If you already own wired headphones or an external DAC, a USB-C specification is not a complete compatibility check. The adapter, application and accessory power arrangement matter together. Prepare a practical trial before buying. This article does not rate sound quality between handsets or promise that an arbitrary converter works with every phone and application.
Identify the entire accessory chain
Record headphone, DAC and cable model names along with the listening application. Direct USB-C headphones differ from a 3.5mm headset with a converter. Apple documents USB-C audio on iPhone, including wired headphones and suitable adapters. That does not certify every third-party DAC.
Samsung explains the need for a compatible DAC adapter. Similar-looking plugs are not proof of Galaxy compatibility. Check the accessory documentation, operating system and phone model, then test the equipment you own instead of buying the handset and guessing the rest.
Use the application and audio you will actually play
Play authorised local material or content from your subscribed service, starting at a low level and adjusting comfortably. Check both channels, pause and resume, and behaviour after locking the display. Keep file and settings consistent when comparing phones; different loudness levels do not establish a sound-quality difference.
For lossless playback, check source, application and converter together. Apple lists lossless playback requirements; on iPhone, rates above 48kHz require an external DAC. A large sample-rate label does not prove better perceived sound or support in every application. Confirm the particular output arrangement rather than assuming the label settles it.
Check calls and microphone, not only music playback
Try volume buttons, pause and call handling if the headset includes them. Playing music does not prove that an adapter supports its microphone. For recording, use the intended application and listen to the saved result on another device to establish that the input actually worked.
Have a helper listen to the other end of a work call, first in a quiet place and then in a setting similar to normal use. Check whether the app changes to the phone microphone or speaker. An unsupported accessory function is not by itself evidence that the handset is defective.
Include power, the case and simultaneous charging
Ask whether the DAC needs its own supply or draws power from the connected device, and verify its requirements. Reconnect, switch applications and use it for a representative session. A short listening test or charger wattage does not establish battery runtime, particularly for a used handset.
Check whether the plug clears your case and whether carrying the setup pulls on the port. For listening while charging, test the intended hub or splitter with the charger and accessories. Multiple ports do not guarantee simultaneous audio and charging; an illustration is not enough to establish the supported functions.
Choose from the tested setup instead of port names
The used iPhone 15 and used Galaxy S23 5G on TECHBUY are USB-C candidates on different operating systems. Chip names, model year and file-transfer speeds do not rank their audio quality. This article has no audio measurements or controlled listening comparison between them.
Inspect a used handset for a loose port, intermittent connection or faults when the cable moves, as well as battery and ordinary phone functions. Include compatible adapters in the total cost. Check price for the actual capacity and condition, then choose the arrangement that passes your trial rather than paying for an advertising label.
Conclusion
Start with the entire wired-audio setup rather than the USB-C socket alone. Confirm stable playback, usable controls, microphone behaviour in the intended app and a workable charging arrangement. If the headphones already meet your needs, prioritise verified compatibility before spending more on a handset or converter.
