Embedded DAC

So here’s a probably stupid question, but I want to check myself. There are a number of IEM manufacturers that are offering IEMs with a lightning connector for iOS phones - those that do not have headphone outputs.

It was my understanding that these devices do not put out analog audio. I don’t know about the input side of things for inline microphones. But I really thought that the lightning port is a digital out port.

If so, there would have to be a DAC embedded in the connecting cord. Hiding electronics in connectors is something that Apple seems to do. Does anybody know if this is the case? If so, what DAC chip are they likely to be using and what, if any control would an end-user have?

Or am I way off base (would not be the first time) and there is analog audio out of a lightning port?

2 Likes

There’s definitely some DAC and ADC (for the one’s with microphones) in them. I believe Apple uses a Cirrus Logic chip in theirs. I think most of that is typically on a small circuit board right above the connector.

ESS also makes DAC chips that tiny… not sure about AKM.

3 Likes

Enjoy:

9 Likes

OK. I was looking on the Etymotic site and they have the ER3 and ER2 with lightning adapter. On some pictures, it’s not clear that this is a separate little dongle just like Apple uses. Before I meandered over to eBay and grabbed|snarfed up a used ER3XR, I asked their online sales people about what DAC was being used. The online person referred it to a support tech person, who denies that they sell any kind of DAC. He must think that it’s just wires in that adapter.

2 Likes

It’s my understanding that the iPhone hasn’t had a DAC in it since they removed the headphone jack. Lightning connection is digital data only, no analog signals coming out of there at all. The Lightning connector standards Apple finalized predate the removal of the headphone jack from iPhones. It only has two data channels.

The same is true of USB-C for Android devices, btw. There is a DAC somewhere in a USB-C headphone dongle.

2 Likes

I started looking into this when I went from iPhone 6 up to iPhone X and could not believe the sound downgrade. Drop and a few other places have dongles in the $75 and up range, but not all of them even say what DAC it is. I got an EarStudio ES100 and was happy with that and passed on running down a dongle rabbit hole.

1 Like

Oh wow, sidenote, the board automatically added an Amazon link for ES100

The iPhone still has a DAC in it as it still has speakers that can be used for music / video. You need something to convert the digital signal of the phone to analog for the speakers to work. Just like a TV. Now, that DAC may not be great but it’s still there. The lightning dongle DAC just bypasses the internal DAC of the phone. I would assume it’s the same with the Android.

5 Likes

I stand corrected. It’s so obvious I feel dumb now.

Thanks

4 Likes

Oh no need to feel dumb. I won’t lie when I said that I looked it up just to make sure because I wasn’t entirely positive myself. Led me down a rabbit hole on TV DACs that I don’t wish upon anyone.

7 Likes

Holy crap :exploding_head: :exploding_head: you’re right. And I had one of the biggest tech blog editors tell me “Yeah, no DAC in there”

2 Likes

That was an “OMG, I’m such an idiot.”moment for me also. Than I realized that iOS simply uses astral projection to transfer the data to my brain’s quantum catheter. The Apple eco-system is so advanced.

2 Likes

Looking forward to that so I can have the annoying USB port on the back of my head removed.

3 Likes