USB-C earphones: why the DAC matters, and what breaks compatibility

Phones dropped the headphone jack, USB-C earphones replaced it, and a confusing situation followed: some work on your phone, some do not, and the listing rarely explains why.

The short version

A headphone jack carries an analogue signal. USB-C carries digital data. Something has to convert one to the other, and that something is a DAC — a digital-to-analogue converter.

The question is only ever: who does the converting?

Two kinds of USB-C earphone

Passive (analogue). No DAC inside. They rely on the phone providing an analogue signal over the USB-C port. Cheap, and they are the ones that silently fail — because many phones, including most recent Samsung and Google models, no longer output analogue over USB-C at all.

Active (with a built-in DAC). The conversion happens in the cable. The phone sends digital data, the earphone converts it. These work on any USB-C device — phone, tablet, laptop, console.

This is the whole compatibility problem

When someone says "USB-C earphones do not work on my phone", they almost always bought a passive pair for a phone that does not output analogue audio. The earphones are fine. The pairing is wrong.

A built-in DAC removes the question entirely.

What to check before buying

• Does the listing say "DAC" or "Hi-Res"? Hi-Res Audio certification requires a DAC — a passive earphone cannot carry it.
• Does it mention laptop or PC support? That implies a DAC, since laptops do not output analogue over USB-C either.
• Is it suspiciously cheap? A DAC is a real chip with a real cost.

What we stock

The JBL Tune 310C at Rs 2,999 has a built-in DAC and carries Hi-Res Audio certification, so it works on any USB-C device. Three EQ modes on the inline remote switch between default, bass and vocal, and there is a microphone for calls.

Nothing to charge and nothing to pair — the practical advantage wired earphones still have over wireless ones.

One honest caveat

These need a USB-C port. They will not fit a 3.5 mm jack without an adapter, and an adapter would defeat the point of the built-in DAC.