It’s old news by now that Apple has removed the 3.5mm headphone jack from the iPhone 7, so instead of focusing on the why, iFixit has instead focused more on how it all works.

Many expected the adapter to be a simple one (it only costs $9), straightforward and relatively uninteresting, but doesn’t appear to be the case. As the publication notes, an x-ray image of the adapter, taken by Creative Electron, shows that there is quite a bit going on under the hood, with an interesting integrated circuit appearing at the Lightning end of the adapter.

An iFixit contributor by the name of oledturkey03 sliced open his adapter, showing off the IC under the plastic, which showcased a part number 338S00140 A0SM1624 TW, which didn’t actually provide many details. However, it’s a reasonable expectation that the IC contains a digital-to-analog convertor (DAC) and an amplifier, along with an analog-to-digital convertor (ADC).

“In past iPhones like the 6s, both DAC and ADC functions were handled internally. The analog inputs and outputs from the headphone jack (and other components) were wrangled by a single chip on the logic board, a custom Apple/Cirrus Logic IC labeled 338S00105. (In the iPhone 7 and 7 Plus, that same exact chip still exists—because even without a headphone jack, the phone still has to shake hands with the built-in loudspeakers and microphones, all of which use analog signals.)”

The size of the IC within the adapter has led many to speculate that Apple cut some corners to get the job done, and the publication has put a side-by-side with the audio chip in the iPhone 7 (on the logic board), right next to the exposed chip in the new adapter:

That chip in the iPhone 7 has to be a bit bigger, because it is also a codec, and doesn’t hold any amplifiers. But the size does appear to be a factor here, so German computer tech magazine, c’t put together an in-depth test to see if the adapter diminished sound at all, compared to simply plugging in 3.5mm headphones into a standard jack, without the adapter.

The findings did show that there are some drop offs in quality, like playing an uncompressed 16-bit audio file. However, the differences they did notice are probably not any that the vast majority of listeners would be able to pinpoint. If a user is plugged in with top-of-the-line headphones then, maybe, they can tell, but with standard headphones the difference appears to be minimal.

In the end, as noted by the original report, it looks like Apple was able to achieve what they were going for with the adapter, without cutting corners, and still reaching a level of quality sound that many would be accustomed to.

Have you tried the adapter yet?