You can do that with USB2 as well, but hardly anyone does, because they aren't forced to do so.

Most people don't want a higher quality DAC than the one built into the phone. High quality DACs are cheap. If the one in your phone isn't good enough for you, in two years you will get a new phone -- pick one with a better DAC, since now you know that's important to you. In the meantime, your $1000 headphones from four years ago will still work on all the phones with 3.5mm jacks, and so will the $6 pair you picked up on the boardwalk when you realized that there was no way in heck you wanted to wear the good headphones out on the beach.

> You can do that with USB2 as well, but hardly anyone does, because they aren't forced to do so.

You can plug a USB2 DAC into your phone?

A ton of people who own good headphones for their computer use a USB sound device instead of the motherboard's built-in audio. But today, similarly good headphones for mobile phones do not exist because phones can't drive them. This may not be a priority for a lot of people yet, but Apple is in a position to hugely increase the size of the market.

I'm not thrilled that it would create headphone lock-in on iOS vs Android, but you have to at least admit that it opens up opportunities for better headphones for phones than what's out there now.

If you'd tried to do this 10 years ago it would have been pointless because people's music libraries were all a bunch of MP3s ripped at 128 kbps. Now that Apple Music exists, Apple has direct control over the quality of the music they're streaming. If they want to make better headphones workable they can push out media in a format that makes them actually worth using.

Using an adapter to 3.5mm headphones doesn't feel like that big a deal to me. I would guess that Apple can output an analog signal over the lightning connector to allow a small passive cable (like DVI-I to VGA).

Going the other direction, someone (guessing Apple won't) could build a 3.5mm device that converts to a Lightning signal, but I'd expect it to also have to plug into a phone's accessory port to get enough power.

Yes, you can plug a USB2 DAC into your phone. There's a list of working configs here:

http://www.head-fi.org/t/595071/android-phones-and-usb-dacs/...

and of course lots of discussion.

Huh, I hadn't seen that before. Still, I have to imagine if you made better audio hardware a built-in feature instead of something that requires dangling a big USB2 device off of your phone, you're going to get a lot more interest from users.

Is it not possible to have a DAC that plugs into the lightning port, while keeping 3.5 mm audio for the masses who don't want/need a separate DAC?

99% of listeners aren't using headphones that are good enough to notice a difference in quality from an offboard DAC.

Yes, you can plug a USB DAC into your phone with most modern Android devices, and I believe the same is true with iPhones. They even support the standard USB audio device class used by many common DACs. People just don't generally do this.

I use a Lightning camera adapter (USB port) to an external DAC and headphone amplifier. It gives me the best possible sound quality, since the audio is pure digital until it hits my DAC, which, I can assure you, is much better quality than any internal DAC included in a smartphone.

Personally, I don't really care about the headphone jack because I never use it. I will admit, I'm different than 99.99% of other users.

Unlikely. The DACs in most of the available chipsets in phones are far superior to something you could put in a pair of headphones or as a bump in a cable - and would need batteries to run it.