The Fujifilm X-T30 includes a USB-C port, which is used for charging and can also be used for monitoring audio when recording video. To use standard earphones with a 3.5mm audio plug, you need an adapter. However, not all USB-C to 3.5mm audio adapters are the same, and so not all will work on the X-T30 for monitoring audio.
The X-T30 uses USB-C passive audio mode to output an analog audio signal through the USB-C port, so adapters that include a DAC (Digital to Analog Converter) will not work. Unfortunately, this includes the majority of currently available adapters . Adapters that are known not to work with the X-T30 include Apple’s USB-C to 3.5mm adapter and the Google USB-C to 3.5mm audio adapter.
Adapters that are known to work
The following USB-C to 3.5mm adapters don’t include a DAC and have been tested to work on the Fujifilm X-T30
OnePlus USB-C to 3.5mm Audio Adapter
Motorola Moto Z USB-C to 3.5mm Adapter
Sony EC270 2-in-1 USB-C to 3.5mm Adapter
Sony EC260 USB Type C to 3.5mm Adapter
Runlink Analog USB C to 3.5mm Headphone Adapter
Other adapters may also work. If an adapter specifically states that it isn’t compatible with the Google Pixel or iPad Pro, then it will probably work with the X-T30 since those devices output digital audio signals and require an adapter with a DAC. If it says that it works on the iPad Pro, it won’t work with the X-T30 so avoid it.