AudioKit: iPad USB-C port not finding "wired microphone" input

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Level 1

4 points

AudioKit: iPad USB-C port not finding "wired microphone" input

I am creating an app using AudioKit which uses a theremin as input and displays sound waveforms fed into the iPad.

The theremin output is 3.5mm trs cable. I have connected a trs->trrs converter, plugged into an iPad headphone port, and "wireless microphone" is detected. However, using an iPad with no headphone jack, I need to plug it into the bottom usb-c port (charging port). I tried an Apple dongle which is 3.5mm female trrs(maybe)->usbc, and the specs on the dongle say it is compatible for mic input. This works on my iPhone with a trrs->lightning dongle, but not on iPad with a trrs->usbc dongle. Can this be done? How do I get an iPad with only a usb-c port to accept output from the trs plug as "wired microphone". Thank you.

MacBook Pro 15″

Posted on Aug 14, 2026 8:52 PM

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Answer 1

Top-ranking reply

LotusPilot

Level 10

321,464 points

Aug 15, 2026 1:39 AM in response to eyebrowman1

There are different wiring standards for TRRS connections. You'll need to ensure that the connecting cable and any additional adapters that you may use are wired for the correct standard...

In general, there are three main wiring standards for 3.5mm TRRS connections - and they are not interchangeable:

CTIA (Apple)
OMTP (Nokia)
Camcorder AV

All Apple devices use the CTIA wiring standard. If you need to use the USB-C charging port of an iPad or iPhone, you will need to use the correct USB-C to 3.5mm Headphone Jack Adapter (or equivalent):

Apple USB-C to 3.5mm Headphone Jack Adapter

Buy USB-C to 3.5mm Headphone Jack Adapter - Apple

This adapter incorporates a DAC/ADC - and supports audio input from a variety of input devices; it is not limited to microphones of a specific type.

As for any issues that you may have using this arrangement with AudioKit and your own code, you would be best advised to seek assistance from the Apple Developer Forums - as they will be better placed to offer specific guidance:

Apple Developer Forums

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Answer 2

WheelieNick

Level 9

54,053 points

Aug 15, 2026 12:34 AM in response to eyebrowman1

While the older Lightning adapter was forgiving, the USB-C adapter will not activate its microphone input channel unless it senses the electrical resistance of a standard electret microphone capsule. Your Theremin outputs a line-level or headphone-level audio signal with a vastly different impedance, causing the USB-C dongle to assume only headphones are attached and completely deactivate its input stage

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Answer 3

eyebrowman1 Author

Level 1

4 points

Aug 16, 2026 4:57 PM in response to WheelieNick

Thank you for the response. What do I need to do to connect a theremin to an iPad mic with only USB-C? Surely there is a way to input signal via USB-C port. We are in need of an answer to this!

(sorry for the duplicate message!)

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Answer 4

eyebrowman1 Author

Level 1

4 points

Aug 15, 2026 1:15 PM in response to WheelieNick

Thank you for the response. What do I need to do to connect a theremin to an iPad mic with only USB-C? Surely there is a way to input signal via USB-C port. We are in need of an answer to this!

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