mentioned everyone else that helped you. Somehow I doubt you went from never using surface mount components to hand reflowing BGAs and designing the circuit board yourself without someone doing at least some of the work. Also, having a month to month lease doesnt make you a nomad lol

  • Timotius Perdana
    Reply

    I have a question, does camera module on iphone 8 plus will work on iphone 7 plus? Since i see the video that ifixit made, looks simillar module in size and connector. Can you make a video about it?

  • James
    Reply

    Its a nice inspiring story of you sir im an electronic technician but honestly i dont know what you did its cool i just inspire to your videos in youtube but honestly i can afford what you did im just a simple man working here in midle east honestly i really love i phone but i cant afford it but one thing i like you is your perseverance and your desire to have your goal done thank you.

  • Alexandre
    Reply

    Hi,
    I am actually working on this project. I checked your kiCad files and I have a question:

    “lightning_to_headphone_adapter” : what does it contain ? Is it the full pcb that is used in the lightning to jack cable sold by Apple ?

    Best regards,

    Alexandre

  • sascha
    Reply

    why not build a “slide over-plug in” cover, slightly longer than the original iphone to install missing features. existing connectors can be bridged and new ones can be added.
    just a bottom half so that you can still use the original screen. that would be easy to adapt for all new iphones.

  • Emi
    Reply

    “I got a fancy binocular microscope for tiny soldering work (including hand soldering my own BGAs)”

    What is the exact model of this? Ypu didn’t mention this in the comments.

  • Gabriel
    Reply

    Hi. What is name of model of this new microscope? (or what are the specifications?)
    I think in my country don’t have any similar in market.
    ps: I love your videos. Thanks

  • Pete Pait
    Reply

    Do you have a guess as to why Apple removed the headphone jack? Was it to make money selling dongles? And do you have a guess as to how many customers like myself that refuse to get new iPhones without a headphone jack? I assume that if Apple were to release an iPhone 6.5 with the performance of a X and a headphone jack plus touch ID, that it would sell tremendously, but would be a slap in the face of the 7, 8 and X owners, and also disrupt dongle sales. I am frustrated by the latest WWDC where they spend a half an hour talking about emojis.

  • Jeremy Bohrer
    Reply

    Your headphone jack is a truly remarkable effort! Being that you have worked at Google before, have you tried any experiences with the Pixel series (Specifically the Pixel 2/3)?

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