CDLA technology: Curious case of the disappearing 3.5mm audio port in smartphones

By Rahul Sethi Of all the upgrades happening in our ever-evolving smartphones, the disappearance of the 3.5mm audio jack is the most unusual. Chinese manufacturer LeEco announced two smartphones last week and – apart from the usual high-end-chipset-low-end-price drama – their use of the CDLA Standard Type-C interface was hotly discussed. It was born out of the painful sacrifice of the phone’s headphone port. Audio is stored in your phone digitally, as strings of 0s and 1s. To convert them into electrical signals that a headphone can play, a chip called DAC (digital-to-audio converter) is used. DAC is connected to the jack that drives the headphone; and since the chip is a miniature version of big-box converters, the quality and power of the output is compromised. The switch started with the Android Lollipop (5.0) update that had the capability to route audio through the phone’s micro USB port. You could now connect external audio processors to playback the phone’s music and ta da…the sound becomes magical. Fast forward to 2016, LeEco deploys a similar technology – CDLA. What is CDLA? Continual Digital Lossless Audio or CDLA is a technology in which the USB port does the job of a headphone jack. Its audio processing chip (DAC) isn’t needed now and is taken out. On the other hand, you need a USB headphone with a dedicated converter chip built inside. A Type-C USB port can provide enough power for proper amplification of signals, or even keep active noise cancellation without the need for a separate power source for the headphone. But no headphone jack also means that you cannot connect the phone with your home audio, car audio, different types of earphones or even DJ consoles. All that only to play FLAC audio? What is FLAC? The very reason you have heard less about FLAC audio than MP3 is because only few select people use it – musicians, audio engineers or connoisseurs of sound. A FLAC file (Free Lossless Audio Codec) is the studio recorded audio that takes up about a few 100 MBs. If MP3-like conversion didn’t exist, not more than one album could be carried on an average smartphone. But when a song is converted, or rather compressed – from a lossless file to something much smaller in size – like an MP3, it loses information. The strumming of a guitar would sound exactly like it was recorded, for example, when you listen to lossless audio on a FLAC player; but dull out comparatively on a phone playing MP3 file. Even if LeEco plans to stream lossless music content through its “Le Ecosystem” for free initially, it would require a lot of data and patience to stream. And it won’t remain free forever. Why you don’t need it? Still not convinced? Well, here’s the truth – if you don’t have FLAC audio to play, you are back to square one. The difference in quality of the MP3 audio playback from USB is not that big that it would make you give up your universal audio jack. Or the freedom to charge your phone from a battery bank while you are snuggled-up in your seat watching a movie, sitting in a bus that takes you someplace real, while the audio technology goes back to…err…19th century? I don’t remember not seeing the plug port on a phone, ever. Do you? The author is a technology writer at Techmagnifier. Apart from writing on technology, he dwells on photography and music.