Wired Headphones USB-C to 3.5mm Adapter on iPhone

How to Plug in Wired Headphones and Microphone with USB-C to 3.5mm Adapter on iPhone.

In this guide I show you how to connect wired headphones and a microphone to your iPhone using a USB-C to 3.5mm jack adapter. This is useful if you have newer iPhone models without a built-in headphone jack but want to use your favorite wired headphones or need microphone input for recording.

I’m showing you this on iOS 26 Beta 8 on an iPhone 16 Pro Max Titanium Black 256 GB, Global model A3296 – MYWV3ZD/A.

Which iPhone Models Use USB-C

The USB-C port is found on iPhone 15 models and later. If you have an older iPhone, you will need a Lightning to 3.5mm jack adapter instead.

Plug in Wired Headphones and Microphone with USB-C to 3.5mm Adapter on iPhone Video

What Adapter You Need

You need a USB-C to 3.5mm jack adapter. I have two here:

• A Xiaomi adapter. This one came free with my Xiaomi Mi9 phone. It is not Apple, but it still works.
• The Apple adapter. This one costs about 10 euros, and I prefer it because the microphone input is really good.

You can use any USB-C to 3.5mm jack adapter. You don’t have to use the Apple one.

How to Connect Wired Headphones

1. Plug the USB-C to 3.5mm adapter into the USB-C port on your iPhone.
2. Plug your headphones into the 3.5mm jack on the adapter.
3. The headphones are now ready to use, just like if your iPhone had a headphone jack.

When you adjust the volume on your iPhone, it adjusts the volume of the headphones.

How to Connect a Microphone

You can also use this adapter to plug in an external microphone.

1. Plug the USB-C to 3.5mm adapter into your iPhone.
2. Plug your microphone into the 3.5mm jack.
3. Open the Voice Memos app or any recording app.
4. Start recording. The audio will come from the external microphone.

I tested this with a small custom-made microphone using a Primo EM258 capsule. It worked and recorded audio through the adapter.

The Difference Between TRS and TRRS Plugs

This part is important if you want to use both headphones and a microphone at the same time.

• TRS plug – This has two plastic rings on the plug. It has one channel for left audio, one for right audio, and a ground. This is for headphones only.
• TRRS plug – This has three plastic rings on the plug. It has left channel, right channel, microphone channel, and ground. This is for headphones with a built-in microphone.

If you use a TRS headphone with this adapter, it will work but without the microphone. If you want both headphones and microphone, you need a headset with a TRRS plug.

How to Use Headphones with a Microphone

If you have a headset with a TRRS plug, you can use it for video calls and voice calls. This means you don’t have to use the built-in microphone and speakers on your iPhone.

1. Plug the adapter into your iPhone.
2. Plug your TRRS headset into the adapter.
3. Make a video call or voice call. The audio will go through your headset.

Troubleshooting Connection Issues

If the adapter is not working, try these steps:

1. Check for debris in the USB-C port. Use a flashlight to look inside and gently remove any lint or dust.
2. Make sure the adapter is fully inserted into the port.
3. Unplug and plug the adapter back in.
4. Try a different adapter if you have one.

Some adapters might not work with microphone input. When you buy an adapter, look for one that supports both audio output and microphone input.

A Note About Microphone Permissions

You may need to give permission for the microphone to work with different apps. If your recording app is not picking up sound, check the app permissions in your iPhone settings.

How to Use an Audio Interface for Stereo Recording

If you want to record in stereo, you can use an audio interface like the Rode AI Micro. This connects to your iPhone with a special cable.

• The USB-C to 3.5mm adapter records mono input for microphone and stereo output.
• An audio interface like the Rode AI Micro records stereo input and stereo output. It is two in, two out.

This works with both iPhone and Android.

Why Use Wired Headphones

• The sound quality through the wire is usually better than Bluetooth.
• You don’t have to worry about charging a battery.
• Wired headphones will always work. They don’t need to be recharged.
• The only inconvenience is the wire itself and needing to carry the adapter.

You can keep the adapter plugged into the headphones all the time if you use them daily. These adapters are really cheap.

Quick Recap

• iPhone 15 and later use USB-C. Older iPhones use Lightning.
• Get a USB-C to 3.5mm adapter. Apple or other brands both work.
• Plug the adapter into your iPhone, then plug in your headphones.
• For microphone use, plug in a microphone or a TRRS headset.
• Check for debris in the port if the connection is not working.
• Use an audio interface for stereo recording.
• Wired headphones give you reliable sound without needing a battery.